Pest management in WisconsinFieldCrops - Corn...

A3646

A guide to managing weeds, insects, and diseases incorn, soybeans, forages, and small grains

Chris BoerboomEileen CullenPaul EskerRoger FlashinskiBryan JensenMark Renz 2009

Pest management inWisconsin Field Crops

A3646-09, Cover:A3646/04, Cover (alt2) 10/16/08 2:59 PM

TOC-FM 10/20/05 10:07 AM

Pest Management inWisconsin Field Crops—2009

A3646 FM filler:A3646 graphics ideas 10/16/08 2:34 PM Page 1

2009

Pest Management inWisconsin Field Crops

A guide to managing weeds, insects, and diseases incorn, soybeans, forages, and small grains

University of Wisconsin–ExtensionCooperative Extension


Pesticide referencesand updatesReferences to pesticide products in this publicationare for your convenience and are not an endorse-ment or criticism of one product over other simi-lar products. You are responsible for using pesti-cides according to the manufacturer’s currentlabel directions. Follow directions exactly to protectthe environment and people from pesticide exposure.Failure to do so violates the law.

Note also that this publication is not a completelist of all pesticide labels. Several pesticides aremarketed in numerous formulations and thecommon names of their active ingredients (e.g.,atrazine, glyphosate, 2,4-D) are generally recog-nizable. These pesticides are referenced by theircommon names. The active ingredients in otherpesticides may be marketed by multiple compa-nies, but their common names are not generallyknown by users. For name recognition purposes,these pesticides are referenced by the trade nameof the primary registrant, but the common nameof the active ingredient is provided as a cross ref-erence for your use. For a listing of commonnames of pesticides, please refer to appendixtable 1.For updates throughout the growing season, con-sult the Wisconsin Crop Manager newsletter. Thenewsletter is available online atipcm.wisc.edu/wcm.Current pesticide labels are available online atwww.cdms.net/manuf/manuf.asp.


v

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNPRINCIPLES

OF

PESTM

NGMT.

Contents

PRINCIPLES OF PEST MANAGEMENT1

Pest management andpesticides

Integrated pest management . . . . . . . . . . . . . . 2Federal pesticide-use law. . . . . . . . . . . . . . . . . 2Wisconsin’s training and

certification program . . . . . . . . . . . . . . . . . . . 3Wisconsin pesticide laws and regulations . . . 3Pesticides and community right-to-know . . . 3Worker Protection Standard (WPS)

for agricultural pesticides . . . . . . . . . . . . . . . 4Oral notification and posting. . . . . . . . . . . . . . 4Restricted entry interval (REI) . . . . . . . . . . . . . 5Pesticide toxicity . . . . . . . . . . . . . . . . . . . . . . . . 5Pesticide safety. . . . . . . . . . . . . . . . . . . . . . . . . . 6Pesticide accidents. . . . . . . . . . . . . . . . . . . . . . . 7Pesticide drift . . . . . . . . . . . . . . . . . . . . . . . . . . . 7Pesticides and groundwater . . . . . . . . . . . . . . 8Calibrating pesticide equipment. . . . . . . . . . . 8Cleaning pesticide sprayers . . . . . . . . . . . . . . . 8Preparing pesticide sprayers for storage . . . . . 9Pesticide disposal . . . . . . . . . . . . . . . . . . . . . . . 9

Weed management principlesfor all crops

Selecting a weed management program . . . 11When to apply herbicides. . . . . . . . . . . . . . . . 11Can herbicide rates be reduced? . . . . . . . . . . 12Mixing herbicides . . . . . . . . . . . . . . . . . . . . . . 12Herbicide/fertilizer combinations . . . . . . . . 12Weather and herbicides . . . . . . . . . . . . . . . . . 13Herbicide residues in soil . . . . . . . . . . . . . . . . 13Herbicides and conservation tillage . . . . . . . 14Herbicide-resistant weeds . . . . . . . . . . . . . . . 14Using new herbicides . . . . . . . . . . . . . . . . . . . 14Selecting herbicides. . . . . . . . . . . . . . . . . . . . . 14

TablesPest management

1-1. Examples of agricultural chemicals subject to Title III of SARA. . . . . . . . . . . . 4

1-2. Toxicity categories of pesticides . . . . . . . 5

Weed management1-3. Listing of herbicides by mode of

action and risk of developing resistantbiotypes. . . . . . . . . . . . . . . . . . . . . . . . . . . 15

A3646/09, I. Intro (6.5) 10/16/08 2:29 PM Page v

vi

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNPRINCIPLES

OF

PESTM

NGMT.

Weed management Atrazine rate limits and restrictions . . . . . . . 18

Burndown herbicides for no-till corn . . . . . . . 22Autumn + 2,4-D. . . . . . . . . . . . . . . . . . . . . . . . 22Basis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22Basis + Express + 2,4-D. . . . . . . . . . . . . . . . . . 22Field Master . . . . . . . . . . . . . . . . . . . . . . . . . . . 23Glyphosate . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23Gramoxone Inteon. . . . . . . . . . . . . . . . . . . . . . 24Rage D-Tech . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Preplant-incorporated and preemergence herbicides

Acetochlor + safener . . . . . . . . . . . . . . . . . . . . 24Acetochlor + atrazine + safener. . . . . . . . . . . 25Atrazine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26Banvel (see dicamba, p.29)Bicep Lite II Magnum . . . . . . . . . . . . . . . . . . . 26Bullet/Lariat. . . . . . . . . . . . . . . . . . . . . . . . . . . 27Callisto . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27Camix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28Clarity (see dicamba, p.29)Define SC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28Degree (see acetochlor+safener, p.24)Degree Xtra

(see acetochlor+atrazine+safener, p.25)Dicamba . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29Dual II Magnum . . . . . . . . . . . . . . . . . . . . . . . . 29FulTime

(see acetochlor+atrazine+safener, p.25)G-Max Lite . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30Harness (see acetochlor+safener, p.24)Harness Xtra

(see acetochlor+atrazine+safener, p.25)Hornet WDG . . . . . . . . . . . . . . . . . . . . . . . . . . 31Keystone LA

(see acetochlor+atrazine+safener, p.25)Lumax . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31Marksman. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32Outlook . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32Princep . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33Prowl H2O . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33Python . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34Resolve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34Sencor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35SureStart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35Surpass (see acetochlor+safener, p.24)TopNotch (see acetochlor+safener, p.24)Valor SX. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

Postemergence herbicidesAccent . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36Atrazine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37Banvel (see dicamba, p.40)Basagran . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37Basis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38Beacon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38Buctril . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39Cadet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39Callisto . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39Celebrity Plus. . . . . . . . . . . . . . . . . . . . . . . . . . 40Clarity (see dicamba, p.40)Dicamba . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40Glyphosate . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41Halex GT. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42Hornet WDG . . . . . . . . . . . . . . . . . . . . . . . . . . 42Ignite . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43Impact . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43Laudis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44Marksman. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44NorthStar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44Option . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45Permit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46Priority . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46Rage D-Tech . . . . . . . . . . . . . . . . . . . . . . . . . . . 46Require Q . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47Resolve Q . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47Resource . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48Roundup formulations (see glyphosate, p.41)Sencor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48Shotgun. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48Status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49Steadfast . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49Stinger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50Stout. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50Unity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50Yukon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 512,4-D Amine or Ester. . . . . . . . . . . . . . . . . . . . 51

CORN PEST MANAGEMENT2

A3646/09, I. Intro (6.5) 10/16/08 2:29 PM Page vi

vii

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNPRINCIPLES

OF

PESTM

NGMT.

Insect managementChemigation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

Predicting soil insect control needs for corn . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

Continuous corn . . . . . . . . . . . . . . . . . . . . . . . 57Corn after soybeans. . . . . . . . . . . . . . . . . . . . . 58Corn after soybeans:

Variant western corn rootworm . . . . . . . . . 58Corn after sod . . . . . . . . . . . . . . . . . . . . . . . . . 59Corn after alfalfa . . . . . . . . . . . . . . . . . . . . . . . 59Corn after sudangrasses . . . . . . . . . . . . . . . . . 59

Insect pests. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59Armyworm. . . . . . . . . . . . . . . . . . . . . . . . . . . . 59Corn earworm . . . . . . . . . . . . . . . . . . . . . . . . . 59Corn flea beetle . . . . . . . . . . . . . . . . . . . . . . . . 60Corn leaf aphid . . . . . . . . . . . . . . . . . . . . . . . . 60Corn rootworm . . . . . . . . . . . . . . . . . . . . . . . . 60Cutworm. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63European corn borer . . . . . . . . . . . . . . . . . . . . 64Slugs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66Stalk borer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66Two-spotted spider mite. . . . . . . . . . . . . . . . . 66Western bean cutworm. . . . . . . . . . . . . . . . . . 67

Bt sprays and transgenic Bt cornfor insect control . . . . . . . . . . . . . . . . . . . . . . . . . 68

Bacillus thuringiensis (Bt) . . . . . . . . . . . . . . . . . 68Transgenic Bt corn . . . . . . . . . . . . . . . . . . . . . . 68Planting pattern options for

20% non-Bt corn refuge areas . . . . . . . . . . . 68

Disease managementDisease management strategies . . . . . . . . . . . 82

Resistant hybrids . . . . . . . . . . . . . . . . . . . . . . . 82Crop rotation and tillage practices . . . . . . . . 82Seed protectants. . . . . . . . . . . . . . . . . . . . . . . . 83Leaf disease control with fungicides . . . . . . 83

Disease problems . . . . . . . . . . . . . . . . . . . . . . . . 86Seed rot and seedling blights. . . . . . . . . . . . . 86Leaf diseases. . . . . . . . . . . . . . . . . . . . . . . . . . . 86Stalk rot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87Root and crown rot . . . . . . . . . . . . . . . . . . . . . 89Nematode diseases . . . . . . . . . . . . . . . . . . . . . 89Ear rot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90Corn molds and livestock disorders

(mycotoxins) . . . . . . . . . . . . . . . . . . . . . . . . . 92Storage diseases . . . . . . . . . . . . . . . . . . . . . . . . 93

TablesWeed management

2-1. Atrazine active ingredient rate limits . . 192-2. Wisconsin rate limits for products

containing atrazine . . . . . . . . . . . . . . . . . 192-3. Weed control ratings of

corn herbicides. . . . . . . . . . . . . . . . . . . . . 202-4. Forage, grazing, and grain harvest

intervals for corn herbicides . . . . . . . . . 522-5. Rate equivalents of corn herbicide

premixes . . . . . . . . . . . . . . . . . . . . . . . . . . 532-6. Rainfree period and adjuvants

required for postemergence corn herbicides . . . . . . . . . . . . . . . . . . . . . . . . . 54

2-7. Application timings for postemergence herbicides . . . . . . . . . . . 55

Insect management2-8. Soil insecticides labeled for

rootworm control at planting . . . . . . . . 622-9. Guide to black cutworm

development and damage in corn . . . . 632-10. Economic thresholds for stalk borer

at three corn prices . . . . . . . . . . . . . . . . . 662-11. Insecticide suggestions for corn pests . 70

Disease management2-12. Fungicides labeled for leaf diseases of

field corn (hybrid seed production and grain) . . . . . . . . . . . . . . . . . . . . . . . . . 84

2-13. Nematode genera associated with corn in Wisconsin . . . . . . . . . . . . . . . . . . 88

2-14. Corn nematode populations associated with yield loss. . . . . . . . . . . . 89

2-15. Directory of nematology laboratories. . 892-16. Directory of mycotoxin laboratories. . . 912-17. Some mycotoxins and their effects . . . . 922-18. Maximum time for storage of shelled

corn at various corn moisture and airtemperatures . . . . . . . . . . . . . . . . . . . . . . 93

2-19. General guide for sampling stored grain . . . . . . . . . . . . . . . . . . . . . . . 93

A3646/09, I. Intro (6.5) 10/16/08 2:29 PM Page vii

Weed management Burndown herbicides for no-till soybean . . . 96

Autumn + 2,4-D. . . . . . . . . . . . . . . . . . . . . . . . 96Canopy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99Canopy EX + 2,4-D . . . . . . . . . . . . . . . . . . . . . 99Enlite . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99Envive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100Extreme . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100Glyphosate . . . . . . . . . . . . . . . . . . . . . . . . . . . 100Gramoxone Inteon. . . . . . . . . . . . . . . . . . . . . 101Rage D-Tech . . . . . . . . . . . . . . . . . . . . . . . . . . 101Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101Synchrony XP + Express + 2,4-D. . . . . . . . . 102Valor XLT . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1022,4-D Ester . . . . . . . . . . . . . . . . . . . . . . . . . . . 102

Preplant-incorporated and preemergence herbicides . . . . . . . . . . . . . . . . 103

Authority Assist. . . . . . . . . . . . . . . . . . . . . . . 103Authority First

(see sulfentrazone+cloransulam, p.109)Authority MTZ . . . . . . . . . . . . . . . . . . . . . . . 103Boundary 6.5EC. . . . . . . . . . . . . . . . . . . . . . . 104Define SC . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104Dual II Magnum . . . . . . . . . . . . . . . . . . . . . . 104FirstRate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105Gangster . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105Intrro . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105Lorox . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106Outlook . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106Prowl H2O . . . . . . . . . . . . . . . . . . . . . . . . . . . 107Pursuit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107Pursuit Plus . . . . . . . . . . . . . . . . . . . . . . . . . . 108Python . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108Sencor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108Sonic

(see sulfentrazone+cloransulam, p.109)Sulfentrazone + cloransulam . . . . . . . . . . . . 109Trifluralin . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109Valor SX. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110

Postemergence herbicides . . . . . . . . . . . . . . . 110Assure II . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110Basagran . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110Cadet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111Classic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111Cobra (see lactofen, p.116)Extreme . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112FirstRate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112Flexstar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113Fusilade DX . . . . . . . . . . . . . . . . . . . . . . . . . . 113Fusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113Glyphosate . . . . . . . . . . . . . . . . . . . . . . . . . . . 114Gramoxone Inteon. . . . . . . . . . . . . . . . . . . . . 115Harmony SG. . . . . . . . . . . . . . . . . . . . . . . . . . 115Ignite . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115Lactofen. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116Outlook . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116Phoenix (see lactofen, p.116)Poast Plus . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116Pursuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117Raptor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117Resource . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118Roundup formulations (see glyphosate, p.114)Select Max . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118Synchrony XP. . . . . . . . . . . . . . . . . . . . . . . . . 119Touchdown (see glyphosate, p.114)Ultra Blazer. . . . . . . . . . . . . . . . . . . . . . . . . . . 119

viii

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNPRINCIPLES

OF

PESTM

NGMT.

SOYBEAN PEST MANAGEMENT3

A3646/09, I. Intro (6.5) 10/16/08 2:29 PM Page viii

ix

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNPRINCIPLES

OF

PESTM

NGMT.

Insect managementInsect pests. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123

Bean leaf beetle . . . . . . . . . . . . . . . . . . . . . . . 123Grasshoppers . . . . . . . . . . . . . . . . . . . . . . . . . 125Green cloverworms. . . . . . . . . . . . . . . . . . . . 125Potato leafhopper . . . . . . . . . . . . . . . . . . . . . 125Seedcorn maggot . . . . . . . . . . . . . . . . . . . . . . 126Soybean aphid . . . . . . . . . . . . . . . . . . . . . . . . 126Stink bugs . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127Thistle caterpillar (painted lady butterfly) 128Two-spotted spider mite. . . . . . . . . . . . . . . . 128

Disease managementResistant or tolerant varieties. . . . . . . . . . . . 138

Crop management. . . . . . . . . . . . . . . . . . . . . . . 138

Fungicides. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138

Soybean diseases . . . . . . . . . . . . . . . . . . . . . . . 140Phytophthora root rot . . . . . . . . . . . . . . . . . . 140Brown stem rot. . . . . . . . . . . . . . . . . . . . . . . . 142Leaf diseases. . . . . . . . . . . . . . . . . . . . . . . . . . 142Soybean rust . . . . . . . . . . . . . . . . . . . . . . . . . . 143Soybean cyst nematode . . . . . . . . . . . . . . . . 144Diaporthe pod and stem blight . . . . . . . . . . 147Sclerotinia stem rot (white mold) . . . . . . . . 147Alfalfa mosaic virus . . . . . . . . . . . . . . . . . . . 149Bean pod mottle virus. . . . . . . . . . . . . . . . . . 149Soybean mosaic virus . . . . . . . . . . . . . . . . . . 149Tobacco streak virus . . . . . . . . . . . . . . . . . . . 149


3-1. Weed control ratings of soybean herbicides . . . . . . . . . . . . . . . . . . . . . . . . . 97

3-2. Rate equivalents of soybean herbicide premixes . . . . . . . . . . . . . . . . 120

3-3. Forage and grain harvest intervals for soybean herbicides . . . . . . . . . . . . . 121

3-4. Rainfree period and adjuvants required for postemergence soybean herbicides . . . . . . . . . . . . . . . . 122

Insect management3-5. Early-season bean leaf beetle

economic thresholds in soybeans . . . . 1243-6. Second-generation bean leaf beetle

economic thresholds in reproductive stage soybeans . . . . . . . . . . . . . . . . . . . . 124

3-7. Treatment decision guidelines for two-spotted spider mites . . . . . . . . . . . 129

3-8. Suggestions for insect control in soybeans . . . . . . . . . . . . . . . . . . . . . . . . . 130

Disease management3-9. Fungicides for treating soybean

seeds for protection against Rhizoctonia, Pythium, Phytophthora, and Phomopsis . . . . . . 140

3-10. Fungicides for foliar and soil application for soybean . . . . . . . . . . . . 141

3-11. Fungicides registered for soybean diseases in Wisconsin . . . . . . . . . . . . . . 145

3-12. Risk assessment of soybean cyst nematode by soil population and soil type. . . . . . . . . . . . . . . . . . . . . . . . . . 146

3-13. Management recommendations forSclerotinia stem rot (white mold) . . . . 148

A3646/09, I. Intro (6.5) 10/16/08 2:29 PM Page ix

x

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNPRINCIPLES

OF

PESTM

NGMT.

FORAGE & PASTURE PEST MANAGEMENTWeed managementForage legumes. . . . . . . . . . . . . . . . . . . . . . . . . 152

Establishing forage legumes without a cover crop (direct seeding). . . . . . . . . . . . . . . 152

Buctril . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154Butyrac 200 . . . . . . . . . . . . . . . . . . . . . . . . . . . 154Eptam . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154Glyphosate . . . . . . . . . . . . . . . . . . . . . . . . . . . 155Poast Plus . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155Pursuit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156Raptor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156Select . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157Treflan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157

Summer seedings . . . . . . . . . . . . . . . . . . . . . . . 158

Weed management in established forage legumes . . . . . . . . . . . . . . 158

Butyrac 200 . . . . . . . . . . . . . . . . . . . . . . . . . . . 158Glyphosate . . . . . . . . . . . . . . . . . . . . . . . . . . . 159Poast Plus . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160Pursuit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160Raptor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160Select . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161Sencor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161Velpar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162

Weed and brush control in grass pastures. . . . . . . . . . . . . . . . . . . . . . . . 162

Ally/Escort. . . . . . . . . . . . . . . . . . . . . . . . . . . 163Banvel/Clarity (see dicamba, p.165)Crossbow . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164Curtail . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164Dicamba . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165Forefront . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165Glyphosate . . . . . . . . . . . . . . . . . . . . . . . . . . . 165Milestone . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166Overdrive . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166Spike . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166Stinger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167Weedmaster . . . . . . . . . . . . . . . . . . . . . . . . . . 1672,4-D for herbaceous weed control . . . . . . . 1672,4-D ester for brush control . . . . . . . . . . . . 168

Pasture renovation. . . . . . . . . . . . . . . . . . . . . . 168Glyphosate . . . . . . . . . . . . . . . . . . . . . . . . . . . 168Gramoxone . . . . . . . . . . . . . . . . . . . . . . . . . . . 169

Insect managementReducing insecticide hazards to bees . . . . . 171

Alfalfa insects . . . . . . . . . . . . . . . . . . . . . . . . . . 172Alfalfa blotch leafminer . . . . . . . . . . . . . . . . 172Alfalfa caterpillar. . . . . . . . . . . . . . . . . . . . . . 173Alfalfa weevil . . . . . . . . . . . . . . . . . . . . . . . . . 173Aphids. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174Grasshoppers . . . . . . . . . . . . . . . . . . . . . . . . . 174Plant bugs . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174Potato leafhopper . . . . . . . . . . . . . . . . . . . . . 174Spittlebugs . . . . . . . . . . . . . . . . . . . . . . . . . . . 175

Insect pests of birdsfoot trefoil, clover, and pasture . . . . . . . . . . . . . . . . . . . . . 175


4-1. Impact of common weeds on forage quality . . . . . . . . . . . . . . . . . . . . . 153

4-2. Legume tolerance and herbicideeffectiveness on weeds commonly found in legumes seeded without a cover crop . . . . . . . . . . . . . . . . . . . . . . 153

4-3. Legume tolerance and herbicideeffectiveness on weeds commonly found in established legume stands . . 159

4-4 Herbicide effectiveness on weedscommonly found in pastures. . . . . . . . 163

4-5 Harvest and/or grazing restrictions for herbicides registered for use inforages and pastures . . . . . . . . . . . . . . . 169

Insect management4-6. Timing of insecticide applications

to avoid bee deaths . . . . . . . . . . . . . . . . 1714-7. Periods to scout for insect pests of

forages. . . . . . . . . . . . . . . . . . . . . . . . . . . 1724-8. Treatment thresholds for potato

leafhoppers on alfalfa . . . . . . . . . . . . . 1744-9. Insecticide suggestions for birdsfoot

trefoil, clover, and pasture . . . . . . . . . . 1754-10. Insecticide suggestions for alfalfa . . . . 176

Disease management4-11. Probability and occurrence of alfalfa

diseases in stands of different ages. . . 1834-12. Products registered for disease

control in alfalfa seedlings and other forage legumes . . . . . . . . . . . . . . 184

4

A3646/09, I. Intro (6.5) 10/16/08 2:29 PM Page x

xi

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNPRINCIPLES

OF

PESTM

NGMT.

Weed managementSmall grains with a legume seeding . . . . . . 188

Buctril . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 188MCPA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 190Buctril vs. MCPA . . . . . . . . . . . . . . . . . . . . . . 191

Small grains without a legume seeding . . . 191Affinity BroadSpec . . . . . . . . . . . . . . . . . . . . 191Banvel/Clarity (see dicamba, p.192)Buctril . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192Callisto . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192Dicamba . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192Harmony Extra SG . . . . . . . . . . . . . . . . . . . . 193Harmony SG. . . . . . . . . . . . . . . . . . . . . . . . . . 193Huskie . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194MCPA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194Orion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194Rage D-Tech . . . . . . . . . . . . . . . . . . . . . . . . . . 195Starane. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 195Stinger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1952,4-D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 196

Insect managementInsect pests of small grains . . . . . . . . . . . . . . 198

Aphids. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 198Armyworms . . . . . . . . . . . . . . . . . . . . . . . . . . 198Grasshoppers . . . . . . . . . . . . . . . . . . . . . . . . . 199Wireworms . . . . . . . . . . . . . . . . . . . . . . . . . . . 199

Disease managementSmall grain diseases . . . . . . . . . . . . . . . . . . . . 200

Barley yellow dwarf (red leaf) . . . . . . . . . . . 200Ergot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 200Leaf rust and stem rust . . . . . . . . . . . . . . . . . 200Powdery mildew . . . . . . . . . . . . . . . . . . . . . . 201

Scab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 201Septoria black stem of oat . . . . . . . . . . . . . . 201Septoria leaf blotch of wheat . . . . . . . . . . . . 201Smut . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 202Take-all . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 202

Figure5-1. Herbicide application periods at

various growth stages of small grains(using Feeke’s scale) . . . . . . . . . . . . . . . 189


5-1. Crop registration, tolerance, andherbicide effectiveness on weedscommonly found in small grains . . . . 190

5-2. Harvest and/or grazing restrictions for herbicides registered for use in small grains . . . . . . . . . . . . . . . . . . . . . . 197

Insect management5-3. Treatment thresholds for aphids to

prevent direct plant damage (not disease reduction) and subsequent grain yield loss. . . . . . . . . . . . . . . . . . . . 199

5-4. Insecticide suggestions for small grains . . . . . . . . . . . . . . . . . . . . . . 199

Disease management5-5. Fungicides for control of foliar

diseases of small grains . . . . . . . . . . . . 2035-6. Seed treatment fungicides for

small grains . . . . . . . . . . . . . . . . . . . . . . 206

SMALL GRAINS PEST MANAGEMENT5

Disease managementAlfalfa leaf and stem diseases . . . . . . . . . . . 183

Alfalfa seedling diseases . . . . . . . . . . . . . . . . 184

Alfalfa root and crown diseases . . . . . . . . . . 184Bacterial wilt. . . . . . . . . . . . . . . . . . . . . . . . . . 185Fusarium wilt. . . . . . . . . . . . . . . . . . . . . . . . . 185Verticillium wilt . . . . . . . . . . . . . . . . . . . . . . . 185Phytophthora root rot . . . . . . . . . . . . . . . . . . 185

Aphanomyces/Phytophthora root rot complex . . . . . . . . . . . . . . . . . . . . . 185

General root and crown rot . . . . . . . . . . . . . 186

Red clover diseases . . . . . . . . . . . . . . . . . . . . . 186Crown and root rots . . . . . . . . . . . . . . . . . . . 186Northern anthracnose. . . . . . . . . . . . . . . . . . 186Powdery mildew . . . . . . . . . . . . . . . . . . . . . . 186Viruses. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 186

Diseases of forage grasses. . . . . . . . . . . . . . . 186

A3646/09, I. Intro (6.5) 10/16/08 2:29 PM Page xi

xii

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNPRINCIPLES

OF

PESTM

NGMT.

Bin preparation . . . . . . . . . . . . . . . . . . . . . . . . . 218

Residual bin sprays and empty-bin fumigation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 218

Grain protection with insecticides . . . . . . . . 219Storcide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 219Actellic 5E . . . . . . . . . . . . . . . . . . . . . . . . . . . . 219Diacon II . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 219

Grain surface spray . . . . . . . . . . . . . . . . . . . . . 219DiPel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 219Diacon II . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 219Actellic 5E . . . . . . . . . . . . . . . . . . . . . . . . . . . . 219Storcide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 220

Indian meal moth . . . . . . . . . . . . . . . . . . . . . . . 220

Grain inspection . . . . . . . . . . . . . . . . . . . . . . . . 220

Safety precautions . . . . . . . . . . . . . . . . . . . . . . 220

Controlling established infestations . . . . . . . 221

Fumigation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 222

Table7-1. The number of live insects (per

kilogram of grain) required for Federal Grain Inspection Servicedesignation as infested . . . . . . . . . . . . . 221

STORED GRAIN INSECT PEST MANAGEMENT7

Appendix Table 1. Pesticide products and related information—1a. Herbicides . . . . . . . . . . . . . . . . . . . . . 224—1b. Insecticides . . . . . . . . . . . . . . . . . . . . 229—1c. Fungicides . . . . . . . . . . . . . . . . . . . . . 230

Appendix Table 2. Planting interval for rotational crops . . . . . . . . . . . . . . . . . . . 232

Appendix Table 3. Herbicide price list . . . . 235Appendix Table 4. Herbicide effectiveness

on listed invasive weeds in CRP fields . . 240Additional resources . . . . . . . . . . . . . . . . . . . 242

APPENDIX

Quackgrass. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 208Accent, Beacon, and Option. . . . . . . . . . . . . 208Assure II, Fusion, Poast Plus, and Select . . 209Glyphosate . . . . . . . . . . . . . . . . . . . . . . . . . . . 209Poast Plus and Select. . . . . . . . . . . . . . . . . . . 209

Wirestem muhly . . . . . . . . . . . . . . . . . . . . . . . . 209Control in soybeans. . . . . . . . . . . . . . . . . . . . 210Control in corn . . . . . . . . . . . . . . . . . . . . . . . . 210Control in other crops . . . . . . . . . . . . . . . . . . 210

Yellow nutsedge . . . . . . . . . . . . . . . . . . . . . . . . 210Acetochlor, Alachlor, Dual II Magnum,

and Outlook. . . . . . . . . . . . . . . . . . . . . . . . . 210Basagran . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 211Classic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 211Permit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 211

Perennial broadleaf control in glyphosate-resistant crops . . . . . . . . . . . . . . . 211

Canada thistle in conventional grain crops and pastures . . . . . . . . . . . . . . . . 212

Dicamba and 2,4-D . . . . . . . . . . . . . . . . . . . . 212Glyphosate . . . . . . . . . . . . . . . . . . . . . . . . . . . 212Stinger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213

Hemp dogbane in conventional crops . . . . . 213Dicamba and 2,4-D . . . . . . . . . . . . . . . . . . . . 213Starane. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 214Glyphosate . . . . . . . . . . . . . . . . . . . . . . . . . . . 214

Table6-1. Summary of herbicides for

perennial weed suppression in corn and soybeans . . . . . . . . . . . . . . . . . 214

PERENNIAL WEED MANAGEMENT6

A3646/09, I. Intro (6.5) 10/16/08 2:29 PM Page xii

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNPRINCIPLES

OF

PESTM

NGMT.

PRINCIPLES OF PEST MANAGEMENT

1

A3646/09, I. Intro (6.5) 10/14/08 5:04 PM Page 1

PEST MANAGEMENT AND PESTICIDES

Controlling a pest is only part of a totalpest management program. Pest control is acorrective measure; you use pesticides orsome other control method to reduce adamaging (or potentially damaging) pestpopulation. Pest management, however,includes preventative measures as well.

The primary goal of your pest manage-ment program is to maintain pest damageat an acceptable level. Eradication of pestsis rarely possible and rarely feasible. In fact,our attempts at eradication may createmore problems than they solve (pesticideresistance, secondary pest outbreaks, etc.).Pesticides are vital, effective tools for agri-culture and for the production of ournation’s food and fiber, but they can nolonger be viewed as a cure-all for all of ourpest problems. Rather, they must be viewedin the context of a total pest managementprogram.

INTEGRATED PESTMANAGEMENT

Integrated Pest Management (IPM) is thecoordinated use of multiple pest controlmethods. By becoming familiar with thecrop, the pest, and all available control tac-tics, you can develop and implement asound IPM program that will help youapply pesticides only when necessary.

To help train growers, field scouts, andconsultants, the University of Wisconsinconducts field scout training classes eachyear in Madison and River Falls, and a Wis-consin crop diagnosis training program atArlington. For more information about theWisconsin IPM program, contact yourcounty Extension agent or call the state IPMcoordinator at 608-263-4073.

FEDERAL PESTICIDE-USE LAWWhen Congress amended the Federal

Insecticide, Fungicide, and Rodenticide Act(FIFRA) in 1972, it included a mandate forthe Environmental Protection Agency(EPA) to evaluate all new and existing pes-ticide products for potential harm they maycause. It also made it illegal to use, exceptas provided by FIFRA, any pesticide in amanner inconsistent with its labeling. Devi-ations from the label not recognized byFIFRA are a violation of the law.

The Food Quality Protection Act (FQPA)of 1996 strengthens the system that regu-lates pesticide residues on food. Recogniz-ing that pesticide residues are present inmore sources than just food, the FQPA setslimits on the total exposure from residuesfound in food, drinking water, and non-dietary sources (such as household, land-scape, and pet uses). As a result, the moreuses a particular pesticide has, the greaterthe chance its total exposure will be metand, thus, some or all of its uses will becanceled.

If, during the pesticide registrationprocess, the EPA finds a product to gener-ally cause unreasonable adverse effects onthe environment, including injury to theapplicator, it will be classified as restricted-use. Because restricted-use products can beused only by certified applicators, theFIFRA amendments also called for eachstate to develop a program for training andcertifying pesticide applicators. The certifi-cation program is designed to ensure thatusers of restricted-use products are prop-erly qualified to handle and apply thesematerials safely and efficiently. A currentlist of restricted-use pesticides registeredfor use in Wisconsin may be downloadedfrom the Pesticide Applicator Training website (ipcm.wisc.edu/pat).

2

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNPRINCIPLES

OF

PESTM

NGMT.

A3646/09, I. Intro (6.5) 10/14/08 5:04 PM Page 2

WISCONSIN’S TRAINING ANDCERTIFICATION PROGRAM

In Wisconsin, responsibility for traininglies with the University of Wisconsin-Extension’s Pesticide Applicator Training(PAT) program, while actual certification isthe responsibility of the Wisconsin Depart-ment of Agriculture, Trade, and ConsumerProtection (WDATCP). The Wisconsin Pes-ticide Law requires that all commercialapplicators for hire participate in the train-ing and certification process if they intendto use any pesticide in the state of Wiscon-sin, whether or not it is restricted-use.

Since 1977, the PAT program has trainedover 201,000 Wisconsin applicators in thesafe handling of pesticides. The trainingprepares the applicators for the written cer-tification exam administered by theWDATCP, which enforces Wisconsin’s pes-ticide regulations.

The selection, use, and potential risks ofpesticides vary depending on the methodof application and what it is you want toprotect from pests. Therefore, there is a sep-arate training manual and certificationexam for 21 pest control categories, includ-ing categories for agricultural producers,the agricultural industry (10 categories), inand around commercial and residentialbuildings (6 categories), in right-of-wayand surface waters (3 categories), and pre-serving wood. Certification is valid for5 years, after which you can recertify bypassing a new exam that is based on arevised training manual.

The regulated community—includingpesticide manufacturers, dealers, and appli-cators—strongly support training and certi-fication as a way to protect people and theenvironment while ensuring that pesticidesremain an option in pest management.Nearly 75% of applicators surveyed at livetraining sessions said they had alreadyadopted or plan to adopt all 24 pesticideuse practices listed on the survey as a directresult of Wisconsin’s training effort; of theremaining applicators, over 90% said theyplan to adopt at least one additional usepractice. We encourage all applicators totake advantage of the training and certifica-tion process, whether or not you userestricted-use pesticides. For more informa-tion about the Wisconsin PAT program,contact your county Extension agent or

visit ipcm.wisc.edu/pat. For informationon Wisconsin’s licensing and certificationprogram, visit datcp.state.wi.us and searchfor “pesticide certification.”

WISCONSIN PESTICIDE LAWSAND REGULATIONS

Operating under the provisions of theWisconsin Pesticide Law and Administra-tive Rule, Chapter ATCP 29 (Register, May1998), the WDATCP has primary responsi-bility for pesticide use and control in thestate. The Wisconsin Department of Nat-ural Resources (WDNR) has responsibilityfor pesticide use involving “waters of thestate,” the control of birds and mammals,and pesticide and container disposal. TheWisconsin Division of Emergency Manage-ment (WDEM) has responsibility for help-ing communities evaluate their prepared-ness for responding to accidental releases ofhazardous compounds, including pesti-cides, under Title III of SARA. The Wiscon-sin Department of Transportation (WDOT)has responsibility for regulating the trans-portation of pesticides listed as hazardousmaterials (shipping papers, vehicle placard-ing, etc.), and for issuing commercial dri-ver’s licenses. It is your responsibility tobecome familiar with all pertinent laws andregulations affecting pesticide use in Wis-consin.

PESTICIDES AND COMMUNITYRIGHT-TO-KNOW

To help communities evaluate their pre-paredness for responding to chemicalspills, Congress passed the EmergencyPlanning and Community Right-to-KnowAct. This law is part of a much larger legis-lation called the Superfund Amendmentsand Reauthorization Act (SARA) and isoften referred to as Title III of SARA. TitleIII sets forth requirements for reporting ofhazardous substances stored in the commu-nity and for developing an emergencyresponse plan.

The first step in emergency planning is toknow which chemicals can cause healthproblems and environmental damage ifaccidentally released. The EPA prepared alist of such chemicals and called themextremely hazardous substances. Thesesubstances are subject to emergency plan-

3

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNPRINCIPLES

OF

PESTM

NGMT.

A3646/09, I. Intro (6.5) 10/14/08 5:04 PM Page 3

ning and the threshold planning quantity,the smallest amount of a substance whichmust be reported. Some of the chemicalslisted are commonly used in agriculturalproduction (see table 1-1).

A complete list of EPA’s extremely haz-ardous substances is available from theLocal Emergency Planning Committee inyour county or from this EPA web site:www.epa.gov/emergencies/content/epcra.

Any facility, including farms, that pro-duces, uses, or stores any of these sub-stances in a quantity at or greater than theirthreshold planning quantity must notifythe WDEM and their Local EmergencyPlanning Committee (LEPC) that it is sub-ject to the emergency planning notificationrequirements of Title III of SARA.

In addition to emergency planning notifi-cation, agricultural service businesses withone or more employees are subject to twocommunity right-to-know reportingrequirements: submission of material safetydata sheets (MSDS) and submission of TierII inventory forms. Tier II forms requestspecific information on each hazardouschemical stored at or above its threshold.

WORKER PROTECTIONSTANDARD (WPS) FORAGRICULTURAL PESTICIDES

The federal Worker Protection Standard(WPS) for Agricultural Pesticides tookeffect January 1, 1995. Its purpose is toreduce the risk of employee exposure topesticides. You are subject to the WPS ifyou have at least one employee who is

involved in the production of agriculturalplants in a nursery, greenhouse, forest, orfarming operation.

The WPS requires employers to do thefollowing:■ Display pesticide safety information in

a central location.■ Train uncertified workers and handlers

on general pesticide safety principles.■ Provide personal protective clothing

and equipment to employees.■ Provide a decontamination site (water,

soap, towels, and coveralls).■ Provide transportation to an emergency

medical facility for employees who arepoisoned or injured by pesticide expo-sure.

■ Provide notification to employees aboutpesticide applications (see below).

For more information about the WPS andthe training requirements for uncertifiedworkers and handlers, download the 2005edition of the EPA’s How To Comply manual(www.epa.gov/agriculture/twor.html).

ORAL NOTIFICATION ANDPOSTING

The WPS requires employers to givenotice of pesticide applications to all work-ers who will be in a treated area or walkwithin 1⁄4 mile of a treated area during thepesticide application or during therestricted entry interval (described in nextsection). Notification may either be oralwarnings or posting of warning signs atentrances to treated sites; both are necessary

4

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNPRINCIPLES

OF

PESTM

NGMT.

Table 1-1. Examples of agricultural chemicals subjectto Title III of SARA

Threshold planning quantity (lb or gal of

Active ingredient Trade name product)

anhydrous ammonia (fertilizer) 610 lbterbufos Counter 15G 667 lbdimethoate Dimethoate 4EC 125 galcarbofuran Furadan 4F 2.5 galphosmet Imidan 70WP 14.3 lbparaquat Gramoxone Inteon 5 galazinphos-methyl Guthion 50WP 20 lbphorate Thimet 20G 50 lb

A3646/09, I. Intro (6.5) 10/14/08 5:04 PM Page 4

if the label requires dual (oral and posting)notification. A current list of dual-noticepesticides registered for use in Wisconsinmay be downloaded from the PesticideApplicator Training web site (ipcm.wisc.edu/pat/).

Wisconsin’s ATCP 29 posting rule isdesigned to protect the general public aswell as workers. Thus, it requires posting ofareas treated with pesticides having a dualnotification statement or, for nonagricul-tural pesticide applications, if the label pre-scribes a restricted entry interval for thatparticular application. Refer to On-FarmPosting of Pesticide-Treated Sites in Wisconsinfor a flow chart guiding users through aseries of questions to determine when post-ing of treated sites is needed, what warningsign to use, and where the sign should belocated. It also covers the separate postingrequirements for chemigation treatments.This publication is available from yourcounty Extension office or online atipcm.wisc.edu/pat.

RESTRICTED ENTRY INTERVAL (REI)

A restricted entry interval (REI) is thelength of time that must expire after pesti-cide application before people can safelyenter the treated site without using per-

sonal protective equipment. Pesticideresidues on a treated crop or in a treatedarea may pose a significant hazard to work-ers or others who enter the area after treat-ment. Therefore, nearly all pesticidesaffected by the WPS (see above) have anREI (see appendix table 1). Check the Agri-cultural Use Requirements section on thelabel for the specific restricted entry inter-val for your product. These intervals mustbe strictly observed.

PESTICIDE TOXICITYThere are four common ways in which

pesticides enter the human body—throughthe skin (dermal), the mouth (oral), thelungs (inhalation), and the eyes. Absorptionthrough the skin is the most common routeof poisoning of agricultural workers.

Perhaps the greatest hazard for the appli-cator is in loading and mixing the pesticideconcentrate, which presents a significantrisk of exposure to the chemical in its mosttoxic form. Although hazards associatedwith the actual application are frequentlymuch less severe, they can still be substan-tial, especially if there is significant drift orif appropriate precautions are ignored. Apesticide may be toxic as a result of expo-sure to a single dose (acute toxicity) or as aresult of repeated exposures over time(chronic toxicity).

5

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNPRINCIPLES

OF

PESTM

NGMT.

Table 1-2. Toxicity categories of pesticides

——————————————Toxicity category——————————————I II III IV

High Moderate Slight LowMeasure of toxicity toxicity toxicity toxicity toxicity

Oral LD50 (mg/kg) 0–50 50–500 500–5,000 >5,000Dermal LD50 (mg/kg) 0–200 200–2,000 2,000–20,000 >20,000Inhalation LC50

gas/vapor (ppm) 0–200 200–2,000 2,000–20,000 >20,000dust/mist (mg/l) 0–0.2 0.2–2 2–20 >20

Eye effects corrosive irritation persists irritation reversible no irritationfor 7 days within 7 days

Skin effects corrosive severe moderate mild irritation irritation irritation

Signal word DANGERa WARNING CAUTION CAUTIONAbbreviations: mg/kg = milligrams per kilogram; mg/l = milligrams per liter; ppm = parts per million; < = less than; > = greater than.aProducts assigned to Category I due to oral, inhalation, or dermal toxicity (as distinct from eye and skin localeffects) also must have the word “poison” and the “skull and crossbones” symbol on the label.

A3646/09, I. Intro (6.5) 10/14/08 5:04 PM Page 5

Acute toxicities are normally expressedas the amount of pesticide required to kill50% of a population of test animals (usuallyrats or rabbits). For oral and dermal expo-sure, this is referred to as the LD50 or“lethal dose to 50%” in milligrams of toxi-cant per kilogram of body weight (mg/kg).For inhalation exposure, it is expressed asthe LC50 or “lethal concentration to 50%” inparts per million (ppm) of toxicant in thetotal volume of air when the toxicant is agas or vapor, and in milligrams per liter(mg/l) of air when the toxicant is a dust ormist. Pesticides with greater acute toxici-ties have lower LD50 and/or LC50 values;that is, it takes less of the chemical to kill50% of the test population.

Labels indicate the relative level of acutetoxicity through the use of signal wordsand symbols (see table 1-2). The toxicitycategory is assigned on the basis of thehighest measured toxicity, be it oral, der-mal, or inhalation; effects on the eyes andexternal injury to the skin are also consid-ered.

In the event of human pesticide poison-ing, the pesticide label is your first sourceof first-aid information. Always bear inmind, however, that first-aid response topesticide exposure is not a substitute forprofessional medical help. Seek medicalattention promptly, and always be sure thatthe label or labeled container is given to thedoctor. The product’s Material Safety DataSheet (MSDS) is a more technical documentthan the label, and it often contains addi-tional treatment instructions for the attend-ing medical professional.

Poison Control Center (1-800-222-1222).You may call the Poison Control Center atany hour for information regarding propertreatment of pesticide poisoning. Whileother hospitals and medical facilities mayhave some information, the Poison ControlCenter has the most complete and currentfiles and their personnel are specificallytrained to deal with poison cases.

Most labels also list a phone number thatyou (or medical personnel) can call for spe-cific information on poisoning (or otheraccidents) involving that particular product.

PESTICIDE SAFETYBefore you handle pesticides, stop and

read the label. Labels contain human safetyprecaution statements and list the specificpersonal protective clothing and equipmentthat you need to wear. Some of the follow-ing may be label requirements; others arecommon-sense guidelines that will helpminimize pesticide exposure to you, yourco-workers, and your family and neighbors.■ Wear a long-sleeved shirt, long pants,

shoes, and socks when handling pesti-cides.

■ Wear coveralls (fabric or chemical-resis-tant) over your work clothes for anadded layer of protection.

■ Unless the label states otherwise,always wear chemical-resistant gloveswhenever you work with pesticides.

■ Wear chemical-resistant footwear,gloves, eyewear, and respirator (if thelabel requires one) when mixing, load-ing, or applying pesticides.

■ If you wear fabric coveralls, also wear achemical-resistant apron when mixingand loading pesticides.

■ Stand in the crosswind when mixing orloading pesticides.

■ Never apply pesticides when there isthe likelihood of significant drift.

■ Never leave a spray tank containingpesticide unattended.

■ Avoid back-siphoning into the watersource.

■ Never eat, drink, or smoke when han-dling pesticides.

■ Wash hands thoroughly after handlingpesticides.

■ If you splash pesticide on yourself,remove contaminated clothing immedi-ately and wash yourself thoroughly.

■ Wash contaminated clothes separatelyfrom other household laundry.

■ Keep pesticides in original containers.■ Store and lock pesticides out of the

reach of children.■ Observe restricted entry intervals on a

treated crop or area.

6

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNPRINCIPLES

OF

PESTM

NGMT.

A3646/09, I. Intro (6.5) 10/14/08 5:04 PM Page 6

PESTICIDE ACCIDENTSPesticide spills. Regardless of the magni-

tude of a spill, the objectives of a properresponse are the same—you must controlthe spill, you must contain it, and you mustclean it up. A thorough knowledge ofappropriate procedures will allow you tominimize the potential for adverse effects.

Spills of any compound need to bereported to the WDNR. However, you donot need to report the spill if it is com-pletely confined within an impervious sec-ondary containment, and the spilledamount can be recovered with no dischargeto the environment. On the other hand, aspill of any amount is reportable if itoccurred outside of secondary containmentand it harmed, or threatens to harm humanhealth or the environment (e.g., backsiphoning). The spill is exempt from theWDNR reporting requirements if you deemthe spill will not harm, or threaten to harm,and the amount spilled would cover lessthan 1 acre if applied at labeled rates and, ifa SARA pesticide, is less than the reportablequantity.

Reportable spills involving SARA sub-stances (see “Pesticides and CommunityRight-to-Know,” above) are also to bereported to the WDEM and to your LEPC.To simplify emergency notification require-ments to state agencies, call the WDEMspill hotline (1-800-943-0003, 24-hour num-ber) whenever a spill of any compoundoccurs. Calling this hotline will not, how-ever, remove your responsibility of notify-ing your LEPC.

Spills of some compounds may requirethat you notify federal authorities by call-ing the National Response Center (1-800-424-8802). Your call to the WDEM spill hot-line should provide you with assistance indetermining whether federal authoritiesneed to be notified.

Pesticide fires. In the event of a fire, callthe fire department and clear all personnelfrom the area to a safe distance upwindfrom smoke and fumes. Isolate the entirearea. Always inform the fire department ofthe nature of the pesticides involved and ofany specific information that may helpthem in fighting the fire and protectingthemselves and others from injury. Forinformation on cleanup and decontamina-tion, contact the WDEM and the pesticidemanufacturer(s).

Livestock poisoning. When you suspectanimal poisoning by pesticides, first callyour veterinarian. If the cause of poisoningcannot be determined, call the WDATCP’sAnimal Toxic Response Team at608-224-4500.

Wildlife poisoning or water contamination.Contact the WDNR district office. Districtoffices are located in Spooner, Rhinelander,Eau Claire, Green Bay, Milwaukee, andFitchburg.

PESTICIDE DRIFTIt is impossible to totally eliminate pesti-

cide drift. Drift occurs because of unfore-seen wind variations and other factors,many of which are beyond the applicator’scontrol. People living in areas subject topesticide drift worry about the acute andchronic effects of exposure to pesticides.State rules governing pesticide driftattempt to strike a balance between theintended benefits of pesticide use and thepotential risks to those exposed to pesticidedrift.

According to state law, people livingadjacent to land that is aerially sprayedwith pesticides can request to be notified atleast 24 hours before application. Beekeep-ers also are entitled to notification of appli-cations that occur within a 1.5-mile radiusof their honey-bee colonies. Both groundand aerial pesticide applications are subjectto advance notification requirements tobeekeepers who request such notification.

For ground applications, you can minimizedrift by following these recommendations:■ Follow all label precautions for specific

drift-reduction measures.■ Spray when wind speed is low.■ Use the maximum size nozzle orifice

without sacrificing pest control activity.■ Keep pressure at the lowest setting pos-

sible without distorting spray patternand distribution.

■ Use drift-control agents when permit-ted by product label.

■ Consider using nozzles specificallydesigned to reduce drift.

■ Leave an untreated border strip next toadjacent property.

For more information about drift—whatit is, how it occurs, and drift managementprinciples—ask for Managing Pesticide Drift

7

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNPRINCIPLES

OF

PESTM

NGMT.

A3646/09, I. Intro (6.5) 10/14/08 5:04 PM Page 7

in Wisconsin: Field Sprayers from yourcounty Extension office. This publicationalso describes the critical role the pesticideapplicator plays in deciding whether tospray when arriving at the site.

PESTICIDES ANDGROUNDWATER

Trace amounts of pesticides are appear-ing in our nation’s groundwater. To mini-mize further contamination, many pesticidelabels contain precautionary statementseither advising against or prohibiting use inareas vulnerable to groundwater contami-nation. A summary of these precautionarystatements is included under “Remarks”for each pesticide in this publication.

To protect our state’s water resources,Wisconsin’s Groundwater Law created twoguidelines to limit the presence of fertilizerand pesticides in groundwater: enforce-ment standards are maximum chemical lev-els allowed in groundwater and preventiveaction limits are set at a percentage of theenforcement standard. When contamina-tion approaches preventive action limits,the responsible party must implement cor-rective measures to prevent further contam-ination.

Through groundwater monitoring stud-ies, the most commonly found pesticide isatrazine. Atrazine rate limits and restrictionsare explained more fully in the corn weedmanagement section of this publication.

Mixing and loading pesticides. Mixing andloading pesticides pose a high risk of pointsource contamination of ground–and sur-face water because of the concentration,quantity, and type of pesticides that areusually handled at a mixing and loadingsite. To minimize this risk of environmentalcontamination, Wisconsin requires that cer-tain mixing and loading sites have sec-ondary containment.

Both private and commercial applicatorsare required to have a mixing and loadingpad if more than 1,500 lb of pesticide activeingredient are mixed or loaded at any onesite in a calendar year, or if mixing andloading occurs within 100 feet of a well orsurface water. In–field mixing is exemptfrom the pad requirements provided mix-ing or loading at the site of applicationoccurs 100 feet or more from a well or sur-face water.

Agricultural Chemical Cleanup Program.Cleanup of contaminated soil or of contam-inated groundwater itself is costly. TheAgricultural Chemical Cleanup programhelps ease the financial burden for facilitiesand farms by reimbursing them for eligiblecosts associated with the cleanup of sitescontaminated with pesticides or fertilizers.For more information, contact theWDATCP at 608-224-4518.

CALIBRATING PESTICIDEEQUIPMENT

Accurate and uniform pesticide applica-tion is basic to satisfactory pest control. Toofrequently a grower does not know exactlyhow much pesticide has been used until theapplication is completed. This leads to sub-stantial monetary losses due to unnecessarypesticide and labor costs, unsatisfactorypest control resulting in reduced yields, andcrop damage. Good pesticide applicationbegins with accurate sprayer or granularapplicator calibration. One method of cali-bration is contained in the Training Manualfor the Private Pesticide Applicator. It also isfound in the Training Manual for the Commercial Pesticide Applicator: Field andVegetable Crops.

CLEANING PESTICIDE SPRAYERSThorough sprayer cleaning is necessary

when switching from pesticide applicationon one crop to the application of a differentpesticide on another crop. This is espe-cially important when the second crop isquite sensitive to the first pesticide. Forexample, residue of dicamba left in asprayer may damage soybeans and otherdicamba-sensitive crops during subsequentpesticide applications. No cleaning methodis 100 percent foolproof. If you apply signif-icant quantities of different types of pesti-cides, reserve one sprayer for crops thatmay be sensitive to herbicides applied withother sprayers.

8

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNPRINCIPLES

OF

PESTM

NGMT.

A3646/09, I. Intro (6.5) 10/14/08 5:04 PM Page 8

Check the label for specific cleaninginstructions. If none are listed, follow theguidelines listed below:1. Park the sprayer on a wash pad and

flush the tank, lines, and booms thor-oughly with clean water and apply thepesticide-contaminated rinsate to siteslisted on label. Simpler still, mount aclean water source on your sprayer andflush the system while in the field.

2. Select the appropriate cleaning solutionfor the pesticide used:—Hormone-type herbicides (e.g., 2,4–D,Banvel). Fill the sprayer with sufficientwater to operate adding 1 quart house-hold ammonia for every 25 gallons ofwater. Circulate the ammonia solutionthrough the sprayer system for 15 to 20minutes and then discharge a smallamount through the boom and nozzles.Let the solution stand for several hours,preferably overnight. (Please note:household ammonia will corrode alu-minum sprayer parts.)—Other herbicides, insecticides, andfungicides. Fill the sprayer with suffi-cient water to operate adding 1⁄4 to 2 lbpowder detergent (liquid detergentmay be substituted for powder at a rateto make a sudsy solution) for every25 to 40 gallons of water. Circulate thedetergent solution through the sprayersystem for 5 to 10 minutes and then dis-charge a small amount through theboom and nozzles. Let the solutionstand for several hours, preferablyovernight.

3. Flush the solution out of the spray tankand through the boom.

4. Remove the nozzles, screens, andstrainers and flush the system twicewith clean water.

5. Scrub all accessible parts with a stiffbristle brush.

PREPARING PESTICIDESPRAYERS FOR STORAGE

Before storing the sprayer at the end ofthe season:1. Clean the sprayer per label instructions

or as specified above.2. Fill the sprayer with sufficient water to

operate adding 1 to 5 gallons of light-weight emulsifiable oil, dependingupon the size of the tank. Circulate theoil/water solution through the sprayersystem for 5 to 10 minutes.

3. Flush the solution out of the spray tankand through the boom; the oil will leavea protective coating on the inside of thetank, pump, and plumbing.

4. Remove the nozzles, screens, andstrainers and place them in diesel fuelor kerosene to prevent corrosion. Coverthe nozzle openings in the boom to pre-vent dirt from entering.

5. As an added precaution to protectpumps, pour 1 tablespoon of radiatorrust–inhibitor antifreeze in each of theinlet and outlet ports. Rotate the pumpseveral revolutions to completely coatthe interior surfaces.

PESTICIDE DISPOSALIt is the legal responsibility of all pesti-

cide users to properly dispose of pesticidewaste in an environmentally acceptablemanner (it is illegal to bury or burn anypesticide containers in Wisconsin).

Some pesticides are considered “haz-ardous” by the EPA. Disposing waste orexcess resulting from use of these pesticidescomes under stringent regulations of theResource Conservation Recovery Act(RCRA). This federal law and the accompa-nying state law (NR 600) regulate genera-tors of hazardous waste—those who needto dispose of hazardous pesticides.

The simplest way to avoid becoming ahazardous-waste generator is to triple rinseall pesticide containers and apply rinsatesto labeled sites. If you must generate haz-ardous waste, disposal procedures may dif-fer depending on the volume of waste gen-erated and its characteristics.

9

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNPRINCIPLES

OF

PESTM

NGMT.

A3646/09, I. Intro (6.5) 10/14/08 5:04 PM Page 9

You can reduce the amount of pesticidewaste (hazardous or not) by followingthese steps: ■ Determine whether the pesticide you

intend to use is considered hazardousby the EPA. A list of these pesticides isavailable from your WDNR regionaloffice. If listed, check for alternativepesticides that are not hazardous andwill provide equivalent pest control.

■ Mix only the amount of pesticideneeded and calibrate equipment so allsolution is applied.

■ Attach a clean water supply to thesprayer unit so the tank can be rinsedand the rinsate applied to the labeledsite while still in the field.

■ Triple rinse all pesticide containers.Even if the pesticides were hazardous, atriple-rinsed container is not hazardouswaste and you can dispose of it in asanitary landfill.

■ Don’t mix hazardous waste with otherpesticide waste. This will result in theentire mixture being considered haz-ardous.

Wisconsin Clean Sweep Program. The Wis-consin Clean Sweep program, sponsoredby the WDATCP and individual counties,offers a way to dispose of most kinds ofpesticide waste including liquids, dry for-mulations, and waste classified as haz-ardous. For details on when a site will beheld in your area, check with your countyExtension office or visit the WDATCP website (datcp.state.wi.us and search for “cleansweep”). Wisconsin Clean Sweep has twocomponents: an agriculture program and ahousehold program.

Plastic Pesticide Container Recycling Program.The best way to dispose of plastic contain-ers is to recycle them. The Wisconsin CropProduction Association (WCPA) sponsorsthis program and sets up collection sites atmember dealers throughout the state. Thisprogram accepts triple-rinsed (dirty con-tainers will not be accepted) plastic pesticidecontainers of all sizes, including mini-bulktanks. Farmers must work through theirdealer to recycle jugs and mini-bulks. Checkthe WCPA web site (www.wicrops.org) fortheir summer and fall recycling schedules.

Please note that this recycling program isnot a Wisconsin Clean Sweep program;waste pesticides will not be accepted atcontainer collection or granulation sites.

Recycling mini-bulk tanks. Although mini-bulk tanks are recycled at the same time asthe smaller jugs, dealers must register withWCPA at least 1 week in advance of ascheduled recycling date for all mini-bulktanks 60 gallons and larger. Visit their website (www.wicrops.org) or call 608-249-4070for details and the registration form.

10

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNPRINCIPLES

OF

PESTM

NGMT.

A3646/09, I. Intro (6.5) 10/14/08 5:04 PM Page 10

WEED MANAGEMENTPRINCIPLES FOR ALL CROPS

The proper combination of cultural,mechanical, and chemical practices canmaintain weeds at non-economically dam-aging levels. The goal of cultural weedmanagement is to allow the crop to com-pete vigorously with weeds. Crop competi-tion is one of the most useful and economi-cal methods of weed control. This isachieved by planting adapted varieties atthe ideal density into a favorable seedbedthat has adequate nutrients. Seeding foragelegumes with a small grain companion cropis an excellent example of using crop com-petition to control weeds. The small graingerminates and grows quickly, preventingmost weeds from becoming established.

Rotation to another crop is another essen-tial component of sound weed manage-ment programs because certain weeds aremore common in some crops than in others.A well-planned cropping system preventsthe buildup of weeds associated withmonocultures. Mechanical control such astilling to prepare a weed-free seedbed,rotary hoeing, and row cultivation areeffective and important components inmany weed management programs.

Herbicides are highly effective chemicalsif carefully selected to match the weedspectrum and if application conditions arefavorable. Still, the best herbicide and/ortillage program will not be acceptable with-out good crop competition.

SELECTING A WEEDMANAGEMENT PROGRAM

Plan your weed management programwell in advance of the planting season.Base it on thorough knowledge of the weedproblem, soil characteristics, and futurecropping plans. As crop production prac-tices change, weed problems change, so agood weed management program must beflexible.

Herbicides vary in the types of plantsthey control. Some treatments control mostbroadleaf and grassy weeds, others controlprimarily annual grasses, and still otherscontrol only broadleaf weeds. Soil charac-teristics may affect herbicide performanceand crop safety. Most soil-applied herbi-cides are less effective on soils high inorganic matter and are almost totally inef-fective on peat and muck soils. Othersshould not be used on light-textured sandysoils, since they leach too readily and maydamage crop seedlings. Still others interactwith organophosphate insecticides to causeserious corn injury. Some herbicides remainin the soil into the next cropping seasonand injure sensitive crops. Check the rota-tional crop restrictions for the herbicidesthat you are considering to prevent injuryof next year’s crop.

WHEN TO APPLY HERBICIDESSome herbicides must be soil-incorpo-

rated before planting for effective control.Others can be surface-applied or soil-incor-porated before planting, or surface-appliedafter planting. And many herbicide treat-ments are registered for application aftercrop emergence.

One reason for incorporating herbicidesis to position them in the soil where weedseeds are germinating and beginninggrowth. Some herbicides require incorpora-tion to prevent loss through volatility orphoto-decomposition. Proper herbicideincorporation is essential; check the herbi-cide label for recommended tillage/incor-poration tools and how deep and fast theyshould be operated. Although rainfall afterpreplant-incorporated herbicide applicationwill improve weed control, it isn’t essential.

Early preplant and preemergence-appliedherbicides depend on rainfall to move theminto the soil. Under Wisconsin conditions,spring rainfall is usually adequate to 11

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNPRINCIPLES

OF

PESTM

NGMT.

A3646/09, I. Intro (6.5) 10/14/08 5:04 PM Page 11

accomplish this. When rainfall is limited, ashallow tillage tool such as a rotary hoe orspike-toothed harrow can provide suffi-cient soil incorporation to activate the her-bicide treatment and destroy the first flushof weed seedlings.

Many postemergence-applied herbicideoptions are available and have increased inuse. The effectiveness of these treatments isdrastically influenced by weed size as wellas temperature, moisture, and other envi-ronmental conditions. Proper timing is crit-ical with postemergence applications tooptimize weed control and minimize therisk of crop injury.

CAN HERBICIDE RATES BE REDUCED?

Producers are reevaluating their weedmanagement practices and some are usinglower herbicide rates than in the past. Uni-versity of Wisconsin research has shownthat the application of rates as much as 50%lower than the normal rates, combinedwith cultivation, can give excellent weedcontrol. While the normal rate of a soil-applied herbicide often gives 60 to 90 daysof weed control, reducing the rate shortensthe length of control; successful full-seasonweed control with reduced rates oftendepends on a timely cultivation 30 to 40days after planting and subsequent cropcompetition. Reducing rates can be effec-tive with both broadcast applications andbanded treatments over the crop row.

If you are considering using reducedrates of herbicides, keep these factors inmind:■ It is not illegal to use less than the

labeled rate of a pesticide. However, themanufacturer and commercial applica-tor are not liable for the performanceunder these conditions. You must beready to cultivate if and when neededto obtain effective full-season control.

■ Try reducing the conventional rate 20 to30% on a few acres the first year. As yougain confidence and experience withthe system, you can decide on the direc-tion and pace of future changes.

■ Be sure that neither equipment norlabor will be limiting factors when it istime to rotary hoe or cultivate.

■ Do not consider reduced rates of soil-applied herbicides if you have hard-to-kill weeds like shattercane, wild prosomillet, yellow nutsedge, or woolly cup-grass. Also, reduced rates may not givesatisfactory performance if your soilshave more than 5% organic matter or ahigh clay content.

■ The safest way to cut herbicide use is tomake banded applications. If you apply10-inch bands over corn in 30-inchrows, then you’ll apply 67% less herbi-cide in the field. You’ll reduce the rateeven more if the rate applied in the bandis less than the conventional rate. Twotimely cultivations normally give ade-quate control with banded treatments.

MIXING HERBICIDESUsing mixtures of two or more herbicides

for simultaneous application has becomepopular in recent years. The objective ofmixing herbicides is to capitalize on theadvantages of all products while diminish-ing their disadvantages. Many such combi-nations have been registered for use. Herbi-cide combinations that are not recom-mended on the label may cause crop injuryor provide ineffective weed control.

When tank-mixing wettable powder, liq-uid flowable, or dry flowable herbicideswith emulsifiable concentrate herbicides,mix the wettable powder with the water orliquid fertilizer first. Then add water or liq-uid fertilizer until you’ve reached approxi-mately 75% of the total spray volume you’lluse. Add the emulsifiable concentrate last,and then bring the mixture to final sprayvolume.

HERBICIDE/FERTILIZERCOMBINATIONS

Herbicide application in liquid fertilizersolutions rather than water is popular.While such combination treatments saveone trip over the field and enhance theburndown of existing weeds in conserva-tion tillage, emerged corn also is usuallyburnt. Many individual herbicides and her-bicide combinations are registered with theEPA for simultaneous application with liq-uid fertilizers. Herbicide labels and accom-panying literature provide helpful mixingsuggestions to minimize compatibility

12

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNPRINCIPLES

OF

PESTM

NGMT.

A3646/09, I. Intro (6.5) 10/14/08 5:04 PM Page 12

problems. If you have any doubt about thecompatibility of a particular herbicide/fer-tilizer combination, run a compatibility testfirst. Adding compatibility agents such asUnite or Compex can reduce mixing prob-lems. Wettable powder, liquid flowable, ordry flowable herbicides that are not mixedproperly will sometimes float when mixedwith liquid fertilizers. Emulsifiable concen-trates occasionally cause mixing problems.

There also has been a trend towardimpregnating herbicides on certain dry fer-tilizers. Some herbicides and herbicidecombinations are registered with the EPAfor this type of application. The herbicidemanufacturer generally provides detaileddirections and guidance for the impregna-tion process. Herbicide-impregnated fertil-izer applications can provide weed controlequal to comparable treatments applied assprays. However, the herbicide/fertilizerblend and its application must be uniform,generally calling for a double spread or anair-flow applicator.

WEATHER AND HERBICIDESHerbicides applied to the soil are taken

up by seeds, roots, and stems of seedlingweeds, and by established perennial plants.Adequate rainfall is necessary to move sur-face-applied herbicides into the soil formaximum uptake by developing weedseedlings. Preplant soil-incorporated treat-ments position herbicide in the soil andminimize the need for rainfall to makethem effective. Only certain herbicides canbe used in this way; others become toodiluted or increase the risk of injuring cornwhen mixed into the soil.

Adequate soil moisture also helps weedseeds germinate quickly, which is desirablewhen using soil-applied herbicides. How-ever, excessive rainfall after herbicide appli-cation may leach the more soluble herbi-cides into the vicinity of germinating cropseeds and cause crop damage, especially onlight, sandy soils. Chemical and microbialdecomposition break down herbicidesmore slowly in cool, dry soil, therebyincreasing the danger that some herbicidesmay carry over and injure sensitive cropsthe following year.

Weather conditions also affect postemer-gence herbicides. Both weed and crop plantsensitivity generally increase with tempera-

ture. Lower herbicide or adjuvant rates aresometimes suggested in hot, humidweather to minimize crop injury. Weeds aremore difficult to kill in dry, cool, or cloudyweather. Mature weeds are always moredifficult to control than weed seedlings.Rainfall after postemergence applicationmay reduce the herbicide’s effectiveness.Check the product label or tables 2-6 (corn)and 3-4 (soybean) for the minimumrequired rain-free period.

HERBICIDE RESIDUES IN SOILMost herbicides control weeds only as

long as the herbicides remain in the soil.Full-season weed control is considereddesirable for any herbicide treatment. Butsoil herbicide residue that persists after har-vest or into the following growing seasonand damages the next crop is objectionable.

Following a few simple rules will reducethe risk of herbicide residue damage.■ Follow crop rotation guidelines listed

on the herbicide product label. Seeappendix table 2 for a listing of rota-tional crop intervals for many commoncrops. Herbicides that have no carry-over risk don’t list rotation restrictions.

■ Use the minimum recommended ratenecessary for adequate weed controland apply it uniformly.

■ Till treated fields before planting a sen-sitive crop the next year.

■ At equal rates of the same herbicide,preplant or preemergence applicationsgenerally present less risk of carryoverthan postemergence applications. Theearlier treatment allows more time forbreak down.

■ Crops vary in their tolerance to carry-over of specific herbicides. Select a cropthat has a high degree of tolerance tothe previous year’s herbicide treatment.

Several years of experience on a particu-lar soil and an appreciation of environmen-tal effects on herbicide carryover are thebest guide to which crops you can safelyplant the year after applying residual herbi-cide. Growers are encouraged to run a soilbioassay to determine whether harmful soilresidues exist.

13

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNPRINCIPLES

OF

PESTM

NGMT.

A3646/09, I. Intro (6.5) 10/14/08 5:04 PM Page 13

HERBICIDES ANDCONSERVATION TILLAGE

In conservation tillage systems, cropresidue protects the soil surface from exces-sive raindrop impact and soil erosion. Thissurface debris can also affect weed seedgermination and herbicide distribution.Generally surface residue of 3,000 lb/a orless (30% or less surface cover) does notinterfere with herbicide performance. Thekey consideration of annual weed manage-ment in conservation tillage is that weedcontrol may or may not be more difficult,but it probably will be different than in con-ventional systems.

HERBICIDE-RESISTANT WEEDSSome biotypes of lambsquarters, smooth

pigweed, velvetleaf, and kochia growing inWisconsin are resistant to atrazine andother triazine herbicides. These problemsdeveloped after using triazine herbicidesfor six or more years without complemen-tary control measures. This allowed theresistant biotype (initially a very small pro-portion of the total population) to produceseed and become the dominant biotype inmany fields. Biotypes of weeds resistant toother herbicides have also been found inWisconsin: giant foxtail and large crabgrassresistant to lipid synthesis inhibitors likePoast Plus, Select, and Assure; giant foxtail,eastern black nightshade, and kochia resis-tant to ALS inhibitors. Careful attention tosound weed management programs is criti-cal if we hope to prevent the appearance ofmore herbicide-resistant biotypes. Compre-hensive lists of herbicide-resistant weedsand other herbicide-resistant weed infor-mation can be found at weedscience.com.

The risk of developing more resistantweed problems is greater if we over useherbicides that kill weeds by affecting onlyone physiological process in plants (that is,they have only a single mode of action).Table 1-3 lists the modes of action of mostcommon herbicides and ranks them accord-ing to the risk of developing resistantweeds.

To minimize the risk of developing resis-tant weeds, a sound herbicide resistancemanagement program uses a combinationof these practices:■ Use herbicides only when necessary.■ Rotate herbicides with different modes

of action from year to year.■ Use multiple modes of action within a

year.■ Use broad crop rotations; three or four

crops in rotation provide more resis-tance protection than only two.

■ Integrate mechanical control practices(rotary hoeing and cultivation) withherbicide use.

■ Scout fields regularly and control escap-ing weeds as needed.

■ Clean tillage and harvest equipmentbefore moving from fields or farms withresistant weeds to other fields.

USING NEW HERBICIDESThe introduction of new herbicides

invariably creates a lot of grower interest.We encourage you to try new products thatappear to fit your weed situation and soilcondition, but we suggest you try thesenew products on a relatively small scale thefirst year.

SELECTING HERBICIDESThe herbicide treatments described in the

following sections have provided effectiveweed control under Wisconsin conditions.For corn and soybeans, review tables 2-3and 3-1 to determine which herbicides con-trol the weeds in your fields. Then reviewthe summary comments of the better herbi-cide options to select the herbicide that bestfits your situation. Tables that summarizerainfree periods and adjuvant requirementsfor postemergence herbicides, forage andgrain harvest intervals, and rotational cropintervals are also included for easy reference.

All herbicide rates are expressed inweight or volume of commercial product asapplied on a broadcast basis. See appendixtable 1 for a list of pesticide products andrelated information.

14

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNPRINCIPLES

OF

PESTM

NGMT.

A3646/09, I. Intro (6.5) 10/14/08 5:04 PM Page 14

15

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNPRINCIPLES

OF

PESTM

NGMT.

Table 1-3. Listing of herbicides by mode of action and risk of developingresistant biotypes

Mode (site) of action Group Herbicide Ingredient

HIGH RISK of developing resistanceAmino acid synthesis inhibitors 2 Accent nicosulfuron

(ALS) Affinity BroadSpec thifensulfuron + tribenuronAlly/Escort metsulfuronArsenal imazapyrAutumn iodosulfuronBasis rimsulfuron + thifensulfuronBeacon primisulfuronCanopy EX chlorimuron + tribenuronCimarron metsulfuronClassic chlorimuronExpress tribenuronFirstRate cloransulamHarmony Extra thifensulfuron + tribenuronHarmony SG thifensulfuronOption foramsulfuronOust sulfometuronPeak prosulfuronPermit halosulfuron Plateau imazapicPursuit imazethapyrPython flumetsulamRaptor imazamoxResolve rimsulfuronSteadfast rimsulfuron + nicosulfuronStout nicosulfuron + thifensulfuronSynchrony chlorimuron + thifensulfuronTelar chlorsulfuron

Lipid synthesis inhibitors 1 Assure II/Targa quizalofop(ACCase) Fusilade DX fluazifop

Fusion fluazifop + fenoxapropPoast Plus sethoxydimSelect Max/Arrow clethodim

MEDIUM RISK of developing resistanceAmino acid inhibitors 9 Roundup/ glyphosate

(EPSP synthetase) Touchdown/etc.Cell membrane disrupters (PPO) 14 Cadet fluthiacet

Cobra/Phoenix lactofenFlexstar/Reflex fomesafenResource flumicloracSpartan sulfentrazoneStarane fluroxypyrUltra Blazer acifluorfenValor flumioxazin

(continued)

A3646/09, I. Intro (6.5) 10/14/08 5:04 PM Page 15

16

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNPRINCIPLES

OF

PESTM

NGMT.

Table 1-3. Listing of herbicides by mode of action and risk of developingresistant biotypes (continued)

Mode (site) of action Group Herbicide Ingredient

MEDIUM RISK of developing resistance (continued)Cell membrane disrupters 22 Gramoxone Inteon paraquat(photosystem I) Reglone diquat

Photosynthesis inhibitors 6 Basagran bentazon—contact (photosystem II) Buctril bromoxynil

Photosynthesis inhibitors 5 AAtrex/etc . atrazine—systemic (photosystem II) Princep simazine

Sencor metribuzinSinbar terbacilVelpar hexazinone

7 Lorox linuronSpike tebuthiuron

Pigment inhibitors 27 Callisto mesotrione(isoprenoid pathway) Impact topramazone

Laudis tembotrione13 Command clomazone

Seedling root growth inhibitors 3 Balan benefin(multiple) Prowl/Pendimax/etc. pendimethalin

Treflan trifluralinLOW RISK of developing resistanceAmino acid inhibitors 10 Ignite glufosinate

(Glutamine synthetase)Growth regulators (multiple) 4 Banvel/Clarity/etc. dicamba

Crossbow triclopyr + 2,4-DCurtail 2,4-D + clopyralidForefront aminopyralid + 2,4-DMCPA MCPAMilestone aminopyralidStarane fluroxypyrStatus diflufenzopyr + dicambaStinger clopyralidThistrol MCPBTordon picloramWeedmaster 2,4-D + dicamba2,4-D 2,4-D

Seedling shoot growth inhibitors 15 Define flufenacet(multiple) Harness/Surpass/etc. acetochlor

Dual II Magnum/ metolachlorCinch/etc.Intrro/etc. alachlorOutlook dimethenamid

8 Eptam/Eradicane EPTCRo-Neet cycloate

A3646/09, I. Intro (6.5) 10/14/08 5:04 PM Page 16

CORN PESTMANAGEMENT

2

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNPRINCIPLES

OF

PESTM

NGMT.

A3646-09, II. Corn:A3646/05, II. Corn 10/14/08 4:42 PM Page 17

These herbicide treatments are specific asto time and method of application, weedsthey control, rates of application to be usedon different soils, and crops that may followin rotation. Failure to apply them accordingto label directions can result in incompleteweed control, excessive crop injury, or dam-age to subsequent crops. If you don’t getsignificant rainfall within 5 to 7 days afterpreemergence herbicide application, use arotary hoe or spike-toothed harrow toincorporate the herbicide into the soil aswell as to destroy many weed seedlings.Whenever possible, use row cultivation tocontrol those weeds that might haveescaped earlier weed control treatments.Many herbicide combinations are regis-

tered for use on corn. The use of herbicidecombinations that are not registered is dis-couraged since liability for performanceand crop injury lie solely with the user.Similarly, the combination of herbicideswith fertilizers or insecticides for simulta-neous application is discouraged unless theherbicide label outlines directions for suchcombination use. Be sure to check the her-bicide label or accompanying literaturecarefully before using herbicides in combi-nation with fertilizers, insecticides, or otherherbicides.

ATRAZINE RATE LIMITS ANDRESTRICTIONSBecause of concern about groundwater

contamination, Wisconsin has enactedatrazine rate restrictions based on surfacesoil texture, prior atrazine use, and geo-graphic location relative to atrazine detec-tion in groundwater. Wisconsin’s AtrazineRule (ATCP 30) imposes a 0.75 to 1.5 lb/arate limit on atrazine use statewide. Anexception is allowed for growers who findit necessary to use atrazine postemergenceto “rescue” seed or sweet corn from weedcompetition. This exception applies only toseed corn and sweet corn and the totalamount of atrazine used at planting andpostemergence may not exceed 1.5 lb/a oncoarse soil and 2 lb/a on medium or finesoil. In addition, atrazine use is prohibitedin extensive areas of Dane county and theentire Lower Wisconsin River valleyextending downstream from the Highway60 bridge at Prairie du Sac to the confluenceof the Wisconsin and Mississippi Rivers.Localized areas of Adams, Brown, Calumet,Chippewa, Columbia, Dodge, Eau Claire,Grant, Green, Green Lake, Iowa, Jackson,Juneau, Lafayette, Manitowoc, Marathon,Marinette, Marquette, Monroe, Outagamie,Pierce, Portage, Richland, Rock, St. Croix,Sauk, Trempealeau, Vernon, Walworth,Waupaca, Waushara, Winnebago, andWood counties have a total prohibition onatrazine use. Contact your county Extensionoffice for detailed maps of atrazine prohibi-tion areas or visit DATCP’s web site(datcp.state.wi.us/arm/agriculture/pest-fert/pesticides/atrazine/index.jsp).

PRINCIPLESO

FPEST

MNGM

T.CO

RNw

eedsSO

YBEANFO

RAGES&

PASTURESAPPENDIX

SMALL

GRAINSPERENNIAL

WEEDS

STORED

GRAININSECTS

18

CORN WEED MANAGEMENT


19 PRINCIPLESO

FPEST

MNGM

T.CO

RNw

eedsSO

YBEANFO

RAGES&

PASTURESAPPENDIX

SMALL

GRAINSPERENNIAL

WEEDS

STORED

GRAININSECTS

19Table 2-1 lists atrazine active ingredientrate limits for various management situa-tions in Wisconsin and table 2-2 lists themaximum rates of atrazine-containingproducts according to these rate limits. Becertain to reduce the use rates of atrazineand atrazine-containing products accordingto the Wisconsin Atrazine Rule.State and federal rules have also estab-

lished setbacks for mixing, loading, andapplying atrazine and atrazine-containingherbicides. Heed the following guidelinesto minimize ground and surface water con-tamination by atrazine.

■ No mixing or loading within 100 feet ofwells, sinkholes, streams, lakes, orreservoirs unless mixing or loadingover a spill containment pad con-structed in compliance with WisconsinAg 29. (Note: In Wisconsin, this ruleapplies for all pesticides. Federal rulesrequire a 50-foot setback for atrazineonly.)

■ No application within 50 feet of a wellor sinkhole or within 200 feet of theshoreline of natural or impounded lakesor reservoirs.

■ No application within 66 feet of wherefield runoff enters streams (perennial orintermittent) and rivers.

■ No application before April 1 or afterJuly 31.

■ Keep atrazine application records for3 years.

Table 2-2. Wisconsin rate limits for productscontaining atrazinea

————— Surface soil texture ——————Coarse— —— Medium/fine ——

Herbicide 0.75 lb limit 1 lb limit 1.5 lb limit

Atrazine 4L 1.5 pt 2.0 pt 3.0 ptAtrazine 90DF 0.83 lb 1.11 lb 1.67 lbBicep II Magnum 0.9 qt 1.3 qt 1.9 qtBicep Lite II Magnum 1.1 qt 1.5 qt 2.2 qtBullet/Lariat 4.0 pt 5.3 pt 8.0 ptDegree Xtra 2.2 qt 2.98 qt 3.7 qtExpert 1.4 qt 1.9 qt 2.8 qtField Master 2.0 qt 2.6 qt 4.0 qtFulTime 1.9 qt 2.5 qt 3.7 qtG-Max Lite 2.2 pt 2.9 pt 3.5 ptGuardsman Max 1.8 pt 2.4 pt 3.6 ptHarness Xtra 3.5 pt 4.7 pt 5.4 ptHarness Xtra 5.6L 2.4 pt 3.2 pt 4.8 ptKeystone 1.3 qt 1.8 qt 2.7 qtKeystone LA 2.0 qt 2.67 qt 3.0 qtLexar 1.7 qt 2.3 qt 3.4 qtShotgun 2.7 pt 3.0 pt 3.0 pta Labeled rates of Lumax and Marksman do not exceed the atrazinerate limits.

Table 2-1. Atrazine activeingredient rate limits

— Statewide atrazine limits —Surface Atrazine used No atrazinesoil texture last year used last year

Coarse 0.75 lb/a 0.75 lb/aMedium and fine 1.0 lb/a 1.5 lb/a


Table 2-3. Weed control ratings of corn herbicidesa

Grasses Broadleaves Perennials

HerbicidesPreplant–incorporatedAcetanilides + atrazine premixesb 5,15 VS G/E G/E G/E G/E F F F F/G G F/G E G/E E E F P P — G PAcetochlor (Harness/Surpass/etc.) 15 VS G/E G/E G/E G/E F F F P F P G F/G G/E F P N N — G NDefine SC 15 VS G/E G/E G/E G/E F F F P P P F/G F F/G P P N N — F NDual II Magnum 15 VS G/E G/E G/E G/E F F F P P P G F G P P N N — G NOutlook 15 VS G/E G/E G/E G/E F F F P P P G F G P P N N — G N

Atrazine 5 N F P P F F P P F/G G F/G G/E G/E G/E E F P P — P P

PreemergenceAcetanilides + atrazine premixesb 5,15 VS E E E E G F F F G F E G/E E E F/G P P P F PAcetochlor (Harness/Surpass/etc.) 15 VS E E E E F/G G F P F P E F/G G/E F P N N N F NDefine SC 15 VS E E E E F F F P P P G F F/G P P N N N F NDual II Magnum 15 VS E E E E F F F P P P G/E F G P P N N N F NOutlook 15 VS E E E E F F F P P P G/E F G P P N N N F N

Atrazine 5 N F P P F P P P F G F G/E G/E G/E E F/G P P P P PCallisto 27 VS P P/F P P P P P F F/G F G/E G/E E G/E G/E P N P P NCamix 15,27 VS E E E E F F F F F/G F E G/E E G/E G/E P N N F NDicamba (Banvel/Clarity) 4 S P P P P P P P F G F F G G G F N P F/G N NHornet WDG 2,4 S N N N N N N N G G/E F G G G G G P P P N NLumax 5,15,27 VS E E E E G F F G G F/G E E E E G/E P P F F PMarksman 4,5 S P P P P P P P F G/E F G G/E E E F/G P P F/G P PPrincep 5 N F F P F P P P F G F G/E G/E G/E E F/G P P P P PProwl 3 S G E E E G F F P N N P G/E G/E P F/G N N N N NPython 2 S N N N N N N N F F P F G G F/G G N P P N NResolve 2 S G P/F F G P P P F P/F P F G G F F P P — P PSureStartc 2,4,15 VS F F F F/G F F F F F P G F/G G F F P P P P NValor 14 S P P P P/F P P P P F P G G G F F P P P/F N N

(continued)

Mod

eof

actio

ngr

oup

Risk

ofco

rnin

jury

Barn

yard

gras

s

Crab

gras

s

Fall

pani

cum

Foxt

ails

Fiel

dSa

ndbu

r

Wild

pros

om

illet

Woo

llycu

pgra

ss

Cock

lebu

r

Com

mon

ragw

eed

Gian

trag

wee

d

East

ern

blac

kni

ghts

hade

Lam

bsqu

arte

rs

Pigw

eeds

Smar

twee

ds

Velv

etle

af

Cana

dath

istle

Hem

pdo

gban

e

Dand

elio

n

Nuts

edge

Qua

ckgr

ass

20

aThese herbicides have been rated for expected weed control, butactual results may vary depending upon rates applied, soil types,weather conditions, and crop management.bAcetanilide + atrazine premixes include Bicep Lite II Magnum, Bullet,Degree Xtra, G-Max Lite, FulTime, Harness Xtra, Keystone LA, andLariat.

cRatings based on full-season control for comparison to other herbi-cides. SureStart is intended for early-season control and to be fol-lowed by glyphosate or Ignite.dGlyphosate can only be used on Roundup Ready corn hybrids.eIgnite can only be used with Liberty Link corn hybrids.

PRINCIPLESO

FPEST

MNGM

T.CO

RNw

eedsSO

YBEANFO

RAGES&

PASTURESAPPENDIX

SMALL

GRAINSPERENNIAL

WEEDS

STORED

GRAININSECTS Abbreviations

Risk of crop injury: M=moderate; S=slight; VS=very slight; N=none.Control ratings: E=excellent; G=good; F=fair; P=poor; N=none; — = insufficient information.


Table 2-3. Weed control ratings of corn herbicidesa (continued)


HerbicidesPostemergenceAccent 2 S G/E P G G/E G G/E G/E P P P P P G G F P P/F P P G/EAtrazine 5 VS F P P F F P F G/E E G E E E E G/E P P F P FBasagran 6 VS N N N N N N N E F/G F/G P F P E G F P P G NBasis 2 S/M G P F/G G P P P P/F F P N G/E G/E G/E G P P P — PBeacon 2 S P P F/G F F P P G/E G G G P/F G G G/E F F P F GBuctril 6 S N N N N N N N E G/E F G G/E G G/E G P/F P P N NCadet 14 S N N N N N N N P P P P F/G G P E — N N N NCallisto 27 VS P F/G P P P P P G F/G G E E E E G/E P/F P F F PCelebrity Plus 2,4,19 S/M G/E P G G/E G G/E G/E G/E G G F/G G/E E E G F/G F/G G N G/EDicamba (Banvel/Clarity) 4 S/M N N N N N N N G/E G G F/G G/E G/E E G F/G F/G G N NGlyphosated 9 VS G G G E G G/E G/E E G/E G G/E G/E G/E G G G/E G F F G/EHalex GT 9,15,27 VS G/E G/E G/E E G/E G/E G/E E G/E G/E E E E E G/E G G G F G/EHornet WDG 2,4 S N N N N N N N E G G F F F G G/E F/G P F/G N NImpact 27 VS F/G F/G F F/G P F F G/E G G G/E E E G G/E F P — P PIgnitee 10 VS F G G G F G G G/E G/E G G G G G/E G F F F/G P FLaudis 27 VS G F/G P G F F/G F/G G/E G G E E E E G/E F P P P —Marksman 4,5 S/M P P P P P P P E E G/E G E E E G/E F/G F G N PNorthStar 2,4 S/M P P F/G F F P P E G/E G/E G G/E G/E E G/E F/G F/G F F GOption 2 S G/E P G G/E G G G P/F F/G P/F G G G P G P — F P G/EPermit 2 VS N N N N N N N E G/E F N P G F/G E P — P G/E NPriority 2,14 S N N N N N N N E E G G G G/E G E P P F G/E NRage D-Tech 4,14 S N N N N N N N G G F G G G F E F F F N NRequire Q 2,4 S G P G G/E P F F F/G F F F F/G G/E F/G G/E F P F P/F FResolve Q 2 S G P G G/E P F F F F P/F N F/G G/E F/G G F P F P/F FResource 14 S N N N N N N N P/F F P P F F P E P — N N NStatus 4,19 S P P P P P P P G/E G G F/G G/E G/E E G F/G F/G G/E N NSteadfast 2 S/M G/E P G G/E G G G P/F P P P P/F G F F P/F P G P/F G/EStinger 4 VS N N N N N N N G/E G G F/G N N F P G/E P G N NStout 2 S G/E P G G/E G G/E G/E P/F P/F P P G G/E G G P/F P/F F P G/EUnity 2 S/M N N N N N N N F F P N G/E E G/E G P P P — NYukon 2,4 S N N N N N N N E E G F G G/E G E P P P/F G/E N2,4–D 4 M N N N N N N N E G G F G/E G/E P G F G F/G N N

Abbreviations

Risk of crop injury: M=moderate; S=slight; VS=very slight; N=none.Control ratings: E=excellent; G=good; F=fair; P=poor; N=none; — = insufficient information.

Mod

eof

actio

ngr

oup

Risk

ofco

rnin

jury

Barn

yard

gras

s

Crab

gras

s

Fall

pani

cum

Foxt

ails

Fiel

dSa

ndbu

r

Wild

pros

om

illet

Woo

llycu

pgra

ss

Cock

lebu

r

Com

mon

ragw

eed

Gian

trag

wee

d

East

ern

blac

kni

ghts

hade

Lam

bsqu

arte

rs

Pigw

eeds

Smar

twee

ds

Velv

etle

af

Cana

dath

istle

Hem

pdo

gban

e

Dand

elio

n

Nuts

edge

Qua

ckgr

ass

21

PRINCIPLESO

FPEST

MNGM

T.CO

RNw

eedsSO

YBEANFO

RAGES&

PASTURESAPPENDIX

SMALL

GRAINSPERENNIAL

WEEDS

STORED

GRAININSECTS


PRINCIPLESO

FPEST

MNGM

T.CO

RNw

eeds(burndow

n)SO

YBEANFO

RAGES&

PASTURESAPPENDIX

SMALL

GRAINSPERENNIAL

WEEDS

STORED

GRAININSECTS

22 BURNDOWN HERBICIDES FORNO-TILL CORNNo-till cropping systems are increasingly

being used due to the economic and envi-ronmental benefits they offer. Weed man-agement is particularly important in thesesystems because no tillage is done beforeplanting and few producers cultivate no-tillfields after planting. The purpose of a burn-down herbicide application is to ensurethat the crop is planted into a weed-free set-ting. Check fields carefully to determine ifsuch a treatment is needed. Give particularattention to perennial weeds like dande-lion, white cockle, and quackgrass pluswinter annuals like shepherd’s purse,chickweeds, buttercups, and pennycress.

Autumn (iodosulfuron) + 2,4-DRate: 0.3 oz/a Autumn + 1.0 pt/a 2,4-D

ester.Adjuvants: Add 1% crop oil concentrate

and either 1.5 to 2.0 qt/a of 28% nitrogensolution or 1.5 to 3.0 lb/a ammonium sul-fate.

Timing: Apply in the fall after harvest or30 days before corn planting in the spring.

Remarks: Autumn + 2,4-D is intended toprovide fall burndown control and limitedresidual activity on broadleaf weedsincluding alfalfa, plantain, dandelion,horseweed, and several mustard species.The Autumn label recommends applicationto annual broadleaf weeds up to 3 inchestall. However, a tank mixture with 2,4-Dwill increase the size of weeds controlled.Autumn can also be mixed with glyphosateto control grass weeds. The 30-day intervalbetween application and corn planting willprimarily limit Autumn’s use to fall appli-cations. Autumn is rainfast in 2 hours. Donot apply to frozen soil or soil with a pHgreater than 8.0. Autumn can be appliedbefore planting field or silage corn, but notseed or sweet corn.

Rotational restrictions: Field corn can beplanted after 30 days; soybeans after 90days; winter wheat after 4 months; andsmall grains and sorghum after 8 to 9months. Other crops cannot be planted for18 months.

Basis (rimsulfuron + thifensulfuron)Rate: 0.33 to 1.0 oz/a.Adjuvants:Add crop oil concentrate at 1%

to the spray mixture plus either 28% nitro-gen solution at 2 qt/a or ammonium sulfateat 2 to 4 lb/a.

Timing:Apply from 7 days before plant-ing to preemergence after planting. Followthe postemergence directions if corn hasspiked.

Remarks: Basis is intended to provideweed burndown and early residual control.It will control foxtails up to 2 inches tall;woolly cupgrass up to 1 inch tall; and lamb-squarters, pigweed, smartweeds, and vel-vetleaf up to 3 inches tall. At 0.5 oz/a ormore, quackgrass and common ragweedshould be controlled. Basis should controlsmall dandelions. Tank-mixing Basis with2,4-D and atrazine will expand the numberof broadleaf weeds controlled. It is labeledfor use on soils with 1 to 3.5% organic mat-ter and should not be used on coarse-tex-tured soils with less than 1% organic mat-ter. Do not tank-mix with Hornet WDG orPython. Basis can be applied with water orliquid fertilizer as the carrier. It can be usedpreemergence on field and silage corn, butnot on seed corn or sweet corn.

Rotational restrictions: Field corn andpotatoes can be planted anytime after Basisapplication; winter wheat after 4 months;spring cereals after 9 months; snap beans,dry beans, soybeans, and sweet corn after10 months; and other crops after 18 months.

Basis (rimsulfuron + thifensulfuron)+ Express (tribenuron) + 2,4-D

Rate: 0.33 oz/a Basis + 0.25 oz/a Express+ 16 oz/a 2,4-D ester.

Adjuvants: Add a crop oil concentrate at1% to the spray mixture.

Timing:Apply in the fall or at least 14days before planting in the spring.

Remarks: Basis is a commonly used cornpostemergence herbicide. Express is a sul-fonylurea herbicide registered for use insmall grains. Fall application of Basis,Express, and 2,4-D provides economicaland broad-spectrum control of most winterannual and several perennial weeds. Thiscombination needs to be applied after fallharvest but before the ground freezes.Treatments made through corn stalks haveperformed well in killing dandelions. If


possible, wait 10 to 14 days after harvest forthe stalks to settle and weeds to be exposedto the spray solution. Basis could also beapplied without Express as a burndowntreatment prior to planting corn in thespring.

Rotational restrictions: Only corn can beplanted the spring following a Basis +Express application.

Field Master* (acetochlor + atrazine+glyphosate+safener)

Rate: 3.5 to 4.0 qt/a.Adjuvant: Add 17 lb ammonium sulfate

per 100 gal of water before adding FieldMaster. Do not use ammonium sulfate iffertilizer is the carrier.

Timing: Preemergence: Apply before orafter planting, but before corn emerges.

Remarks: The atrazine ratio in this premixmay limit its use. Field Master at 2.6 qt/aprovides the equivalent of 1 lb/a atrazine,0.36 lb ae/a glyphosate, and 1.5 pt/a Har-ness. Field Master at 2 qt/a provides theequivalent of 0.75 lb/a atrazine, 0.28 lbae/a glyphosate, and 1.1 pt/a Harness.This premix is designed for no-till and con-servation tillage field corn, seed corn, andsilage corn production. Annual weeds up to6 inches tall may be controlled. The resid-ual activity of acetochlor and atrazine willcontrol annual grass and broadleaf weeds.Tank mixtures with 2,4-D, dicamba, Prin-cep, or additional glyphosate or Harnesscan be made to improve weed control.Apply only in water or 28 to 32% nitrogenfertilizer. Do not apply in 10-34-0 or othercomplex liquid fertilizers. Do not use onsands with less than 3% organic matter, onloamy sand with less than 2% organic mat-ter, or on sandy loams with less than 1%organic matter when depth to groundwateris less than 30 feet.

Rotational restrictions: Only corn,sorghum, or soybeans should be plantedthe year following application.

GlyphosateRate: 0.38 to 0.56 lb ae/a for annuals and

0.75 to 1.5 lb ae/a for quackgrass. See labelsfor specific rate recommendations.Glyphosate conversion table

——Rate for——Formulation 0.38 lb 0.75 lb

Name (lb ae/gal) ae/a ae/a

Many 3.0 16 oz 32 ozDurango DMA 4.0 12 oz 24 ozTouchdown Total 4.17 12 oz 23 ozRoundup 4.5 11 oz 21 ozWeatherMaxTouchdown HiTech 5.0 10 oz 19 oz

Adjuvants:Ammonium sulfate at 8.5 to 17lb/100 gal of spray mixture is frequentlyrecommended, especially when tank-mixingglyphosate with residual herbicides. Checkthe label to see if the glyphosate formula-tion requires additional surfactant.

Timing: Preplant—Apply to annual weedsless than 6 inches tall or to quackgrass 6 to8 inches tall and actively growing. With theexception of Roundup Ready corn, do notinclude glyphosate in any spray mixture ifcorn has emerged.

Remarks: Glyphosate can be included as acomponent of a preplant residual herbicidetreatment to provide burndown of existingvegetation. Annual weeds emerging afterglyphosate application must be controlledby a residual herbicide or a postemergenceherbicide. Where a preplant treatment ismade as a split application, includeglyphosate with the first application, butonly if weeds are present at the time oftreatment. If quackgrass is present, includeglyphosate in the second applicationinstead of the first. Glyphosate can be tank-mixed with 2,4-D or dicamba for improvedannual broadleaf weed burndown.To control quackgrass, apply 0.75 lb ae/a

of glyphosate to 6 to 10 inch quackgrass ifthe field will be tilled after application.Delay tillage for 3 days after application.Increase the rate of glyphosate to 1.5 lbae/a if the field will be no-till planted.Glyphosate can be applied in 28% nitrogensolution rather than in water, but it is notrecommended when treating perennials.

*Contains atrazine.See pages 18–19for rate restrictions.

PRINCIPLESO

FPEST

MNGM

T.CO

RNw

eeds(burndow

n)SO

YBEANFO

RAGES&

PASTURESAPPENDIX

SMALL

GRAINSPERENNIAL

WEEDS

STORED

GRAININSECTS

23


Rotational restriction: Glyphosate formu-lations, have no rotational restrictions forWisconsin field crops except for a 30-dayinterval before tobacco.

Gramoxone Inteon (paraquat)Rate: Apply 2.0 to 2.5 pt/a when weeds

are 1 to 3 inches tall, 2.5 to 3.0 pt/a whenweeds are 3 to 6 inches tall, and 3.0 to 4.0pt/a when weeds are taller than 6 inches.

Adjuvants: Include nonionic surfactant at0.125% or crop oil concentrate at 1% to thespray mixture.

Timing: Preplant—Apply preplant orbefore corn has emerged.

Remarks: Gramoxone can be includedwith preplant residual herbicides to provideburndown of existing vegetation. Where apreplant treatment is made as a split appli-cation, include Gramoxone with the firstapplication, but only if weeds are present atthe time of treatment. Annual weedsemerging after Gramoxone application mustbe controlled by the residual herbicide.Tank-mixing Gramoxone with atrazine orPrincep can increase burndown activity.Use a minimum of 10 gal/a of water at

30 to 50 psi pressure with ground applica-tions. Flat fan nozzles are more effectivethan flood nozzles at delivering the finespray droplets necessary for thoroughspray coverage. If applying less than 20gal/a of water, only use flat fan nozzles. Donot apply Gramoxone when conditions pre-vent uniform coverage or when excessivespray drift may occur.

Rotational restrictions: None.

Rage D-Tech (Aim + 2,4-D premix)Rate: Apply 8 oz/a for weeds less than

6 inches tall. Increase the rate to 16 oz/a forweeds greater than 12 inches tall.

Adjuvants: Add nonionic surfactant at0.25% or crop oil concentrate at 1.5 to 2%.Nitrogen fertilizer may be added ifrequired by a tank-mix partner.

Timing: Apply 3, 7, and 14 days beforeplanting corn when using the 8, 16, and32 oz/a rates, respectively.

Remarks: Rage D-Tech will control manywinter and summer annual broadleafweeds. The Aim component will provide afaster burn of weed foliage than 2,4-Dalone. Rage D-Tech can be tank-mixedglyphosate or Gramoxone for annual grasscontrol. It can also be tank-mixed with pre-

emergence residual herbicides. Do notapply Rage D-Tech on sandy soils or soilswith less than 1% organic matter.

Rotational restrictions: Corn or soybeanscan be planted after the required intervalafter burndown treatments. Most othercrops can be planted after 30 days.

PREPLANT-INCORPORATED &PREEMERGENCE HERBICIDES

Acetochlor + safenerRate: Degree—2.25 to 5 pt/a. On soils

with 6 to 10% organic matter, use 4.5 to 6.25pt/a. Apply 6.25 pt/a on soils with greaterthan 10% organic matter.

Harness—1.25 to 2.75 pt/a. On soils with6 to 10% organic matter, use 2.5 to 3.4 pt/a.Apply 3.4 pt/a on soils with greater than10% organic matter.

Surpass—1.5 to 3 pt/a. Use 2.0 to3.75 pt/a of Surpass on soils with greaterthan 7% organic matter.

TopNotch—2 to 3 qt/a.Preplant-incorporated: Apply and incorpo-

rate 1 to 2 inches deep within 14 daysbefore planting.

Preemergence: Apply after planting butbefore weed emergence.

Postemergence: Acetochlor can be appliedto corn from emergence to 11 inches tall forresidual grass control. Acetochlor will notcontrol emerged weeds so a tank-mix part-ner is generally necessary for initial control.Add adjuvants according to requirementsof the tank-mix partner. Acetochlor labelsvary, but most allow tank mixtures withmany postemergence grass and broadleafherbicides, including glyphosate andIgnite, on resistant hybrids. Use water as acarrier when applying these postemergencetreatments. Using liquid fertilizer as a car-rier may cause severe crop injury. Ace-tochlor and the tank mixtures may causetemporary leaf burn.

No-till: Degree and TopNotch are micro-encapsulated formulations of acetochlor +safener marketed for use in no-till. Degreeat 2.75 to 5.5 pt/a can be surface applied upto 30 days before planting. TopNotch canbe surface applied up to 40 days beforeplanting. Higher rates are recommendedfor applications made more than 10 daysbefore planting. Harness is recommendedat 1.5 to 3 pt/a in no-till. Surpass is recom-

24

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNw

eeds(pre/ppi)

PRINCIPLESO

FPEST

MNGM

T.


mended at 2 to 3 pt/a in no-till. Surpass orHarness can be applied up to 30 daysbefore planting, but it gives the best controlwhen applied closer to planting and beforeweeds emerge. Acetochlor can be tank-mixed with atrazine, Hornet, Princep, orPython in conservation tillage systems. Ifweeds are present at the time of treatment,tank-mix glyphosate, Gramoxone, or 2,4-Dwith either formulation for annual weedburndown.

Remarks: Acetochlor provides good toexcellent control of foxtails, crabgrass, andfall panicum, but has no effect on quack-grass. It controls some small-seededbroadleaf weeds, but only suppresses vel-vetleaf. Acetochlor can be tank-mixed withatrazine, dicamba, Hornet, Princep, orPython for improved broadleaf weed con-trol. When preplant-incorporated, a mini-mum of 4.5 pt/a of Degree, 2.5 pt/a of Har-ness or Surpass, or 2.5 qt/a of TopNotch isrequired to provide reasonable yellownutsedge suppression on medium- andfine-textured soils, but preemergence appli-cations only partially control yellownutsedge. Do not use on sands with lessthan 3% organic matter, on loamy sandswith less than 2% organic matter, or onsandy loams with less than 1% organic mat-ter when depth to groundwater is less than30 feet. All acetochlor formulations containa chemical safener to protect corn from her-bicide injury. However, acetochlor-treatedcorn sprouting in cold, wet soils may occa-sionally leaf out underground. Acetochlorcan be mixed with liquid fertilizer orimpregnated onto certain dry fertilizers forsimultaneous application. It may be usedon field corn, seed corn, and sweet corn.

Rotational restrictions: Wheat can beplanted 4 months after application; alfalfa,barley, potato, and oat can be planted thefollowing year. Snap beans and peas cannotbe planted for 2 years.

Acetochlor + atrazine +safener*

Rate: Degree Xtra—2.9 to 3.7 qt/a.FulTime—2.5 to 3.7 qt/a.Harness Xtra—1.8 to 2.3 qt/a.Keystone LA—1.6–3.0 qt/a.

Preplant incorporated: Apply and incorpo-rate 1 to 2 inches deep within 14 daysbefore planting.

Preemergence: Apply after planting andwithin 5 days of the last tillage.

Postemergence: Acetochlor + atrazine canbe applied to corn from emergence to 11inches tall unless limited by a tank-mixpartner. This premix will control smallannual broadleaf weeds, but generally willnot control emerged annual grasses unlessthey have only one or two leaves. Largeremerged weeds need to be controlled by atank-mix partner. Acetochlor + atrazine willthen provide residual weed control. Includeadjuvants according to requirements of thetank-mix partner. Acetochlor + atrazinelabels vary, but most allow tank mixtureswith many postemergence grass andbroadleaf herbicides, including glyphosateand Ignite, on resistant hybrids. Use wateras a carrier when applying these postemer-gence treatments. Using liquid fertilizer asa carrier may cause severe crop injury. Ace-tochlor + atrazine and the tank mixturesmay cause temporary leaf burn.

No-till: Preplant surface-applied ace-tochlor + atrazine can be applied up to 30days before planting, but it gives the bestcontrol when applied closer to planting andbefore weeds emerge. If weeds are presentat the time of treatment, include glyphosate,Gramoxone, or 2,4-D in the spray mixturefor annual weed burndown.

Remarks: Several formulations of this pre-mix are marketed. The Harness Xtra 5.6Land Keystone formulations contain ahigher concentration of atrazine than Har-ness Xtra and Keystone LA, respectively. Tostay below Wisconsin’s atrazine rate limits,the rates of Harness Xtra 5.6L that can beused do not provide the desired amount ofacetochlor. The rates of Degree Xtra, Har-ness Xtra, and Keystone LA closely matchour atrazine rate limits with the properamount of acetochlor for good grass con-trol. FulTime has a higher ratio of atrazineto acetochlor than Harness Xtra or Key-stone LA. Acetochlor + atrazine providesgood to excellent control of foxtails, crab-grass, fall panicum, and most annualbroadleaf weeds, but will have little effecton quackgrass. Some velvetleaf mayescape. Preplant incorporated applicationsprovide reasonable nutsedge control. Pre-emergence applications provide only par-tial yellow nutsedge control. Acetochlor +atrazine can be tank-mixed with Princep toenhance broadleaf weed control. The

25

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNw

eeds(pre/ppi)

PRINCIPLESO

FPEST

MNGM

T.



Degree Xtra and Fultime labels also recom-mend Hornet WDG, Marksman, andPython tank mixtures. Do not use on sandswith less than 3% organic matter, loamysands with less than 2% organic matter, orsandy loams with less than 1% organic mat-ter when depth to groundwater is less than30 feet. All formulations contain a chemicalsafener to protect corn from herbicideinjury. It can be mixed with liquid fertilizeror impregnated onto certain dry fertilizersfor simultaneous application. Acetochlor +atrazine may be used on field corn, seedcorn, and sweet corn.

Rotational restrictions: Corn, sorghum,and soybeans can be planted after the yearafter application. Wheat can be planted 15months after application of FulTime orKeystone.

Atrazine*Rate: 4L formulation—1.5 to 3.0 pt/a.

90DF formulation—0.83 to 1.67 lb/a.Preplant-incorporated: Shallowly incorpo-

rate atrazine within 2 weeks before plant-ing.

Preemergence: Apply after planting, butbefore emergence.

No-till: Because of the 1.5 to 3.0 pt/a (4Lformulation) rate limit, soil-appliedatrazine treatments are generally inade-quate for complete weed control in no-tillcorn production. However, postemergence-applied atrazine can provide annualbroadleaf weed control.

Remarks: These atrazine rates alone areinadequate to control annual grass weedsexcept on very coarse-textured, low organicmatter soils and when combined withrotary hoeing and/or row cultivation.Otherwise, atrazine controls most annualbroadleaf weeds. Some velvetleaf and giantragweed often escape control. Theseatrazine treatments are ineffective on peator muck soils. These rates will not controlperennial weeds. Many cases of atrazine(triazine) resistant common lambsquarters,smooth pigweed, velvetleaf, and kochiahave been documented in Wisconsin.Increasing the atrazine rate or alteringapplication timing will not control triazine-resistant weeds.

Atrazine can be mixed with liquid fertil-izer for simultaneous preplant-incorpo-rated or preemergence applications.Atrazine may be used on field, silage, seed,and sweet corn.

Rotational restrictions: Atrazine may per-sist and damage susceptible crops the fol-lowing growing season. Corn, sorghum,and soybeans may be planted the followingyear. If atrazine is applied after June 10, thetreated area must be planted to corn orsorghum the following year. Do not plantwinter wheat or rye after corn silage har-vest nor sugar beets, tobacco, vegetables(including dry beans), spring-seeded smallgrains, or small-seeded legumes andgrasses the year following application, orinjury may occur.

BanvelSee dicamba (page 29).

Bicep Lite II Magnum*(Dual II Magnum + atrazine premix)

Rate: 0.9 to 2.2 qt/a.Preplant-incorporated: For best results,

apply and blend into the top 2 inches of soilwithin 14 days before planting. In dry sea-sons, preplant-incorporated applicationswill provide better annual weed controlthan preemergence applications.

Preemergence: Apply after planting, butbefore weed emergence.

Postemergence: S-metolachlor + atrazinecan be applied to corn up to 5 inches tall oras a directed application to corn 12 inchestall. This premix will control small annualbroadleaf weeds, but generally will notcontrol emerged annual grasses. Largeremerged weeds need to be controlled by atank-mix partner. This premix will thenprovide residual weed control. Includeadjuvants according to requirements of thetank-mix partner. Labeled tank mix part-ners include glyphosate and Ignite on resis-tant hybrids. Only use water as a carrierwhen applying these postemergence treat-ments; liquid fertilizer is not permitted as acarrier because of the risk of crop injury.

No-till: This treatment can be split withone-half of the herbicide applied early andthe remainder applied at planting. Whencorn will be planted in 7 days, make a sin-gle application either ahead of or at plant-ing. If weeds are present at the time oftreatment, include Gramoxone or

26

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNw

eeds(pre/ppi)

PRINCIPLESO

FPEST

MNGM

T.



glyphosate in the spray mixture forimproved annual weed burndown. It maybe tank-mixed with Princep as a conserva-tion tillage treatment.

Remarks: This premix contains the correctratio of atrazine to s-metolachlor to main-tain the full rate of s-metolachlor with themaximum allowable rate of atrazine forWisconsin.This premix provides good to excellent

control of foxtails, crabgrass, fall panicum,and most annual broadleaf weeds, but haslittle effect on quackgrass. Some velvetleafand giant ragweed may escape. Preplant-incorporated applications at 2.2 qt/a willgenerally provide reasonable yellownutsedge suppression, but preemergenceapplications only partially control yellownutsedge. It may be tank-mixed with otherlabeled preemergence herbicides. S-meto-lachlor + atrazine is ineffective on peat ormuck soils.These formulations contain a chemical

safener to protect corn and injury isunlikely. It can be mixed with liquid fertil-izer for simultaneous preplant-incorpo-rated or preemergence applications and canalso be impregnated onto certain dry fertil-izers. Bicep Lite II Magnum and Cinch ATZLite may be used on field corn, silage corn,and sweet corn.

Rotational restrictions: Only corn,sorghum, or soybeans should be plantedthe year following application.

Bullet/Lariat*(alachlor + atrazine premixes)

Rate: 5 to 8 pt/a.Preplant-incorporated: Apply to dry soil

within 7 days before planting, blending theherbicide into the top 1 to 2 inches of soilduring seedbed preparation. In dry sea-sons, preplant-incorporated applicationswill provide better annual weed controlthan preemergence applications.

Preemergence: Apply after planting butwithin 5 days after the last tillage for weedcontrol.

No-till: Apply 6 to 8 pt/a Bullet/Lariatpreemergence. See label for early preplantrates. If weeds are present at the time oftreatment, include Gramoxone orglyphosate in the spray mixture for

improved annual weed burndown. Bul-let/Lariat may be tank-mixed with Princepas a conservation tillage treatment.

Remarks: These treatments provide goodto excellent control of foxtails, crabgrass,fall panicum, and most broadleaf annualweeds but have little effect on quackgrass.Some velvetleaf may escape. Bullet/Lariatmay be tank-mixed with other labeled pre-emergence herbicides. These treatments areineffective on peat or muck soils. Do notapply if wind exceeds 10 miles per hour.Bullet/Lariat generally doesn’t injure

corn. However, under some circumstances,corn injury is possible. Bullet/Lariat can bemixed with liquid fertilizer for simultane-ous preplant-incorporated or preemergenceapplication. Preplant-incorporated Bullet/Lariat can also be impregnated onto certaindry fertilizers. Bullet/Lariat may be usedon field corn, silage corn, and sweet corn.

Rotational restrictions: Only corn,sorghum, or soybeans should be plantedthe following year.

Callisto (mesotrione)Rate: 6.0 to 7.7 oz/a or 5 to 6 oz/a when

tank-mixed with an atrazine-containingherbicide.


Remarks: Callisto controls many annualbroadleaf weeds including lambsquarters,nightshade, pigweed, common ragweed,and velvetleaf. Callisto can be tank-mixedwith other preemergence grass herbicidesfor broad-spectrum weed control. Corn hasgood tolerance to preemergence applica-tions of Callisto. Do not tank-mix Callistowith grass herbicides that have an emulsifi-able concentrate formulation and applyafter corn has spiked because injury mayoccur. Callisto drift will bleach the leaves ofsensitive plants. Do not apply Callisto ifwind speed exceeds 10 miles per hour. Cal-listo can be applied with water or liquidfertilizer (except suspension fertilizers) asthe carrier. Callisto can be applied to field,silage, seed, and sweet corn.

Rotational restrictions: Small grains canbe planted 120 days after application.Alfalfa, soybeans, potatoes, and tobaccocan be planted after 10 months. Other cropscannot be planted until 18 months aftertreatment.

27

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNw

eeds(pre/ppi)

PRINCIPLESO

FPEST

MNGM

T.



Camix (Dual II Magnum + Callistopremix)

Rate: 2 qt/a on soils with less than 3%organic matter and 2.4 qt/a on soils with3% organic matter or more.

Preplant: Up to 14 days before planting.Preemergence: Apply after planting, but

before grass weed emergence.Postemergence: Camix can be applied to

corn from emergence to 30 inches tall or theV8 stage, but the treatment will not controlemerged grasses unless tank-mixed withAccent, Basis, or Steadfast (drop nozzlesshould be used if corn is taller than 12inches). Broadleaf weeds less than 3 inchestall should be controlled. Add nonionic sur-factant (preferred) or crop oil concentratewhen making postemergence applications,but do not add a nitrogen source. TheCamix rate can be reduced to 1.6 qt/a whenmixed with glyphosate or Ignite. Whentank-mixing with Ignite, use ammoniumsulfate as the only adjuvant. When tank-mixing with glyphosate, add a surfactantand ammonium sulfate if the glyphosateformulation requires surfactant. If theglyphosate does not require surfactant,only add ammonium sulfate. Do not applypostemergence if the corn was treated withCounter.

No-till: Camix can be applied before orafter no-till planting and should be tank-mixed with glyphosate or Gramoxone tocontrol emerged weeds. It can also be tank-mixed with 2,4-D to enhance control ofbroadleaf weeds like dandelion, but grassweeds would not be controlled with thismixture. Use the adjuvant recommendedby the burndown herbicide.

Remarks: Camix provides good to excel-lent control of foxtails, crabgrass, fall pan-icum, and most annual broadleaf weeds,but has little effect on quackgrass. The Cal-listo in this premix improves velvetleaf con-trol compared to Bicep Lite II Magnum orother acetamide plus atrazine premixes, butsome giant ragweed may still escape con-trol. Yellow nutsedge will be suppressed.Atrazine or Princep can be tank-mixed withCamix for added broadleaf weed control.Corn has good tolerance to preemergence

applications of Camix. Although it containsa safener to protect corn, corn sprouting incold, wet soil may occasionally leaf outunderground. Camix drift will bleach the

leaves of sensitive plants. Do not applyCamix if wind speed exceeds 10 miles perhour. Camix can be applied preemergencewith water or liquid fertilizer (except sus-pension fertilizers) as the carrier. Camix canbe applied to field, silage, seed, and sweetcorn.

Rotational restrictions:Winter wheat canbe planted 4.5 months after a Camix appli-cation; potatoes, small grains, and soybeanscan be planted the year after application.Other crops should not be planted for18 months. Only corn and sorghum can beplanted the following year if Camix isapplied after June 1.

ClaritySee dicamba (page 29).

Define SC (flufenacet)Rate: 15 to 25 oz/a.Preplant incorporated: Apply within 2

weeks before planting and incorporate intothe top 1 to 2 inches of soil.

Preemergence: Apply after planting andbefore weed and crop emergence. Rotaryhoe if it doesn’t rain within 7 to 10 days.

Postemergence: Define can be applied tocorn from emergence through the 5-collar(V5) stage. Define will not control emergedweeds so a tank-mix partner is generallynecessary for initial control. Define willthen provide residual grass control. Addadjuvants according to requirements of thetank-mix partner. Supplemental labellingrecommends 7 to 15 oz/a of Define inOption or Ignite tank mixtures. Use wateras a carrier when applying Define poste-mergence; liquid fertilizer is not recom-mended as a carrier because of the risk ofcrop injury.

No-till: Preplant surface applications canbe made up to 45 days before planting. Ifapplying more than 30 days before plant-ing, split the treatment into two applica-tions. Use a higher rate if applying morethan 14 days before planting. If weeds arepresent at the time of application, includeglyphosate, Gramoxone, or 2,4-D in thespray mixture for their control.

Remarks: Define provides good to excel-lent control of foxtails and other annualgrasses, but does not control quackgrass. Itwill suppress several small-seededbroadleaf weeds. Define is labeled for tankmixtures with atrazine, dicamba, Hornet,

28

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNw

eeds(pre/ppi)

PRINCIPLESO

FPEST

MNGM

T.


Python, or Sencor for improved broadleafweed control. Define is not recommendedfor soils with more than 20% organic mat-ter. Corn should be planted at least 1.5inches deep to minimize the risk of injury.This herbicide may occasionally cause leaf-ing out underground. Define may be mixedwith liquid fertilizer or impregnated on cer-tain dry fertilizers for simultaneous appli-cation. Define may be used on field corn,silage corn, seed corn, but not sweet corn.

Rotational restrictions: Corn and soybeanscan be planted anytime after application.Potatoes can be planted after 1 month; cab-bage and carrots can be planted after 4months; and alfalfa, barley, beans, oats,peas, sweet corn, and wheat can be plantedafter 12 months.

DegreeSee acetochlor + safener (page 24).

Degree Xtra*See acetochlor + atrazine + safener

(page 25).

DicambaRate: Banvel or Clarity—0.5 to 1.0 pt/a.Adjuvants: Adding a surfactant for

improved spray coverage is recommendedfor burndown treatments.

Preemergence: Apply after planting andbefore corn emergence. Delay applicationfor 5 to 7 days after planting to reduce riskof corn injury.

No-till: Apply 1 pt/a of dicamba before orimmediately after corn planting to controlemerged and actively growing annualbroadleaf weeds. Use the 0.5 pt/a rate oncoarse-textured soils or on medium- orfine-textured soils with less than 2.5%organic matter. When planting into alegume sod, apply dicamba after 4 to 6inches of regrowth has occurred. For addedcontrol of dandelion or plantain, add 0.25to 0.5 lb/a 2,4-D to the spray mixture. Ifgrass weeds are present at the time of treat-ment, include Gramoxone or glyphosate inthe spray mixture. Dicamba may be tank-mixed with acetochlor, atrazine, Dual II,Outlook, or Princep as pre-plant/preemergence treatments in no-till.

Remarks: Dicamba gives early seasonresidual control of many broadleaf weeds,but some velvetleaf often escapes. Preplantand preemergence applications will not

suppress perennials like Canada thistle andhemp dogbane. Dicamba can be tank-mixed with acetochlor, atrazine, Dual IIMagnum, Outlook, pendimethalin, or Prin-cep as preemergence treatments. Do notapply dicamba preemergence to coarse-tex-tured soils. Do not apply Clarity to soilswith less than 2.5% organic matter except ifcorn was no-till planted. The Banvel labelallows use on soils with at least 2% organicmatter. Do not apply preemergence if cornis planted less than 1.5 inches deep. Soy-beans, tobacco, and most vegetables andflowers are extremely sensitive to dicambaso avoid drift. Two applications of dicambamay be made during a growing season, butcannot exceed a total of 1.5 pt/a. Allow atleast 2 weeks between applications.Dicamba may be used on field corn andsilage corn, but not on sweet corn.

Rotational restrictions: Dicamba will notpersist after harvest. Any crop can beplanted 120 days after an application ofClarity. Soybeans can be replanted 14 daysafter 8 oz/a Clarity and 28 days after 16oz/a Clarity. Grass crops can be planted 15and 30 days after 8 and 16 oz/a Clarity,respectively.

Dual II Magnum (s-metolachlor +safener)

Rate: 1.0 to 2.0 pt/a.Preplant-incorporated: Apply within 14

days before planting, blending the herbi-cide into the top 2 inches of soil duringseedbed preparation. In dry seasons, pre-plant-incorporated applications will pro-vide better annual weed control than pre-emergence applications.

Preemergence: Apply after planting butbefore corn or weeds emerge.

Postemergence: Dual II Magnum can beapplied to corn up to 40 inches tall. Dropnozzles are recommended for applicationsto corn taller than 5 inches. Dual II Magnumwill not control emerged weeds so a tank-mix partner is generally necessary for ini-tial control. Dual II Magnum will then pro-vide residual grass control. Include adju-vants according to requirements of thetank-mix partner. Labeled tank mixesincludeAccent, Beacon, Ignite, andglyphosate on resistant hybrids. Only usewater as a carrier when applying Dual II

29

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNw

eeds(pre/ppi)

PRINCIPLESO

FPEST

MNGM

T.




STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNw

eeds(pre/ppi)

PRINCIPLESO

FPEST

MNGM

T.

30 Magnum postemergence; liquid fertilizer isnot permitted as a carrier because of therisk of crop injury.

No-till: Apply 1.67 to 2.0 pt/a as a pre-plant surface treatment. This treatment canbe split with one-half applied early and theremainder applied at planting. When cornwill be planted in 7 days, make a singleapplication either ahead of or at planting. Ifweeds are present at the time of treatment,include glyphosate, Gramoxone, Marks-man, or 2,4-D in the spray mixture forimproved annual weed burndown. Onsands, loamy sands, and sandy loams,apply 1.33 pt/a within 14 days beforeplanting.

Remarks: Dual II Magnum provides goodto excellent control of foxtails, crabgrass,and fall panicum, but has no effect onquackgrass. It fails to control velvetleaf andseveral other annual broadleaf weeds. Itcan be tank-mixed with atrazine, Hornet,Princep, or Python for added broadleafweed control. Preplant-incorporated appli-cations at 2 pt/a will generally provide rea-sonable yellow nutsedge control, but pre-emergence applications provide only par-tial yellow nutsedge control. On soils with6 to 20% organic matter, use up to 2.5 pt/a.It is not labeled for use on peat or mucksoils. Both formulations contain a chemicalsafener to protect corn. However, treatedcorn sprouting in cold, wet soil may occa-sionally leaf out underground. It can bemixed with liquid fertilizer for simultane-ous application and preplant-incorporatedDual II Magnum can also be impregnatedonto certain dry fertilizers. Dual II Mag-num may be used on field corn, silage corn,and sweet corn.

Rotational restrictions: Dual II Magnumwill not persist into the fall or the followinggrowing season.

FulTime*See acetochlor + atrazine + safener

(page 25).

G-Max Lite*(Outlook + atrazine premix)

Rate: 2.0 to 3.5 pt/a.Preplant-incorporated: Apply and incorpo-

rate 1 to 2 inches deep within 14 daysbefore planting. In dry seasons, preplant-

incorporated treatment provides betterannual weed control than preemergencetreatment.

Preemergence: Apply after planting andbefore weed and corn emergence.

Postemergence: G-Max Lite can beapplied to corn up to 12 inches tall. Applybefore weeds exceed 1.5 inches tall. Sincethe Outlook in this premix will not controlemerged grasses, it is important to treatearly while the grasses are small enough tobe burned down by the atrazine. Largeremerged weeds need to be controlled by atank-mix partner. G-Max Lite will then pro-vide residual weed control. Add adjuvantsaccording to requirements of the tank-mixpartner. G-Max Lite can be tank-mixed withmost postemergence grass and broadleafherbicides, including glyphosate andIgnite, on resistant hybrids. Use water as acarrier when applying G-Max Lite poste-mergence; liquid fertilizer is not recom-mended as a carrier because of the risk ofcrop injury.

No-till: Use 3.5 pt/a G-Max Lite to com-pensate for early preplant treatmentand/or heavy crop residue. Usually a splitapplication where one-half of the herbicideis applied early and the remainder appliedat planting provides better weed control.When corn will be planted in 7 days, makea single application either ahead of or atplanting. If weeds are present at the time oftreatment, include Gramoxone orglyphosate in the spray mixture forimproved annual weed burndown. Earlypreplant treatment is not recommended oncoarse-textured soils.

Remarks: The G-Max Lite premix containsthe correct ratio of atrazine to Outlook tomaintain the full rate of both componentsto fit within Wisconsin’s atrazine rule.G-Max Lite provides good to excellent con-trol of foxtails, crabgrass, fall panicum, andmost annual broadleaf weeds, but has littleeffect on quackgrass. Some velvetleaf andgiant ragweed may escape. The maximumrate applied preplant-incorporated gener-ally provides reasonable yellow nutsedgecontrol, but preemergence-applied treat-ments only partially control yellownutsedge. G-Max Lite is not recommendedon soils with more than 20% organic matter.It generally does not injure corn, but undersome circumstances corn injury is possible.G-Max Lite can be mixed with liquid fertil-


izer or impregnated onto certain dry fertil-izers for simultaneous application. It maybe used on field corn, silage corn, seedcorn, and sweet corn.

Rotational restrictions: Only corn,sorghum, or soybeans should be plantedthe year following treatment.

HarnessSee acetochlor + safener (page 24).

Harness Xtra*(Harness + atrazine premix)See acetochlor + atrazine + safener

(page 25).

Hornet WDG(Python + Stinger premix)

Rate: 3 to 5 oz/a.Preplant-incorporated: Apply up to 30

days before planting and incorporate intothe top 2 to 3 inches of soil. In dry seasons,preplant-incorporated applications willprovide better annual weed control thanpreemergence applications.


No-till: Apply as a preplant-surface appli-cation up to 30 days before planting. Ifapplying more than 14 days before plant-ing, use the higher rate listed for that soiltexture. If weeds are present at time oftreatment, include glyphosate, Gramoxone,or 2,4-D for annual weed burndown. Hor-net WDG gives partial control of emergedCanada thistle in no-till, but will not affectplants that have not yet emerged.

Remarks: Hornet WDG provides residualcontrol of many annual broadleaf weeds.Because it is a broadleaf herbicide, it willgenerally be tank-mixed with grass herbi-cides such as acetochlor, Dual II Magnum,or Outlook. Do not use on peat or mucksoils or on soils with pH less than 5.9 andorganic matter above 5% because ofreduced weed control. The flumetsulamcomponent in this premix can cause cornstunting. The injury may be due to cornemerging in cold soils or to other factors. Tominimize the risk of injury, plant corn atleast 1.5 inches deep and use on soils withat least 1.5% organic matter. Dow does notrecommend using Hornet WDG if Counteror Thimet have been applied (but theCounter label allows Hornet use with

banded Counter applications). Apply othersoil insecticides in a T-band to avoid cropinjury. Do not use if soil pH is greater than7.8 and organic matter is less than 3% toavoid crop injury. Hornet WDG can beapplied with liquid fertilizer or impreg-nated onto certain dry fertilizers for simul-taneous applications, but the water solublepackages need to be slurried before mixingor impregnation. Hornet WDG may beused on field corn, but not sweet corn orpopcorn.

Rotational restrictions: Small grains can beplanted 4 months after application; alfalfa,dry beans, peas, soybeans, and specificsweet corn hybrids (listed on the label orsupplements) can be planted after 10.5months; and potatoes, non-listed sweetcorn hybrids, and tobacco can be plantedafter 18 months.

Keystone LA*See acetochlor + atrazine + safener

(page 25).

Lumax* (Dual II Magnum + atrazine +Callisto premix)

Rate: 2.5 qt/a on soils with less than 3%organic matter; 3 qt/a on soils with 3%organic matter or more.

Preplant: Up to 14 days before planting.Preemergence: Apply after planting but

before grass weeds emerge.Postemergence: Lumax can be applied to

corn from emergence to 12 inches tall, butthe treatment will not control emergedgrasses unless tank-mixed with Accent,Basis, or Steadfast. Broadleaf weeds lessthan 3 inches tall should be controlled. Addnonionic surfactant or crop oil concentratewhen making postemergence applications,but do not add a nitrogen source. TheLumax rate can be reduced to 2 qt/a whenmixed with glyphosate or Ignite. Whentank-mixing with Ignite, use ammoniumsulfate as the only adjuvant. When tank-mixing with glyphosate, add a surfactantand ammonium sulfate if the glyphosateformulation requires surfactant. If theglyphosate does not require surfactant,only add ammonium sulfate. Do not applypostemergence if the corn was treated withCounter.

31

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNw

eeds(pre/ppi)

PRINCIPLESO

FPEST

MNGM

T.



32

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNw

eeds(pre/ppi)

PRINCIPLESO

FPEST

MNGM

T.

No-till: Lumax can be applied before orafter planting and should be tank-mixedwith glyphosate or Gramoxone to controlemerged weeds. It can be tank-mixed with2,4-D to enhance control of broadleaf weedslike dandelion, but grass weeds would notbe controlled with this mixture. Use theadjuvant recommended by the burndownherbicide.

Remarks: Lumax provides good to excel-lent control of foxtails, crabgrass, fall pan-icum, and most annual broadleaf weeds,but has little effect on quackgrass. The Cal-listo in this premix improves velvetleaf con-trol compared to acetamide plus atrazinepremixes, but some giant ragweed may stillescape control. Yellow nutsedge will besuppressed. Lumax is not recommended onsoils with more than 10% organic matter.The amount of atrazine in Lumax will notexceed atrazine rate limits. Additionalatrazine or Princep can be tank-mixed withLumax for added broadleaf weed control.Corn appears to have good tolerance topreemergence applications of Lumax.Although it contains a safener to protectcorn, corn sprouting in cold, wet soil mayoccasionally leaf out underground. Lumaxapplied after other organophosphate insec-ticides may cause injury. Lumax drift willbleach the leaves of sensitive plants. Do notapply Lumax if wind speed exceeds 10miles per hour. Lumax can be applied pre-emergence with water or liquid fertilizer(except suspension fertilizers) as the carrier.Lumax may be applied to field, silage, seed,and sweet corn.

Rotational restrictions: Winter wheat canbe planted 4.5 months after a Lumax appli-cation and small grains and soybeans canbe planted the year after application. Othercrops should not be planted the year afterapplication. Only corn or sorghum can beplanted the following year if applied afterJune 1.

Marksman*(dicamba + atrazine premix)

Rate: 3.5 pt/a.Preemergence: Apply after planting and

before corn emergence.No-till: Apply 3.5 pt/a of Marksman

before or after corn planting to controlemerged and actively growing broadleafweeds. Use 2 pt/a on coarse-textured soils

or soils with less than 2.5% organic matter.When planting into a legume sod, applyMarksman after 4 to 6 inches of regrowthhas occurred. For added control of dande-lion or plantain, add 0.25 to 0.5 lb/a 2,4-Dto the spray mixture. If grass weeds are pre-sent at the time of treatment, includeGramoxone or glyphosate in the spray mix-ture. Marksman may be tank-mixed withacetochlor, atrazine, Bladex, Dual II Mag-num, or Outlook as conservation tillagetreatments.

Remarks: This treatment provides goodcontrol of most annual broadleaf weedsplus some residual weed control. Marks-man can be tank-mixed with acetochlor,Axiom, Dual II, Outlook, or pendimethalinas three-way preemergence treatments.Only apply Marksman to soils with at least2.5% organic matter. These treatments canprovide good to excellent annual weed con-trol. The dicamba component of Marksmancan cause corn injury. Do not apply tocoarse-textured soils or any soil with lessthan 2.5% organic matter until after cornemergence. Plant corn at least 1.5 inchesdeep. Broadleaf crops are sensitive toMarksman and drift may result in cropinjury. Do not apply Marksman neartobacco, tomatoes, or other highly sensitivecrops. Marksman may be used on field cornand silage corn, but not on sweet corn.

Rotational restrictions: Corn, sorghum,and soybeans can be planted the year afterapplication. If applied before June 10, smallgrains can be planted after 10 months.

Outlook (dimethenamid-P)Rate: 12 to 21 fluid oz/a.Preplant-incorporated: Blend the herbicide

into the top 1 to 2 inches of soil within the14 days before planting. In dry seasons,preplant-incorporated treatment providesbetter annual weed control than preemer-gence treatment.

Preemergence: Apply after planting, butbefore weeds emerge.

Postemergence: Outlook can be applied tocorn up to 12 inches tall or as a layby appli-cation. Outlook will not control emergedweeds so a tank-mix partner is generallynecessary for initial control with Outlookproviding residual grass control. Includeadjuvants according to requirements of thetank-mix partner. Labeled tank mixesinclude most postemergence grass and



broadleaf herbicides, including glyphosateand Ignite, on resistant hybrids. Use wateras a carrier when applying Outlook poste-mergence; liquid fertilizer is not recom-mended as a carrier because of the risk ofcrop injury.

No-till: Usually a split application whereone-half of the herbicide is applied earlyand the remainder applied at planting pro-vides better weed control. When corn willbe planted in 7 days, make a single applica-tion either ahead of or at planting. If weedsare present at the time of treatment, includeglyphosate, Gramoxone, or 2,4-D in thespray mixture for annual weed burndown.Early preplant treatment is not recom-mended on coarse-textured soils.

Remarks: Outlook provides good to excel-lent control of foxtails, crabgrass, and fallpanicum, but has no effect on quackgrass. Itfails to control velvetleaf and several otherannual broadleaf weeds. Preplant-incorpo-rated Outlook at the highest rate for the soiltype generally provides reasonable yellownutsedge suppression, but preemergence-applied Outlook only partially controls yel-low nutsedge. Adjust the rate according toeither soil cation exchange capacity or soiltexture and organic matter content. Use21 oz/a of Outlook on all soils with greaterthan 8% organic matter. Do not use on sandwith less than 3% organic matter whendepth to groundwater is less than 30 feet.Outlook generally doesn’t injure corn.However, Outlook-treated corn sproutingin cold, wet may occasionally leaf outunderground. Outlook can be mixed withliquid fertilizer or impregnated onto certaindry fertilizers for simultaneous application.It may be used on field corn, silage corn,sweet corn, and seed corn.

Rotational restrictions: Outlook will notpersist into the fall or following growingseason.

Princep (simazine)Rate: 4 pt/a of Princep 4L or equivalent.Preplant-incorporated: Apply and incorpo-

rate within 14 days before planting. In dryseasons, preplant-incorporated applicationsprovide better annual weed control thanpreemergence applications.

Preemergence: Apply before weeds andcorn emerge.

No-till: Where corn will be planteddirectly into a sod, cover crop, or previouscrop residue, Princep may be tank-mixedwith Gramoxone.

Remarks: Atrazine has largely replacedPrincep because of its greater water solubil-ity—less rainfall is necessary to make iteffective. Nonetheless if rainfall is ade-quate, Princep will control annual weedsnearly equal to atrazine. Princep can betank-mixed with acetochlor, atrazine, DualII Magnum, or Outlook. The longer soilresidual of Princep may be of value in con-servation tillage. Princep will not controltriazine-resistant common lambsquarters,smooth pigweed, velvetleaf, or kochia.Princep can be mixed with liquid fertilizerfor simultaneous application. Princep maybe used on field corn, silage corn, andsweet corn.

Rotational restrictions: The carryoverpotential of Princep is greater than atrazine.Corn or soybeans can be planted the yearafter application.

Prowl H2O (pendimethalin)Rate: 2 to 4 pt/a.Preemergence: Apply after planting, but

before corn and weeds emerge.Postemergence: Prowl can be applied to

corn up to 30 inches tall or until the V8stage. Prowl will not control emergedweeds so a tank-mix partner is generallynecessary for initial control. Prowl will thenprovide residual grass control. Includeadjuvants according to requirements of thetank-mix partner. Prowl can be tank-mixedwith most labeled postemergence grass andbroadleaf herbicides, including glyphosateand Ignite, on resistant hybrids. Use wateras a carrier when applying these postemer-gence treatments. Do not use liquid fertil-izer as the carrier because severe cropinjury may occur.

No-till: Prowl can be used on field corn orsilage corn where emerged weeds will becontrolled by a tank-mix partner. Applyonly after corn planting and be certain thatthe seed furrow has been thoroughly closedand leveled before treatment. Plant corn atleast 1.5 inches deep. Corn seed contactwith Prowl will cause stand loss.

Remarks: Prowl provides excellent controlof foxtails, crabgrass, and fall panicum, buthas no effect on quackgrass, nutsedge, orother perennial weeds. It provides fair con-

33

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNw

eeds(pre/ppi)

PRINCIPLESO

FPEST

MNGM

T.


34

FORAGES

&PASTURES

CORN

weeds

(pre/ppi)STO

REDGRAIN

INSECTSPERENNIAL

WEEDS

SMALL

GRAINSAPPENDIX

SOYBEAN

PRINCIPLESO

FPEST

MNGM

T.

trol of many annual broadleaf weedsincluding velvetleaf, but will not controlragweeds or mustards. To improvebroadleaf control, Prowl is labeled for tankmixes with atrazine, Banvel, Hornet WDG,Marksman, and Python. Prowl is ineffectiveon peat and muck soils. Under cold, wetconditions, Prowl may cause stunting andyellowing of seedling corn. It may alsocause root pruning and occasional lodging.Do not soil-incorporate Prowl or corninjury will occur. Plant corn at least 1.5inches deep. Do not apply Prowl ahead ofplanting because the planter shoe mayincorporate sufficient Prowl into the seedfurrow to damage corn. If post-plant tillageis necessary to break a soil crust or to con-trol weed escapes, use shallow tillage suchas a rotary hoe or shallow row cultivation.Preemergence-applied Prowl can be mixedwith liquid fertilizer for simultaneousapplication. Preemergence application maybe made to field corn, silage corn, and pro-cessing varieties of sweet corn.

Rotational restrictions: Prowl generallydoesn’t persist into the following season,but winter wheat or winter barley shouldnot be planted within 120 days after appli-cation.

Python (flumetsulam)Rate: 0.8 to 1.33 oz/a.Preplant-incorporated: Apply and incorpo-

rate into the top 2 to 3 inches of soil within30 days before planting. The lower rateswithin each soil texture category need to beapplied within 14 days of planting.

Preemergence: Apply after planting, butbefore weeds emerge. Applications to spikestage corn are permitted.

No-till: If weeds are present at the time oftreatment, include Gramoxone, glyphosate,or 2,4-D in the spray mixture for annualweed burndown. Do not include Gramox-one or glyphosate if corn has spiked.

Remarks: Python controls lambsquarters,pigweed, and velvetleaf at lower labeledrates. Higher rates are labeled to controlsmartweed and nightshade. Some commonand giant ragweed will escape control, evenat higher rates. It can be tank-mixed withother grass or broadleaf herbicides toexpand the spectrum of weeds controlled.Do not use on peat or muck soils or on soilswith pH less than 5.9 and organic matter

above 5% because of reduced weed control.Python and Hornet WDG contain flumetsu-lam. Do not apply more than 0.07 lb/aflumetsulam per year. Python may causestunting, which may be due to corn emerg-ing in cold soils or other factors. To mini-mize the risk of injury, plant corn at least1.5 inches deep and use on soils with atleast 1.5% organic matter. Do not use if soilpH is greater than 7.8 and organic matter isless than 3.0% to avoid crop injury. Do notuse if Counter or Thimet have beenapplied. Apply other soil insecticides in aT-band or surface band to avoid crop injurywhen using this herbicide. Python can bemixed with liquid fertilizer or impregnatedonto certain dry fertilizers for simultaneousapplications. Python can be applied to fieldcorn, silage corn, or tested seed corn lines.

Rotational restrictions: Field and seed corncan be replanted anytime. Do not plantalfalfa, dry or snap beans, small grains, orpeas until 4 months after application;tobacco until 9 months after application; orpotatoes until 12 months after application.Sweet corn should not be planted until 18months after application, with the excep-tion of the specific hybrids listed on thelabel or supplements that can be plantedafter 10.5 months. Crops not listed on thelabel require a 26-month rotational interval.

Resolve (rimsulfuron)Rate: 1 oz/a.Adjuvants: If applied alone, add 1% crop

oil concentrate plus either 2 lb/a of ammo-nium sulfate or 2 qt/a of 28% nitrogen solu-tion. No adjuvant is required if tank-mixingwith a glyphosate formulation that alreadycontains all the necessary adjuvant (fullyloaded).

Timing: Corn—Apply preplant or pre-emergence after planting.

Weeds—Apply before woolly cupgrassexceeds 1 inch and barnyardgrass, foxtails,and fall panicum exceed 2 inches.

Remarks: Resolve will control or suppressmany small annual grass and broadleafweeds and provide some residual control.If tank-mixed with glyphosate, it will pro-vide some residual control until postemer-gence herbicides are applied. If tank-mixedwith atrazine, it can help control emergedgrasses and contribute to residual controluntil postemergence herbicides are applied.


Requires rainfall within several days afterapplication for residual activity. Do not applyResolve preemergence to coarse-texturedsoils with less than 1% organic matter.Resolve can be used on field corn, but notseed or sweet corn.

Rotational restrictions: Corn and potatoescan be planted anytime after application;winter wheat after 3 months; small grainsafter 9 months; and alfalfa, sweet corn, soy-beans, snap beans, and dry beans after 10months. Any crop not listed on the labelcannot be planted for 18 months.

Sencor (metribuzin)Rate: 2 to 4 oz/a of Sencor DF when

applied 9 days preplant to preemergence or2 to 5.3 oz/a Sencor DF when applied 10 to30 days preplant.

Timing: Apply either preplant or preemer-gence.

No-till: Sencor can be tank-mixed withglyphosate, Gramoxone, or 2,4-D LVE, toimprove the burndown of many annualbroadleaf weeds. Sencor will also providelimited early season residual control ofbroadleaf weeds.

Remarks: Sencor can be tank-mixed withmost residual corn herbicides to assist withthe residual control of several annualbroadleaf weeds. The amount of residualactivity will depend on the rate and time ofapplication. Do not use for residual controlon peat or muck soils. Sencor has thepotential to injure corn if over applied or ifcold, wet conditions exist. Observe the fol-lowing precautions: plant corn at least 1.5inches deep; do not apply to soils with lessthan 1.5% organic matter or a pH greaterthan 7.0; and do not apply more than4 oz/a Sencor DF on soils with less than2.0% organic matter. Sencor may be usedon field corn, silage corn, and seed cornvarieties that are known to be tolerant.

Rotational restrictions: Sencor will not per-sist into the following year. Alfalfa andwheat can be planted in the fall.

SureStart(Surpass + Python + Stinger premix)This product is only labeled for use on

Roundup Ready and Liberty Link field andsilage corn.

Rate: Apply 1.5–2.0 pt/a.Timing: Preplant incorporated—Apply and

incorporate into the top 2 inches of soilwithin 14 days before planting.

Preemergence—Apply after planting butbefore weed emergence.

Postemergence—SureStart may be appliedto corn from postemergence to 11-inch tallcorn for residual grass and broadleaf con-trol. SureStart will not control emergedgrass weeds and will only control certainsmall broadleaf weeds, so tank mixtureswith glyphosate or Ignite are required tocontrol emerged weeds. Use water as a car-rier when making postemergence applica-tions. Do not use liquid fertilizer as a car-rier as this may cause severe injury. AMSmay be used in tank mixtures withglyphosate or Ignite.

No-till: Apply as a preplant surface appli-cation up to 30 days before planting.SureStart should be tank-mixed withglyphosate, Gramoxone, or 2,4-D to controlemerged weeds.

Remarks: SureStart is a premix that pro-vides approximately half rates of the ingre-dients in Surpass and Hornet. SureStartprovides early season preemergence controlof many annual grass and broadleaf weeds.Follow SureStart with a postemergenceapplication of glyphosate in RoundupReady corn or Ignite in Liberty Link corn.SureStart should allow these postemer-gence herbicides to be delayed if neededwith less risk of early season weed compe-tition. Do not use on soils with a pH of lessthan 5.9 and organic matter above 5%because of reduced weed control. To mini-mize the risk of injury, plant corn at least1.5 inches deep and use on soils with atleast 1.5% organic matter and avoid soilswith a pH above 7.8. Soil-appliedorganophosphate insecticides should beapplied in a T-band or banded to avoidinjury and Counter and Thimet should notbe used. When depth to groundwater is lessthan 30 feet, do not use on sands with lessthan 3% organic matter, on loamy sandswith less than 2% organic matter, or on

35

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNw

eeds(pre/ppi)

PRINCIPLESO

FPEST

MNGM

T.


36

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNw

eeds(post)

PRINCIPLESO

FPEST

MNGM

T.

sandy loams with less than 1% organic mat-ter. Soil-applied SureStart can be mixedwith liquid fertilizer or impregnated ontocertain dry fertilizers for simultaneousapplication. It may be used on field cornand seed corn, but not sweet corn.

Rotational restrictions: Field corn can beplanted anytime after application; wheatcan be planted after 4 months; and soy-beans and sorghum can be planted as rota-tional crops after corn harvest. One of theserotational crops must be grown beforeplanting other crops.

SurpassSee acetochlor + safener (page 24).

TopNotchSee acetochlor + safener (page 24).

Valor SX (flumioxazin)Rate: 1 to 3 oz/a.Timing: Apply 14 to 30 days before plant-

ing.No-till: Valor can be tank-mixed with

glyphosate, Gramoxone, 2,4-D, or otherburndown herbicides to improve control ofemerged broadleaf weeds. Valor SX willalso provide residual control of broadleafweeds depending on rate.

Remarks: Valor SX can only be used in no-till fields where residue has not been incor-porated. At a 1 oz/a rate with glyphosate,more rapid control may be observed pluslimited residual suppression of annualbroadleaf weeds, but this application mustbe made at least 2 weeks before planting.At rates of 2 to 3 oz/a, residual annualbroadleaf weed control should extend pastcorn planting. Valor SX should not be tank-mixed with acetochlor, Define, Dual, Out-look, or products containing these ingredi-ents because of potential injury. Do not irri-gate corn from emergence until after the V2stage. Valor SX can be used on field andsilage corn, but not on seed or sweet corn.

Rotational restrictions: At Valor rates up to3 oz/a, tobacco and wheat can be plantedafter 2 months; barley, snap and dry beans,and sweet corn can be planted after 4months; and alfalfa and oats can be plantedafter 5 months if tilled.

POSTEMERGENCE HERBICIDES

Accent (nicosulfuron)Rate: 0.67 oz/a.Adjuvants: Add crop oil concentrate at 1%

(preferred) or nonionic surfactant at 0.25 to0.5% to the spray solution. Also add 2 to 4qt/a of 28% nitrogen solution or 2 to 4 lb/aof spray grade ammonium sulfate.

Timing: Corn—Apply from emergencethrough the 6-collar stage (V6), but beforecorn is 20 inches tall. Use drop nozzles for20- to 36-inch-tall corn. Do not apply tocorn taller than 36 inches or exhibiting 10 ormore collars (V10), whichever comes first.Do not apply Accent to seed corn or pop-corn that is more than 20 inches tall orexhibits 6 or more collars.

Weeds—Apply to 4-inch foxtails, fall pan-icum, barnyardgrass, and woolly cupgrass;4-inch wild proso millet; 12-inch shatter-cane; and 10-inch quackgrass. Accent alsocontrols pigweed, annual smartweed, andjimsonweed. Weeds that exceed listed weedsizes by up to 50% may be partially con-trolled with Accent rates between 0.67 and1.33 oz/a.

Remarks: Accent is effective on manyannual grasses and quackgrass, but will notcontrol crabgrass. Crabgrass can be con-trolled if Accent is tank-mixed with a pre-emergence grass herbicide and appliedbefore crabgrass emerges. Accent lacksresidual control, but if a second flush ofweeds develops, a second application maybe made. The total quantity applied shouldnot exceed 1.33 oz/a. Half-rate applicationsof Accent applied to actively growingquackgrass, followed by a timely cultiva-tion, have consistently given acceptablecontrol. Accent can be tank-mixed withatrazine, Beacon, Buctril, Callisto, dicamba,Marksman, NorthStar, or Status to providebroadleaf control. Crop oil concentrate isthe preferred adjuvant for all these tankmixtures except dicamba where a nonionicsurfactant is preferred. Include a nitrogenadditive with all tank mixes. Do not tank-mix Accent with postemergence herbicideslike Basagran, Laddok, or 2,4-D becausecrop injury or antagonism may occur.Tank-mixing Accent with dicamba mayincrease the risk of rat-tailing if applied tosmall corn.



37

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNw

eeds(post)

PRINCIPLESO

FPEST

MNGM

T.

Do not use Accent on fields treated withCounter CR applied in-furrow at plantingor over-the-row at cultivation. Accent mayinjure corn treated with Counter CR, Lors-ban, or Thimet if soil has less than 4%organic matter. Accent may be used on fieldcorn, silage corn, seed corn, popcorn, andon specific sweet corn hybrids approved byDuPont.

Rotational restrictions: Soybeans may beplanted 15 days after Accent application.Winter wheat may be planted 4 monthsafter application. Barley, oats, or springwheat can be planted 8 months after appli-cation. Alfalfa, dry beans, peas, red clover,and snap beans may be planted 10 monthsafter Accent application. Sweet corn can beplanted 10 months after Accent application,except that the varieties Carnival, Merit,and Sweet Success should not be planteduntil 15 months after Accent use. Other cropsmay be planted either 10 or 18 months afterAccent use depending on soil pH.

Atrazine*Rate: 1.5 to 3.0 pt/a of the 4L formulation

or equivalent.Adjuvants: Add 1 qt/a of crop oil concen-

trate.Timing: Corn—Apply before corn exceeds

12 inches tall.Weeds—Apply before annual broadleaf

weeds exceed 4 inches tall. Treat lambs-quarters and pigweeds before 6 inches tall.

Remarks: This treatment controls mostannual broadleaf weeds, but fails to controlannual grasses and triazine-resistantweeds. Many cases of triazine-resistantcommon lambsquarters, smooth pigweed,velvetleaf, and kochia have been docu-mented in Wisconsin. Increasing theatrazine rate or altering time of applicationwill not control triazine-resistant weeds.Wisconsin ATCP 30 allows postemergencerescue treatments to seed and sweet cornonly of up to 3 pt/a (coarse soils) or 4 pt/a(medium or fine soils) of the atrazine 4Lformulation or equivalent. This rescuetreatment cannot be used in atrazine prohi-bition areas. Oil-based adjuvants speedweed burndown, but can also burn leafmargins and occasionally stunt corn. Injuryis increased by cold, wet weather or anyother condition that puts corn under stress.Risk of corn injury is greatest with inbredcorn lines or breeding stock. Multipurpose

surfactants, wetting agents, and soaps aregenerally less effective than oil-base addi-tives except where weeds are primarilyannual broadleaf and relatively small.Atrazine may be used on field corn, silagecorn, and sweet corn.

Rotational restrictions: Atrazine may per-sist and damage susceptible crops the fol-lowing growing season. Corn, sorghum,and soybeans may be planted the followingyear. If atrazine is applied after June 10, thetreated area must be planted to corn orsorghum the following year. Do not plantsugar beets, tobacco, vegetables (includingdry beans), spring-seeded small grains, orsmall-seeded legumes and grasses the yearfollowing application, or injury may occur.

BanvelSee dicamba (page 40).

Basagran (bentazon)Rate: 1.5 to 2.0 pt/a.Adjuvants: For common lambsquarters

and/or common ragweed, add 1 qt/a ofcrop oil concentrate in the spray mixture. Ifvelvetleaf is the primary weed problem,add 2 to 4 qt/a of 28% nitrogen solution or2.5 lb/a of spray grade ammonium sulfatein the spray mixture. If all are present, usecrop oil concentrate plus a nitrogen additive.

Timing: Corn—Applications are generallymade to 1- to 5-leaf corn, but all stages aretolerant.

Weeds—The 2 pt/a rate will suppress2-inch common lambsquarters and control3-inch common ragweed, 5-inch velvetleaf,and 6-inch giant ragweed, and 10-inchcocklebur. The 2 pt/a Basagran rate pluscrop oil concentrate will suppress 6- to8-inch yellow nutsedge and Canada thistlefrom 8 inches to bud stage.

Remarks: Basagran controls severalbroadleaf weeds, but is weak on pigweeds,lambsquarters, and nightshade. Basagranmay be tank-mixed with atrazine, Clarity,glyphosate (Roundup Ready only), Ignite(Liberty Link only), and Marksman. Corn isquite tolerant to Basagran, but slight, tem-porary leaf speckling may occur. Basagranmay be used on field corn, silage corn, seedcorn, and sweet corn.

Rotational restrictions: None.


38

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNw

eeds(post)

PRINCIPLESO

FPEST

MNGM

T.

Basis(rimsulfuron + thifensulfuron premix)

Rate: 0.33 oz/a.Adjuvants: Add nonionic surfactant at

0.25% or crop oil concentrate at 1 to 2% tothe spray mixture. Also add 2 to 4 qt/a 28%nitrogen solution or 2 to 4 lb/a ammoniumsulfate.

Timing: Corn—Apply from emergence to4-leaf (2-collar) stage.

Weeds—Apply before barnyardgrass, fox-tails, or fall panicum exceed 2 inches andbefore lambsquarters, redroot pigweed,smartweeds, and velvetleaf exceed 3 inches.

Remarks: Basis controls many annualweeds but will not control crabgrass ornightshade, nor will it control quackgrass,wild proso millet, or woolly cupgrass,which emerge after application. Basis canbe tank-mixed with atrazine, Callisto, orHornet WDG to improve broadleaf activity.Tank-mixing Basis with a preemergencegrass herbicide will improve crabgrass con-trol (use nonionic surfactant rather thancrop oil concentrate if tank-mixing withProwl). Tank-mixing Basis with dicambamay increase the risk of rattailing. BecauseBasis is applied early and has limited resid-ual activity, a cultivation following treat-ment is often necessary. Accent can beapplied 14 days or more after Basis forsequential control of grasses. Injury fromBasis has occasionally occurred, especiallyif applied after the 2-collar stage. Do notapply to hybrids with relative maturities ofless than 88 days or they may be injured.Applying Basis to corn treated withCounter CR, Lorsban, or Thimet may causeinjury. Applying Basis after Aztec, Force, orFortress should not cause injury. Basis mayonly be used on field corn and silage corn.

Rotational restrictions: Field corn andpotatoes can be planted anytime after Basisapplication; soybeans after 15 days; winterwheat after 4 months; spring cereals, peas,snap beans, and dry beans after 8 months;alfalfa, popcorn, sweet corn, and sugarbeets after 10 months; and other crops after18 months.

Beacon (primisulfuron)Rate: 0.76 oz/a.Adjuvants: Add nonionic surfactant at

0.25% to the spray solution or 1 to 4 pt/a ofcrop oil concentrate in the spray mixture.Adding 2 to 4 qt/a of 28% nitrogen solutionor 2 to 4 lb/a ammonium sulfate mayimprove the control of some weeds.

Timing: Corn—Apply to 4- to 20-inchcorn, but before the 6-collar (V6) stage. Bea-con may injure corn smaller than 4 inches.Use drop nozzles for corn taller than 20inches and before tassel emergence.

Weeds—Apply to 4- to 12-inch shatter-cane, 4- to 8-inch quackgrass, and less than2-inch fall panicum. Treat 1- to 4-inch night-shades, pigweed, smartweeds, velvetleaf,and other broadleaf weeds listed on thelabel. Common and giant ragweed can betreated when 2 to 9 inches tall.

Remarks: Beacon controls many annualbroadleaves and quackgrass, but is weakon lambsquarters. Beacon can be tank-mixed with atrazine, Buctril, dicamba,Resource, or 2,4-D to improve broadleafweed control; with Accent for improvedannual grass control; or with glyphosate foruse on Roundup Ready corn. Injury symp-toms in quackgrass may appear slowly (7to 10 days) and herbicide action may not becomplete until 30 days after application. Donot cultivate fields before applying Beaconas this will reduce quackgrass control. Half-rate applications of Beacon applied toactively growing quackgrass, followed by atimely cultivation, have consistently givenacceptable quackgrass control.Corn is reasonably tolerant of Beacon, but

temporary yellowing and/or stunting mayoccur when this herbicide is applied to cornthat is stressed. Do not apply Beacon ifCounter CR was applied in-furrow; Beaconapplied after surface band or T-bandCounter CR may cause unacceptable corninjury. If other organophosphate insecti-cides (i.e., Dyfonate, Lorsban, or Thimet)were used at planting, Beacon may causetemporary corn injury. Do not applyorganophosphate insecticides within 10days before or 7 days after applying Bea-con. Beacon can be used on IR corn hybridsthat were treated with any organophos-phate insecticides (including Counter)without increasing the chance of injury. IThybrids should be managed like conven-


39

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNw

eeds(post)

PRINCIPLESO

FPEST

MNGM

T.

tional hybrids to prevent the Bea-con/insecticide injury interaction. Do notapply if wind speed exceeds 10 miles perhour. Beacon may be used on field corn,silage corn, and on inbred lines of fieldcorn, but severe injury may occur on someinbreds. Do not use on sweet corn.

Rotational restrictions: Winter wheat orrye may be planted 3 months after Beaconapplication. Alfalfa, sweet corn, popcorn,dry beans, peas, soybeans, spring-seededsmall grains, and tobacco may be planted 8months after Beacon use. Any crop may beplanted 18 months after application.

Buctril (bromoxynil)Rate: 1.0 to 1.5 pt/a. Rates can be

increased to 2 pt/a under stress conditions.Adjuvants: Do not use adjuvants with

Buctril unless required for a tank mixture.Timing: Corn—Apply 1 pt/a after emer-

gence or 1.5 pt/a after the 4-leaf stage butbefore tassel emergence.

Weeds—See label for maximum weedheight and rate required for control.

Remarks: Many broadleaf weeds are sus-ceptible to Buctril, but pigweed controlrequires the maximum rate. When corn isso large that it interferes with the spray pat-tern, use drop nozzles to direct the herbi-cide beneath the corn leaves and onto theweeds. To broaden the spectrum of weedcontrol, the labeled rate of Buctril can betank-mixed with 2,4-D or Banvel. However,this tank mixture introduces risk of 2,4-D orBanvel damage. Use application precau-tions as when applying 2,4-D or Banvel.Buctril can also be tank-mixed withatrazine, Accent, Beacon, Permit, or Stinger.Buctril usually causes temporary leaf burn,but injury may be excessive if appliedbefore the 4-leaf stage. Buctril tank mix-tures that require a surfactant may increaseleaf burn. Buctril is a contact herbicide, sogood spray coverage is important. Buctrilmay be used on field corn and silage corn,but not on sweet corn.

Rotational restrictions: Do not plant rota-tional crops for 30 days after application.

Cadet (fluthiacet)Rate: 0.4 oz/a in glyphosate mixtures, 0.5

oz/a with other mixtures, or 0.6 to 0.9 oz/aif applied alone.

Adjuvants: Add nonionic surfactant at0.25% or crop oil concentrate at 1 to 2 pt/ato the spray solution. 28% nitrogen solutionat 1 to 2 qt/a or ammonium sulfate at 1 to 2lb/a may be added. If mixed with a fullyloaded glyphosate, only add ammoniumsulfate as required for glyphosate.

Timing: Corn—Apply from V2 until 48inches tall or tasseling, whichever occursfirst.

Weeds—At the 0.9 oz/a rate, apply beforelambsquarters and waterhemp exceed 2inches, before pigweed exceeds 4 inches,and before velvetleaf exceeds 36 inches.

Remarks: Cadet may cause temporaryspotting of corn leaves. Cadet has excellentactivity on velvetleaf and controls plants upto 36 inches tall at 0.6 oz/a or at lower ratesin tank mixtures. At the 0.9 fl oz/a rate, it islabeled to control lambsquarters, water-hemp, jimsonweed, and pigweed, but theseweeds are only listed as suppressed atlower rates. Cadet has contact activity andrequires good spray coverage with a mini-mum of 15 gallons per acre spray volumeand 20 psi spray pressure. It is an optionwhen targeting velvetleaf alone or toimprove the control of other broadleaf her-bicides. Cadet is labeled for mixtures withnumerous grass or broadleaf weeds. Do notapply if wind speed exceeds 10 miles perhour. Cadet can be used on field, silage,seed, and sweet corn.

Rotational restrictions: Corn or soybeanscan be replanted anytime if the crop is lost.Other crops should not be planted until thefollowing year.

Callisto (mesotrione)Rate: 3 oz/a.Adjuvants:Add crop oil concentrate at 1%

plus either 28% fertilizer at 2.5% or ammo-nium sulfate at 8.5 lb/100 gal (do not addnitrogen adjuvants when treating sweetcorn). Do not use methylated seed oil as anadjuvant because injury may occur.

Timing: Corn—Apply from emergence to30 inches tall or the 8-collar (V8) stage.


Weeds—Apply before lambsquarters,nightshade, pigweed, giant ragweed,smartweed, and velvetleaf exceed 5 inchesand before large crabgrass exceeds 2 inches.

Remarks: Callisto controls many annualbroadleaf weeds, but will not control mostgrasses. Callisto can be tank-mixed withatrazine at 0.25 to 0.5 lb/a to improve com-mon ragweed control in corn less than 12inches tall. It is also labeled for tank mix-tures with Basagran, glyphosate (RoundupReady only), and Ignite (Liberty Link only).Syngenta and DuPont have supplementallabels for tank-mixing Callisto with Accent,Basis, Steadfast, and Stout. Syngenta rec-ommends a full Callisto rate while DuPontrecommends a reduced rate for manybroadleaf weeds. Corn has good toleranceto postemergence applications of Callisto,but occasional yellowing may be seenunder stressful conditions. Do not poste-mergence apply tank mixes of Callisto andemulsifiable concentrate formulations ofpreemergence grass herbicides becauseinjury may occur. Do not apply Callisto ifthe corn was treated with Counter becauseinjury may occur. Corn may also be injuredif Lorsban was applied. Do not tank-mixCallisto with organophosphate or carba-mate insecticides or apply these insecticideswithin 7 days of Callisto because injurymay occur. Callisto drift will bleach theleaves of sensitive plants such as peas. Donot apply Callisto if wind speed exceeds 10miles per hour. Callisto can only be appliedto field, silage, seed, and sweet corn.

Rotational restrictions: Small grains can beplanted 120 days after application. Alfalfa,soybeans, potatoes, and tobacco can beplanted after 10 months. Other crops cannotbe planted until 18 months after treatment.

Celebrity Plus(Accent + Distinct premix)

Rate: 4.7 oz/a.Adjuvants:Add nonionic surfactant at 0.25

to 0.5% to the spray mixture. Also add 1 to2 qt/a of 28% nitrogen solution or 1 to 2lb/a of ammonium sulfate.

Timing: Corn—Apply when corn is 4 to 20inches tall, but before the 6-collar (V6) stage.Celebrity Plus can be applied to 24-inchcorn using drop nozzles.

Weeds—Apply to 2- to 4-inch foxtails, fallpanicum, barnyardgrass, and woolly cup-grass; 1- to 4-inch wild proso millet; 4- to12-inch shattercane; and 4- to 10-inchquackgrass. Annual broadleaves are con-trolled best when less than 3 inches tall.

Remarks: Celebrity Plus provides theequivalent of 0.67 oz/a Accent and 4 oz/aof Distinct. It is effective on many annualgrasses and quackgrass, but will not controlcrabgrass. The Distinct component willcontrol many annual broadleaf weeds.Celebrity Plus may be tank-mixed withatrazine for added broadleaf weed controlor with Accent for control of larger grasses.Corn is relatively tolerant to Celebrity Plus,but temporary yellowing and/or stuntingmay occur when applied to stressed corn orif excess herbicide is applied over the row.Broadcast applications after the V6 stagemay cause pinched ears. Celebrity Plus hasthe same potential for causing injury asAccent due to interactions withorganophosphate insecticides. See the pre-cautions listed for Accent if usingorganophosphate insecticides. CelebrityPlus may be used on field corn, silage corn,and seed corn, but not sweet corn.

Rotational restrictions: Corn can beplanted 7 days after Celebrity Plus applica-tion; soybean and winter wheat after4 months; spring cereals after 8 months;alfalfa, dry and snap beans, and peas after10 months. Sweet corn may be planted after10 months except for Carnival, Merit, andSweet Success which require 15 months.Other crops may be planted after 10 or18 months depending on soil pH.

ClaritySee dicamba (this page).

DicambaRate: Early postemergence—0.5 to 1.0 pt/a

Banvel or Clarity.Late postemergence—0.5 pt/a of Banvel or

Clarity.Adjuvants: Adding 2 to 4 qt/a of 28%

nitrogen solution or 2.5 lb/a ammoniumsulfate to the spray mixture will improvecontrol of wild mustard and velvetleaf thatare over 5 inches tall or growing underdrought stress.

Timing: Corn—Apply early postemer-gence treatments from emergence throughthe 5-leaf stage, but before 8 inches tall.

40

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNw

eeds(post)

PRINCIPLESO

FPEST

MNGM

T.


Apply late postemergence treatments whencorn is 8 to 36 inches tall and at least 15days before tasseling. Use drop nozzles if(1) corn leaves prevent proper spray cover-age, (2) sensitive crops are growing nearby,or (3) Banvel is tank-mixed with 2,4-D.

Weeds—Annual broadleaf weeds are con-trolled best when they’re less than 3 inchestall. Treat perennials like Canada thistle andhemp dogbane when they are 10 to 18inches tall.

Remarks: Dicamba controls many annualbroadleaf weeds and suppresses perennialbroadleaves. Dicamba can be tank-mixedwith most postemergence herbicides asearly postemergence treatments. To lessenthe chance of injury, use the 0.5 pt/a rate onloamy sands and sandy loams. Do not useon sand with less than 3% organic matterwhere ground water depth is shallow. Corninjury from dicamba is only slightly lesslikely than with 2,4-D. Some stalk brittle-ness and lodging may occur. Do not culti-vate for at least 7 days after treatment oruntil injury symptoms disappear. Soybeans,tobacco, and most vegetables or gardensare extremely sensitive to dicamba, soavoid drift. Do not apply dicamba whensoybeans are nearby if (l) corn is taller than24 inches, (2) soybeans are taller than 10inches, or (3) soybeans have begun to blos-som. Two applications of dicamba may bemade during a growing season, but do notexceed a total of 1.5 pt/a. Allow at least 2weeks between applications. Dicamba maybe used on field corn and silage corn, butnot on sweet corn.

Rotational restrictions: Dicamba will notpersist after harvest. Any crop can beplanted 120 days after an application ofClarity. Soybeans can be replanted 14 daysafter 8 oz/a Clarity and 28 days after 16oz/a Clarity. Grass crops can be planted 15and 30 days after 8 and 16 oz/a Clarity,respectively.

GlyphosateOnly use on Roundup Ready corn

hybrids.Rate: 0.56 to 0.75 lb ae/a. A total of 1.5 lb

ae/a may be applied in-season, but 0.75 lbae/a is the maximum rate for a singleapplication. Hybrids with the RoundupReady 2 trait can be treated with a maxi-mum of 1.13 lb ae/a per application and2.25 lb ae/a per season.

Glyphosate conversion table




Adjuvants:Ammonium sulfate at 8.5 to 17lb/100 gal of spray mixture is frequentlyrecommended, especially when tank mix-ing glyphosate with residual herbicides.Check the label to see if the glyphosate for-mulation requires additional surfactant.

Timing: Corn—Apply from emergence tothe V8 stage (8 collars) or 30 inches,whichever occurs first. Roundup Ready 2corn hybrids can be sprayed with drop noz-zles from 30 to 48 inches tall.

Weeds—Apply the 0.56 lb ae/a rate beforecrabgrass, foxtails, wild proso millet, andwoolly cupgrass exceed 6 inches. Applybefore lambsquarters, common ragweed,and giant ragweed exceed 12 inches. Applythe 0.75 lb ae/a rate to 6-inch velvetleaf.

Remarks: Glyphosate provides nonselec-tive control of annual grass and broadleafweeds and will suppress or control peren-nial weeds. Unless following a preemer-gence herbicide, glyphosate applicationswill need to be made before the weedstages listed above to prevent yield lossesfrom early season weed competition. Mon-santo has recommended reduced rates ofpreemergence herbicides that should beapplied at planting, which will lessen thisconcern. If applied early in the season, theglyphosate application may be before theoptimum timing for control of perennialbroadleaf weeds. Glyphosate does not haveresidual activity, but tank mixtures withacetochlor or atrazine are labeled toimprove residual control. When applyingglyphosate, be cautious to avoid drift andmake sure the spray tank is cleaned beforespraying a sensitive crop. Roundup Readycorn hybrids have good tolerance toglyphosate. Roundup Ready corn can beharvested for silage or grain after single orsequential applications of glyphosate.

41

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNw

eeds(post)

PRINCIPLESO

FPEST

MNGM

T.


Rotational restriction: Glyphosate formu-lations have no rotational restrictions forWisconsin field crops except for a 30-dayinterval before tobacco.

Halex GT (Dual Magnum + Callisto +glyphosate premix)Use only on Roundup Ready hybrids.Rate: 3.6 to 4 pt/a.Adjuvants: Add nonionic surfactant at

0.25 to 0.5% and ammonium sulfate at8.5 to 17 lb/100 gal. Use of 28% nitrogensolution is not recommended because of therisk of injury.

Timing: Corn—Apply from emergence to30 inches tall or the 8-collar (V8) stage.

Weeds—Apply before grass and broadleafweeds exceed 4 inches tall. Apply beforeweeds exceed 10 inches when tank-mixedwith atrazine.

Remarks: Halex GT will provide poste-mergence control of most annual weeds.The timing may be too early for optimallong-term control of perennials althoughexisting shoots will be killed. Theglyphosate rate in this premix will controlweeds at the 4-inch stage. The Callisto com-ponent provides a second ingredient withpostemergence broadleaf activity, whichwould improve control of glyphosate-resis-tant weeds. This premix contains about ahalf rate of Dual and a full rate of Callisto,which will provide residual weed control ifrain is received after application. Halex GTcan be applied after other preemergenceherbicides, but 1.6 qt/a of Camix or 2 qt/aof Lumax are the maximum rates of theseherbicides because they also containmesotrione. Halex GT can be tank-mixedwith atrazine for improved weed controland 0.25 to 0.5 lb/a are recommended. Driftfrom Halex GT can injure adjacent crops orvegetation. Thoroughly clean the spraytank after use because residues can injureglyphosate- or Callisto-sensitive crops. Donot tank-mix with emulsifiable concentrategrass herbicides because injury may occur.Halex GT may injure corn if the corn wastreated with Counter, Lorsban or otherorganophosphate soil insecticides orapplied within 7 days of a foliarorganophosphate insecticide. Halex GT canonly be used on glyphosate-resistant fieldor silage corn.

Rotational restrictions: Field or sweet corncan be replanted anytime; barley and wheatcan be planted after 120 days; alfalfa,potato, soybeans, and tobacco can beplanted after 10 months; and other cropscan be planted after 18 months.

Hornet WDG(Python + Stinger premix)

Rate: Spike stage—3 to 6 oz/a.Postemergence —2 to 5 oz/a.

Adjuvants: Add nonionic surfactant at0.25% or crop oil concentrate at 1% to thespray mixture. When droughty, also add2.5% of 28% nitrogen solution.

Timing: Corn—Spike stage is from emer-gence to 2 inches, but before the first leafunfurls. Other postemergence applicationscan be made to corn through the 6-collar(V6) stage.

Weeds—Apply 2 oz/a when broadleafweeds are less than 3 inches tall; 3 oz/awhen broadleaf weeds are up to 6 inchestall; and 4 oz/a when broadleaf weeds areup to 8 inches tall.

Remarks: Spike stage applications willcontrol many annual broadleaf weeds ifadequate rainfall occurs before weed emer-gence. When applied at the 2 oz/a post-emergence rate, cocklebur and velvetleafshould be controlled, but common andgiant ragweed, smartweed, and Canadathistle are only suppressed. At higher rates,common and giant ragweed, smartweed,and Canada thistle control improves, butblack nightshade, common lambsquarters,and pigweed will only be suppressed. Hor-net WDG can be tank-mixed with otherlabeled herbicides to improve control, butdo not mix with Basagran or Laddok. Donot apply Hornet if Counter or Thimetwere applied.Hornet WDG at 4 to 5 oz/a will provide

reasonable Canada thistle control. The3 oz/a rate may only control the topgrowth of Canada thistle. Best results onCanada thistle will be obtained in no-tillcorn because the weed will be more devel-oped when the treatment is made. Adding2 to 4 oz/a of Stinger to Hornet WDG willimprove long-term control of Canada thistle.Hornet WDG may be used on field and

silage corn.

42

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNw

eeds(post)

PRINCIPLESO

FPEST

MNGM

T.


43

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNw

eeds(post)

PRINCIPLESO

FPEST

MNGM

T.

Rotational restrictions: Small grains can beplanted 4 months after application; alfalfa,dry beans, peas, soybeans, and specificsweet corn hybrids listed on the supple-mental label can be planted after 10.5months; and potatoes, non-listed sweetcorn hybrids, and tobacco can be plantedafter 18 months.

Ignite (glufosinate)Only use on glufosinate-resistant or Lib-

erty Link corn hybrids.Rate: 22 oz/a.Adjuvants: The Ignite formulation con-

tains surfactants. Do not add additionalsurfactants or crop oils. Add 3 lb/a ofammonium sulfate prior to adding Ignite tothe spray tank.

Timing:Apply between dawn and 2 hoursbefore sunset.

Corn—Apply from emergence up to theV5 stage.

Weeds—For grasses, apply before barn-yardgrass, crabgrass, fall panicum, and yel-low foxtail exceed 3 inches; and beforegiant and green foxtail, wild proso millet,and woolly cupgrass exceed 6 inches. Forbroadleaves, apply before pigweed and vel-vetleaf exceed 3 inches; before lambs-quarters exceeds 4 inches; and before night-shade, common and giant ragweed, andsmartweeds exceed 6 inches.

Remarks: Ignite is a nonselective contactherbicide that controls many annual weedsand will burn the topgrowth of perennialweeds. Ignite can be tank-mixed withatrazine or most other postemergence her-bicides to enhance weed control or provideresidual activity. A second application ofIgnite can be made if needed, but use dropnozzles after the V5 stage. Do not apply ifwind speed exceeds 10 miles per hour.Ignite is rainfast in 4 hours. Glufosinate-resistant hybrids have good tolerance toIgnite, but conventional hybrids will beseverely injured.

Rotational restrictions: Ignite lacks resid-ual soil activity and will not injure rota-tional crops. However, the label prohibitsplanting small grains for 70 days afterapplication and other crops for 180 days.

Impact (topramazone)Rate: 0.5 to 0.75 oz/a; use the lower rate

if rotating to soybeans or snap beans.Adjuvants: Add 1.0 to 1.5% methylated

seed oil (preferred) or crop oil concentrate.Also add 1.25 to 2.5% of 28% nitrogen solu-tion or 8.5 to 17 lb/100 gal of ammoniumsulfate.

Timing: Corn—Apply from emergenceuntil 45 days before corn harvest.

Weeds—Apply 0.5 oz/a beforesmartweeds exceed 2 inches; before com-mon lambsquarters, nightshades, commonragweed, pigweeds, and velvetleaf exceed4 inches; and before giant ragweed exceeds5 inches.

Remarks: The full rate on the federal labelis 0.75 oz/a, which would control weedslarger than listed above. However, the rota-tional interval to soybeans is 18 months atthis rate in Wisconsin. A supplemental labelallows a lower rate of 0.5 oz/a, which per-mits rotation to soybeans at 9 months afterapplication. This rate is effective on manyannual broadleaf weeds. Crabgrasses andgiant foxtail are labeled as controlled at thehigher rate, but may only be suppressed atthis lower rate. A preemergence grass her-bicide application or postemergence grassherbicide tank mix may be advised for totalgrass weed control. Impact works synergis-tically with atrazine, so tank mixtures with0.25 to 1.0 lb/a atrazine are recommended.It can also be tank-mixed with most otherpostemergence herbicides, includingglyphosate and Ignite, on resistant hybrids.Corn has good tolerance to Impact, butunder stressful conditions, nonionic surfac-tant should be used in tank mixtures with2,4-D or dicamba to reduce the risk ofinjury. Impact has no insecticide use restric-tions. Impact drift will bleach the leaves ofsensitive plants. Do not apply if windspeed exceeds 10 miles per hour. Impact israinfast in 1 hour. Impact can be used onfield corn (grain, silage, and seed) andsweet corn.

Rotational restrictions: Corn can beplanted anytime after application; smallgrains after 3 months; alfalfa, peas, pota-toes, and sorghum after 9 months; andother crops after 18 months. If the 0.5 oz/arate is used, soybeans or snap beans can beplanted after 9 months; otherwise, theycannot be planted for 18 months.



44

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNw

eeds(post)

PRINCIPLESO

FPEST

MNGM

T.

Laudis (tembotrione + safener)Rate: 3 oz/a.Adjuvants: Add 1% crop oil or methylated

seed oil plus 1.5 qt/a 28% nitrogen solutionor ammonium sulfate at 8.5 lb/100 gal.Methylated seed oil is preferred over cropoil if Laudis is being used as a one-passpostemergence program to maximize thegrass weed control.

Timing: Corn—Apply from emergence upto the 8-collar (V8) stage.

Weeds—Apply before broadleaf weedsexceed 6 inches tall. Apply before largecrabgrass, giant and green foxtail, woollycupgrass exceed 3 inches; before wild prosomillet exceeds 4 inches; before barnyard-grass exceeds 5 inches; and before shatter-cane exceeds 6 inches.

Remarks: Laudis provides good control ofmany broadleaf weeds and several grassweeds. Control of broadleaf weeds is gener-ally greater than grass weeds. It is lesseffective on green foxtail and fall panicummay not be controlled. Using Laudis in atwo-pass program when it is applied after apreemergence grass herbicide may be pre-ferred. If so, crop oil could be used as theadjuvant as broadleaf weeds are the pri-mary target. Laudis is synergized with 0.5lb/a atrazine, which would be a commontank mixture. If corn is taller than 12 inchestall and atrazine cannot be used, 6 oz/a ofBuctril can be used instead of atrazine.Laudis can be tank-mixed with Accent,Option, Stout, and Steadfast for additionalgrass activity. In resistant corn, Laudiscould also be mixed at 2 oz/a with Ignite orat 3 oz/a with glyphosate. With the safenerin Laudis, field corn has excellent toleranceto Laudis. Laudis can be applied to field,silage, seed, and sweet corn.

Rotational restrictions: Small grains can beplanted after 4 months; soybean can beplanted after 8 months; and alfalfa, peas,potato, and snap bean can be planted after10 months.

Marksman*(dicamba + atrazine premix)

Rate: 2.0 to 3.5 pt/a.Adjuvants: Add surfactant at 0.125 to

0.25% or 28% nitrogen solution at 2 to 4qt/a, or ammonium sulfate at 2.5 lb/a tothe spray mixture, particularly underdroughty conditions. Do not use petro-leum-based crop oils.

Timing: Corn—Apply from emergencethrough the 5-leaf stage, but before 8 inchestall.

Weeds—Annual broadleaf weeds are con-trolled best when less than 3 inches tall.

Remarks: Marksman provides good con-trol of most annual broadleaf weeds plussome residual weed control. Postemergencetreatment is intended primarily as a follow-up to an earlier annual grass treatment andminimizes the potential for corn injurycompared to preemergence dicamba appli-cations. Marksman may be tank-mixedwith Accent, glyphosate (Roundup Readycorn), Ignite (Liberty Link corn), and mostpostemergence broadleaf and residualgrass herbicides as early postemergencetreatments. Different treatment timingsapply for each tank-mix partner. Slight buttemporary corn leaf burn and stalk brittle-ness may occur. Do not cultivate for at least7 days after treatment or until injury symp-toms disappear. Use the 2 pt/a rate oncoarse-textured soils. Broadleaf crops aresensitive to Marksman and drift may resultin crop injury. Do not apply Marksmannear tobacco, tomatoes, or other highly sen-sitive crops. It may be used on field corn orsilage corn, but not on sweet corn.

Rotational restrictions: Corn, sorghum,and soybeans can be planted the year afterapplication. If applied before June 10, smallgrains can be planted after 10 months.

NorthStar (Beacon + dicamba premix)Rate: 5 oz/a.Adjuvants: Add nonionic surfactant at

0.25% to the spray solution or 1 to 4 pt/a ofcrop oil concentrate if corn is less than 12inches tall. Adding 2 to 4 qt/a of 28% nitro-gen solution or 2 to 4 lb/a ammonium sul-fate may improve the control of someweeds.


45

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNw

eeds(post)

PRINCIPLESO

FPEST

MNGM

T.

Timing: Corn—Apply to 4- to 20-inch corn(applications before 4 inches may causeinjury and after the V6 stage may causepinched ears). Use drop nozzles for cornfrom 20 inches to 36 inches tall.

Weeds—Apply to 4- to 12-inch shatter-cane, 4- to 8-inch quackgrass, and 3-inchfall panicum. Apply before lambsquarters,smartweed, and velvetleaf exceed 4 inches;pigweeds exceed 5 inches; cocklebur andnightshade exceed 6 inches; and commonand giant ragweed exceed 9 inches.

Remarks: NorthStar controls many annualbroadleaves and quackgrass, but will onlysuppress most annual grasses. NorthStarcan be tank-mixed with atrazine, dicamba,Marksman, or Resource to improvebroadleaf weed control or tank-mixed withAccent for added annual grass control.Corn occasionally may show temporaryyellowing (from the Beacon component) orleaning/brittleness (from the dicamba com-ponent) after application. Delay cultivationuntil normal growth occurs to prevent stalkbreakage. Soybeans, tobacco, and most veg-etables are extremely sensitive to thedicamba component in NorthStar, so avoiddrift. To prevent residues from injuringother crops like soybeans, use an ammoniasolution to clean the sprayer after use. Donot apply NorthStar if Counter CR wasapplied in-furrow. NorthStar applied aftersurface banded or T-banded Counter CRmay cause injury. NorthStar applicationsafter Dyfonate, Lorsban, and Thimet mayalso cause temporary injury. NorthStar canbe used on IR corn hybrids regardless ofinsecticide use without increasing risk ofinjury, but IT corn hybrids should betreated as conventional hybrids. NorthStarcan be used on field corn, silage corn, andseed corn. Do not use on sweet corn.

Rotational restrictions: Field corn may beplanted 14 days after NorthStar applica-tion; winter wheat after 3 months; alfalfadry and green beans, sweet corn, peas,potatoes, soybeans, small grains, andtobacco after 8 months. Other crops may beplanted 18 months after application.

Option (foramsulfuron + safener)Rate: 1.5 oz/a.Adjuvants: Add methylated seed oil at 1.5

pt/a plus either 28% fertilizer at 1.5 to 2qt/a or ammonium sulfate at 1.5 to 3 lb/a.

Timing: Corn—Apply from the 1-collarthrough the 6-collar (V6) stage.

Weeds—Apply before woolly cupgrassexceeds 2 inches; before green and yellowfoxtails, wild proso millet, and fall panicumexceed 3 inches; before barnyardgrassexceeds 4 inches; before giant foxtailexceeds 6 inches; and before quackgrassand wirestem muhly exceed 10 inches.Broadleaf weeds should be treated beforelambsquarters, common ragweed, and vel-vetleaf exceed 2 inches; before pigweedexceeds 3 inches; and before nightshadeexceeds 4 inches. Weeds beyond thesestages may be treated with a 1.75 oz/a rate.

Remarks: Option controls many annualgrass weeds and quackgrass, but it will notcontrol smooth crabgrass. Large crabgrassand wirestem muhly may only be sup-pressed. Grasses like crabgrass and woollycupgrass that emerge after application willnot be controlled adequately becauseOption has short residual activity. Option isan ALS inhibitor like the Accent family ofherbicides. As a result, ALS-resistantgrasses will likely be cross resistant toOption. Option can be tank-mixed withatrazine, Beacon, Callisto, dicamba, Hornet,Marksman, NorthStar, Status, or Yukon toimprove broadleaf weed control or withacetochlor, Camix, Define, Lumax, or Prowlfor residual activity. Corn is tolerant toOption, which contains a safener toenhance herbicide metabolism, but stressedcorn may be temporarily yellowed orstunted. Do not use Option if Counter (in-furrow), Dyfonate, or Thimet was appliedbecause of the risk of injury. Option maycause temporary injury if Lorsban orCounter (T-band) was applied. Optionshould not be applied within 7 days of theapplication of an organophosphate insecti-cide. Option can be applied to field corn,silage corn, and sweet corn. It is not recom-mended on seed corn.

Rotational restrictions: Corn can bereplanted 7 days after application and soy-beans can be planted 14 days after applica-tion. All other crops can be planted 60 daysafter application.


46

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNw

eeds(post)

PRINCIPLESO

FPEST

MNGM

T.

Permit (halosulfuron)Rate: 0.67 to 1.33 oz/a.Adjuvants: Add nonionic surfactant at

0.25% or crop oil concentrate at 1% to thespray mixture. A 28% nitrogen solutionmay be added at 2 to 4 qt/a or ammoniumsulfate at 2 to 4 lb/a if required by a tank-mix partner.

Timing: Corn—Apply from emergence tolayby stage (about 36 inches tall).

Weeds—At the low rate, apply beforesmartweed exceeds 2 inches, before pig-weed and giant ragweed exceed 3 inches,and before cocklebur, common ragweed,and velvetleaf exceed 9 inches. At 1.0 to1.33 oz/a, Permit controls 4- to 12-inch yel-low nutsedge and larger stages of the previ-ous weeds.

Remarks: Permit controls severalbroadleaf weeds and nutsedge, but it doesnot control black nightshade and only sup-presses common lambsquarters. Permit canbe tank-mixed with atrazine, Buctril,dicamba, Marksman, or 2,4-D to broadenthe spectrum of broadleaf weed control.Tank mixtures can also be made withAccent, Accent Gold, or Beacon to controlspecific grasses. Corn appears to have goodtolerance to Permit. Permit can be appliedto field corn, silage corn, and seed corn, butnot sweet corn.

Rotational restrictions: Field corn can bereplanted 1 month after application; smallgrains can be planted 2 months after appli-cation; sweet corn can be planted after3 months; and alfalfa, dry and snap beans,peas, potatoes, and soybeans can beplanted after 9 months.

Priority (Aim EW + Permit)Rate: 1.0 oz/a.Adjuvants: Add 0.25% nonionic surfac-

tant. Nitrogen additives or crop oil concen-trates may be used if required by a tank-mix partner.

Timing: Corn—Apply from emergencethrough the 8-collar (V8) stage.

Weeds—Apply before smartweed exceeds2 inches, before lambsquarters and giantragweed exceed 3 inches, before nightshadeand pigweed exceed 4 inches, before cock-lebur and common ragweed exceed9 inches, and before velvetleaf exceeds18 inches.

Remarks: Priority provides the equivalentof 0.5 oz/a of Aim EW and 0.67 oz/a ofPermit. It provides excellent velvetleaf con-trol plus good control of several broadleafweeds and yellow nutsedge. Priority can betank-mixed with postemergence grass her-bicides like Accent, Accent Gold, Basis, andSteadfast, or with other postemergence her-bicides to control weeds not controlled byPriority. The Aim component will causesome speckling of corn leaves. Avoid spray-ing within 6 to 8 hours before rain or irriga-tion or spraying excessive rates in thewhorl as excessive leaf burn may occur.Adjust the spray boom to spray at least 18inches above the corn. Priority may be usedon field corn, silage corn, seed corn, andsweet corn, but Priority should only beapplied to seed corn using drop nozzles.

Rotational restrictions: Field corn can bereplanted 1 month after application; smallgrains can be planted 2 months after appli-cation; sweet corn can be planted after3 months; soybeans can be planted after9 months; and alfalfa, dry and snap beans,peas, and potatoes can be planted after12 months.

Rage D-Tech (Aim + 2,4-D premix)Rate: 8 oz/a.Adjuvants: Add nonionic surfactant at

0.25%.Timing: Corn—Apply from spike to

8 inches tall. Drop nozzles can be used oncorn up to 36 inches tall.

Weeds—Apply before broadleaf weedsexceed 6 inches tall.

Remarks: Rage D-Tech should controllambsquarters, nightshade, pigweed, andvelvetleaf. Tank mixtures with atrazine orglyphosate (Roundup Ready corn only) arerecommended to broaden the spectrum ofweed control. The Aim component willprovide a faster burn of weed foliage than2,4-D alone. Rage D-Tech will cause sometemporary speckling of corn leaves andmay cause stalk twisting or brittleness.Avoid spraying within 6 to 8 hours of rainor irrigation or when dew exists becauseexcessive leaf burn may occur. Rage D-Techcan be used on field and silage corn, butnot seed or sweet corn.

Rotational restrictions: Corn or soybeanscould be replanted after the required inter-val indicated for burndown treatments.


47

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNw

eeds(post)

PRINCIPLESO

FPEST

MNGM

T.

Snap beans, peas, and tobacco can beplanted after 12 months. Most other cropscan be planted after 30 days.

Require Q (Resolve + dicamba +safener premix)

Rate: 4 oz/a.Adjuvants: If applied alone, add 0.25%

nonionic surfactant plus either 2 lb/a ofammonium sulfate or 2 qt/a of 28% nitro-gen solution. Surfactant is not required iftank-mixing with a glyphosate formulationthat already contains all the necessary sur-factant (fully loaded) or with Ignite.

Timing: Corn—Apply from 4 to 20 inchestall (V2 to V6 stage).

Weeds—Apply before barnyardgrass, fox-tails, or fall panicum exceed 2 inches andbefore pigweed and velvetleaf exceed 3inches.

Remarks: Require Q will control or sup-press several small annual and broadleafweeds and will provide limited residualcontrol. Require Q is being marketed to bemixed with glyphosate or Ignite to increasetheir postemergence activity and provideresidual activity. Rainfall or irrigationwithin several days after application is nec-essary to obtain residual activity of vel-vetleaf, pigweed, lambsquarters, and fox-tails. Require Q may also be tank-mixedwith preemergence grass herbicides orreduced rates of Lumax for greater residualactivity or with Impact plus atrazine forgreater postemergence activity. Corn occa-sionally may lean briefly after applicationbecause of the dicamba component. Do nottank-mix Require Q with Basagran or Lad-dok because corn injury may occur. Soy-beans, tobacco, and most vegetables areextremely sensitive to the dicamba compo-nent in Require Q, so avoid drift. To pre-vent residues from injuring other crops likesoybeans, use an ammonia solution to cleanthe sprayer after use. Do not use on fieldstreated with Counter CR applied in-furrowor over the row at cultivation. Require Qmay injure corn treated with Counter CR,Lorsban, or Thimet if soil has less than 4%organic matter. Require Q can be used onfield corn, but not on seed or sweet corn.

Rotational restrictions: Corn can beplanted anytime after application; winterwheat after 3 months; potatoes after 4months; small grains after 9 months; and

alfalfa, peas, sweet corn, soybeans, snapbeans, and dry beans after 10 months. Anycrop not listed on the label cannot beplanted for 18 months.

Resolve Q (Resolve + Harmony SG +safener premix)

Rate: 1.25 oz/a.Adjuvants: If applied alone, add 0.25%

nonionic surfactant plus either 2 lb/a ofammonium sulfate or 2 qt/a of 28% nitro-gen solution. Surfactant is not required iftank-mixing with a glyphosate formulationthat already contains all the necessary sur-factant (fully loaded) or with Ignite.

Timing: Corn—Apply from emergence to20 inches tall, but before the V7 stage.

Weeds—Apply before barnyardgrass, fox-tails, or fall panicum exceed 2 inches andbefore pigweed and velvetleaf exceed 3inches.

Remarks: Resolve Q will control or sup-press several small annual and broadleafweeds and will provide limited residualcontrol. Resolve Q is being marketed to bemixed with glyphosate or Ignite to increasetheir postemergence activity and provideresidual activity. Rainfall or irrigationwithin several days after application is nec-essary to obtain residual activity of vel-vetleaf, pigweed, lambsquarters, and fox-tails. Resolve Q may also be tank-mixedwith preemergence grass herbicides orreduced rates of Lumax for greater residualactivity or with Impact plus atrazine forgreater postemergence activity. Do nottank-mix Resolve Q with Basagran or Lad-dok because crop injury may occur. Do notuse on fields treated with Counter CRapplied in-furrow or over the row at culti-vation. Resolve Q may injure corn treatedwith Counter CR, Lorsban, or Thimet if soilhas less than 4% organic matter. Resolve Qcan be used on field corn, but not on seedor sweet corn.

Rotational restrictions: Corn can beplanted anytime after application; potatoesafter 1.5 months; winter wheat after 3months; small grains after 9 months; andalfalfa, peas, sweet corn, soybeans, snapbeans, and dry beans after 10 months. Anycrop not listed on the label cannot beplanted for 18 months.


Resource (flumiclorac)Rate: Broadcast applications—4 to 6 oz/a.

Drop nozzle applications—4 to 8 oz/a.Tank mixtures—4 oz/a.

Adjuvants: Add 1 pt/a crop oil concen-trate for broadcast application or 2 pt/a fordrop nozzle applications. See label for tankmixture recommendations.

Timing: Corn—Apply from V2 to V10 (2-to 10-collar stage). Tank-mix applicationscan be made from V2 through the maximumstage allowed by the tank-mix partner.

Weeds—Apply broadcast applications of6 oz/a Resource before common ragweedand smooth pigweed exceed 3 leaves andbefore velvetleaf exceeds 6 leaves. Largerweeds can be controlled with drop nozzleapplications at 8 oz/a.

Remarks: Resource may cause temporaryspotting of corn leaves. Resource is highlyeffective on velvetleaf, controlling up to10-leaf velvetleaf at 8 oz/a. It is less effec-tive on other broadleaf weeds and must beapplied early for control. Resource can betank-mixed at low rates with numerousbroadleaf herbicides to enhance the vel-vetleaf control of the tank-mix partner.Resource may be used on field corn andsilage corn, but not on sweet corn.

Rotational restrictions: Corn and soybeanscan be planted anytime. Other crops can beplanted 30 days after application.

Roundup formulationsSee glyphosate (page 41).

Sencor (metribuzin)Rate: 2 to 3 oz/a of Sencor 75DF or equiv-

alent of other Sencor formulations.Adjuvants: Never use crop oil concentrate.

Do not use adjuvants in 2,4-D, Buctril, orMarksman tank mixes. In tank mixtureswith atrazine or dicamba, 1 qt of nonionicsurfactant per 100 gal of spray mixture maybe added; in tank mixtures with Laddok, 2to 4 qt/a of 28% nitrogen solution may beadded. Pursuit tank mixtures require 1 qt ofnonionic surfactant per 100 gal of spraymixture plus 1 to 2 qt/a 28% nitrogen solu-tion. Surfactant or 28% nitrogen solutionmay be added to Basagran tank mixtures.

Timing: Corn—Sencor can be applied fromemergence to tasseling, but timing isrestricted by the tank-mix partner.

Weeds—Maximum size of broadleafweeds controlled depends on the tank-mixpartner. See label for specifics.

Remarks: Sencor has been labeled as atank-mix partner for atrazine, dicamba,Basagran, Buctril, Laddok, Marksman, and2,4-D to enhance broadleaf weed control.Sencor may cause some corn leaf burn, butthe effects are generally temporary. Do notapply over coarse-textured soils with lessthan 0.5% organic matter or to cold-stressedcorn. If a preemergence application of Sen-cor was applied, do not apply more than atotal of 5.3 oz/a Sencor. Sencor may beapplied to field corn and silage corn, butnot to sweet corn.

Rotational restrictions: Injury to rotationalfield crops is not a concern with these lowrates of Sencor.

Shotgun*(atrazine + 2,4-D ester premix)

Rate: 2 to 3 pt/a; see comments undertiming.

Adjuvants: Do not add adjuvants to thespray mix or apply in liquid fertilizer.

Timing: Corn—Apply 2 pt/a from emer-gence to the 4-leaf stage or before 8 inchestall on any soil texture or with drop nozzlesto corn up to 5 leaves or 12 inches tall oncoarse textured soils. Three pt/a can beapplied broadcast to 4-leaf or 8 inch tallcorn or with drop nozzles to 5-leaf or 12-inch corn on medium and fine texturedsoils.

Weeds—Annual broadleaf weeds are bestcontrolled if less than 4 inches tall.

Remarks: Shotgun controls many com-mon annual broadleaf weeds. Corn stalksmay become brittle during the week fol-lowing Shotgun application. To minimizethe risk of injury, make early applicationsor use drop nozzles at larger growth stagesto avoid spraying excessive rates in thewhorl of the corn plant. Later applicationsalso increase the risk of deformed braceroots. Be cautious when applying Shotgunat temperatures above 85°F because 2,4-Dester vapors may drift to injure nearby sen-sitive plants. Shotgun may only be used onfield corn and silage corn.

Rotational restrictions: Corn, sorghum,and soybeans can be planted the year afterapplication.

48

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNw

eeds(post)

PRINCIPLESO

FPEST

MNGM

T.



49

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNw

eeds(post)

PRINCIPLESO

FPEST

MNGM

T.

Status (dicamba + diflufenzopyr +safener premix)

Rate: 5 to 10 oz/a. Can be tank-mixed at2.5 oz/a with glyphosate or Ignite on resis-tant corn hybrids.

Adjuvants:Add 0.25% nonionic surfactantor 1% crop oil concentrate. Also add either28% nitrogen solution at 1.25% to the spraymixture or ammonium sulfate at 5 lb per100 gal of spray.

Timing: Corn—4 to 36 inches tall or V10.Weeds—The label does not specify maxi-

mum weed sizes for treatment. However,broadleaf weeds should be treated beforeweed competition occurs and while weedsare still easily controlled. It seems wise totreat before most annual broadleaf weedsexceed 4 inches.

Remarks: Status controls many annualbroadleaf weeds and suppresses perennialbroadleaves. Status may also suppressgrowth of annual grasses that escape con-trol after a preemergence grass herbicideapplication, but do not rely on Status forannual grass control. Status can be tank-mixed with other postemergence grass orbroadleaf herbicides with the followingexceptions: Celebrity Plus, dicamba, HornetWDG, Marksman, Northstar, and 2,4-D.Tank-mixing with emulsifiable concentrateformulations of preemergence grass herbi-cides are not recommended because ofpotential injury. Corn injury (stalk brittle-ness or twisting) from Status should be lessthan injury from other dicamba productsbecause of the safener added to the formu-lation. Soybeans, tobacco, and most vegeta-bles or gardens are extremely sensitive toStatus, so avoid drift. To prevent residuesfrom injuring other crops like soybeans, thesprayer should be cleaned after use with astrong detergent or spray tank cleaner. Donot use Status on soils classified as sandwith less than 3% organic matter and wheregroundwater depth is shallow. Status canbe used on field corn, silage corn, and seedcorn, but not on sweet corn.

Rotational restrictions: Field corn can bereplanted 7 days after application andalfalfa, small grains, and soybeans can beplanted 30 days after application if 5 oz/aor less was applied and 1 inch of rain wasreceived. Otherwise, crops should not beplanted for 120 days.

Steadfast(rimsulfuron + Accent premix)

Rate: 0.75 oz/a.Adjuvants:Add crop oil concentrate at 1%

(preferred) or nonionic surfactant at 0.25 to0.5% to the spray solution. Also add 2 qt/aof 28% nitrogen solution or 2 lb/a ammo-nium sulfate.

Timing: Corn—Apply from emergence to20 inches, but before the 7-collar (V7) stage.For corn with 77- to 88-day maturities,apply before 12 inches or V6 stage.

Weeds—Apply before large crabgrassexceeds 1 inch; before woolly cupgrassexceeds 3 inches; before foxtails, barnyard-grass, fall panicum, and wild proso milletexceed 4 inches; and before quackgrassexceeds 8 inches.

Remarks: Steadfast is effective on manyannual grasses and quackgrass. Smoothcrabgrass will not be controlled and largecrabgrass may only be suppressed. Crab-grass can be controlled if Steadfast is tank-mixed with a preemergence grass herbicideand applied before the crabgrass emerges.Do not add a nitrogen fertilizer if tank-mix-ing with Lumax. Steadfast is labeled fortank mixtures with lower rates of atrazine,Callisto, dicamba, Hornet, Impact, Marks-man, or Status to provide broadleaf weedcontrol. Tank-mixing with Permit or Yukonwill also provide nutsedge control. Tank-mixing Steadfast with dicamba mayincrease the risk of rattailing when appliedto small corn. Do not tank-mix Steadfastwith Basagran, Laddok, or 2,4-D becausecrop injury or antagonism may occur. Onlytank-mix with ALS herbicides when recom-mended by DuPont. Do not apply tohybrids with relative maturities of less than77 days or injury may occur. Do not useSteadfast on fields treated with Counter CRapplied in-furrow at planting or over-the-row at cultivation. Steadfast may injurecorn treated with Counter CR, Lorsban, orThimet if soil has less than 4% organic mat-ter. Do not apply organophosphate insecti-cides within 7 days before or 3 days afterSteadfast applications. Steadfast may onlybe used on field and silage corn.

Rotational restrictions: Field corn can beplanted anytime after Steadfast application;soybeans after 15 days; winter wheat after


4 months; spring cereals after 8 months;and alfalfa, dry beans, snap beans, peas,potatoes, and sweet corn after 10 months.

Stinger (clopyralid)Rate: 0.25 to 0.5 pt/a for annual weeds

and 0.33 to 0.5 pt/a for Canada thistle.Adjuvants: Not required.Timing: Corn—Apply from emergence

through 24 inches tall.Weeds—Apply before annual broadleaf

weeds exceed 5 leaves. Apply to Canadathistle after 6 to 8 inches, but before budstage.

Remarks: Stinger controls many weeds inthe sunflower family including cocklebur,sunflower, common and giant ragweed,Jerusalem artichoke, and Canada thistleplus some weeds in the nightshade, buck-wheat, and legume families. For Canadathistle control, do not cultivate before appli-cation and delay cultivation 2 to 3 weeksafter application for maximum effective-ness. For lighter Canada thistle infestations,the 0.33 pt/a rate is recommended on thelabel and has been effective in Wisconsin.Stinger may be used on field corn andsilage corn, but not sweet corn.

Rotational restrictions: Small grains, fieldcorn, and grasses can be planted anytimeafter a Stinger application. Do not plantalfalfa, dry beans, soybeans, or sweet cornfor 10.5 months after application or peas andpotatoes for 18 months after application.

Stout (Accent + Harmony GT premix)Rate: 0.5 to 0.75 oz/a.Adjuvants: Add 1% crop oil concentrate

plus 2 lb/a of ammonium sulfate or 2 qt/aof 28% nitrogen solution. Nonionic surfac-tant may be used instead of crop oil, butcontrol of perennial grasses and woollycupgrass may be reduced.

Timing: Corn—Apply from emergence to16 inches tall, but not after the 5-collar (V5)stage.

Weeds—At the 0.75 oz/a rate, applybefore foxtails, wild proso millet, andwoolly cupgrass exceed 4 inches; beforequackgrass exceeds 10 inches; and beforecommon lambsquarters, pigweeds,smartweeds, and velvetleaf exceed 4 inches.

Remarks: Stout will control many annualgrasses, quackgrass, and some broadleafweeds, but it will not control crabgrass.Crabgrass can be controlled if Stout is tank-

mixed with a preemergence grass herbicideand applied before the crabgrass emerges.Consult the label for adjuvant recommen-dations when tank-mixing with preemer-gence grass herbicides. Additionalbroadleaf weeds can be controlled whenmixed with atrazine, Callisto, Hornet,Impact, or low rates of dicamba or Status.See the label for specific recommendationson rates and adjuvants. Tank-mixing Stoutwith dicamba may increase the risk of rat-tailing when applied to corn less than 4inches tall or before the V3 stage. Do nottank-mix with Basagran, Laddok, or 2,4-Dbecause crop injury may occur. Do notapply to hybrids with relative maturities ofless than 88 days or injury may occur. Donot use Stout on fields treated with CounterCR applied in-furrow or over the row atcultivation. Stout may injure corn treatedwith Counter CR, Lorsban, or Thimet if soilhas less than 4% organic matter. Stout canbe used on field corn, but not on seed orsweet corn.

Rotational restrictions: Corn can beplanted anytime after application; soybeansafter 15 days; winter wheat after 4 months;spring small grains after 8 months; alfalfa,sweet corn, soybean, pea, potato, snapbeans, and dry beans after 10 months. Anycrop not listed on the label cannot beplanted for 18 months.

Unity (thifensulfuron)Rate: 0.083 oz/a (1⁄12 oz/a).Adjuvants: Add nonionic surfactant at

0.25% or crop oil concentrate at 1% pluseither 2 to 4 qt/a 28% nitrogen solution or2 to 4 lb/a of ammonium sulfate. Withglyphosate tank mixtures, only ammoniumsulfate is needed if the glyphosate is fullyloaded with surfactant.

Timing: Corn—Apply to 1 to 5 collar (V1to V5) stages, but before 16 inches tall.

Weeds—Apply before lambsquartersexceeds 4 inches, before smartweeds andvelvetleaf exceed 6 inches, and before pig-weed exceeds 12 inches.

Remarks: Unity has the same active ingre-dient as Harmony SG, but is labeled for useon field corn to control the broadleaf weedsmentioned above. It is labeled to be mixedwith atrazine to improve the spectrum ofbroadleaf weeds controlled or withglyphosate on resistant hybrids. It has min-imal soil residual activity. Unity may injure

50

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNw

eeds(post)

PRINCIPLESO

FPEST

MNGM

T.


stressed corn. Do not apply to corn withmaturities of less than 88 days. ApplyingUnity to corn treated with Counter CR,Lorsban, or Thimet may cause injury. Unitycan only be used on field and silage corn.

Rotational restrictions: Corn, soybeans,and small grains can be planted anytimeafter application. Any other crop can beplanted after 45 days.

Yukon (Permit + dicamba premix)Rate: 4 to 8 oz/a.Adjuvants: Add nonionic surfactant at

0.25 to 0.5% (preferred) or crop oil concen-trate at 1% to the spray solution. If requiredby a tank-mix partner, 2 to 4 qt/a of 28%nitrogen solution or 2 to 4 lb/a ammoniumsulfate may be added.

Timing: Corn—Apply from emergence to36 inches.

Weeds—At the low rate, apply beforesmartweed exceeds 3 inches; before lambs-quarters, nightshade, and giant ragweedexceed 6 inches; and before nutsedge, pig-weed, and common ragweed exceed 12inches.

Remarks: Yukon at 4 oz/a is equivalent tothe standard 0.67 oz/a rate of Permit plus4 oz/a of dicamba. It controls many annualbroadleaf weeds and provides good controlof yellow nutsedge. Yukon is labeled fortank mixtures with atrazine, Accent, Bea-con, Callisto, Impact, and Steadfast. It canbe tank-mixed with glyphosate or Ignite onresistant hybrids. Corn has good toleranceto early postemergence applications, butcertain hybrids may have temporary twist-ing or brittleness because of the dicambacomponent. Soybeans, tobacco, and mostvegetables are extremely sensitive to thedicamba component in Yukon, so avoiddrift. To prevent residues from injuringother crops like soybeans, clean the sprayerafter use with a detergent solution followedby an ammonia solution. Yukon can beused on field, silage, and seed corn, but noton sweet corn.

Rotational restrictions: Field corn can beplanted 1 month after application; smallgrains can be planted 2 months after appli-cation; sweet corn can be planted after 3months; and alfalfa, dry and snap beans,peas, potatoes, and soybeans can beplanted after 9 months.

2,4-D Amine or EsterRate: Early postemergence—0.5 to 1.0 pt/a

of 2,4-D amine or 0.33 to 0.67 pt/a of 2,4-Dlow volatile ester, assuming 3.8 lb ae/gal.

Late postemergence—1 pt/a of 2,4-D amineor low volatile ester.

Adjuvants: Do not add crop oil or seriouscorn injury may occur. Add surfactant ifdirected by tank-mix partner.

Timing: Corn—Apply early postemer-gence broadcast applications to 4- to 8-inchcorn. Make late postemergence drop-nozzleapplications to corn between 8 inches talluntil 1 week before tassel emergence. Pre-harvest applications can be made after silksbrown.

Weeds—Annual broadleaf weeds are con-trolled best when less than 3 inches tall.Perennial broadleaves should be 10 inchesor more in height when treated.

Remarks: Corn injury is most likely whencorn is growing rapidly under high temper-ature and high soil moisture conditions.Under such circumstances, delay cultiva-tion for 8 to 10 days to allow corn to over-come any temporary stalk brittleness. Cornhybrids vary in their tolerance to 2,4-D. Forearly postemergence applications, use thelower rate for treatment in hot, humidweather. For late drop-nozzle applications,adjust the application rate in direct propor-tion to the amount of the field area actuallybeing treated. If the entire row and inter-row area is being treated, no rate reductionis necessary. Direct the spray toward thebase of the corn row to obtain maximumweed coverage with minimum corn injury.Smartweeds and wild buckwheat are some-what tolerant of 2,4-D, especially the amineform.

51

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNw

eeds(post)

PRINCIPLESO

FPEST

MNGM

T.


52

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNw

eeds(post)

PRINCIPLESO

FPEST

MNGM

T.

Table 2-4. Forage, grazing, and grain harvest intervals for corn herbicidesa

Product Forage/grazing interval Grain harvest interval

Accent 30 days No restrictionsAcetochlor No restrictions No restrictionsAcetochlor + atrazine 60 days No restrictionsAlachlor + atrazine 21 days No restrictionsAtrazine 60 days No restrictionsBasagran 12 days No restrictionsBasis 30 days 30 daysBeacon Grazing: 30 days; silage: 45 days 60 daysBicep Lite II Magnum 60 days No restrictionsBuctril 30 days Apply before tassel emergenceCadet 30 days 90 daysCallisto 45 days 45 daysCamix 45 days 45 daysCelebrity Plus 32 days 72 daysDefine SC 75 days No restrictionsDicamba Delay harvest until milk stage No restrictionsDual II Magnum 30 days No restrictionsEradicane No restrictions No restrictionsGlyphosate–broadcast 50 days 7 daysG-Max Lite 60 days No restrictionsHalex GT 45 days 45 daysHornet WDG 45 days 85 daysIgnite 60 days 70 daysImpact 45 days 45 daysLaudis 45 days No restrictionsLumax 60 days 45 daysMarksman Delay harvest until milk stage No restrictionsNorthStar Grazing: 30 days; silage: 45 days 60 daysOption 45 days 70 daysOutlook 40 days No restrictionsPermit 30 days No restrictionsPrincep 60 days 60 daysPriority 30 days No restrictionsProwl H2O 21 days No restrictionsPython 85 days 85 daysRage D-Tech 7 days 3 daysRequire Q 30 days and after milk stage 30 daysResolve Q 30 days 30 daysResource 28 days 28 daysSencor 60 days 60 daysShotgun 21 days No restrictionsStatus 32 days 72 daysSteadfast 30 days No restrictionsStinger 40 days No restrictionsStout 30 days No restrictionsSureStart No restrictions 85 daysUnity 30 days 30 daysYukon 30 days No restrictions2,4-D amine or ester 7 days No restrictionsaLabels may have changed after this table was prepared. Consult current labels to verify the information.


*Coatrpagfortion

53

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNw

eedsPRINCIPLES

OF

PESTM

NGMT.

Table 2-5. Rate equivalents of corn herbicide premixes

Herbicide Rate/acre Provides the equivalent of:

Basis 75DF 0.33 oz 0.66 oz Resolve 25DF + 0.17 oz Harmony SGBicep II Magnum 5.5L 1.9 qt 1.2 pt Dual II Magnum 7.64EC + 1.6 lb atrazine 90DFBicep Lite II Magnum 6L 1.5 qt 1.3 pt Dual II Magnum 7.64EC + 1.1 lb atrazine 90DFBullet 4ME 3 qt 3.75 pt Micro-Tech 4ME + 1.25 lb atrazine 90DFCamix 3.67L 2.4 qt 2.1 pt Dual II Magnum 7.64EC + 6.3 oz Callisto 4LCelebrity Plus 70DF 4.7 oz 5 oz Status + 0.66 oz Accent 75DFDegree Xtra 4.04CS 3.7 qt 2.85 pt Harness 7EC + 1.38 lb atrazine 90DFField Master 4.06L 4 qt 2.3 pt Harness 7.0EC + 1.67 lb atrazine 90DF

+ 0.56 lb ae glyphosateFulTime 4CS 3.5 qt 2.5 pt Surpass 6.4EC + 1.55 lb atrazine 90DFG-Max Lite 5L 3 pt 18 fl oz Outlook 6EC + 1.1 lb atrazine 90DFGuardsman Max 5L 3.6 pt 16 oz Outlook 6EC + 1.67 lb atrazine 90DFHalex GT 3.6 pt 1 pt Dual Magnum 7.64EC + 3 fl oz Callisto 4L

+ 0.9 lb ae glyphosateHarness Xtra 5.6L 2.3 qt 2 pt Harness 7.0EC + 1.6 lb atrazine 90DFHarness Xtra 6L 2 qt 2.46 pt Harness 7.0EC + 0.94 lb atrazine 90DFHornet 68.5WDG 4 oz 0.92 oz Python 80WG + 5.3 fl oz Stinger 3SCKeystone 5.25L 2.6 qt/a 2.4 pt Surpass 6.4EC + 1.63 lb atrazine 90DFKeystone LA 5.5L 2 qt 2.5 pt Surpass 6.4EC + 0.83 lb atrazine 90DFLaddok S-12 5L 1.67 pt 1 pt Basagran 4SC + 0.58 lb atrazine 90DFLumax 3.95L 3 qt 2.1 pt Dual II Magnum 7.64EC + 6.4 fl oz Callisto 4L

+ 0.83 lb atrazine 90DFMarksman 3.2L 3.5 pt 0.96 pt Banvel 4SC + 1.02 lb atrazine 90DFNorthStar 47.4WG 5 oz 0.5 oz Beacon 75WG + 4 fl oz Clarity 4SCPriority 62.5DG 1 oz 0.67 oz Permit 75WDG + 0.5 fl oz Aim EWRage D-Tech 8 oz 0.5 fl oz Aim EW + 8.3 fl oz 2,4-D LV4 (3.8 lb ae/gal)Require Q 4 oz 1 oz Resolve 25WDG + 3.8 fl oz Clarity 4SResolve Q 1.25 oz 0.9 oz Resolve 25WDG + 0.1 oz Harmony SGShotgun 3.25L 2 pt 0.625 lb atrazine 90DF + 8.42 fl oz Low Vol 4

(3.8 lb ae/gal)Status 5 oz 0.8 oz ae diflufenzopyr + 4 fl oz Clarity 4SSteadfast 75WDG 0.75 oz 0.5 oz Accent 75DF + 0.75 oz Resolve 25DFStout 72.5WDG 0.75 oz 0.67 oz Accent 75DF + 0.075 oz Harmony SGSureStart 1.5 pt 0.88 pt Surpass 6.4EC + 2.3 oz Stinger 3SC

+ 0.45 oz Python 80WGYukon 67.5WDG 4 oz 0.67 oz Permit 75WDG + 4 fl oz Clarity 4S


Table 2-6. Rainfree period and adjuvants required for postemergence corn herbicides

Hours to ————————————Recommended adjuvants————————————Herbicide be rainfast Nonionic surfactant Crop oil concentrate Nitrogen additivea

Accent 4 0.25–0.5% or 1% plus 28% N at 2–4 qt/a orAMS at 2–4 lb/aAtrazine 6–8 1 qt/aBasagranb 4 1 qt/a or 28% N at 2–4 qt/a orAMS at 2.5 lb/aBasis 4 0.25–0.5% or 1–2% plus 28% N at 2–4 qt/a orAMS at 2–4 lb/aBeacon 4 0.25% or 1–4 pt/a 28% N at 2–4 qt/a or

AMS at 2–4 lb/a may be addedBuctril 1 Add as directed by tank-mix partnerCadet 4 0.25% or 1–2 pt/a plus 28% N at 1–2 qt/a orAMS at 1–2 lb/a

may be addedCallisto 1 1% plus 28% N at 2.5% orAMS at 8.5 lb/100 galCelebrity Plus 4 0.25–0.5% plus 28% N at 1–2 qt/a orAMS at 1–2 lb/aDicamba 4 28% N at 2–4 qt/a orAMS at 2.5 lb/a

may be added for velvetleafGlyphosate 2–6 Check label to see if surfactant is needed Add AMS at 8.5–17 lb/100 galHalex GT 0.25–0.5% plus AMS at 8.5–17 lb/100 galHornet WDG 2 0.25% or 1% Add 28% N at 2.5% if droughtyIgnite 4 Add AMS at 3 lb/aImpact 1 1.0–1.5% (methylated plus 28% N at 1.25–2.5% orAMS at

seed oil preferred) 8.5–17 lb/100 galLaddok S-12b 4 1 qt/a or 28% N at 1 gal/a orAMS at 2.5 lb/aLaudis 1 1% (methylated plus 28%N at 1.5 qt/a orAMS at 8.5 lb/100 gal

seed oil preferred)Marksmanc 4 A surfactant, 28% N, or AMS may be added, especially if droughtyNorthStar 4 0.25% or 1–4 pt/a if corn <12" 28% N at 2–4 qt/a orAMS at 2–4 lb/a

may be addedOption 2 Add 1.5 pt/a methylated seed oil plus 28% N at 1.5–2.0 qt/a orAMS at

1.5–3.0 lb/aPermit 4 0.25–0.5% or 1% 28%N at 2–4 qt/a orAMS at 2–4 lb/a may

be added if required by tank-mix partnerPriority 4 0.25% 28%N at 2–4 qt/a orAMS at 2–4 lb/a may

be added if required by tank-mix partnerRage D-Tech 0.25%Require Q 4 0.25% plus 28% N at 2 qt/a orAMS at 2 lb/aResolve Q 4 0.25% plus 28% N at 2 qt/a orAMS at 2 lb/aResource 1 1 pt/ad

Shotgun 4 Do not add adjuvantsStatus 4 0.25% or 1% plus 28% N at 1.25% orAMS at 5–17 lb/100 galSteadfast 4 0.25% or 1% plus 28% at 2 qt/a orAMS at 2 lb/aStinger 6–8 Adjuvants not requiredStout 4 0.25% or 1% plus 28% N at 2 qt/a orAMS at 2 lb/aUnity 4 0.25% or 1% plus 28% N at 2–4 qt/a orAMS at 2–4 lb/aYukon 4 0.25–0.5% or 1% 28%N at 2–4 qt/a orAMS at 2–4 lb/a may

be added if required by tank-mix partner2,4-D amine 6–8 Do not add crop oil; add surfactant if directed by tank-mix partner2,4-D ester 2–3 Do not add crop oil; add surfactant if directed by tank-mix partner

54

PRINCIPLESO

FPEST

MNGM

T.CO

RNw

eedsSO

YBEANFO

RAGES&

PASTURESAPPENDIX

SMALL

GRAINSPERENNIAL

WEEDS

STORED

GRAININSECTS

azine.–XXtions.

aAMS = ammonium sulfate.bAdd crop oil concentrate for lambsquarters and common rag-weed control, add a nitrogen additive for velvetleaf control, oradd both if all three weeds are present.

cDo not use petroleum based crop oil concentrates.dUse 2 pt/a for drop nozzle applications.


55

PRINCIPLESO

FPEST

MNGM

T.CO

RNw

eedsSO

YBEANFO

RAGES&

PASTURESAPPENDIX

SMALL

GRAINSPERENNIAL

WEEDS

STORED

GRAININSECTS

Herbicidea Corn stage Rate/a

Abbreviations: lf = leaf, NR = no restrictions on corn growth stage, V2 = 2 collar corn, V6 = 6 collar corn, (continued)V7= 7 collar corn, V10 = 10 collar corn, BH = before harvest, BT = before tasseling, — = not labeled for control.aDrop nozzles allow these herbicides to be applied before stages listed: Shotgun up to 12 inches; Celebrity Plus up to 24 inches;Accent up to 36 inches or 10 collars; Dicamba, Hornet, Ignite, NorthStar, Rage D-Tech, and Status up to 36 inches; Option up toV8; and Beacon and 2,4-D before tasseling.

Cock

lebu

r

Lam

bsqu

arte

rs

Nig

htsh

ade

Pigw

eed

Ragw

eed,

com

mon

Ragw

eed,

gian

t

Smar

twee

d

Velv

etle

af

Barn

yard

gras

s

Foxt

ail,

gian

t

Foxt

ail,

gree

n

Foxt

ail,

yello

w

Fall

pani

cum

Wild

pros

om

illet

Woo

llycu

pgra

ss

Larg

ecr

abgr

ass

Table 2-7. Application timings for postemergence herbicidesLabeled rates for certain herbicides may be higher or lower than the rate included in this table.At different rates, the maximum weed size labeled for control may change.

——————Maximum size in inches or leaf stage (lf)——————Accenta 0–20" or V6 0.67 oz — — — 4 — — 4 — 4 4 4 4 4 4 4 —Acetochlor 0–11" variable Acetochlor does not control emerged weeds.Atrazine 4L 0–12" 1 qt 4 6 4 6 4 4 4 4 — — 1.5 1.5 — — — —Basagran NR 2 pt 10 2 — — 3 6 10 5 — — — — — — — —Basis 0–V2 0.33 oz — 3 — 3 — — 3 3 2 2 2 2 2 — 1 0.5Beacona 4–20" or V6 0.76 oz 4 — 4 4 9 9 4 4 — — — — 2 — — —Bicep Lite II Magnum 0–5" variable 2 lf 2 lf — 2 lf 2 lf — 2 lf 2 lf 2 lf 2 lf 2 lf 2 lf 2 lf — — 2 lfBuctril 4 lf–BT 1.5 pt 10 8 6 2 6 6 6 5 — — — — — — — —Cadet V2–48" 0.9 oz — 2 — 4 — — — 36 — — — — — — — —Callisto 0–30" or V8 3 oz 5 5 5 5 — 5 5 5 — — — — — — — 2Camix 0–30" or V8 2.4 qt 3 3 3 3 3 3 3 3 — — — — — — — —Celebrity Plusa 4–24" or V6 4.7 oz 3 3 3 3 3 3 3 3 4 4 4 4 4 4 4 —Define SC 0–V5 variable Define does not control emerged weeds.Dicambaa 0–8" or 5 lf 1 pt 4 4 4 4 4 4 6 4 — — — — — — — —Dual II Magnum 0–40" variable Dual II Magnum does not control emerged weeds.Glyphosate 0–30" or V8 0.75 lb ae 24 12 6 18 12 12 6 6 6 12 12 12 12 12 12 12G-Max Lite 0–12" variable 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 — — 1.5Hornet WDGa 0–V6 3 oz 6 — — — 6 6 6 6 — — — — — — — —Halex GT 0–30" or V8 3.6 pt 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4Ignitea V5 22 oz 6 4 6 3 6 6 6 3 3 6 6 3 3 6 6 3Impact 0–45 BH 0.5 oz 5 4 4 4 4 5 2 4 — — — — — — — —Laudis 0–V8 3 oz 6 6 6 6 6 6 6 6 5 3 — 3 — 4 3 3Lumax 0–12" 3 qt 3 3 3 3 3 3 3 3 — — — — — — — —Marksman 0–8"or 5 lf 3.5 pt 6 6 6 6 6 6 6 6 — — — — — — — —NorthStara 4–20" (V2–V6) 5 oz 6 4 6 5 9 9 4 4 — — — — 3 — — —Optiona V1–V6 1.5 oz 2 2 4 3 2 — — 2 4 6 3 3 3 3 2 2Outlook 0–12" variable Outlook does not control emerged weeds.Prowl H2O 0–30" or V8 variable Prowl H2O does not control emerged weeds.Permit 0–36" 0.67 oz 9 — — 3 9 3 2 9 — — — — — — — —Priority 0–V8 1 oz 9 3 4 4 9 3 2 18 — — — — — — — —Rage D-Tech 0–8" 8 oz 6 6 6 6 — — 6 6 — — — — — — — —Require Q 4–20" (V2–V6) 4 oz — — — 3 — — — 3 2 2 2 2 2 — 1 0.5Resolve Q 0–20" or V6 1.25 oz — — — 3 — — — 3 2 2 2 2 2 — 1 0.5

Broadleaves Grasses


PRINCIPLESO

FPEST

MNGM

T.CO

RNw

eedsSO

YBEANFO

RAGES&

PASTURESAPPENDIX

SMALL

GRAINSPERENNIAL

WEEDS

STORED

GRAININSECTS

Cock

lebu

r

Lam

bsqu

arte

rs

Nig

htsh

ade

Pigw

eed

Ragw

eed,

com

mon

Ragw

eed,

gian

t

Smar

twee

d

Velv

etle

af

Barn

yard

gras

s

Foxt

ail,

gian

t

Foxt

ail,

gree

n

Foxt

ail,

yello

w

Fall

pani

cum

Wild

pros

om

illet

Woo

llycu

pgra

ss

Larg

ecr

abgr

ass

Table 2-7. Application timings for postemergence herbicides (continued)Labeled rates for certain herbicides may be higher or lower than the rate included in this table.At different rates, the maximum weed size labeled for control may change.

Herbicidea Corn stage Rate/a

Broadleaves Grasses

Resource V2–V10 6 oz — 3 lf — — 3 lf — — 6 lf — — — — — — — —Shotguna 0–8" 2 pt 4 4 4 4 4 4 4 4 — — — — — — — —Status 4–36" or V10 5 oz 4 4 4 4 4 4 4 4 — — — — — — — —Steadfast 0–20" or V6 0.75 oz — — — 4 — — 3 — 4 4 4 4 4 4 3 1Stinger 0–24" 0.25 pt 5 lf — — — 5 lf 5 lf — — — — — — — — — —Stout 0–16" or V5 0.75 oz — 4 — 4 — — 4 4 4 4 4 4 3 4 4 —Unity V1–V5 or 16" 0.083 oz — 4 — 12 — — 6 6 — — — — — — — —Yukon 0–36" 4 oz 14 6 6 12 12 6 3 12 — — — — — — — —2,4-Da 4–8" 1 pt 4 4 4 4 4 4 — 2 — — — — — — — —Abbreviations: lf = leaf, NR = no restrictions on corn growth stage, V2 = 2 collar corn, V6 = 6 collar corn, V7= 7 collar corn,V10 = 10 collar corn, BH = before harvest, BT = before tasseling, — = not labeled for control.aDrop nozzles allow these herbicides to be applied before stages listed: Shotgun up to 12 inches; Celebrity Plus up to 24 inches; Accentup to 36 inches or 10 collars; Dicamba, Hornet, Ignite, NorthStar, Rage D-Tech, and Status up to 36 inches; Option up to V8; andBeacon and 2,4-D before tasseling.

——————Maximum size in inches or leaf stage (lf)——————

56


PRINCIPLESO

FPEST

MNGM

T.CO

RNinsects

SOYBEAN

FORAGES

&PASTURES

APPENDIXSM

ALLGRAINS

PERENNIALW

EEDSSTO

REDGRAIN

INSECTS

57

Insecticides suggested in this section areintended as a guide to assist you in select-ing chemical control options. While sugges-tions provide an overview of product regis-trations for specific field crop insect pests,this guide is not intended as an exhaustiveinsecticide label source. Product inclusionor omission does not imply endorsementby the University of Wisconsin-Extension.Keep in mind that certain insecticides areproduced by more than one manufacturerand directions for use, rate, and method ofapplication may vary by formulation.Therefore, always read the insecticide labelcompletely before using the material.A number of the products listed in this

section are restricted-use insecticides. Wediscuss restricted-use pesticides in thebeginning of this publication. Refer toappendix table 1 for a list of pesticides thatcurrently require certification to be applied.It is possible that additional insecticideswill be classified before the next growingseason. Contact your county Extensionagent for additional information on insecti-cide restrictions.Common and trade names of insecticides

are often used interchangeably. Tradenames such as Lorsban are capitalized,while common chemical names, chlorpyri-fos in this example, are not.

CHEMIGATIONSome insecticides, such as Ambush 2E,

Cobalt, Lorsban Advanced, Pounce 3.2 EC,Penncap-M, Sevin, and Warrior II, can beapplied through certain sprinkler irrigationsystems, as specified on the label, for con-trol of various aboveground corn insectpests. Consult product labels for specificinstructions. Wisconsin has stringent regu-lations regarding application of pesticidesthrough irrigation water, and an approved

anti-siphon system is required. Contact theWisconsin DATCP for information on legalrequirements.

PREDICTING SOIL INSECTCONTROL NEEDS FOR CORNCrop rotation patterns significantly influ-

ence the occurrence and extent of soil insectproblems in corn. Awareness of these rela-tionships, along with field scouting infor-mation, can help predict the need for aplanting-time application of a soil insecti-cide, a seed-applied insecticide, or selectionof a Bt corn hybrid. Exceptions occasionallycan occur because of weather fluctuations,abundance or lack of natural enemies,tillage, etc. The following are guidelines forpredicting soil insect problems in corn andselecting insect pest management tacticsaccordingly.

Continuous cornCorn rootworm is known as a continuous

corn pest because it requires corn roots tocomplete development. Rootworms causedamage beginning the second year whenoverwintering eggs hatch and larvae feedon corn roots to complete development.(Larvae that emerge in fields planted tonon-host crops such as alfalfa or soybeanswill not complete development.) A cornrootworm control strategy usually isneeded at planting in the rootworm area ofthe state. A line from Green Bay to EauClaire typically marks the northern limitsof corn rootworm problems during mostyears. However, along the MississippiRiver, relatively high populations extendinto St. Croix County. Muck and non-irri-gated sandy soil seldom have damagingrootworm populations. For more detailsabout rootworms and control options, seethe discussion under Insect Pests.

CORN INSECT MANAGEMENT


Corn after soybeansThe incidence of soil insect problems in

corn following soybeans is typically low,and the use of a planter box or direct com-mercial seed treatment for control of soil-dwelling secondary insect pests (e.g., seed-corn maggot, wireworm, white grub) willnormally be sufficient. Check seed-appliedinsecticide labels for pests controlledand/or suppressed. Soil-applied insecti-cides are seldom necessary.In most of the state, corn rootworm dam-

age is not a problem when corn is rotatedannually with soybeans or other crops as theadult beetles primarily lay their eggs in cornfields. Larvae that hatch in fields other thancorn will starve to death. This makes croprotation a highly reliable cultural control.In some cases, not all northern corn root-

worm eggs will hatch after the first winter.Some northern corn rootworm eggs remainin a dormant state for two or more wintersbefore hatching. This behavior, known asextended diapause, is more prevalent instates west of Wisconsin. In a 3-year succes-sive rotation of corn/soybean/corn, thiscan result in economic rootworm injuryduring the year that corn follows soybean.Therefore, damage to corn that follows soy-bean in rotation, does not necessarily meanthat rootworm beetles laid eggs in soybean.Additionally, corn rootworm beetles pre-sent in corn fields that follow soybean,alfalfa, or another crop in rotation did notnecessarily emerge from the soil in thosefields. Rootworm beetles are mobile and arecapable of dispersing to new fields verysoon after emergence. In areas not affectedby the variant western corn rootworm (seenext section), if beetles are present in cornfields that follow a crop other than corn,they are likely migrants and did not emergein such fields.Although rootworm beetles can be found

in “clean” soybean fields, they are espe-cially attracted to weedy fields or those thatcontain volunteer corn. In these cases, root-worm beetles may deposit enough eggs insoybean fields to cause economic damagewhen corn is planted the following year.Control of grassy weeds and volunteer cornwill help reduce potential problems fromcorn rootworm as well as larval wireworm,white grub, stalk borer, hop vine borer, andpotato stem borer the following year, sincethe weeds can be attractive to egg-layingadults during the summer.

Corn after soybeans:Variant western corn rootwormAvariant strain of the western corn root-

worm has developed a behavioral adapta-tion to the corn-soybean rotation in someareas of the Midwest, including parts ofWisconsin. This strain no longer requirescorn as an egg-laying site. Like normalwestern corn rootworm beetle populations,this variant moves readily between corn andother crops. Unlike normal rootworm beetles,this variant can lay heavy populations of eggsin soybean fields, resulting in economicinjury to corn planted the following year.The variant western corn rootworm (vari-

ant WCR) has been documented in south-eastern Wisconsin, the northern two thirdsof Illinois, much of Indiana, southernMichigan, and western Ohio. A team ofUW-Extension researchers, corn-soybeangrowers, and Wisconsin DATCP specialistsis studying the variant WCR and has con-firmed its presence in Kenosha, Racine,Walworth, and Rock counties. The team isalso monitoring neighboring counties forthe spread of this pest. Contact your UW-Extension agent for the most current infor-mation on variant WCR in your area.In affected areas, producers and consul-

tants should take steps to minimize the riskof corn rootworm damage to first-year cornfollowing soybeans. It’s important to scoutto determine whether the variant WCR ispresent in sufficient numbers to cause eco-nomic damage. Treating first-year cornwithout first establishing the need is bothcostly and environmentally unsound.Unbaited yellow sticky traps, available

from Gempler’s and Great Lakes IPM, areused to monitor beetle abundance in soy-beans and predict the need for at-plantingcorn rootworm treatment the followingyear. For assistance implementing a scout-ing program, contact your county Exten-sion agent.If you determine that control is needed,

there are several options for reducingdamage the following year:1. Use a granular or liquid soil insecticide

at planting.2. Plant a Bt rootworm corn hybrid.3. Plant corn treated with a corn root-

worm-rate insecticidal seed treatment.

PRINCIPLESO

FPEST

MNGM

T.CO

RNinsects

SOYBEAN

FORAGES

&PASTURES

APPENDIXSM

ALLGRAINS

PERENNIALW

EEDSSTO

REDGRAIN

INSECTS

58


Corn after sodTrue grass sod, including grassy legume

fields, may harbor pests such as white grubs,wireworms, cutworms, sod webworms,and grasshoppers. Species of wirewormsand white grubs that take longer than1 year to develop also may be a problemthe second and third years if not controlledthe first year. Seedcorn maggot flies also maybe attracted to the increased organic matterof a grass sod broken for corn planting.Insecticidal seed treatments will control

seedcorn maggots, but soil insecticide treat-ments may be needed for pests like wire-worms and white grubs. Several soil insec-ticides labeled for corn rootworm controlare also labeled for control of wirewormsand white grubs. In addition, low-ratenicotinoid insecticidal seed treatments arelabeled for wireworms and white grubs.Minimum tillage of true grass sods is

favorable to such corn insect pests as cut-worms, armyworms, grasshoppers, andstalk borers.

Corn after alfalfaRootworms occasionally can be a prob-

lem in corn following alfalfa, but this iseven less common than damage to cornplanted after soybean. Adult rootwormbeetles attracted to alfalfa or weed blos-soms during the summer egg-laying periodoccasionally have laid enough eggs to causeeconomic damage the following summer.There also is a potential for damage from

wireworms and white grubs when corn fol-lows grassy alfalfa and clover fields.Some insecticides (Ambush 2E, Brigade

2EC, Pounce 3.2EC, andWarrior II) arelabeled for preventative treatment for occa-sional pests such as black cutworm, early-season armyworm, and stalk borer, particu-larly when corn is no-till planted into sod.However, because of the erratic occurrenceof these pests, scouting of seedling cornplants combined with timely insecticideapplication at insect pest thresholds is amore cost-effective and environmentallysound approach. Your county Extensionagent can assist you in developing a scout-ing program.

Corn after sudangrassesAlthough corn rootworm beetles can be

found in sudangrass, sudex, and other sim-ilar grasses, the beetles apparently return to

corn fields to lay their eggs, because wehave not observed rootworm damage incorn planted after these grasses in rotation.

INSECT PESTS

ArmywormThe true armyworm causes serious dam-

age in some areas of the state almost everyyear. Armyworms will climb into cornwhorls or even attack tasseled corn and“rag” the leaves from the outside edgestoward the midrib, sometimes leaving onlymidribs on the stalk or eventually eatingthe stalks to the ground. Defoliation belowthe ear zone is not as detrimental as leaffeeding above the ear.Armyworm moths will lay eggs on grass

in corn fields; thus grass weed control incorn is important. If a corn field has aheavy infestation of grassy weeds, scout thefield carefully. Look on the ground, underdebris, and on the weeds.“Weed-free” fields will not guarantee

immunity from armyworm attack. Thearmyworm also can migrate into corn fromnearby harvested alfalfa, pea, or smallgrain fields, or other grassy areas. Monitor-ing these kinds of fields when they bordercorn is necessary. When the armywormmigrates into corn from adjoining areas,only a few border rows may need treatmentif infestation is detected early enough.If you find signs of armyworm feeding,

check five sets of 20 plants at random.Record the number of damaged plants andthe number of worms per plant. Spot treat,if possible, when you find two or morearmyworms (3⁄4-inch or smaller) per planton 25% of the plants or one per plant on75% of the plants. Finding the worms whilethey are still small and before damage tocorn is severe increases the value of control.Young worms also are easier to control thanthose nearing maturity.

Corn earwormHybrid seed corn production fields occa-

sionally need protection from corn ear-worm. Moths lay eggs on green and yellowcolor-stage silks, and larvae crawl down thesilk channel and feed on kernels. Corn ear-worm larvae can be confused with Euro-pean corn borer larvae, which also feedwithin the ears.

PRINCIPLESO

FPEST

MNGM

T.CO

RNinsects

SOYBEAN

FORAGES

&PASTURES

APPENDIXSM

ALLGRAINS

PERENNIALW

EEDSSTO

REDGRAIN

INSECTS

59


Pheromone traps can be used to trapmale moths and monitor population trends.Treat with an insecticide (see table 2-11) at10% silk if traps capture 5 to 10 malemoths/night. A second application may beneeded 7 to 10 days later if traps continueto catch 5 to 10 moths per night. Moths willnot lay eggs on dry silks.

Corn flea beetleAs the name implies, corn flea beetles are

small (1⁄16 inch) and will leap great dis-tances when disturbed. These black beetlesoverwinter in clumps of grass near cornfields and move to corn seedlings shortlyafter they emerge in the spring. Feedingdamage appears as long, thin, white-silverystreaks. Although heavily injured leavesturn brown and wilt, beetle populations inWisconsin are rarely large enough to causethis type of damage. The corn flea beetle ismore important for its role in transmitting abacterial disease known as Stewart’s wilt orStewart’s disease. This disease is an occa-sional problem in Wisconsin. Beetles canspread the bacterium, Erwinia stewartii, dur-ing feeding. The bacterium can overwinterwithin the beetle, on plant debris, or in thesoil. For more information about Stewart’swilt, see the corn disease section.Sweet corn and inbred corn can be highly

susceptible to Stewart’s wilt and should bescouted from seedling emergence to the V5stage. An insecticide may be warranted ifthere are two to three beetles per plant andif 10% of the plants exhibit feeding injury.Flea beetle survival and Stewart’s wilt

potential are predicted using the averagemonthly temperatures for December, Janu-ary, and February. Typically, Stewart’s wiltcauses significant losses only one or twoyears in a 20-year period. For flea beetlepredictions, consult early spring issues ofthe UW-ExtensionWisconsin Crop Managernewsletter (ipcm.wisc.edu/wcm) or theWisconsin Department of Agriculture,Trade and Consumer ProtectionWisconsinPest Bulletin (pestbulletin.wi.gov).

Corn leaf aphidCorn leaf aphids are greenish-blue, soft

bodied, and about the size of a pinhead.Their sap sucking stresses plants and inter-feres with ear production. Soil moisturestress reduces the plant’s ability to with-stand attack. Moisture stress and heavy

infestations (tassel and upper leaves plas-tered with aphids) can result in barrenplants.The most critical period for damage is the

late-whorl to pollen-shed stages. If aphidpopulations are high by the time corn hastasseled and pollinated, major damage willalready be done. Because of this, beginscouting fields approximately 2 to 3 weeksbefore tassel emergence. (You will have topull and unroll whorl leaves to do this.)Treatment is suggested if 50% of the plantshave more than 50 aphids per plant andplants are in the late-whorl to early tasselstages.Apply sprays before tassels have com-

pletely emerged but not before the upperwhorl leaves have opened to expose thetassels.Remember that the presence of predators

and adequate soil moisture can influencetreatment decisions. However, we are oftenfaced with long summer dry spells duringthe tassel emergence period.

Corn rootwormNorthern and western corn rootworms

overwinter in the egg stage in the soil. Lar-vae usually can be found feeding on devel-oping corn roots by mid-June, peaking byearly July. After completing three larvalstages, larvae will leave the roots, form anearthen cell, and pupate. The pupae changeinto adults, which make their way out ofthe soil to feed on pollen, silks, and, in thecase of the western corn rootworm, eventender corn foliage. At Arlington, Wiscon-sin, first adults normally begin to appear inmid-July. Because of the prolonged egghatch, all stages (larvae, pupae, and adults)can be found in July and August. Most ofthe eggs will be laid from mid- to lateAugust.The potential for damage and need for a

rootworm control strategy in fields of cornthat follow corn are based on the number ofbeetles present in fields during the summer.If beetle numbers averaged 0.75 or moreper plant during late July and August, or iflodging or “goosenecking” due to larvalfeeding were noted during that period, theuse of a corn rootworm control tactic (soilinsecticide, seed treatment, or Bt corn root-worm hybrid) is recommended if corn isplanted again in the field the followingyear. Consult Extension publication Corn

PRINCIPLESO

FPEST

MNGM

T.CO

RNinsects

SOYBEAN

FORAGES

&PASTURES

APPENDIXSM

ALLGRAINS

PERENNIALW

EEDSSTO

REDGRAIN

INSECTS

60


Rootworms (A3328) for information aboutscouting corn fields for rootworm beetlesand about predicting the need for root-worm control.

Rootworm control by crop rotation. Wherecropping systems allow and where the vari-ant western corn rootworm is not estab-lished, crop rotation is an excellent methodof controlling corn rootworm. Larvae willperish soon after hatching if a crop otherthan corn is planted.Late-planted corn fields are attractive to

rootworm beetles. The corn’s green silksand pollen can attract large numbers ofbeetles from surrounding, more maturefields and result in massive numbers ofeggs being deposited in the soil. Since soilinsecticides will not control all of the root-worm larvae, an unacceptable amount ofroot feeding could still occur in fields withheavy egg populations. In these cases, croprotation is a better alternative when possible.Resistance to insecticides is possible

whenever a population of insects is sub-jected continually to selection pressurefrom one insecticide class. Because of this,we strongly encourage the use of crop rota-tion as a control alternative to insecticideuse for corn rootworm control.

Two-year life cycle of the northern cornrootworm. Corn rootworm beetles lay eggsfrom late July to early September in cornfield soil. These eggs will not hatch untilthe following spring. This is why crop rota-tion is an effective method of controllingcorn rootworms; the larvae will starve if acrop besides corn is planted the followingspring.There are pockets of northern corn root-

worms in some areas of the Corn Beltwhere a large portion of the eggs gothrough two winters before they hatch.Most of the documented cases of this two-year life cycle (or extended diapause) haveoccurred in areas of Minnesota, Illinois, andIowa where they practice extensive annualcorn and soybean rotation. Apparently, thisannual crop rotation pattern has selectedfor northern corn rootworms with theextended diapause trait.So far, we have documented only a few

incidences of this extended northern cornrootworm life cycle in Wisconsin, and,based on this evidence, we believe that use

of a rootworm insecticide on first-year cornis seldom justified under Wisconsin condi-tions.The exception to this guideline for first-

year corn is the presence of the variantwestern corn rootworm affecting corn aftersoybeans in some fields in southeast Wis-consin. Refer to the earlier section on cornafter soybeans for important information(page 58).

Insecticidal control of rootworms. Althougha soil insecticide will not kill all corn root-worms in a field, the level of controlachieved normally is adequate to preventeconomic damage. However, extremelyhigh larval populations, heavy rains,improper calibration, and other factors canresult in poor control.Following are suggestions for using root-

worm insecticides.1. At planting:Apply a granular or liquid

insecticide labeled for rootworm control(e.g., Aztec, Capture LFR, Counter,Force, Lorsban 15G, etc.) as an in-fur-row or banded application at thelabeled rate. Refer to product label forinstructions. Regent is to be appliedusing application equipment providedby the manufacturer.

2. At cultivation: Counter, Force, or Lors-ban granules can be applied at the baseof stalks with a cultivator applicator atlabeled rates and covered lightly withsoil. Note that Counter 15G is limited to8.7 lb/a of product per year. Be awareof the herbicide-use restrictions associ-ated with Counter. For applicationsmade at cultivation, Counter 15G maybe applied 7 days AFTER application ofALS-inhibiting herbicides. Carbofuran(Furadan 4F) and chlorpyrifos (e.g.,Lorsban 4E) are also labeled for applica-tion at cultivation. Apply the treatmentto each side of the row immediatelyahead of the cultivator shovels. Refer tolabels for complete details and productrestrictions. Use extreme caution whenusing liquid formulations.Treatments are most effective whenapplied close to peak egg hatch, usuallybetween May 25 and June 15. Suchapplications should be done no laterthan mid-June; it is suggested only as a“rescue” treatment because dry weatherfollowing application can limit insecti-

PRINCIPLESO

FPEST

MNGM

T.CO

RNinsects

SOYBEAN

FORAGES

&PASTURES

APPENDIXSM

ALLGRAINS

PERENNIALW

EEDSSTO

REDGRAIN

INSECTS

61


cide activation and result in marginalcontrol. Planting time treatments arepreferred.

3. Control of rootworm beetles to preventegg laying: Properly timed insecticideapplications may reduce beetle popula-tions enough to eliminate the need forsoil insecticides the following year toprotect corn roots. Success using thisprogram requires frequent and carefulscouting. Scouts must be able to differ-entiate between the two beetle species(western and northern), determine thesex of the beetles, and tell when thefemales contain eggs (are gravid).Treatments include Penncap-M (methylparathion) and Sevin (carbaryl). Singleapplication treatments for beetle controlare not always sufficient, due to beetlemigration and weather conditions. Aer-ial application is standard in an adultbeetle control program. These insecti-cides are hazardous to honey bees. Donot apply or allow product to drift ontoblooming crops and/or bloomingweeds if bees are foraging the area to betreated. Notify local beekeepers whenusing such programs.

Corn rootworm beetle resistance hasdeveloped to methyl parathion and car-baryl in some areas of the Corn Beltwhere there has been a history of adultrootworm control.Slam and Compel are also available foradult rootworm control. Slam containsSevin (carbaryl) and cucurbitacin, arootworm feeding stimulant. Compelcontains cucurbitacin and a stickingagent; it is combined with a smallamount of insecticide, usually carbaryl,just before application. The strategybehind these “bait” compounds is thatbeetles will feed heavily once theyencounter the cucurbitacin, allowinguse of very low rates of carbaryl.Although Slam and Compel have beenshown to reduce beetle populations,they have provided inconsistent protec-tion of corn roots from feeding by lar-vae the following year.

4. Alternating the use of insecticide activeingredients:Avoid using the same insec-ticide for several consecutive years.There are four classes of soil insecticidesavailable: organophosphate, syntheticpyrethroid, phenyl pyrazole, and carba-mate. Continuous use of the same classof material, uninterrupted by crop rota-

Table 2-8. Soil insecticides labeled for rootworm control at planting

Ounces ofproduct per 40” 38” 36” 30”

Insecticide Class 1,000 ft of row rows rows rows rows

Granular formulations ———lb/a of product———Aztec 2.1G organophosphate 6.7 5.5 5.8 6.1 7.3

+ synthetic pyrethroidAztec 4.67Ga organophosphate 3.0 2.5 2.6 2.7 3.3

+ synthetic pyrethroidCounter 15Gb organophosphate 8 6.5 6.9 7.3 8.7Force 3G synthetic pyrethroid 4 3.3 3.4 3.6 4.4Fortress 2.5G organophosphate 6.0–9.0 4.9–7.4 5.2–7.8 5.5–8.2 6.5–9.8Fortress 5Ga organophosphate 3.0–4.5 2.5–3.7 2.6–3.9 2.8–4.1 3.3–4.9Lorsban 15G organophosphate 8 6.5 6.9 7.3 8.7Liquid formulations ——fluid oz/a of product——Brigade 2EC synthetic pyrethroid 0.30 3.9 4.1 4.4 5.1Capture LFR synthetic pyrethroid 0.49 6.4 6.8 7.1 8.5Force CS synthetic pyrethroid 0.46 6.0 6.3 6.7 8.0

0.57 7.5 7.9 8.3 10.0Regent 4SC phenyl pyrazole 0.24 3.12 3.29 3.47 4.16aAztec 4.67G and Fortress 5G are for use in the SmartBox system only.bALS inhibiting herbicides should not be used if Counter 15G has been applied to corn at the time of planting.

PRINCIPLESO

FPEST

MNGM

T.CO

RNinsects

SOYBEAN

FORAGES

&PASTURES

APPENDIXSM

ALLGRAINS

PERENNIALW

EEDSSTO

REDGRAIN

INSECTS

62


tion or periodic rotation of insecticideclass, can lead to development of insectresistance and loss of product efficacy.

— If the material you used last year per-formed poorly, switch to another insec-ticide class this year, or rotate to a cropother than corn if possible.

— Do not use carbamates during succes-sive years.

— Avoid using the same organophosphateor pyrethroid during several consecu-tive years.

Insecticidal seed treatment for rootwormcontrol. Seed treatment with insecticidesfrom the nicotinoid class of compounds arelabeled for corn rootworm. These com-pounds are systemic, translocated withinthe plant as the seed germinates and theplant grows. This is a selective, early seasonchemical control tactic as the active ingredi-ent is applied directly to the seed and notthe surrounding soil.Cruiser Extreme 1250 (thiamethoxam)

and Poncho 1250 (clothianidin) are labeledat 1.25 mg a.i. per kernel for corn root-worm. Corn seed is treated by commercialseed treaters in conjunction with seed deal-ers before it is bagged and sold. Check withyour seed dealer to obtain corn seed treatedat the high rate labeled for corn rootworm(1.25 mg a.i. per kernel).

Bt corn for corn rootworm control. Trans-genic Bt corn contains a gene from the soilbacterium Bacillus thuringiensis (Bt)enabling the plant to express Bt toxin activeagainst rootworms. For details, see the fol-lowing section on transgenic Bt corn.

CutwormAlthough the glassy cutworm can cause

serious damage, our most common cut-worm pest in corn is the black cutworm.Young cutworms feed upon corn foliage;early detection of this injury allows time totreat before extensive cutting occurs. Forthis reason, monitor fields carefully asplants emerge. Check for signs of leaf feed-ing, cut, wilting, or missing plants. Leaffeeding is due to small cutworms (less than1⁄2 inch long); cutworms do not start to cutplants until they are approximately halfgrown.Treat cutworms when they are still small

and are leaf feeders. It is difficult to set athreshold for treatment because several fac-tors influence this decision (stage of plantgrowth, original plant population, growthstage of cutworms, soil moisture, etc.). Themost important aspect of cutworm controlis careful field scouting as soon as plantsbegin to emerge. Remember that there havebeen instances of cutworms cutting plantsas fast as they emerge.Carefully monitor low wet fields, or low

wet areas within fields, and late-plantedfields where cutworm problems tend to bemost common. Marking off defined areas ofa field makes it easier to evaluate the cut-worm situation. Check these areas every2 to 3 days for at least 2 to 3 weeks aftercorn begins to emerge. Keep records ofplant stand, number of cut plants, andplants with leaf feeding. This helps evalu-ate whether populations are increasing ordecreasing. If you find occasional cutplants, consider corrective measures. Onecutworm is capable of cutting severalplants, and the level of damage can

Table 2-9. Guide to black cutworm development anddamage in corn

Larval Head Approximate Potential number of plantsinstar capsule days left ——that may be cut——(stage) width to feed 1 leaf 2 leaf 4 leaf

4 25 4 3 15 21 4 3 16 14 4 3 17 5 1 1 1

PRINCIPLESO

FPEST

MNGM

T.CO

RNinsects

SOYBEAN

FORAGES

&PASTURES

APPENDIXSM

ALLGRAINS

PERENNIALW

EEDSSTO

REDGRAIN

INSECTS

63


increase dramatically from one day to thenext. Consult table 2-9 for assistance indetermining how long a cutworm will feedand continue to damage corn. For example,a fourth instar (stage) cutworm (larva) willfeed for approximately 25 days and will cutoff four plants, if the plants are in the 1-leafstage.Body length is not always an accurate

indicator of how “old” a cutworm is. Thebest technique is to measure the width ofthe insect’s head capsule. Place the headcapsule (head) of the cutworm between theshaded areas under the Head CapsuleWidth column in table 2-9 and match it toone of the size categories available. Thiswill help you determine the age of the cut-worm and approximately how long it willcontinue to feed on corn.Treatment is suggested when 5% or more

of the plants have been damaged. Broad-cast spray insecticide when the suggestedthreshold is reached (see table 2-11). “Res-cue” treatments can be very effective ifinfestations are found soon enough. How-ever, hot, dry weather can reduce the effec-tiveness of these treatments by causing theblack cutworm to spend more time under-ground, thereby reducing exposure to theinsecticide. Incorporating Lorsban sprayswith shallow cultivation or a rotary hoeduring such weather conditions mayenhance Lorsban’s activity. However, donot incorporate Ambush, Asana, Pounce, orWarrior as this may reduce their cutwormactivity.If widespread cutworm damage necessi-

tates replanting, you may need to use pre-emergence “rescue” treatments. Dependingon cutworm size when corn is replanted,feeding injury could occur before, during,and after seedling emergence. In these situ-ations, treating fields after planting butbefore seedling emergence may beadvisable.Soil insecticides such as Aztec 2.1G,

Brigade 2EC, Force 3G and CS, Fortress,and Lorsban 15G are labeled for applicationat planting time for cutworm control. Theseproducts should be applied the same as forrootworm control (refer to table 2-8). Cur-rent research suggests that some of theseproducts are relatively effective in control-ling light to moderate infestations whenapplied at planting. However, data forheavy infestations are limited, and reports

of unacceptable levels of damage fromheavy infestations have occurred. Becauseof these factors and the difficulty of predict-ing cutworm outbreaks, the “preventiveapproach” to black cutworm control is notsuggested. Field scouting and applying baitor sprays is more reliable.Lorsban 4E also is labeled for cutworm

control at 2 pt/a (1 lb ai/a) as a broadcastspray.

European corn borerThe European corn borer has two genera-

tions per year in most of Wisconsin. Borersoverwinter as 5th instar larvae in corn-stalks, crib corn, and large-stemmed weeds.Moths emerge to begin warm-night egglaying on undersides of leaves about mid-June (in the extreme south of the state).Eggs hatch into very small, black-headed,whitish, smooth larvae (borers) that crawlinto the whorl. Early planted corn is mostapt to be infested. Late-planted corn usu-ally avoids first-generation borers but isattractive to the second generation. “Early”borer leaf feeding shows as irregular pin-hole damage in leaves growing out of thewhorl. “Recent” leaf feeding can be founddown in the whorl and is evidence of liveborers. Once corn reaches 18 inchesextended leaf height, examine 10 consecu-tive plants in 10 areas of the field for leaffeeding. Pull the whorl leaves from twoinfested plants in each area and unroll theleaves to look for corn borer larvae. Calcu-late the percentage of plants with recentleaf feeding (“plants infested”) and theaverage number of European corn borerlarvae per infested plant. Consult the man-agement worksheet for first-generationcorn borer (see box) to determine whethertreatment is necessary.The best time to control first-generation

corn borers is during a 5-day period ofaccumulated 800 to 1,100 modified growingdegree days (above 50°F average). Inextreme southern Wisconsin this fallsaround July 1 to 4.Second-generation European corn borer

egg laying occurs over a long period oftime and infestations can go unnoticeduntil ears begin to drop and stalks begin tobreak in the fall. Due to the extended egg-laying period, one sampling of a field is notsufficient. Scout fields weekly looking forwhite egg masses on the undersides of

PRINCIPLESO

FPEST

MNGM

T.CO

RNinsects

SOYBEAN

FORAGES

&PASTURES

APPENDIXSM

ALLGRAINS

PERENNIALW

EEDSSTO

REDGRAIN

INSECTS

64


leaves near the midrib. Most of the eggswill be laid on leaves near the ear andabove. Use the management worksheet forsecond-generation corn borers to determinewhether treatment will be economicallyworthwhile. If possible, treat when tinyblack dots are apparent on most of the eggmasses. At this “black-head” stage, the eggsare almost ready to hatch.Most borers are killed when corn is cut

for silage or shredded for fodder if stubbleis under 2 inches. Dry-stalk shredding maykill 80% of the borers. Plowing under cropstubble and shredding stalks in the fall to

destroy overwintering larve will reducecorn borer populations. However, mold-board plowing is often unacceptablebecause of the potential for soil erosion.

Bt corn for European corn borer control.Transgenic Bt corn contains a gene from thesoil bacterium Bacillus thuringiensis (Bt)enabling the plant to express Bt toxin activeagainst European corn borers. For details,see the following section on transgenic Btcorn.

Management worksheet forSECOND-GENERATION European corn borer

_____ number of egg masses/planta x 2 borers/egg massb

= _____ borers/plant_____ borers/plant x 4% loss/borerc = _____ % yield loss_____ % yield loss x _____ expected yield = _____ bu/a loss_____ bu/a loss x $_______ price/bu = $________ loss/a$_______ loss/a x 75% control = $_______ preventable loss/a$_______ preventable loss/a – $________ cost of control/a

= $_______ gain (+) or loss (–) per acre if treatment is appliedaUse cumulative counts, taken 7 days apartbAssumes survival rate of 2 borers/egg masscUse 3% loss/borer if infestation occurs after silks are brown. The potentialeconomic benefits of treatment decline rapidly if infestations occur aftercorn reaches the blister stage.

Management worksheet forFIRST-GENERATION European corn borer

_____ % of 100 plants infested x _____ ave. # borers/infested planta

= _____ borers/plant_____ borers/plant x 5% yield loss/borer = _____ % yield loss_____ % yield loss x _____ expected yield (bu/a) = _____ bu/a loss_____ bu/a loss x $_______ price/bu = $_______ loss/a$________ loss/a x _____ % controlb = $_______ preventable loss/a$________ preventable loss/a – $________ cost of control/a

= $________ gain (+) or loss (–) per acre if treatment is appliedaDetermined by checking whorls from 10 plantsbAssume 80% control for most products; assume 50% control for Asana,Furadan, and Lorsban sprays.

PRINCIPLESO

FPEST

MNGM

T.CO

RNinsects

SOYBEAN

FORAGES

&PASTURES

APPENDIXSM

ALLGRAINS

PERENNIALW

EEDSSTO

REDGRAIN

INSECTS

65


SlugsSlugs have soft slimy bodies and range in

color from light gray to dark brown. Theyskeletonize leaf tissue with their rasp-likemouths. Cool, damp weather and high cropresidue cover can lead to severe outbreaks.Commercially prepared baits containingmetaldehyde are fairly effective againstmoderately heavy infestations. However,prolonged favorable weather conditions willlead to a resurgence of slug populations.

Stalk borerStalk borer moths predominately lay their

eggs on grass weeds during late summerand fall. In addition, giant ragweed is oneof the few broadleaf plants to serve as apreferred egg-laying host. Larvae will hatchfrom these hosts in the spring and movequickly to corn. The first indication of dam-age is a series of small “pin-hole” feedingsites running across the leaves of V1 corn.As the larvae grow, the feeding holes willincrease in size and the larvae will tunnelinto the plant. This stem boring can be seenin the wilting of the central leaves of theseedling. When this type of injury is wide-spread it is too late to apply an insecticide.Stalk borers tunnel only in the above-ground portions of the stem, whereas cut-worms, hop vine borer, and potato stemborer feed in the underground portion ofthe stem.Damage will often be heavy in the four to

eight rows that are near fencerows, grassterraces, and waterways. In these cases thelarvae are migrating from adjacent vegeta-tion. Patches of injury throughout the fieldindicate significant levels of host weeds

that escaped the weed control program forthe previous year. The best insect manage-ment tactic is to modify your weed controlprogram using a different herbicide, croprotation, or increased mechanical cultivation.Small corn is most susceptible to injury;

once plants reach the V7 stage (seven col-lars) it is unlikely that they will be killed bystalk borers. Research suggests scoutingborder rows when 1,300 to 1,400 degreedays have occurred. Iowa State Universitystudies indicate that 10% of the larvae willhave moved into corn from adjacentbromegrass, quackgrass, ragweed, andother host weeds, when 1,400 degree dayshave accumulated and 50% will havemigrated by 1,700 degree days. Larvae willstart to move when they have outgrown thegrass stems in which they have been feed-ing. However, damage from larvae origi-nating within the field (from last year’sweed patches) will start earlier becausecorn is the only food source. You shouldmap these spots during fall harvest so thatyou can check them the following year,starting at about 900-1,000 degree days.Treatment thresholds for stalk borer can befound in table 2-10. Planting Bt hybrids willnot protect the field from stalk borer damage.The current Bt transgenic hybrids are not effec-tive against stalk borer, hop vine borer, or potatostem borer.

Two-spotted spider mite“Spider” mites are relatives of insects and

are so small that 10X or greater magnifica-tion is required for them to be seen dis-tinctly. They damage plants by piercing thecells and sucking sap. Small chloroticlesions on the leaf surface are the first indi-cations of damage. As mite populationsbuild and damage progresses, the webbingproduced by the mites will become appar-ent, and leaves may die. Plant death is pos-sible if populations are heavy.Mites are not a problem in Wisconsin

unless dry weather persists. Infestationsnormally start at field edges where miteshave migrated from adjacent weeds, alfalfa,or other vegetation. Control is suggested ifyou find active mite colonies on one-thirdof the leaves on 50% of the plants, or if 15 to20% of the leaf area is covered with mitesor their damage.

Table 2-10. Economic thresholds forstalk borer at three corn pricesa

—— Corn prices ($/bu) ——Leaf stage $2.00 $3.00 $4.00

——% infested corn ——1 10 7 52 12 8 63 15 10 74 16 11 85 17 12 96 34 23 177 100 100 100

aBased on $13.00/acre control costs and 80% controlwith insecticides (source: Iowa State University)

PRINCIPLESO

FPEST

MNGM

T.CO

RNinsects

SOYBEAN

FORAGES

&PASTURES

APPENDIXSM

ALLGRAINS

PERENNIALW

EEDSSTO

REDGRAIN

INSECTS

66


PRINCIPLESO

FPEST

MNGM

T.CO

RNinsects

SOYBEAN

FORAGES

&PASTURES

APPENDIXSM

ALLGRAINS

PERENNIALW

EEDSSTO

REDGRAIN

INSECTS

67Insecticides applied for mite control willnot kill eggs and you will have to samplethe field 4 to 5 days after the initial sprayand look for mite adults and nymphs. Asecond application may be necessary.Mites are usually on the undersides of

plant leaves, making treatment difficult. Byair, apply no less than 4 to 5 gallons of fin-ished spray per acre. During periods ofextreme heat, try to make applications latein the day to reduce the amount of insecti-cide lost by volatilization.

Western bean cutwormWestern bean cutworm (WBCW) is native

to North America and has traditionallyinfested crops in the western Corn Beltstates. Since 2000, this pest has expandedits range eastward and has been detectedconsistently in Wisconsin since 2005. Dam-age in Wisconsin has been sporadic, withlow to moderate levels of damage.Adult WBCW are brown colored moths

3⁄4-inch long with an extended wingspan of11⁄ 2 inches. There are three distinctivemarkings on each forewing: a white wingbar along the front leading edge, one circu-lar spot approximately in the center, andanother boomerang-shaped spot towardthe tip of the forewing.Moths lay white egg masses on the upper

surface of corn leaves. These egg massescontain 5 to 200 tightly clustered eggs. Asthey develop, the eggs change color fromcreamy white to tan. They remain tan for2 to 5 days, then turn a deep purple 12 to24 hours before the larvae emerge.Young larvae are dark brown, with a

black head. Full-grown larvae are 1½-incheslong, cream to tan in color with two broadbrown stripes on the pronotum (“neck”area behind the head). They have no mark-ings or warts on their body.WBCW has one generation per year and

overwinters as a full-grown larva inside asoil chamber. Spring development beginswhen temperatures exceed 50°F. Larvaepupate in May and moths begin to emergein late June. Peak emergence in the upperMidwest is typically between the secondand third weeks of July.The female moth is most attracted to corn

just before tasseling and lays eggs on theupper leaf surface of the top-most leaf onthe plant. If the tassel has not yet emergedwhen eggs hatch, larvae crawl into the

whorl and feed on pollen. As the tasselemerges, larvae switch to feeding on greensilks and enter the developing ear throughsilk channels or chew directly through thehusk to feed anywhere on the ear. Multiplelarvae may be found feeding on one ear.Pheromone traps or degree-days can be

used to monitor adult emergence, egg-laying, and larval hatch in the field. Fordetails, consult midsummer issues of theUW-Extension Wisconsin Crop Managernewsletter (ipcm.wisc.edu/wcm) or theWisconsin DATCPWisconsin Pest Bulletin(pestbulletin.wi.gov).Once WBCW degree-day accumulations

indicate 25% moth emergence, or when thefirst moths are detected in a pheromonetrap in your area, examine 20 consecutivecorn plants at five locations in the field toobtain a representative field sample. Checkthe upper three to four leaves of each plantfor egg masses and small larvae. Scoutfields that are tasseling first.Foliar insecticides effectively suppress

larval populations, but only if appliedbefore larvae enter the ear to feed. Once lar-vae have tunneled into the ear, they’re pro-tected from foliar insecticides.For field corn, insecticide treatment

should be considered when 8% of the100 plants sampled have egg massesand/or small larvae; for processing sweetcorn the threshold is lowered to 4% infesta-tion. Application timing is critical. In fieldsthat have reached or exceeded economicthreshold, if eggs have hatched, the insecti-cide should be applied after 95% tasselemergence, but before larvae enter the silks.If egg hatch has not yet occurred and plantshave tasseled, time insecticide applicationas close to expected egg hatch as possible,when egg masses have reached the darkpurple color stage.Transgenic corn is another option for

managing WBCW in field corn, but onlyhybrids containing the Bt protein Cry1Foffer protection against this insect. Onevery farm where a Bt corn hybrid isplanted, a 20% insect resistance manage-ment (IRM) non-Bt corn refuge must beplanted. This non-Bt corn refuge is requiredby law, through the U.S. EnvironmentalProtection Agency, as a condition of regis-tration and market availability of Bt corntechnology. For details, see the followingsection on transgenic Bt corn.


PRINCIPLESO

FPEST

MNGM

T.CO

RNinsects

SOYBEAN

FORAGES

&PASTURES

APPENDIXSM

ALLGRAINS

PERENNIALW

EEDSSTO

REDGRAIN

INSECTS

68 BT SPRAYS AND TRANSGENICBT CORN FOR INSECT CONTROL

Bacillus thuringiensis (Bt)The soil bacterium Bacillus thuringiensis

(Bt) occurs naturally worldwide. Sporesproduced by the bacterium contain a pro-tein which, when ingested by a susceptibleinsect, ruptures the insect’s midgut mem-brane, prevents further feeding, and killsthe insect. There are many different strainsof the Bt bacterium, each with specificitytoward different groups of insects.Bt has been commercially available as a

microbial foliar insecticide for lepidopteralarvae such as European corn borer fordecades. Bt spray formulations are appliedto leaves and other areas where the insect

larvae feed. Bt sprays have a relativelyshort residual in the field, thus a well-timedsingle application or, more typically, multi-ple applications based on pest insect scout-ing and target pest life stage are necessaryto maintain control.Microbial Bt sprays DiPel, Biobit, and

Javelin are approved by the Organic Mate-rials Review Institute (OMRI) for use inUSDA certified organic production. Refer toproduct labels for lepidoptera species con-trolled. Bt sprays are safe for beneficialinsects such as parasitic wasps that attackEuropean corn borer eggs, and predatorssuch as lady beetles that feed on other pestinsect eggs, immatures and/or adults.

Transgenic Bt cornTransgenic Bt corn hybrids are genetically

modified organisms (GMOs) in which cornhas had a gene inserted from an unrelatedorganism, in this case Bt. The introducedgene produces a Bt protein toxin withinsecticidal activity against a particular tar-get insect group. Plants with this trait arecommonly referred to as Bt crops.Unlike Bt microbial spray formulations,

which have a field residual measured indays, the Bt toxin in transgenic Bt corn isactive for the life of the plant. This can leadto more consistent and economic insectcontrol when target insect populationsreach economic threshold levels.However, there is a significant risk that

with constant exposure of the target insectpopulation to Bt toxins, resistant popula-tions may develop. To help protect againstthis, the U.S. Environmental ProtectionAgency (US EPA) has mandated limits tothe percentage of Bt corn that can be grownon each farm. Up to 80% of corn acres maybe planted to Bt corn with at least 20%planted to a corn refuge that does not con-tain a Bt trait for the pest group targeted inthe main planting. (See the shaded box fordetails about refuge planting patterns andtypes of corn that can be planted). This cre-ates a refuge of susceptible target insectsthat are not exposed to the Bt toxin foundin Bt corn. As susceptible insects from therefuge mate with resistant insects thatcould potentially emerge from the Bt corn,susceptibility to the Bt toxin is passed on totheir offspring.

Planting pattern options for20% non-Bt corn refuge areas

For all Bt hybrids (corn borer, corn rootworm, stacked insect traits):

— Plant a block of non-Bt corn directly next to the Bt cornfields.

— Plant a block of non-Bt corn within the Bt corn fields.— Split planter strips of non-Bt corn that are at least four

rows wide within the Bt corn fields.— Plant field edges and end rows to a non-Bt corn refuge

(must meet the 20% refuge requirement).For corn borer hybrids only:

— Plant non-Bt corn borer corn refuge area up to 1⁄’2 mile awayfrom the Bt corn borer field (1⁄4 mile or less preferred).

What can you plant in the refuge areas?If you’ve planted Bt corn hybrid with lepidoptera protection,

the refuge area must be planted with a hybrid that does notcontain a Bt trait for control of any of the “caterpillar” pests.For example, conventional, herbicide-resistant, or Bt root-worm corn may be planted in the refuge; but one type of Btlepidoptera corn (e.g., YieldGard Corn Borer) cannot serve as arefuge for another group such as Herculex I or Agrisure CB/LL.For fields planted to Bt corn rootworm corn, the refuge area

may be planted to conventional, herbicide-resistant, or cornborer resistant corn.For stacked insect trait hybrids, only non-Bt corn (conven-

tional or herbicide-resistant) may be planted using a single,common refuge within or directly next to Bt corn fields. Grow-ers may also plant separate refuges for corn rootworm andcorn borers. For information on separate refuge options,please consult the appropriate product use guide and contactyour county Extension agent.


Bt corn for corn borer control. Transgeniccorn hybrids with activity against Euro-pean corn borer have been commerciallyavailable since 1996. Some hybrids haveactivity against a few other lepidopterancorn pests as well. For example, YieldGardCB and Agrisure CB/LL corn control firstand second generation European corn boreras well as southwestern corn borer andsuppress corn earworm. Herculex I cornprovides protection from first and secondgeneration European corn borer, southwest-ern corn borer, fall armyworm, black cut-worm, and western bean cutworm, andsuppresses corn earworm.It is important to understand the Euro-

pean corn borer’s biology when determin-ing planting strategies. In Wisconsin, all butthe northern tier of counties has two gener-ations of European corn borer. In May andJune, first-generation moths are attracted tothe tallest plants where they lay eggs; typi-cally, these are the earliest planted fields.Second-generation moths are attracted tofields that are pollinating; usually these arethe later planted full-season hybrids. Totake advantage of the behavioral differ-ences between these generations, the rec-ommended planting strategies differaccording to the anticipated length of theplanting period.

Short planting period If all of the corncan be planted within a week, plant theBt corn (and corresponding refugeareas) first and then the non-Bt hybrids.Many growers will try to plant theirmost productive fields first; the cornwill often grow more quickly in suchfields and they will be taller when thespring moths start to fly. This shouldattract the moths and concentrate egglaying in the Bt corn fields, where thelarvae will die.Longer planting period If planting isgoing to take well over a week, considerplanting 80 to 90% of the Bt corn (andcorresponding refuge areas) first, fol-lowed by the non-Bt corn, and then fin-ish with the remaining 10 to 20% of theBt corn (and corresponding refuge areas).

Bt corn for corn rootworm control. Bt root-worm corn hybrids (Agrisure RW,Herculex RW, and YieldGard RW) controlwestern, northern and Mexican corn root-worm species during the larval feeding

period. These hybrids are sold pre-treatedwith a low-rate nicotinoid insecticidal seedtreatment for secondary soil insect pests.

Bt corn for corn borer and corn rootwormcontrol (stacked insect traits). Bt cornhybrids with stacked insect traits, such asAgrisure CB/LL/RW, Herculex XTRA, andYieldGard Plus, control both corn borersand corn rootworms. Stacked trait cornhybrids target all of the pests listed on therespective Bt corn borer and Bt rootwormlabels for each product brand. Hybridswith stacked insect traits are available withor without one or more herbicide-resistanttraits and are sold pre-treated with a low-rate nicotinoid seed treatment for sec-ondary soil insect pest control.

Refuge requirements. Insect resistancemanagement (IRM) requirements for Btcorn specify that up to 80% of corn acres oneach farm may be planted to Bt corn; how-ever, a minimum of 20% of the corn acresmust include a refuge area of non-Bt corn.Seed mixtures of Bt corn and refuge cornare not permitted. The sidebar outlinesapproved planting patterns and types ofcorn that can be planted in refuges.

Summary. Effective refuge hybrids shouldhave a relative maturity that is compatiblewith the Bt corn. Plant the refuge at thesame time as the Bt corn and plant it in anarea with the same crop rotation history.Refuge corn may be treated with an

insecticide other than Bt. The non-Bt root-worm refuge may be treated with soil-applied or seed-applied insecticides labeledfor corn rootworm at planting. The non-Btcorn borer refuge may be treated with con-ventional insecticides only if target pestpressure reaches economic thresholds. Itwill not be practical to spray the non-Btcorn in a strip configuration within a field.When selecting corn varieties, keep in

mind that Bt insect protection is only one ofmany factors that should go into the deci-sion. Data from the University of WisconsinDepartment of Agronomy corn hybridyield trials can help you choose the besthybrid for your location. This informationis updated annually and is availablethrough your county Extension office.

69

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNinsects

PRINCIPLESO

FPEST

MNGM

T.


STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNinsects

PRINCIPLESO

FPEST

MNGM

T.

Table 2-11. Insecticide suggestions for corn pestsa

Amount ofInsect Insecticideb product/acre Placement Remarks, precautions

Armyworm Treatment is suggested if worms are 3⁄4 inch long or less, and two or more worms per plant can be found on 25% ofthe stand; or if one worm per plant can be found on 75% of the stand.Ambush 2E 6.4–12.8 oz broadcast Do not apply within 30 days of harvest.Asana XL 5.8–9.6 oz broadcast Do not apply within 21 days of harvest.Baythroid XL 1.6–2.8 oz broadcast Preharvest interval for grain and fodder is

21 days. Do not exceed 11.2 oz/a per season.Brigade 2EC 2.1–6.4 oz broadcast Do not apply within 30 days of harvest. Do not

exceed 0.3 lb ai/a per season, including pre andppi, at plant, and foliar applications. Do notgraze livestock in treated areas or cut treatedcrops for feed within 30 days of last application.

Cobalt 13.0–26.0 oz broadcast Do not apply within 14 days of harvest forsilage or 21 days for grain. Do not exceed 126oz/a per season.

Delta Gold 1.5EC 1.5–1.9 oz broadcast Do not apply within 21 days of harvest of fieldcorn for grain or fodder, or within 12 days ofcutting or grazing field corn for forage. Do notexceed 8.1 oz/a (0.095 lb ai/a) per season.

Hero 4.0–10.3 oz broadcast Do not apply within 30 days of harvest forgrain stover or 60 days for forage. Do notexceed 0.4 lb ai/a per season.

LorsbanAdvanced 1.0–2.0 pt broadcast Do not exceed 2 pt/a per application or 6 pt/aper season. Do not apply within 14 days ofharvest for silage or 21 days for grain.

Mustang Max 3.2–4.0 oz broadcast Do not exceed 0.1 lb ai/a per season. Do notapply within 30 days of harvest for grain orwithin 60 days for forage.

Penncap-M 2.0–3.0 pt broadcast Do not apply within 12 days of harvesting, cut-ting or grazing. Do not apply during pollenshed if bees are foraging in the areas to betreated.

Pounce 3.2EC 4.0–8.0 oz broadcast Do not apply within 30 days of harvest forgrain or fodder. Do not exceed 0.6 lb ai/a perseason.

Proaxis 2.56–3.84 oz broadcast For control of first and second instars only. Donot exceed 0.06 lb ai (0.96 pt)/a per season. Donot apply within 21 days of harvest.

Sevin XLR Plus 1.0–2.0 qt broadcast Do not apply within 48 days of harvest of grainor fodder, or within 14 days of harvest or graz-ing of forage or silage.

Tracer 2.0–3.0 fl oz broadcast Do not apply more than 6 fl oz (0.188 lbspinosad) per acre per year. Do not applywithin 28 days of grain or fodder harvest orwithin 7 days of harvest for forage.

Warrior II, 1.28–1.92 oz broadcast Do not apply within 21 days of harvest. Do notSilencer 1EC 2.56–3.84 oz exceed 0.12 lb ai/a per season; 0.06 lb ai/a after

silk initiation; or 0.03 lb ai/a after corn hasreached the milk stage. Use high rates of War-rior for larger larvae; Silencer controls first andsecond instars only.

70

(continued)


71

aThis is intended as a guide for corn planted in 30-inch rows. Some insecticides are produced (continued)by different manufacturers; follow label directions for use, rates, method of application, etc.bMultiple trade names listed within a row indicate products with the same active ingredient(s).

PRINCIPLESO

FPEST

MNGM

T.CO

RNinsects

SOYBEAN

FORAGES

&PASTURES

APPENDIXSM

ALLGRAINS

PERENNIALW

EEDSSTO

REDGRAIN

INSECTS

Billbug Cobalt 38.0–42.0 oz broadcast Do not apply within 14 days of harvest forsilage or 21 days for grain. Do not exceed 126oz/a per season.

Counter 15G 8.0 oz per 7-inch band or Do not exceed 8.7 lb/a per year. When applied1000 ft row in furrow in band, incorporate evenly into top inch of soil.

Cruiser Extreme 1250 seed treatment Purchase treated seed from seed dealer or seedtreatment representative. (1.25 mg ai per kernel)

Force CS 0.46–0.57 fl oz 7-inch T-band Suppression only.per 1000 ft row

LorsbanAdvanced 2.0 pt broadcast Do not exceed 2 pt/a per application or 6 pt/aper season. Do not apply within 14 days ofharvest for silage or 21 days for grain.

Poncho 1250 seed treatment Reduces early season feeding damage.Purchase treated seed from seed dealer or seedtreatment representative. (1.25 mg ai per kernel)

Regent 4SC 0.24 oz per broadcast in-furrow Do not apply more than 0.13 lb ai/a (4.2 fl oz/a).1000 ft row

Corn earworm Control occasionally required in hybrid seed production fields. Treat before brown silk stage.Ambush 2E 6.4–12.8 oz broadcast Do not apply within 30 days of harvest.Asana XL 5.8–9.6 oz broadcast Do not apply within 21 days of harvest.Baythroid XL 1.6–2.8 oz broadcast Preharvest interval for grain and fodder is



Cobalt 19.0–38.0 oz broadcast Make direct application to silks for best results.Do not apply within 14 days of harvest forsilage or 21 days for grain. Do not exceed 126oz/a per season.

Delta Gold 1.5EC 1.5–1.9 oz broadcast Do not apply within 21 days of harvest of fieldcorn for grain or fodder, or within 12 days ofcutting or grazing field corn for forage. Do notexceed 8.1 oz/a (0.095 lb ai/a) per season.

Hero 4.0–10.3 oz broadcast Do not apply within 30 days of harvest forgrain stover or 60 days for forage. Do notexceed 0.4 lb ai/ a per season.


Mustang Max 1.76–4.0 oz broadcast For control before larvae bore into the plantstalk or ear. Do not exceed 0.1 lb ai/a per sea-son. Do not apply within 30 days of harvest forgrain or within 60 days of harvest for forage.


Table 2-11. Insecticide suggestions for corn pestsa (continued)



72

Proaxis 1.92–3.20 oz broadcast For control before larvae bore into the plantstalk or ear. Do not apply within 21 days of har-vest. Do not exceed 0.06 lb ai (0.96 pt)/a perseason; 0.03 lb ai (0.48 pt) after silk initiation; or0.015 lb ai (0.24 pt) after milk stage.


silk initiation; or 0.03 lb ai/a after corn hasreached the milk stage.

Corn leaf aphid Treat if 50% of the plants have more than 50 aphids per plant and plants are in the late whorl to early tassel stages.Asana XL 5.8–9.6 oz broadcast Do not apply within 21 days of harvest.Brigade 2EC 2.1–6.4 oz broadcast Do not apply within 30 days of harvest. Do not



Delta Gold 1.5EC 1.5–1.9 oz broadcast Suppression only. Do not apply within 21 daysof harvest for grain or fodder, or within 12 daysof cutting or grazing field corn for forage. Donot exceed 8.1 oz/a (0.095 lb ai/a) per season.


Lannate LV 0.75–1.50 pt broadcast Do not apply within 3 days of harvest for for-age. Do not apply within 21 days of harvest forears or fodder.

Lannate SP 0.25–0.50 lb broadcast Do not apply within 3 days of harvest for for-age. Do not apply within 21 days of harvest forears or fodder.


Penncap-M 2.0–3.0 pt broadcast Do not apply within 12 days of harvesting, cut-ting or grazing. Do not apply during pollenshed if bees are foraging in the areas to betreated.

Corn rootworm Aztec 2.1G 6.7 oz per 7-inch band, Amaximum of 7.3 lb/a may be appliedlarvae 1000 ft row T-band, or in furrow per season. For applications made within 20

yards of aquatic sites, apply in-furrow only.Aztec 4.67G 3.0 oz per 7-inch band, Must be applied with the SmartBox system.

1000 ft row T-band, or in furrow Amaximum of 3.27 lb/a may be applied perseason.

Brigade 2EC 0.3 fl oz per 5- to 7-inch T-band Do not apply within 30 days of harvest. Do not1000 ft row apply more than 0.10 lb ai/acre at planting.

Capture LFR 6.8–8.5 oz 5- to 7-inch T-band Do not exceed 0.1 lb ai/a at planting oror 0.39–0.49 oz or in furrow 0.3 lb ai/a per season including at-plant plusper 1000 ft row foliar applications of other bifenthrin products

(e.g., Brigade 2EC).



(continued)

PRINCIPLESO

FPEST

MNGM

T.CO

RNinsects

SOYBEAN

FORAGES

&PASTURES

APPENDIXSM

ALLGRAINS

PERENNIALW

EEDSSTO

REDGRAIN

INSECTS

Corn earworm(cont.)


Brigade 2EC 0.3 oz per 5- to 7-inch T-band Do not apply within 30 days of harvest. Do not1000 ft row exceed 0.10 lb ai/a at planting.

Counter 15G 8.0 oz per 7-inch band or Do not exceed 8.7 lb/a. When applied in a band,1000 ft row seed furrow incorporate evenly into top inch of soil.

Cruiser Extreme 1250 seed treatment To provide corn rootworm protection in light tomoderate infestations. Consult your seeddealer and/or seed treatment representative toobtain treated seed at the 1.25 mg ai/kernelrate for corn rootworm larvae.

Force 3G 4.0–5.0 oz per 7-inch band, T-band, Do not rotate to other crops within 30 days1000 ft row or in furrow after application.

Force CS 0.46–0.57 fl oz 7-inch T-band or T-band applications must be incorporated.per 1000 ft row in furrow

Fortress 2.5G 7.5–9.0 oz per T-band or in furrow Do not make more than 1 application per year.1000 ft row

Fortress 5G 3.0–4.5 oz per T-band or in furrow Must be applied with the SmartBox system.1000 ft row

Furadan 4F 2.5 oz per 7-inch band or1000 ft row seed furrow

Lorsban 15G 8.0 oz per 7-inch band, T-band, Do not exceed the equivalent of 16 oz of1000 ft row or in furrow Lorsban 15G/1,000 ft of row per season.

Poncho 1250 seed treatment For use by commercial seed treaters only. Con-sult your seed dealer and/or seed treatmentrepresentative to obtain seed treated at the 1.25mg ai/kernel rate for corn rootworm larvae.

Regent 4SC 0.24 oz per in-furrow Do not apply more than 0.13 lb ai/a (4.2 fl oz/a).1000 ft row

Corn rootworm Treat before 75% of the plants have silked if you find at least five beetles per plant and silk clipping is observed.beetle For pollination protection only.

Ambush 2E 6.4–12.8 oz broadcast Do not apply within 30 days of harvest.Asana XL 5.8–9.6 oz broadcast Do not apply within 21 days of harvest.Baythroid XL 1.6–2.8 oz broadcast Preharvest interval for grain and fodder is




Delta Gold 1.5EC 1.5–1.9 oz broadcast Do not apply within 21 days of harvest forgrain or fodder, or within 12 days of cutting orgrazing field corn for forage. Do not exceed 8.1oz/a (0.095 lb ai/a) per season.





73

PRINCIPLESO

FPEST

MNGM

T.CO

RNinsects

SOYBEAN

FORAGES

&PASTURES

APPENDIXSM

ALLGRAINS

PERENNIALW

EEDSSTO

REDGRAIN

INSECTS

Corn rootwormlarvae (cont.)



Mustang Max 2.72–4.0 oz broadcast Do not exceed 0.1 lb ai/a per season. Do notapply within 30 days of harvest for grain orwithin 60 days of harvest for forage.

Penncap-M 1.0–2.0 pt broadcast Do not apply within 12 days of harvesting, cut-ting, or grazing. Do not apply during pollenshed if bees are foraging in the areas to betreated.


Proaxis 2.56–3.84 oz broadcast Do not apply within 21 days of harvest. Do notexceed 0.06 lb ai (0.96 pt)/a per season; 0.03 lbai (0.48 pt) after silk initiation; or 0.015 lb ai(0.24 pt) after milk stage.

Sevin XLR Plus 1.0–2.0 qt broadcast Do not apply within 48 days of harvest of grainand fodder, or within 14 days of harvest orgrazing of forage or silage.



Cutworm Treat when 5% of the plants show cutting activity.Ambush 2E 6.4–12.8 oz broadcast Do not apply within 30 days of harvest.Asana XL 5.8–9.6 oz broadcast Do not apply within 21 days of harvest.Baythroid XL 0.8–1.6 oz broadcast Preharvest interval for grain and fodder is




Delta Gold 1.5EC 1.0–1.5 oz broadcast Do not apply within 21 days of harvest orwithin 12 days of cutting or grazing for forage.Do not exceed 8.1 oz/a per season.

Cruiser Extreme 250 seed treatment Cutworm suppression. Purchase treated seedfrom seed dealer or seed treatment representa-tive. (0.125–0.80 mg ai/a per kernel)

Force CS 0.34–0.46 fl oz 7-inch T-band This is the rate if cutworm is the only pest. If cornper 1000 ft row rootworm is also targeted, use corn rootworm

rate. Must be incorporated (see label).Hero 2.6–6.1 oz broadcast Do not apply within 30 days of harvest for

grain stover or 60 days for forage. Do notexceed 0.4 lb ai/ a per season.

LorsbanAdvanced 1.0–2.0 pt broadcast Do not exceed 2 pt/a per application or 6 pt/aper season. Do not apply within 14 days of har-vest for silage or 21 days for grain.



(continued)

PRINCIPLESO

FPEST

MNGM

T.CO

RNinsects

SOYBEAN

FORAGES

&PASTURES

APPENDIXSM

ALLGRAINS

PERENNIALW

EEDSSTO

REDGRAIN

INSECTS

74

Corn rootwormbeetle (cont.)



Penncap-M 4.0 pt broadcast For best control of black cutworm, apply whensoil is moist. Do not apply or allow product todrift onto blooming crops or weeds if bees areforaging area to be treated. Do not harvest, cutfor forage, or graze within 12 days of applica-tion. Do not exceed 12 pt/a per year.

Poncho 250 seed treatment Early season protection. Purchase treated seedfrom seed dealer or seed treatment representa-tive. (0.25 mg ai per kernel)





European See management worksheet in European corn borer description. Application must be made before larvae bore into plant.corn borer Ambush 2E 6.4–12.8 oz broadcast Do not apply within 30 days of harvest.

Asana XL 9.6 oz broadcast Do not apply within 21 days of harvest.Bacillus see label see label No waiting period to harvest. Apply whilethuringiensis— larvae are small.BioBit, Dipel, JavelinBaythroid XL 1.6–2.8 oz broadcast Preharvest interval for grain and fodder is



Cobalt 26.0–38.0 oz broadcast For chemigation applications, may use 19–38oz/ a. Do not apply within 14 days of harvestfor silage or 21 days for grain. Do not exceed126 oz/a per season.

Delta Gold 1.5EC 1.5–1.9 oz broadcast Do not apply within 21 days of harvest orwithin 12 days of cutting or grazing for forage.Do not exceed 8.1 oz/a (0.095 lb ai/a) per season.

Hero 4.0–10.3 oz broadcast Do not apply within 30 days of harvest forgrain stover or 60 days for forage. Do not applymore than 0.4 lb ai/ a per season.

Lorsban 15G 5.0–6.5 lb broadcast Do not apply within 35 days of harvest. Do notexceed 13.0 lb/a of Lorsban 15G per season forfoliar insect control.




75

PRINCIPLESO

FPEST

MNGM

T.CO

RNinsects

SOYBEAN

FORAGES

&PASTURES

APPENDIXSM

ALLGRAINS

PERENNIALW

EEDSSTO

REDGRAIN

INSECTS

Cutworm (cont.)


76



Penncap-M 2.0–4.0 pt broadcast Do not apply within 12 days of harvesting, cut-ting or grazing. Do not apply if bees areactively foraging near the area to be treated.


Proaxis 2.56–3.84 oz broadcast For control before larvae bore into the stalk orear. Do not apply within 21 days of harvest. Donot exceed 0.06 lb ai (0.96 pt)/a per season; 0.03lb ai (0.48 pt) after silk initiation; or 0.015 lb ai(0.24 pt) after milk stage.

Tracer 1.0–3.0 fl oz broadcast Do not apply more than 6 fl oz (0.188 lb spin-osad) per acre per year. Do not apply within 28days of grain or fodder harvest or within 7days of harvest for forage.



Grasshopper Asana XL 5.8–9.6 oz broadcast Do not apply within 21 days of harvest.Baythroid XL 2.1–2.8 oz broadcast Preharvest interval for grain and fodder is





dimethoate see label see labelFuradan 4F 1.0 pt broadcast Do not apply within 30 days of harvest.Hero 2.6–6.1 oz broadcast Do not apply within 30 days of harvest for

grain stover or 60 days for forage. Do not applymore than 0.4 lb ai/ a per season.


Mustang Max 2.72–4.0 oz broadcast Do not exceed 0.1 lb ai/a per season. Do notapply within 30 days of harvest for grain orwithin 60 days of harvest for silage.

Penncap-M 2.0–3.0 pt broadcast Do not apply during pollen shed if bees are vis-iting the area to be treated. Do not apply within12 days of harvesting, cutting, or grazing.



(continued)

PRINCIPLESO

FPEST

MNGM

T.CO

RNinsects

SOYBEAN

FORAGES

&PASTURES

APPENDIXSM

ALLGRAINS

PERENNIALW

EEDSSTO

REDGRAIN

INSECTS

European cornborer (cont.)


Proaxis 2.56–3.84 oz broadcast Do not apply within 21 days of harvest. Do notexceed 0.06 lb ai (0.96 pt)/a per season; 0.03 lbai (0.48 pt)/a after silk initiation; or 0.015 lb ai(0.24 pt)/a after milk stage.

Sevin XLR Plus 1.0–3.0 pt broadcast Do not apply within 48 days of harvest forgrain or fodder, or within 14 days of harvest orgrazing of forage or silage.

Warrior II, 1.28–1.92 oz broadcast Do not apply within 21 days of harvest. Do notSilencer 1EC 2.56–3.84 fl oz exceed 0.12 lb ai/a per season; 0.06 lb ai/a after


Hop vine borer Treatments are most effective if applied when damage is detected in seedling-stage corn. Hop vine borer attacks theplant below the soil surface.Cobalt 19.0–38.0 oz broadcast Do not apply within 14 days of harvest for

silage or 21 days for grain. Do not exceed 126oz/a per season.


Mustang Max 2.72–4.0 oz broadcast Do not exceed 0.10 lb ai/a per season. Do notapply within 30 days of harvest for grain orwithin 60 days of harvest for silage.

Pounce 3.2EC 4.0–8.0 oz broadcast Do not apply within 30 days of harvest forgrain. Do not exceed 0.6 lb ai/a per season.



Seedcorn beetle, Aztec 2.1G 6.7 oz per 7-inch band or Amaximum of 7.3 lb/a may be appliedseedcorn maggot 1000 ft row seed furrow per season. For applications made within

20 yards of aquatic sites, apply in-furrow only.Aztec 4.67G 3.0 oz per T-band or Must be applied with a SmartBox system. Do

1000 ft row in furrow not exceed 3.27 lb/a per season.Brigade 2EC 0.15–0.30 fl oz 5- to 7-inch T-band Do not apply within 30 days of harvest. Do not

per 1000 ft row apply more than 0.10 lb ai/acre at planting.Capture LFR 0.20–0.39 fl oz 5- to 7-inch T-band Do not exceed 0.1 lb ai/a at planting or

per 1000 ft row or in furrow 0.3 lb ai/a per season including at-plant plusfoliar applications of other bifenthrin products(e.g., Brigade 2EC).

Cobalt 2.87 fl oz per 5- to 6-inch T-band Do not apply more than 126 oz/season.1000 ft row

Counter 15G 8.0 oz per 7-inch band or Do not exceed 8.7 lb/a. When applied in a band,1000 ft row seed furrow incorporate evenly into top inch of soil.

Cruiser Extreme 250 seed treatment Treat at 0.125–0.80 mg ai per kernel.Force 3G 4.0–5.0 oz per 7-inch band or Do not rotate to other crops within 30 days

1000 ft row seed furrow after application.Force CS 0.46–0.57 fl oz T-band or in furrow T-band applications must be incorporated (see

per 1000 ft row label).




77

PRINCIPLESO

FPEST

MNGM

T.CO

RNinsects

SOYBEAN

FORAGES

&PASTURES

APPENDIXSM

ALLGRAINS

PERENNIALW

EEDSSTO

REDGRAIN

INSECTS

Grasshopper(cont.)


78

Fortress 2.5G 6.0–7.5 oz in furrow Do not make more than 1 application per year.per 1000 ft row Labeled for seedcorn maggot, not the beetle.

Fortress 5G 3.0–3.75 oz in furrow Must be applied with a SmartBox system.per 1000 ft row Labeled for seedcorn maggot, not the beetle.

Kernel Guard see label planter-box Contains permethrin as the active ingredientSupreme seed treatment (not lindane).Lorsban 15G 8.0 oz per seed furrow or Do not exceed the equivalent of 16 oz of

1000 ft row 7-inch band product/1,000 ft of row per season.Poncho 250 seed treatment Early season protection. Purchase treated seed

from seed dealer or seed treatment representa-tive. (0.25 mg ai per kernel)

Regent 4SC 3.0–4.2 oz/a in-furrow Do not apply more than 0.13 lb ai/a (4.2 fl oz/a).(0.17–0.24 ozper 1000 ft row

Slug metaldehyde bait see label broadcastStalk borer Treatments most effective if applied while larvae are still small and wilting of seedlings is just beginning.

Ambush 2E 6.4–12.8 oz broadcast Do not apply within 30 days of harvest.Asana XL 5.8–9.6 oz broadcast Do not apply within 21 days of harvest.Baythroid XL 1.6–2.8 oz broadcast Preharvest interval for grain and fodder is






LorsbanAdvanced 2.0 pt broadcast Do not exceed 2 pt/a per application or 6 pt/aper season. Do not apply within 14 days ofharvest for silage or 21 days for grain.




Warrior II, 1.28–1.92 oz over row as spray Do not apply within 21 days of harvest. Do notSilencer 1EC 2.56–3.84 oz exceed 0.12 lb ai/a per season; 0.06 lb ai/a after




(continued)

PRINCIPLESO

FPEST

MNGM

T.CO

RNinsects

SOYBEAN

FORAGES

&PASTURES

APPENDIXSM

ALLGRAINS

PERENNIALW

EEDSSTO

REDGRAIN

INSECTS

Seedcorn beetle,seedcorn maggot(cont.)


Two-spotted Brigade 2EC 5.12–6.4 oz broadcast Do not apply within 30 days of harvest. Do notspider mite exceed 0.3 lb ai/a per season, including pre and

ppi, at plant, and foliar applications. Do notgraze livestock in treated areas or cut treatedcrops for feed within 30 days of last application.

dimethoate see label see labelHero 10.3 oz broadcast Do not apply within 30 days of harvest for

grain stover or 60 days for forage. Do not applymore than 0.4 lb ai/ a per season.

Western bean Ambush 2E 6.4–12.8 oz broadcast Do not apply more than 0.6 lb ai/a per season.cutworm Do not apply within 30 days of harvest of grain

or fodder (stover).Asana XL 2.9–5.8 oz broadcast Apply before larvae enter the ear. Do not

exceed 0.25 lb ai/a per season or apply within21 days of harvest.

Baythroid XL 1.6–2.8 oz broadcast Do not apply within 21 days of harvest forgrain and fodder. Do not exceed 11.2 fl oz/aper season (0.088 lb ai/a per season).

Brigade 2EC 2.1–6.4 oz broadcast Do not apply more than 0.3 lb ai/a per season.Do not apply within 30 days of harvest.

Colbalt 13.0–26.0 oz broadcast Do not exceed 126 oz/a per season. Do notapply within 14 days of harvest for silage orwithin 21 days for grain.

Delta Gold 1.5 EC 1.0–1.5 oz broadcast Do not apply within 21 day of harvest of fieldcorn for grain or fodder, or within 12 days ofcutting or grazing field corn for forage. Do notexceed 8.1 oz/a (0.095 lb ai/a) per season.

Hero 2.6–6.1 oz broadcast Do not apply more than 0.4 lb ai/a per season.Do not apply within 30 days of harvest forgrain and stover or within 60 days for forage.


Mustang Max 1.76–4.0 oz broadcast For control before the larva bores into the plantstalk or ear. Do not exceed 0.10 lb ai/a per sea-son including at-plant plus foliar applications.Do not apply within 30 days of harvest forgrain and stover or within 60 days for forage.

Penncap-M 2.0–4.0 pt broadcast Do not apply during pollen shed if bees are for-aging in the areas to be treated. Do not exceed12 pt/a per year. Do not harvest, cut for forage,or graze within 12 days of application.

Pounce 3.2 EC 2.0–4.0 oz broadcast Up to 0.6 lb ai/a may be used per season.Allow at least 6 days between treatments. Donot apply within 30 days before harvest ofgrain or fodder.



PRINCIPLESO

FPEST

MNGM

T.CO

RNinsects

SOYBEAN

FORAGES

&PASTURES

APPENDIXSM

ALLGRAINS

PERENNIALW

EEDSSTO

REDGRAIN

INSECTS


79


Proaxis 1.92–3.2 oz broadcast For control before the larva bores into the plantstalk or ear. Do not apply within 21 days of har-vest. Do not exceed 0.12 lb ai/a per season. Donot apply more than 0.06 lb ai/a after silk initi-ation, or 0.03 lb ai/a after corn has reached themilk stage.

Sevin XLR Plus 2.0 qt broadcast Treat at economic threshold and at 90–100%tassel emergence. Treatment after 100% silkemergence will reduce effectiveness. Do notapply within 48 days of harvest for grain orfodder or within 14 days of harvest or grazingfor forage or silage. Do not exceed 8 qt/a percrop.

Warrior II, 0.96–1.6 oz broadcast For control before the larva bores into the plantSilencer 1EC 1.92–3.2 oz stalk or ear. Do not apply within 21 day of har-

vest. Do not exceed 0.12 lb ai/a per season. Donot apply more than 0.06 lb ai/a after silk initi-ation, or 0.03 lb ai/a after corn has reached themilk stage.

White grub Aztec 2.1G 6.7 oz per 7-inch band or Amaximum of 7.3 lb/a may be applied1000 ft row seed furrow per season. For applications made within





Cobalt 2.87 fl oz per 5- to 6-inch T-band Do not exceed 126 oz/a per season.1000 ft row

Counter 15G 8.0 oz per seed furrow or Do not exceed 8.7 lb/a. Incorporate evenly into1000 ft row 7-inch band top inch of soil if applied in a band.

Cruiser Extreme 250 seed treatment Early season seed and seedling protection.Purchase treated seed from seed dealer or seedtreatment representative. (0.125–0.80 mg ai perkernel)

Force 3G 4.0–5.0 oz per 7-inch band or Do not rotate to other crops within 30 days1000 ft row seed furrow after application.

Force CS 0.46–0.57 fl oz T-band or in furrow Use the higher rate for heavy infestations. Forper 1000 ft row best wireworm and/or white grub control,

apply as an in-furrow treatment.Fortress 2.5G 6.0–7.5 oz in furrow Do not make more than 1 application per year.

per 1000 ft rowFortress 5G 3.0–3.75 oz in furrow Must be applied with a SmartBox system.

per 1000 ft rowGaucho seed treatment Early season seed and seedling protection. Pur-

chase treated seed from seed dealer or seedtreatment representative. (1.34 mg ai per kernel)

Lorsban 15G 8.0–12.0 oz per seed furrow Do not exceed the equivalent of 16 oz of1000 ft row product/1,000 ft of row per season.

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNinsects

PRINCIPLESO

FPEST

MNGM

T.



80(continued)

Western beancutworm (cont.)


Poncho 250 seed treatment Early season protection. Purchase treated seedfrom seed dealer or seed treatment representa-tive. (0.25 mg ai per kernel)

Regent 4SC 0.24 oz per in-furrow Do not apply more than 0.13 lb ai/a (4.2 fl oz/a).1000 ft row

Wireworm Aztec 2.1G 6.7 oz per 7-inch band or Amaximum of 7.3 lb/a may be applied1000 ft row seed furrow per season. For applications made within





Cobalt 2.87 fl oz per 5- to 6-inch T-band Do not exceed 126 oz/a per season.1000 ft row

Counter 15G 8.0 oz per seed furrow or Do not exceed 8.7 lb/a. Incorporate evenly into1000 ft row 7-inch band top inch of soil if applied in a band.

Cruiser Extreme 250 seed treatment Early season seed and seedling protection. Pur-chase treated seed from seed dealer or seedtreatment representative. (0.125–0.80 mg ai perkernel)

Force 3G 4.0–5.0 oz per 7-inch band or Do not rotate to other crops within 30 days1000 ft row seed furrow after application.

Force CS 0.46–0.57 fl oz T-band or in furrow Use the higher rate for heavy infestations. Forper 1000 ft row best wireworm and/or white grub control,

apply as an in-furrow treatment.Fortress 2.5G 6.0–7.5 oz in furrow Do not make more than 1 application per year.

per 1000 ft rowFortress 5G 3.0–3.75 oz in furrow Must be applied with a SmartBox system.

per 1000 ft rowGaucho seed treatment Early season seed and seedling protection. Pur-

chase treated seed from seed dealer or seedtreatment representative. (1.34 mg ai per kernel)

Kernel Guard see label planter-box Contains permethrin, not lindane, as the activeSupreme seed treatment ingredient.Lorsban 15G 16.0 oz per 7-inch band or Do not exceed the equivalent of 16 oz of

1000 ft row seed furrow product/1,000 ft of row per season.Poncho 250 seed treatment Early season protection. Purchase treated seed

from seed dealer or seed treatment representa-tive. (0.25 mg ai per kernel)

Regent 4SC 3.0–4.2 oz/a in-furrow Do not apply more than 0.13 lb ai/a (4.2 fl oz/a).(0.17–0.24 ozper 1000 ft row

aThis is intended as a guide for corn planted in 30-inch rows. Some insecticides are produced by different manufacturers;follow label directions for use, rates, method of application, etc.bMultiple trade names listed within a row indicate products with the same active ingredient(s).

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNinsects

PRINCIPLESO

FPEST

MNGM

T.



81

White grub(cont.)


82

PRINCIPLESO

FPEST

MNGM

T.CO

RNdiseases

SOYBEAN

FORAGES

&PASTURES

APPENDIXSM

ALLGRAINS

PERENNIALW

EEDSSTO

REDGRAIN

INSECTS

82

Corn diseases, like those of other crops,vary in severity from year to year and fromone locality or field to another. There aremany factors that influence disease devel-opment—including environmental condi-tions, the resistance of the corn hybrid, andthe population density of the diseaseorganisms that are present. Thus, it isimportant for growers to distinguish whenpoor crop development is due to diseasesand when insect, nutrient deficiencies, soilconditions, herbicide injury, or weatherconditions are the problem.

DISEASE MANAGEMENTSTRATEGIESCorn diseases can be managed by plant-

ing resistant or tolerant corn hybrids, rotat-ing crops, using appropriate cultural prac-tices, and applying pesticides. Although asingle control procedure can be effective, asound disease control program integratesall these crop management techniques.

Resistant hybridsSelecting corn hybrids that are resistant

or tolerant to major corn diseases can be aneffective and economical method of diseasecontrol. Your seed dealer should be a goodsource of information on specific hybridreaction to disease. Terms describinghybrid reaction to disease are somewhatconfusing. “Disease-resistant hybrids”should be regarded only as a general termthat suggests resistance to specific diseases;it cannot be an all-inclusive statement, sinceno hybrid is resistant to all corn diseases.Also, hybrids are not described as beingresistant/tolerant to a specific disease.Rather, leaf health, seedling cold tolerance,root size, and stalk strength are character-ized, but each relate to reactions to plantpathogens.

Many hybrids have good resistance toeyespot, Gibberella ear rot, northern cornleaf blight (NCLB), northern leaf spot(NLS), rust, smut, and stalk rot. If you havehad a history of problems with one or moreof these diseases, ask about hybrid reac-tions to these specific diseases.Resistance does not mean immunity—

complete freedom from infection or diseasedevelopment. A resistant hybrid shouldwithstand damage but may show some dis-ease development when conditions favorthe disease but not suffer much yieldreduction. In other words, there is a grada-tion among hybrids ranging from suscepti-ble to resistant to highly resistant to dis-ease. Changes in cultural practices, newforms (races) of known pathogens, and newpathogens can result in disease in hybridsthat were thought resistant.Learn to identify the major diseases of

corn and evaluate disease reactions of thehybrids you grow. Disease reactions of vari-ous hybrids can differ with each farm orlocality because of different local weatherconditions, tillage operations, soil type, andsoil fertility.

Crop rotation andtillage practicesCrop rotation and clean tillage are effec-

tive disease control procedures. In manycases, the fungi that cause corn diseasesoverwinter in stalks, leaves, and roots.Once this corn debris is thoroughlydecayed, many corn pathogens perish orare greatly reduced in numbers. Therefore,crop rotation and tillage programs thatallow residue decay in a given field beforethe next corn crop is grown will helpreduce diseases, especially leaf andseedling diseases.We support the concept of no-till or mini-

mum tillage for crop production because ofits soil-conserving potential. However,

CORN DISEASE MANAGEMENT


PRINCIPLESO

FPEST

MNGM

T.CO

RNdiseases

SOYBEAN

FORAGES

&PASTURES

APPENDIXSM

ALLGRAINS

PERENNIALW

EEDSSTO

REDGRAIN

INSECTS

83growers using no-till or minimum tillageshould be alert for an increase in crop pestproblems; the potential is greater for dis-ease problems with reduced tillage thanwith conventional tillage systems. The riskof increased corn disease problems is evenhigher when reduced tillage is associatedwith continuous corn, planting of suscepti-ble hybrids, and climatic conditions favor-able for disease development. Corn hybridsthat perform well in conventional tillagesystems may decline in performance ifgrown in no-till systems.Minimum tillage can affect root rot and

stalk rot development in at least two ways:first, the associated pathogens become con-centrated in the upper root zone (with con-ventional plowing they are distributed andthus diluted to a greater depth in the soil),and second, potassium may be less avail-able to plants under a reduced tillage situa-tion. You may need to supplement potas-sium to prevent N:K imbalance and subse-quent stalk-rot problems.Certain diseases are more prevalent if

debris from the previous year’s corn crop isleft on the surface during wet seasons.Northern leaf spot, eyespot, and Gibberellaear rot are examples.If you are considering continuous

reduced tillage or no-till corn production,we suggest the following steps to minimizecorn diseases:1. Select corn hybrids with resistance or

tolerance to major leaf diseases.2. Select hybrids tolerant to stalk and ear

rot.3. Consider chopping stalks in the fall.

Many organisms do not survive as wellwhen the debris is close to the soil.

4. Examine fields periodically during thegrowing season to spot any sign of dis-ease development. Early harvest canminimize losses.

5. Consider crop rotation to help curb thebuildup of corn pathogens that may bedeveloping.

6. Select corn hybrids rated superior forseedling cold tolerance.

7. Consider planting corn seed treatedwith metalaxyl or mefenoxam.

Seed protectantsChemicals registered for protecting corn

seed against seedling rot include captan,fludioxonil (Maxim), mefenoxam (Apron),pentachloronitrobenzene (PCNB), metalaxyl,and mancozeb. (Check the labels to be surechemicals include corn seed treatment), butother fungicides can be applied in theplanter box. Treatment is especially benefi-cial when seed vigor is low and duringcold, wet spring weather. Virtually all cornseed on the market today is already treatedwith a fungicide. Many hybrid seed corncompanies have changed from Captan toMaxim or Maxim-Apron. Some companiestake specific requests so you can tailor seedtreatments to field conditions. For example,the use of trifloxystrobin (Trilex) in additionto the Maxim-Apron combination offersgood protections if planting in cool, wetsoils with a high risk of Pythium seed rot.

Leaf disease controlwith fungicidesFoliar fungicides (table 2-12) can effec-

tively reduce severity of northern corn leafblight, northern leaf spot, eyespot, gray leafspot, and rust. It is rarely economical forcommercial corn producers to use fungi-cides for leaf disease control. However,seed corn producers must control these dis-eases because inbreds can be very suscepti-ble to them.Should any of these leaf diseases threaten

during the period between tasseling anddent (about 35 days), treatment may be eco-nomical. Early detection is critical; monitorfields of susceptible hybrids/inbredsweekly.Check the label for specific limitations on

the amount of product that can be used peracre per season, the preharvest interval,growth stage limitations, and feedingrestrictions. Chlorothalonil (Bravo formula-tions) is registered for Helminthosporiumleaf blights (northern corn leaf blight,northern leaf spot, southern leaf blight) andrust on fresh market sweet corn and corngrown for seed. Bravo is not labeled for useon processing sweet corn. Corn treatedwith Bravo cannot be fed to livestock,ensiled, or used as livestock forage. Labelinstructions must be followed carefully foreffective use.


84

PRINCIPLESO

FPEST

MNGM

T.CO

RNdiseases

SOYBEAN

FORAGES

&PASTURES

APPENDIXSM

ALLGRAINS

PERENNIALW

EEDSSTO

REDGRAIN

INSECTS

Table 2-12. Fungicides labeled for leaf diseases of field corn (hybrid seed production and grain)

Active Chemical FRAC Amount ofTrade name ingredient family codea product/acre Remarks

Bravo Weather Stik chlorothalonil chloronitriles M5 0.75–2.0 pt Common rust, Helminthosporium leaf blight:(seed protection only) For use only on corn grown for seed. For

advanced disease problems, use 1.5–2.0 pt/a.Do not exceed 12 pt/a (9 lb ai/a) per season.Do not apply within 14 days of harvest.

Bumper 41.8 EC propiconazole triazole 3 2–4 fl oz Helminthosporium leaf blight:Apply 2–4 floz/a when disease first appears and continueon a 7- to 14-day schedule.Rusts:Apply 4 fl oz/a when rust pustules firstappear and continue on a 7- to 14-day schedule.Gray leaf spot, eye spot: Apply 4 fl oz/a whendisease first appears. If conditions favorable fordisease persist, repeat at 14-day intervals.—Do not apply Bumper to field corn or to fieldcorn grown for seed after silking. Do not applymore than 16 fl oz/a per season. Do not harvestfor forage within 30 days of application.

Dithane DF Rainshield dithiocarbamate mancozeb M3 1.5 lb Common rust, Helminthosporium leaf blight:DithaneF-45Rainshield 1.2 qt Treat when symptoms first appear. DependingDithaneM45 1.5 lb on disease severity, repeat applications on a 4-

to 14-day schedule. Adding Latron CS-7 willimprove performance. Do not apply within40 days of harvest. See label for seasonal ratelimitations.

Headline pyraclostrobin methoxy- 11 see remarks Common rust, gray leaf spot: Apply 6–9 fl oz/a.carbamate Anthracnose, northern corn leaf blight,

northern corn leaf spot:Apply 9–12 fl oz/a.—Do not apply within 7 days of harvest. Donot exceed 72 fl oz/a or two applications perseason. If applying Headline sequentially, alter-nate to a labeled fungicide that is not Group 11.

Manzate ProStick dithiocarbamate mancozeb M3 1.5 lb Common rust, gray leaf spot, HelminthosporiumManzate Flowable 1.2 qt leaf blight. Treat when symptoms first appear,

repeat at 4- to 7-day intervals. Use sufficientwater for thorough coverage. Do not exceed15 lb or 12 qt/a per season. Do not feed treatedforage to livestock. Do not apply within 40days of harvest.

Penncozeb 75DF dithiocarbamate mancozeb M3 1.0–1.5 lb Common rust, gray leaf spot, HelminthosporiumPenncozeb 80WP 1.0–1.5 lb leaf blight. Treat when symptoms first appearPenncozeb 4FL 0.8–1.2 lb and repeat as needed. Do not apply within 40

days of harvest. See label for limitations onamount that can be applied per season.

PropiMax EC propiconazole triazole 3 see remarks Common rust. Apply 4 fl oz/a when rust pus-tules first appear. Repeat at 7- to 14-day intervals.Gray leaf spot, eye spot. Apply 4 fl oz/awhen disease first appears. If conditions favor-able for disease persist, repeat at 14-day intervals.Helminthosporium leaf blight.Apply 2–4 floz/a when disease first appears. Repeat at 7- to14-day intervals.—Apply by ground or aerial application orthrough irrigation equipment. Do not apply aftersilking. Do not exceed 16 fl oz/a per season. Donot harvest within 30 days of application.


PRINCIPLESO

FPEST

MNGM

T.CO

RNdiseases

SOYBEAN

FORAGES

&PASTURES

APPENDIXSM

ALLGRAINS

PERENNIALW

EEDSSTO

REDGRAIN

INSECTS

Table 2-12. Fungicides labeled for leaf diseases of field corn (hybrid seed production and grain)

Active Chemical FRAC Amount ofTrade name ingredient family codea product/acre Remarks

Quadris azoxystrobin methoxyacrylate 11 see remarks Gray leaf spot.Apply 9.0–15.5 fl oz/a at dis-ease onset. A second application may berequired if favorable conditions persist.Common rust, northern corn leaf blight, andnorthern corn leaf spot.Apply 6.0–9.0 fl oz/afor rust and 9.0–15.5 fl oz/a for the other dis-eases. Treatment should begin before symp-toms appear and continue throughout the sea-son every 7–14 days. Do not make more thantwo consecutive applications of Quadris orother Group 11 fungicides before alternatingwith a fungicide with a different mode ofaction. Do not exceed two applications per yearof Quadris or other Group 11 fungicides.—Do not apply more than 2 lb ai/a per seasonof azoxystrobin-containing products. Do notapply within 7 days of harvest.

Quilt azoxystrobin methoxyacrylate 3,11 7–14 fl oz Northern corn leaf blight, northern corn leaf+ propiconazole + triazole spot, rusts, gray leaf spot, eye spot.Apply

when disease first appears. Continue on a 7- to14-day schedule. Use the low rate when diseasepressure is low. Apply the high rate underheavy disease pressure or when conditions arefavorable for disease development. Do notmake more than two applications per year ofQuilt or any other Group 11 fungicide per year.

Stratego propiconazole triazole 3,11 see remarks Common rust.Apply 7–10 fl oz/a.+ trifloxystrobin +oximinoacetate Eye spot, gray leaf spot, Helminthosporium

leaf blight.Apply 10–12 fl oz/a.—Treat when corn is between V4 (4-leaf) andsilking—do not apply after silking. Applywhen disease first appears and continue on a 7-to 14-day interval if favorable conditions fordisease persist. Use the higher application rateand shorter spray intervals when disease pres-sure is severe. Do not exceed 24 fl oz/a percrop. Do not make more than 2 sequentialapplications of Stratego. Do not make morethan 3 applications of Stratego or other strobil-uron fungicide per crop. Do not graze or har-vest for forage within 30 days of application.

Tilt propiconazole triazole 3 see remarks Common rust. Apply 4 fl oz/a when rust pus-tules first appear and continue on a 7- to 14-dayschedule.Gray leaf spot and eye spot. Apply 4 fl oz/awhen disease first appears. If conditions favor-able for disease persist, repeat on a 14-dayschedule.Helminthosporium leaf blight. Apply 2–4 floz/a when disease first appears and continueon a 7- to 14-day schedule.—Do not apply after silking. Do not exceed 8 floz/a per season on field corn to be harvestedfor forage; for all other uses, the limit is 16 floz/a per season. Do not apply within 30 daysof harvest for forage, grain, or stover.

aFungicide group numbers indicate the modes of action; multiple applications of fungicideswith the same group number increases the chances for disease resistance. 85


PRINCIPLESO

FPEST

MNGM

T.CO

RNdiseases

SOYBEAN

FORAGES

&PASTURES

APPENDIXSM

ALLGRAINS

PERENNIALW

EEDSSTO

REDGRAIN

INSECTS

86 Consider the following factors beforedeciding to apply a foliar fungicide:1. The susceptibility of the inbred/hybrid

to the disease or diseases that threaten it.2. The anticipated time of disease devel-

opment and severity. Severe leaf diseasedevelopment usually occurs post-tassel.Consequently, wet weather or contin-ued heavy dews signal possible blightproblems on fields already showingmodest leaf spotting. If the blightalready has invaded much of the leafsurface above the ear, the treatmentbenefits will be minimal.

3. Treatment cost versus expected benefit.Each treatment costs about $20 to $30/afor the chemical, wetting agent, andapplication.

DISEASE PROBLEMS

Seed rot andseedling blightsFungicide seed protectants generally con-

trol or minimize seed rot and seedlingblights of corn. However, seed rot andseedling blight can be expected if corn isplanted in wet and cool soils. Hybrids thathave good seedling vigor are generally lesssusceptible to seed rot and seedling blights.Watch for reduced stands and stunted ordying seedlings. Often infected seedlingsmay develop into a mature plant, but thesame disease organisms can cause root rotand stalk rot later on. Because injury fromherbicides, insecticides, starter fertilizer,and soil insects can cause similar symp-toms and results, accurate diagnosis isimportant.

Leaf diseasesLeaf diseases vary in prevalence and

severity from year to year and from onelocality to another, depending largely onenvironmental conditions. Humid weatheralong with heavy dew favors the spreadand development of leaf diseases caused byfungi. Leaf diseases can be found on corngrown in poor and rich soils; soil fertilitydoes not seem to affect these diseases asmuch as weather conditions, the geneticmakeup of a hybrid, and tillage practices.More leaf disease can be expected when no-till or minimum tillage in continuous corn

fields is employed. Growers using over-head irrigation should be more watchfulfor leaf disease development. Leaf diseasesare found especially in fields located in val-leys and in lowland areas along streamsand rivers. These field locations can haveprolonged periods of high relative humid-ity and low or moderate temperatures thatfavor most leaf diseases of corn. If it is nec-essary for you to plant hybrids susceptibleto leaf diseases, only plant them in uplandfields with good air drainage, where corndebris from the previous crop has beenthoroughly covered by plowing or wherecorn does not follow corn in the rotation.

Northern corn leaf blight (NCLB) occursstatewide, but it has historically been moresevere in low-lying fields.Many hybrids have some tolerance to

northern corn blight. In addition to a multi-ple gene resistance which imparts fair togood resistance in some hybrids, the singledominant “Ht1” gene has been introducedinto many hybrids to provide an apparenthigh degree of resistance. The addition ofthis gene within one parent of a hybridcross can change a susceptible hybrid to aresistant form, while leaving the generalagronomic characteristics of the hybridunaffected. If your seed dealer indicatesthat a formerly NCLB-susceptible hybrid isnow resistant, this may be the reason. Somehybrids may contain both forms of geneticresistance. NCLB resistance is desirablethroughout the state.A strain of the NCLB fungus is common

in the Midwest and will infect hybrids orinbreds with the “Ht1” gene. Wisconsincorn growers should be watchful for theoccurrence of NCLB in hybrids rated asresistant. In addition an “HtN” gene isbeing incorporated in some hybrids to con-trol this new race.Northern corn leaf blight is not affected

by tillage or crop rotation.Northern leaf spot (NLS) can be a problem

for some corn hybrids. A new strain of thefungus that causes northern leaf spot, Bipo-laris zeicola, has appeared recently. Thispathovar causes considerable damage tocertain corn inbreds produced in the uppermidwest. Inbreds with B73 backgroundappear to be most susceptible. This is apopular inbred for the region. Hybridsfrom affected crosses show limited foliagesymptoms with no apparent effect in


yields. Thus, this pathovar is primarily aproblem for the seed corn industry. Twosets of symptoms have occurred in Wiscon-sin—one affecting foliage, the other affect-ing root and crown of young plants.Lesions, or leaf spots, develop first on thelower leaves. Given warm, wet conditions,the lesions move rapidly upward. Symp-toms are variable depending in part uponthe cultivar affected. Most often the lesionsare elliptical, or football shaped, 1⁄8 to1⁄2 inch long, and have dark margins andlight tan centers. There may be some yel-lowing, or chlorosis, surrounding the spots.On other inbreds, the spots have appearedquite narrow and linear, at least initially.The seedling blight phase of NLS has

been prevalent in susceptible inbreds insome fields. Plants just emerging to 15inches tall collapsed after showing suddenwilting—symptoms similar to cutworminjury. Root and crown examinationrevealed extensive dark brown internal andexternal discoloration beginning in thecrown area of the plant.Crop rotation is not a highly effective

control measure, and chemical controlshave proven inconsistent to date. If tryingfungicides, watch for symptoms on foliageespecially after tasseling. Begin treatment iflesions are present and if weather is warmand wet. Continue applications every 7days during favorable weather up until 10days before harvest. Seed treatments do notprotect seedlings from the root and crownphase of the disease.

Eyespot can be severe when unusuallycool, wet weather prevails, when corn isinfrequently rotated, and when corn isgrown under no-till or minimum tillage.Early-maturing hybrids appear to be moresusceptible than full-season hybrids. Eye-spot is most prevalent in western Wiscon-sin. Eyespot can directly reduce grainyields; severe eyespot may predisposeplants to stalk rot and ear rot because ofearly death and dryness.

Common rust occurs each year but gener-ally develops too late in the season to causeyield losses. The rust fungus does not over-winter in Wisconsin but is carried by windsfrom the southern states. This factor, alongwith its sensitivity to weather conditions,makes it a difficult disease to predict. Thefungus produces oval or elongated cinna-mon-brown blisters (pustules) scattered on

both surfaces of the leaves. As the cornmatures, the pustules become black. Rustcan prematurely kill corn leaves if the dis-ease develops early in the season and wetweather prevails. Most corn hybrids areconsidered resistant or tolerant.

Gray leaf spot (GLS) is common in south-ern Wisconsin and is becoming moresevere. GLS is more severe if corn isplanted continuously and if corn residue isleft on the soil surface. Corn hybrids differin reaction to GLS.

Corn smut can be recognized by the graygalls that form on all plant parts. When thegalls mature, they break open—exposingthe black powdery spores of the fungus.Galls that form on the ears and on the stalkabove the ear can reduce yield. Mosthybrids have good resistance to smut, butthis resistance can be altered by hot, dryweather, mechanical injury, hail, and herbi-cide injury. Excessive application of nitro-gen or manure may result in more smutthan normal. Smutty corn is not harmful iffed to livestock.

Stewart’s bacterial wilt has appeared insouthern Wisconsin and its incidence andseverity is higher than normal becausewarmer than normal winters are allowingsurvival of the corn flea beetle. Stewart’swilt is caused by a bacterium that is trans-mitted by the corn flea beetle. The severityof Stewart’s bacterial wilt is directly relatedto beetle population levels.There are two phases of the disease. One

phase affects young plants that are infectedby corn flea beetles that survive the winter.Usually infected seedlings rapidly wilt anddie. The second and more common phase isa leaf blight that is most apparent after tas-seling. Lesions on leaves are gray to greento yellow green and develop as streaks longthe veins. Symptoms of Stewart’s bacterialwilt may be confused with symptoms asso-ciated with northern corn leaf blight causedby a fungus. The use of resistant cornhybrids is the most economical control.

Stalk rotStalk rot causes substantial losses each

year through early plant kill or preharveststalk lodging. It causes premature death ofsome plants, fermenting or rotting stalks,and a discolored pith that weakens thestalk. Stalk rot is caused by a complex offungal organisms that are particularly dam-

PRINCIPLESO

FPEST

MNGM

T.CO

RNdiseases

SOYBEAN

FORAGES

&PASTURES

APPENDIXSM

ALLGRAINS

PERENNIALW

EEDSSTO

REDGRAIN

INSECTS

87


aging to plants subjected to stress duringthe growing season. High soil moisture inAugust appears to favor root infection ofPythium spp. This fungal infection leads toearly plant death and subsequent stalk rot.Small ears and lodging often are the resultof the early plant kill phase of the stalk rotdisease.Complete control of stalk rot is difficult,

but you can take several steps to reduce theproblem:1. Select hybrids that perform best under

your system of farming.2. Maintain a high level of potassium in

accordance with soil test recommenda-tions.

3. Control blight diseases, which causeearly leaf kill and increase the suscepti-bility to stalk rot.

4. Grow full-season corn hybrids wherepossible; early-maturing hybrids gener-ally suffer more from stalk rot.

5. Harvest as early as practical to preventgreater losses from stalk lodging.

6. Minimize plant stresses during thegrowing season by controlling leaf-feeding insects and borers and irrigat-ing during droughty conditions. Also,avoid unprofitably high plant popula-

tions and excessive applications ofnitrogen, as both of these stressesincrease stalk rot severity.The nitrogen stabilizer nitrapyrin

(N-Serve) reduces soil nitrogen losses fromleaching, and it also reduces the incidenceand severity of stalk rots in some tests. Lessstalk lodging may be another benefit ofN-Serve.

Anthracnose symptoms generally appearon the stalk after tasseling as narrow, verti-cal or oval, water-soaked lesions in therind. These lesions become tan to reddishbrown and eventually dark brown to blacklate in the season. Black lesions and patchesmay cover the lower internodes or theentire stalk. Black specks (spore-bearingstructures) occasionally are found on thestalk rind. The black external lesions formlarge, shiny black areas or streaks that maybe sunken. Internally, the pith tissues willbe decayed and brown to black.Occasionally, leaves above the ear may

die 4 to 6 weeks after pollination while thelower portions of the plant remain green.The upper leaves may turn yellow or red,lodge, and drop off. In some cases, plantsmay die prematurely and later lodge. Lodg-ing normally is found higher on the stalkwhen compared to other stalk rot diseases.Anthracnose also can cause a leaf spot

Table 2-13. Nematode genera associated with corn in Wisconsin

Genus and Incidence in Potentialcommon name Wisconsin damage Symptoms Other hosts

Pratylenchus very common moderately Smaller-than-normal root system. Grasses, cereals, legumes,(Root lesion) damaging Darkened and discolored roots. and vegetables. Host range

Moderate stunting. is different for each speciesof root-lesion nematode.

Longidorus common very damaging in Severe stunting, chlorosis. Severe Grasses and potatoes.(Needle) sandy soils root pruning. Root system consists

mainly of short, stubby, thickenedside roots that appear somewhatswollen.

Hoplolaimus occasionally moderately Reduced root system. Darkened and Grasses and legumes.(Lance) damaging discolored roots. Moderate stunting.Xiphinema occasionally moderately Severe plant stunting, chlorosis. Grasses and legumes.(Dagger) damaging Few fine feeder roots.Helicotylenchus occasionally damaging only Smaller-than-normal root system. Grasses and legumes.(Spiral) at high populations Root decay. Mild stunting.Tylenchorhynchus occasionally damaging only Smaller-than-normal root system. Grasses, cereals, and(Stunt) at high populations Moderate stunting, chlorosis. legumes.Trichodorus rarely very damaging Stubby lateral roots, coarse roots, Grasses, legumes, potatoes,(Stubby root) excessive upper roots. Severe cabbages, and beets.

stunting, chlorosis.

PRINCIPLESO

FPEST

MNGM

T.CO

RNdiseases

SOYBEAN

FORAGES

&PASTURES

APPENDIXSM

ALLGRAINS

PERENNIALW

EEDSSTO

REDGRAIN

INSECTS

88


phase which usually is not important onfield corn but sometimes damages sweetcorn.Control recommendations are resistant

hybrids (especially in minimum tillagefields), crop rotation or deep incorporationof corn debris, and balanced fertility.

Root and crown rotSevere root and crown infections can

cause sudden, premature death of plantsearly in the season or in late August andearly September. Affected plants typicallydevelop a uniformly gray to light greenappearance a few days before they turnwhite. Kernels soon shrivel and are some-what loose on the ears. Stalks are usuallyfirm at this stage, although stalk rot fre-quently follows.Symptoms often occur in pockets,

although plants can be individually dam-aged. The primary effect on the crop is aloss from premature plant kill andincreased harvesting problems.Roots usually collapse and appear discol-

ored from their tips toward the base of thestalk. Symptoms progress internally fromthe crown tissue upward into the stalk.Brace roots are also affected. The base ofbrace roots appear shriveled though notnecessarily discolored. Pythium, a “watermold” fungus, is believed to be the primarypathogen causing root rot in Wisconsin.Damage may be more severe in low, poorlydrained sites and in many sites duringyears when abundant rains occur in Julyand August.

No control measures are available,although varieties appear to differ in sus-ceptibility. No relationship to stalk-rot tol-erance is believed to exist. The influence ofrotations and fertility is not known. Earlyharvest of severely affected fields shouldminimize losses.

Nematode diseasesHigh populations of nematodes reduce

corn yields. Fields with nematode problemsoccur in most regions of the state on sandyto clay loam soils. The lesion, lance, andneedle nematodes appear to be the mostprevalent nematode species associated withcorn.Disease caused by nematodes can be con-

fused with other plant stresses such as lowmoisture, nutrient deficiencies, and soilcompaction. Nematode damage may actu-ally intensify the effects of low soil mois-ture and low soil fertility. Typical symptomsare small stalks, small ears, and nutrientdeficiency symptoms. Nematode problemsare diagnosed by examining the soil androots for these microscopic soil organisms.

Table 2-14. Corn nematode populations associatedwith yield loss

Nematodes/ Nematodes/Genus and common name 100 cc of soil gram of dry root

Pratylenchus (Lesion) 100 500Longidorus (Needle) 1Hoplolaimus (Lance) 100 300Xiphinema (Dagger) 50Helicotylenchus (Spiral) 200Tylenchorhynchus (Stunt) 200Trichodorus (Stubby root) 50

WisconsinPlant Disease Diagnostic ClinicDepartment of Plant PathologyUW-Madison1630 Linden DriveMadison, Wl 53706-1598(608) 262-2863

IowaDr. Gregory L. TylkaDepartment of Plant Pathology320 Bessey Halllowa State UniversityAmes, IA 50011(515) 294-3021

Midwest Laboratories13611 B StreetOmaha, NE 68144(402) 334-7770

Pest ProsP.O. Box 188Plainfield, Wl 54966(715) 335-4046

Table 2-15. Directory of nematology laboratories

State laboratories Private laboratories

PRINCIPLESO

FPEST

MNGM

T.CO

RNdiseases

SOYBEAN

FORAGES

&PASTURES

APPENDIXSM

ALLGRAINS

PERENNIALW

EEDSSTO

REDGRAIN

INSECTS

89


Sampling for corn nematodes. Anematodeassay can be used to confirm a suspectednematode problem or to eliminate nema-todes as one of several possible causes ofpoor plant growth.The best results are obtained when soil

and root samples are taken 6 to 10 weeksafter planting. Nematode populations atthis time appear to correlate best withyields obtained in the fall. However, latesummer or fall samples also can be usefulin predicting next year’s problems. Springsamples are less valuable.Nematode damage to corn often appears

in circular or oval pockets in the field.Rarely does an entire field show severesymptoms. Sample the suspected area.There are several ways to take a soil sam-

ple for nematode analysis. The following isa general guide:1. Use a soil probe or narrow-bladed

trowel or shovel. Take samples close toplants at a depth of 8 to 10 inches. Dis-card the upper 2 inches of soil, espe-cially if it is dry. Be sure to include plantroots.

2. One sample is adequate for a 10-acrefield or for a suspected area within thefield. Sample soil and roots from 12 to20 plants and mix into one sample; 1 to2 pt of soil is adequate. Sample fromplants in the margins of suspected areasand not from their centers.

3. Place samples in sturdy plastic bags,fasten the open end securely, and accu-rately label samples. Keep the samplesfrom becoming dry and overheated.Mail samples early in the week to avoiddelays in transit.Laboratories will report the number of

nematodes in nematode per pint of soil(500 cc), per 100 cc of soil, or per gram ofdry root. Each lab may have its own dam-age thresholds for individual nematodespecies. However, each lab will give anassessment regarding the possibility of eco-nomic damage.Corn growers can use soil-test reports

and strip tests (effective nematicides com-pared to no treatment) to determine ifnematodes are reducing corn yields ontheir farms. If rootworms are present in afield, the strip test should include an effec-

tive insecticide/nematicide rather than aproduct that gives rootworm control but nonematode control.If economic populations of nematodes

are detected, you can use these control rec-ommendations:1. For chemical control, *Counter 15G and

*Mocap 15G are registered nematicidesfor corn. These nematicides are moreeffective if applied in a 7-inch band atplanting rather than in the furrow. Fol-low label directions closely. (Counter15G is also registered as a corn soilinsecticide, such as corn rootworm con-trol. However, rates differ for nematodecontrol. See corn rootworm discussionin “Insect Pests for additional informa-tion on this chemical.)

2. Maintain high soil fertility. Nutrient-deficient plants are more susceptible tonematode injury.

3. Practice good weed control. Manyweeds are good hosts and will helpmaintain or even increase nematodepopulations.

4. Crop rotation may be valuable, but littleis known about the susceptibility ofother crops to nematodes commonlyfound on corn.

*Thimet 20G, Lorsban 15G, and all othersoil insecticides are not registered asnematicides.Most laboratories require a fee to process

samples for nematode analysis. You maywant to contact the laboratory before sub-mission. Table 2-15 lists laboratories thattest for nematodes.

Ear rotCorn is susceptible to several ear rot

fungi that reduce the yield, quality, andfeeding value of the grain. Many of thesefungi are capable of producing mycotoxinsthat affect animal health. Gibberella andFusarium ear rot are the most common earrot diseases in Wisconsin. The prevalenceand severity of ear rot is associated withabove-normal rainfall from July throughOctober, insect feeding on ears, severity ofleaf diseases, and hail injury to ears.Many fungi that cause ear rots also pro-

duce mycotoxins that are harmful if fed tolivestock. The fungus that causes Gibberella

PRINCIPLESO

FPEST

MNGM

T.CO

RNdiseases

SOYBEAN

FORAGES

&PASTURES

APPENDIXSM

ALLGRAINS

PERENNIALW

EEDSSTO

REDGRAIN

INSECTS

90


State laboratory

Wisconsin Department ofAgriculture, Trade and Consumer ProtectionCentral Animal Health Laboratory6101 Mineral Point RoadMadison, WI 53705(608) 266-2465Mycotoxin screenVomitoxin quantitativeZearalenone quantitative

Animal health laboratories

These laboratories are accessed through veteri-narians. (Individuals may not submit samples tothem on their own).

Veterinary Diagnostic LaboratoryUniversity of IllinoisP.O. Box U2001 S. Lincoln Ave.Urbana, IL 61801(217) 333-1620Mycotoxin quantitativeVomitoxin quantitativeZearalenone quantitative

Veterinary Diagnostic LabIowa State University1600 South 16th St.Ames, IA 50011(515) 294-1950Vomitoxin quantitativeZearalenone quantitative

Veterinary Diagnostic LaboratoryNorth Dakota State University174 Van Es HallFargo, ND 58105(701) 231-8307Mycotoxin quantitative

Veterinary Medical Diagnostic LaboratoryAttn: Toxicology1600 E. RollinsColumbia, MO 65211(573) 882-6811Fusarium quantitativeVomitoxin quantitativeZearalenone quantitative

Commercial laboratories

Covance Laboratories3305 Kinsman BlvdMadison, WI 53707(608) 241-4471Vomitoxin quantitativeZearalenone quantitative

Dairyland Laboratories217 East Main StreetArcadia, WI 54612(608) 323-2123Vomitoxin test kitZearalenone test kit

Midwest Laboratories13611 B StreetOmaha, NE 68144(402) 334-7770Vomitoxin test kitZearalenone test kit

Romer Labs712 St. Ann’s RoadP.O. Box 2095Washington, MO 63090(314) 239-3009Fusarium quantitativeVomitoxin quantitativeZearalenone quantitative

Woodson-Tenent Laboratories3507 Delaware Avenue 345 Adams AvenueP.O. Box 1292 P.O. Box 2135Des Moines, IA 50313 Memphis, TN 38103(515) 265-1461 (800) 328-3285Fusarium quantitativeVomitoxin quantitativeZearalenone quantitative

Table 2-16. Directory of mycotoxin laboratoriesContact laboratories directly for information about prices and services,submitting samples, and other details.

PRINCIPLESO

FPEST

MNGM

T.CO

RNdiseases

SOYBEAN

FORAGES

&PASTURES

APPENDIXSM

ALLGRAINS

PERENNIALW

EEDSSTO

REDGRAIN

INSECTS

91


ear rot produces mycotoxins that causereproductive problems in swine. It also pro-duces a mycotoxin called a refusal factor. Ifthe refusal factor is present, swine will noteat the grain.The following suggestions may help con-

trol corn ear rots.1. Corn hybrids differ in susceptibility.

Ears that are well covered by husks andthose that mature in a reclining positionhave less rot than ears with open husksor those that mature upright. Hybridsthat are susceptible to leaf diseases mayhave more ear rot. Full-season hybridshave fewer ear rot problems comparedto early-maturing hybrids.

2. Control corn earworms and corn borerswhere practical.

3. Harvest early.

Consider the following strategies whenear rots are prevalent.

1. Harvest early; the risk of mycotoxinproduction increases as the harvest sea-son progresses.

2. Harvest as shelled corn or silage. Thefungi associated with ear rots will ceaseactivity in corn with less than 20%moisture content and will not survivethe activities of fermentation in the silo.Problems may continue if stored ascribbed ear corn.

Corn molds and livestockdisorders (mycotoxins)Moldy grain is not only a grading factor

in determining the quality and price of theproduct, but it can also affect livestockhealth and milk quality. Some molds underthe right environment produce poisonousmetabolites called mycotoxins. These mayaccumulate in the field as corn matures or,more often, during transportation and/orstorage.Several common fungi associated with

corn produce many different mycotoxins.Some fungi, such as the Fusarium (alsocalled Gibberella) fungus that causes “pinkear rot,” may start in the field. Infectioncommonly occurs during the silking stageand gradually develops, especially as thegrain matures during cool, wet fall periods.This fungus produces several known tox-ins, which actually develop most com-monly after fungal growth has occurred,when moderately cool temperatures prevail(50 to 70°F) and kernel moisture is above20%. These conditions not only exist duringmany fall seasons, but they can occur whengrain sits in bins before grain drying or infeeder boxes. The Aspergillus flavus fungus,which was associated with the aflatoxinproblem of the drought season of 1988, canalso have its start in the field, but like mostother mycotoxin-associated fungi, it islikely to be more damaging as it developsin storage.Each fungus has its own environmental

niche for growth and development. Cla-dosporium, a black fungus found in cold,wet fields, will grow below freezing. Fortu-nately, it doesn’t produce any known toxin.Most Aspergillus and Penicillium speciesare “storage” fungi only; they’re not foundabundantly in field corn, and most arefavored by higher temperatures. However,Aspergillus glaucus can grow at 13.5% grain

Table 2-17. Some mycotoxins and their effects

Toxin or syndrome and(primary) fungal source Possible animal effects

Aspergillus toxins (primarily)

Aflatoxins (B1, B2, G1, and Liver damage; carcinogenic; reducedG2—B1 is most important) growth; hemorrhaging

Ochratoxins Kidney and liver damage; abortion

Sterigmatocystin Generally toxic; carcinogenic

Tremorgenic toxin Tremors and convulsionsPenicillium toxins (primarily)

Patulin Lung and brain hemorrhages; edema;kidney damage; possibly carcinogenic

Rubratoxin Liver damage; hemorrhaging

Citrinin Kidney damageFusarium toxins

Emetic factor, vomitoxin Vomiting; feed refusal by swine, cats,(deoxynivalenol, DON) and dogs

Feed refusal factor Feed refusal by swine(may be same as above)

Other trichothecenes Inflammation of gastrointestinal tract;such as T-2, MAS, DAS possible hemorrhaging, edema,vomit-

ing, infertility, and other symptoms

Zearalenone and zearalenol Increased estrogenic activity; infertility(estrogenic syndrome)

PRINCIPLESO

FPEST

MNGM

T.CO

RNdiseases

SOYBEAN

FORAGES

&PASTURES

APPENDIXSM

ALLGRAINS

PERENNIALW

EEDSSTO

REDGRAIN

INSECTS

92


moisture (72% relative humidity), andsome Penicillium species can grow at 35°Fand perhaps around 16% moisture. Growthis slow at first, but heat and moisturemigration encourages more rapid moldgrowth.Fortunately, the presence of a particular

fungus does not mean the poison also ispresent, but it can be cause for concern. Themolds are not always easy to see. Moreover,in most instances, once the poison has beenproduced, it is not readily destroyed, evenwhen the fungus itself is stopped or killed.Consequently the steps outlined to preventmold buildup—and possibly subsequentmycotoxin development—are important tofollow.Mold control recommendations include

prompt drying after harvesting to 13%moisture or below (for longer term storage,especially), or removing oxygen—requiredfor mold growth—by proper ensiling. Feedcorn can also be treated for temporary stor-age with propionic or other labeled organicacids. None of these destroy toxins, butthey prevent accumulated buildup. See

additional comments under “Storage Dis-eases.” Should you suspect a moldy feedproblem, stop using that feed and call a vet-erinarian. Several laboratories will test feedfor some of the toxins listed above (table 2-16).Table 2-17 shows some recognized myco-

toxins associated with certain fungi attack-ing corn, together with possible animaleffects.

Storage diseasesYou can store grain for several years with

little or no loss of quality if you maintain itat a proper moisture content. For example,corn at a moisture content of 13% or lowercan be stored indefinitely regardless of tem-perature. Note that this is below the 15.5%moisture content required for No. 2 gradecorn. Corn at 15.5% moisture content can besafely stored for extended periods of time ifthe grain temperature is low. However,problems can develop as the grain tempera-ture rises in the spring and during the sum-mer. Table 2-18 charts how long grain canbe stored at various temperatures beforecorn will begin to decay given the grain’smoisture content.Microbial activity may result in loss of

nutrients in the grain; microbes produceheat during growth, and heat damage canoccur. Certain microorganisms, mainlyfungi, produce toxins (mycotoxins) that cancause illness or even death when consumedby livestock or humans. Since microorgan-

Table 2-19. General guide forsampling stored grain

——Bin diameter——Probe depth <24 ft >24 ft

Temperature probes —samples/bin—Shallow 1 1a

Deep 3 5Moisture probesShallow 1a 3Deep 5 10

aIn the bin center.

Table 2-18. Maximum time for stor-age of shelled corn at various cornmoisture and air temperaturesa

Storage air ——Corn moisture content——temperature 15% 20% 25% 30%

Fahrenheit ————days————75° 116 12.1 4.3 2.670° 155 16.1 5.8 3.565° 207 21.5 7.8 4.660° 259 27.0 9.6 5.855° 337 35.0 12.5 7.550° 466 48.0 17.0 10.045° 725 75.0 27.0 16.040° 906 94.0 34.0 20.035° 1,140 118.0 42.0 25.0a The times given above are those in which moldgrowth will cause enough loss in corn quality tobring about a lowering of grade or permit mold growthwhich could result in mycotoxin formation. Data arefrom USDA Farmer’s Bull. No. 2238, Guidelinesfor Mold Control in High-Moisture Corn.

PRINCIPLESO

FPEST

MNGM

T.CO

RNdiseases

SOYBEAN

FORAGES

&PASTURES

APPENDIXSM

ALLGRAINS

PERENNIALW

EEDSSTO

REDGRAIN

INSECTS

93


PRINCIPLESO

FPEST

MNGM

T.CO

RNdiseases

SOYBEAN

FORAGES

&PASTURES

APPENDIXSM

ALLGRAINS

PERENNIALW

EEDSSTO

REDGRAIN

INSECTS

94 isms affect the value of stored grains inmany ways, it is extremely important tominimize this activity.Storage life of shell corn depends on a

combination of factors including moisturecontent, temperature, degree of invasion bystorage fungi, and length of time the corn isto be stored.The following suggestions may help con-

trol corn storage diseases.1. Clean bins thoroughly before filling.2. Dry shell corn to 12 or 13% moisture

content. No damaging invasion by stor-age fungi will occur at moisture con-tents below 13%.

3. Store shelled corn in weather-tight bins.Snow and rain are external sources ofmoisture that can raise the moisturecontent of stored grain.

4. Check stored grain frequently, espe-cially during warm weather. Collectgrain samples from several areas in thebin, including the center. A samplingprocedure is outlined in table 2-19.In circular bins, the grain surface can bedivided into “pie sections” for sam-pling. Make temperature samples byprobing the grain 12 to 15 ft with ashielded small-diameter thermometerscrewed onto a threaded pipe exten-sion. A good routine to follow is toleave the temperature probe in placewhile making probes for moisture con-tent. A 6-ft compartmentalized graintrier or implement is best for makingprobes for moisture content determina-tions. Do not combine samples whenmaking moisture content determina-tions. It is important to know the high-est moisture content of the bin andwhere it is located, not an overall binaverage. The highest moisture area canserve as a source for moisture migrationand is the area where storage fungi willfirst become active.Never inspect grain bins alone. Manypeople have been covered by grain andsuffocated. Work in teams of three. Onemember of the team should wear asafety line while inside the bin, whilethe other two people handle the lineoutside. Also, place a sign outside thebin that warns others that people areinside the facility.

5. Aeration systems for grain bins canmaintain grain quality by reducing thetemperature of stored corn and keepingthe temperature uniform throughoutthe bin to prevent moisture migration.You can minimize the problem of mois-ture migration by keeping the tempera-tures of the grain in the center of the binwithin 10°F of the average grain tem-perature near the bin wall. To do this,use aeration fans that pull the air downthrough the grain at air flow rates of atleast 1⁄10 cubic foot per minute for eachbushel of grain in the bin. Aerate thegrain until the temperature of the grainmass is within 10°F of the averagemonthly temperature. It is not neces-sary to lower grain temperatures below40°F because most grain storage fungiare not active below this temperature.Also, aeration systems should not beused to raise the temperature above60°F because fungi and insects are moreactive above this temperature.

6. Control storage insects; their activitiescan increase the moisture content ofgrain. Fumigation may rid grain ofinsects but not storage fungi.

7. Store high-moisture grain in air-tightsilos or treat grain with organic acids.

When “hot spots” or a crust of moldycorn is found, follow these steps:1. The decayed and moldy corn should be

discarded if mold is severe. Corn withsome mold can be dried and fed to live-stock. Exercise caution when feedingmoldy corn to livestock. Moldy corncan be fed with less risk if mixed withsound corn. Moldy corn is consideredunsafe for all breeding animals.

2. The remaining corn can be turned andthoroughly mixed to redistribute mois-ture and to allow heat to escape. Aera-tion does this more cheaply and effec-tively than transferring grain from binto bin, and it does not crush and breakkernels.


STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

SOYBEAN

CORN

PRINCIPLESOF

PESTMNGM

T.

SOYBEAN PESTMANAGEMENT

3

A3646-09, III. Soybean:A3646/05, III. Soybean 10/14/08 4:47 PM Page 95

SOYBEAN WEED MANAGEMENT

These herbicide treatments are specific asto time and method of application, weedsthey control, rates of application to be usedon different soils, and crops that may fol-low in rotation. Failure to apply themaccording to label directions can result inincomplete weed control, excessive cropinjury, or damage to subsequent crops.Assist your herbicide treatment with arotary hoe and row cultivation where soy-beans are planted in wide rows. For narrow-row soybeans, use a rotary hoe and anincreased planting rate to place soybeanseedlings in the most competitive positionwith weeds. Mechanical weed control isseldom an option in no-till soybeans. Checkfields regularly to be sure that weeds arebeing managed on a timely basis.Many herbicide combinations are regis-

tered for use on soybeans. The use of herbi-cide combinations that are not registered isdiscouraged since liability for performanceand crop injury lie solely with the user.Similarly, the combination of herbicideswith fertilizers or insecticides for simulta-neous application is discouraged unless theherbicide label outlines directions for suchcombination use. Be sure to check the her-bicide label or accompanying literaturecarefully before using herbicides in combi-nation with fertilizers, insecticides, or otherherbicides.

BURNDOWN HERBICIDES FORNO-TILL SOYBEANNo-till cropping systems are increasingly

popular because they offer economic andenvironmental benefits. Weed managementis particularly important in these systemsbecause no tillage is done before plantingand few producers cultivate no-till fieldsafter planting. The purpose of a burndownherbicide application is to ensure that thecrop is planted into a weed-free setting.No-till soybean fields are more likely to

need a burndown application than cornbecause soybeans are planted later. Checkfields carefully to determine if such a treat-ment is needed. Give particular attention toperennial weeds like dandelion, whitecockle, and quackgrass as well as winterannuals like shepherd’s purse, chickweeds,buttercups, and pennycress.

Autumn (iodosulfuron) + 2,4-DRate: 0.3 oz/a Autumn + 1 pt/a 2,4-D

ester.Adjuvants: Add 1% crop oil concentrate

and either 1.5 to 2 qt/a of 28% nitrogensolution or 1.5 to 3 lb/a ammonium sulfate.Timing: Apply in the fall after harvest and

90 days before soybean planting in thespring.Remarks: Autumn + 2,4-D is intended to

provide fall burndown control and limitedresidual activity on several broadleaf weedsincluding alfalfa, plantain, dandelion,horseweed, and several mustard species.The Autumn label recommends applicationto annual broadleaf weeds up to 3 inchestall. However, a tank mixture with 2,4-Dwill provide control of larger weeds.Autumn can also be mixed with glyphosateto control grass weeds. The 90-day intervalbetween application and soybean plantinglimits its use to fall applications. Autumn israinfast in 2 hours. Do not apply to frozensoil or soil with a pH greater than 8.Rotational restrictions: Field corn can be

planted after 30 days, soybeans after 90days, winter wheat after 4 months, andspring small grains and sorghum after 8 to9 months. Other crops cannot be plantedfor 18 months.

96

STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

SOYBEAN

weeds

(burndown)

CORN

PRINCIPLESOF

PESTMNGM

T.

(continued)


Table 3-1. Weed control ratings of soybean herbicidesa


Herbicides

Preplant incorporated

Prowl H2O 3 VS G/E G/E G/E G/E G F F N N N P F/G G/E F F N N N N NTrifluralin (Treflan) 3 VS G/E G/E G/E G/E G F F N N N P F/G G/E P P N N N N N

Pursuit Plus 2,3 VS G/E E E E –– F F F/G F F E G/E E E E N P P N P

Preemergence

Dual II Magnum 15 VS G/E G/E G/E G/E F F F N F P G/E F/G G P P N N N F NIntrro 15 VS G/E G/E G/E G/E F F F N F P E F G P P N N N F NOutlook 15 VS G/E G/E G/E G/E F F F N F P G/E F/G G P P N N N F N

Authority Assist 2,14 S/M F/G F F G P P/F P F F F E G/E E G/E G/E P P P F PAuthority MTZ 5,14 S/M F F F F P P P F/G G F G G/E G/E E G/E P P P F PBoundary 5,15 M G G G G F F F F/G G F G G G/E E G P P P F PEnlite 2,14 S/M P/F P/F P/F F P P P P F/G P/F G G/E G/E F F P P P/F P NEnvive 2,14 S P P P P P N N F G F G G/E G G F/G P P P/F P NFirstRate 2 S P P P P N N N G E E N G G/E E G N — — N NGangster 2,14 S/M P/F P/F P/F P/F P P P G G/E G/E G G/E E E G P P F P NLorox 7 M F F F F P P P F G/E G F G G/E G/E G P N P N NPrefix 14,15 S G G G G F F F P G F G/E G G/E G P P P P P NPursuit 2 VS F/G F F F/G –– F/P P F F F E G/E E G/E E N P P N PPython 2 VS N N N N N N N F F/G F F/G G G G G/E N P P N NSencor 5 M F P P F P P P F/G G/E F P G/E G/E E G/E P P P P PSulfentrazone + cloransulam 2,14 S P/F P/F P/F P/F N N N G E E G E E E G P P P F N(Authority First/Sonic)

Valor SX 14 S/M P/F P/F P/F P/F P P P P F/G P G G/E G/E F F P P P/F P NValor XLT 2,14 S P P P P P N N F G F G G/E G G F/G P P P/F P N

Abbreviations (continued)Risk of crop injury: H=high; M=moderate; S=slight; VS=very slight; N=none.Control ratings: E=excellent; G=good; F=fair; P=poor; N=none; — = insufficient information.

aThese herbicides have been rated for expected weed control, but actual results may vary depending upon rates applied, soil types,weather conditions, and crop management.

Modeof

actio

ngroup

Risk

ofsoybeaninjury

Barnyardgrass

Crab

grass

Fallpanicum

Foxtails

Fieldsandbur

Wild

prosomillet

Woolly

cupgrass

Cocklebur

Common

ragw

eed

Giantrag

weed

Easternblacknightshade

Lambsquarters

Pigw

eeds

Smartweeds

Velvetleaf

Canada

thistle

Hempdogb

ane

Dandelion

Nutsedge

Quackgrass N

“m

G/

97

STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

SOYBEAN

weeds

CORN

PRINCIPLESOF

PESTMNGM

T.


STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

SOYBEAN

weeds

CORN

PRINCIPLESOF

PESTMNGM

T.

Table 3-1. Weed control ratings of soybean herbicidesa (continued)


Herbicides

Postemergence

Basagran 6 S N N N N N N N N E F/G F F P P/F E G/E F P P G NCadet 14 M P P P P P N P P P P P F F/G F/G P E P P P N NFlexstar 14 M/H P P P P P P P P F/G G/E G G F G/E G F F P P N NLactofen (Cobra/Phoenix) 14 H P P P P P P P P G/E G/E G G F G/E G F/G F F P P NResource 14 M P P P P P P P P F F/G P P F F P E P P P — PUltra Blazer 14 H P P P P P P P P G G F/G G F G/E G/E F P F P P N

Classic 2 VS N N N N N N N N E G F/G P P G/E G F/G F P P G NFirstRate 2 S N N N N N N N N E E E N P P G G F — — F NHarmony SGb 2 M N N N N N N N N F F P N E E G/E G P P P — NPursuit 2 S G F G G F P P F G F/G F E P E G G/E F P P N P/FRaptor 2 M G F G G/E F G F/G F G/E F/G G E G E G G/E F — — F FSynchrony XPb 2 M N N N N N N N N G/E G F/G N G E G G P P P P N

Glyphosatec,d 9 N E E E E E E E E E E G/E G/E G/E E G G/E E G/E F F/G E

Extremed 2,9 S E E E E E E E E E E G/E E G/E E G/E G/E G G F F/G G/E

Sequencec,d 9,15 VS E E E E E E E E E E G/E G/E G/E E G G/E E G/E F F/G E

Ignite 10 S F G G G F F G G G/E G/E G G G G G/E G F F F/G P F

Assure II 1 N E E E E E E E G N N N N N N N N N N N N G/E

Fusilade DX 1 N E E E G/E E E E G N N N N N N N N N N N N G/E

Fusion 1 N E E E E E E E G N N N N N N N N N N N N G

Poast Plus 1 N E E E E E G E G N N N N N N N N N N N N F/GSelect Max 1 N E E E E E E E G N N N N N N N N N N N N F/G

Abbreviations

Risk of crop injury: H=high; M=moderate; S=slight; VS=very slight; N=none.Control ratings: E=excellent; G=good; F=fair; P=poor; N=none; — = insufficient information.

aThese herbicides have been rated for expected weed control, but actual results may vary depending upon rates applied, soil types, weatherconditions, and crop management.bRisk of injury on STS soybeans is very slight.cOnly apply to Roundup Ready soybeans or severe injury will occur.dWill not control Roundup Ready volunteer corn.

Modeof

actio

ngroup

Risk

ofsoybeaninjury

Barnyardgrass

Crab

grass

Fallpanicum

Foxtails

Fieldsandbur

Volunteercorn

Wild

prosomillet

Woolly

cupgrass

Cocklebur

Common

ragw

eed

Giantrag

weed

Easternblacknightshade

Lambsquarters

Pigw

eeds

Smartweeds

Velvetleaf

Canada

thistle

Hempdogb

ane

Dandelion

Nutsedge

Quackgrass

98


Canopy (Classic + Sencor premix)Canopy can be used south of I-90

between LaCrosse and Madison and southof I-94 between Madison and Milwaukee.Rate: 2.25 oz/a.Adjuvants: Add 1% crop oil concentrate.

Add 0.25% nonionic surfactant if tank mix-ing with glyphosate.Timing: Apply up to 45 days before plant-

ing or preemergence after planting. Annualbroadleaf weeds should be less than3 inches tall and annual grasses should beless than 2 inches tall.Remarks: Canopy provides burndown

control of many no-till weeds such as dan-delions, lambsquarters, prickly lettuce,mustard species, common and giant rag-weed, and foxtails. Tank-mix 1 pt/a of2,4-D ester for horseweed control. Forlarger weeds or an expanded spectrum,Canopy can be tank-mixed with Assure II,glyphosate, Gramoxone, or 2,4-D. If mixedwith 2,4-D, planting must be delayed7 days after application. Canopy will alsoprovide early season residual control ofmany annual broadleaf weeds like lambs-quarters, pigweed, common ragweed,smartweed, and velvetleaf and suppressionof foxtails and crabgrasses. Canopy can bemixed with a preemergence herbicide orfollowed by a postemergence herbicide fora complete weed control program. About1 inch of rainfall is needed for full residualactivity. Do not use on soils that exceed asoil pH of 7.6. Canopy is rainfast 1 hourafter application.Rotational restrictions:Wheat and barley

can be planted 4 months after application;alfalfa, field corn, and tobacco after10 months; snap beans and peas after12 months; and sweet corn after 18 months.Oats, potatoes and crops not listed on thelabel cannot be planted for 30 months.

Canopy EX (Classic + Express premix)+ 2,4-DCanopy EX can only be applied south of I-90

west of Madison and I-94 east of Madison.Rate: 1.1 oz/a Canopy EX + 1 pt/a 2,4-D.Adjuvants: 1% crop oil concentrate (or

0.25% nonionic surfactant if crop oil concen-trate is prohibited by a tank-mix partner).Timing:Apply in the fall or spring at least

7 days before planting soybeans.

Remarks: Canopy EX provides burndowncontrol of dandelions plus several winterannual broadleaves such as mustards (fieldpennycress, shepherd's purse, etc.), com-mon chickweed, henbit, and horseweed.Canopy will provide residual weed controldepending on application timing. Otherherbicides such as Assure II, glyphosate,Gramoxone, or Sencor can be tank-mixed tocontrol additional grass or broadleafweeds. Do not apply to soils with a pHgreater than 7.6 and do not apply any addi-tional Classic or Synchrony if the pHexceeds 7.0. Canopy EX is rainfast in 2hours.Rotational restrictions: Begin counting the

time interval at soybean planting ratherthan at application. Small grains can beplanted after 3 months; peas, snap beans,and corn can be planted after 9 months;alfalfa can be planted after 12 months; andsweet corn can be planted after 18 months.

Enlite (Valor SX + Classic +Harmony SG premix)Rate: 2.8 oz/a.Adjuvants:Add 1% crop oil concentrate

(preferred) or 0.25% nonionic surfactant.Timing:Apply in the fall after soil temper-

ature is less than 50°F or after October 15 orin the spring until planting. Spring applica-tions must be made within 3 days afterplanting.Remarks: Enlite will provide burndown

and residual control of several broadleafweeds. Applications in the fall shouldinclude 2,4-D or glyphosate for dandelioncontrol. Spring burndown treatments arelabeled to control 3-inch-tall weeds likemustards, lambsquarters, pigweed, andsmartweed. A tank mix with 2,4-D orglyphosate is recommended to improvecontrol of horseweed and other broadleafweeds. The residual control from the Valorcomponent fits well in the spring to controllambsquarters, horseweed, nightshade, andpigweeds and to suppress other broadleafweeds. Annual grasses and giant ragweedwill also be suppressed. Burndown treat-ments should include glyphosate or AssureII to control grasses if present. Either fall orspring applications of Enlite should be fol-lowed with a postemergence glyphosateapplication in Roundup Ready soybean or

99

STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

SOYBEAN

weeds

(burndown)

CORN

PRINCIPLESOF

PESTMNGM

T.


100

STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

SOYBEAN

weeds

(burndown)

CORN

PRINCIPLESOF

PESTMNGM

T.

conventional herbicides for complete weedcontrol. Do not tank-mix with Define, Dual,Intrro, or Outlook.Rotational restrictions:Wheat and barley

can be planted 4 months after an Enliteapplication; field corn, sweet corn, peas,and snap beans after 9 months; alfalfa andoats after 12 months; and potatoes after 30months.

Envive (Valor SX + Classic +Harmony SG premix)Envive can only be used south of I-90

between LaCrosse and Madison and southof I-94 between Madison and Milwaukee.Rate: 2.5 oz/a.Adjuvants: Add 1% crop oil concentrate

(preferred) or 0.25% nonionic surfactant.Timing: Apply in the fall after soil tem-

perature is less than 50°F or after October15 or in the spring until planting. Springapplications must be made within 3 daysafter planting.Remarks: Envive contains a similar ratio

of Valor to Classic as Valor XLT. The higherrate of Classic in Envive limits its use tosouthern Wisconsin because of potentialcarryover. Enlite contains a lower rate ofClassic and will be predominant formula-tion marketed in Wisconsin. See Valor XLT(page 102) for comments applicable toEnvive.Rotational restrictions:Wheat and barley

can be planted 4 months after application;field corn after 10 months; alfalfa, peas, andsnap beans after 12 months; sweet cornafter 18 months; and potatoes after 30months.

Extreme (Pursuit + glyphosate premix)Rate: 3 pt/a.Adjuvants:Add nonionic surfactant at

0.125% to the spray mixture plus ammo-nium sulfate at 8.5 to 17 lb/100 gal.Timing: Preplant or preemergence—Apply to

annual weeds. Do not apply Extreme if soy-beans have emerged unless they areRoundup Ready.Remarks: Extreme will control emerged

weeds and provide residual control of sev-eral annual weeds. It can be tank-mixedwith 2,4-D or pendimethalin if appliedbefore planting.

The Extreme premix provides an eco-nomical way to combine the broad-spec-trum burndown activity of glyphosate withthe residual activity of Pursuit on severalbroadleaf weeds.Rotational restrictions: Because this pre-

mix contains Pursuit, it can persist anddamage certain rotational crops. Do notplant wheat until 3 months after applica-tion; alfalfa, edible beans, peas, and ryeuntil 4 months after application; conven-tional field and seed corn until 8.5 monthsafter application; barley and tobacco until9.5 months after application; oats and sweetcorn until 18 months after application; andpotatoes until 26 months. Allow 40 monthsbefore planting all other crops.

GlyphosateRate: 0.38 to 0.56 lb ae/a for annuals and

0.75 to 1.5 lb ae/a for quackgrass. See labelsfor specific rate recommendations.Glyphosate conversion table




Adjuvants:Ammonium sulfate at 8.5 to 17lb/100 gal of spray mixture is frequentlyrecommended, especially when tank-mixingglyphosate with residual herbicides. Checkthe label to see if the glyphosate formula-tion requires additional surfactant.Timing: Preplant—Apply to annual weeds

less than 6 inches tall or to quackgrass thatis 6 to 8 inches tall and actively growing.Do not include glyphosate in any spraymixture if soybeans have emerged, unlessthey are Roundup Ready.No-till: Glyphosate can be included as a

component of a preplant residual herbicidetreatment to provide burndown of existingvegetation. Annual weeds emerging afterglyphosate application must be controlledby a residual herbicide or a postemergenceherbicide. Where a preplant treatment ismade as a split application, includeglyphosate with the first application, but


only if weed growth is present at the timeof treatment. If quackgrass is present,include glyphosate in the second applica-tion instead of the first. Glyphosate can betank-mixed with 2,4-D ester for improvedannual and perennial broadleaf weed burn-down, but must be applied at least 7 daysbefore planting.Remarks: To control quackgrass, apply

0.75 lb ae/a of glyphosate to 6 to 10 inchquackgrass if the field will be tilled afterapplication. Delay tillage for 3 days afterapplication. Increase the rate of glyphosateto 1.5 lb ae/a if the field will be no-tillplanted. Glyphosate can be applied in 28%nitrogen solution rather than in water, butit is not recommended when treatingperennials.Rotational restriction: Glyphosate formu-

lations have no rotational restrictions forWisconsin field crops except for a 30-dayinterval before tobacco.

Gramoxone Inteon (paraquat)Rate: Apply 2.0 to 2.5 pt/a when weeds

are 1 to 3 inches tall, 2.5 to 3.0 pt/a whenweeds are 3 to 6 inches tall, and 3.0 to 4.0pt/a when weeds are taller than 6 inches.Adjuvants: Include nonionic surfactant at

0.125% or crop oil concentrate at 1% to thespray mixture.Timing: Preplant—Apply preplant or

before soybeans have emerged.No-till: Gramoxone can be included with

preplant residual herbicides to provideburndown of existing vegetation. Where apreplant treatment is made as a split appli-cation, include Gramoxone with the firstapplication, but only if weed growth is pre-sent at the time of treatment. Annual weedsemerging after Gramoxone applicationmust be controlled by the residual herbi-cide.Remarks: Tank-mixing Sencor or Lorox

with Gramoxone usually increases burn-down activity. Use a minimum of 10 gal/aof water at 30 to 50 psi pressure withground applications. Flat fan nozzles aremore effective than flood nozzles at deliver-ing the fine spray droplets necessary forthorough spray coverage. If applying lessthan 20 gal/a of water, only use flat fannozzles. Do not apply Gramoxone whenconditions prevent uniform coverage orwhen excessive spray drift may occur.Rotational restrictions: None.

Rage D-Tech (Aim + 2,4-D premix)Rate: 8 to 16 oz/a; the lower rate is rec-

ommended for weeds less than 6 inchestall.Adjuvants: Add nonionic surfactant at

0.25% or crop oil concentrate at 1.5 to 2%.Nitrogen fertilizer may be added ifrequired by a tank-mix partner.Timing: Apply 7 days before planting soy-

beans when using up to 16 oz/a.Remarks: Rage D-Tech will control many

winter and summer annual broadleafweeds. The Aim component will provide afaster burn of weed foliage than 2,4-Dalone. Rage D-Tech can be tank-mixedglyphosate or Gramoxone for annual grasscontrol. It can also be tank-mixed with pre-emergence residual herbicides. Do notapply Rage D-Tech on sandy soils or soilswith less than 1% organic matter.Rotational restrictions: Corn or soybeans

can be planted after the required intervalafter burndown treatments. Most othercrops can be planted after 30 days.

Sequence (s-metolachor + glyphosatepremix)Rate: 2.5 to 4.0 pt/a based on soil texture

and weed height.Adjuvants:Ammonium sulfate may be

added at 8.5 to 17.0 lb/100 gal.Timing: Preplant or preemergence—Do not

apply if soybeans have emerged unlessthey are Roundup Ready.Postemergence—If soybeans are Roundup

Ready, applications can be made throughthe third trifoliate stage.Remarks: Sequence will control emerged

weeds and provide residual control ofannual grass weeds. Sequence at 2.5 pt/aprovides 0.7 lb ae/a glyphosate; it shouldbe effective on most annual weeds iftreated before the 6-inch height. The labelhas specific rates for individual weedheights. It can be tank-mixed with 2,4-D toincrease broadleaf burndown activity ifapplied before planting or other preemer-gence herbicides. Sequence contains theequivalent of 1.0 to 1.6 pt/a of Dual II Mag-num over the labeled rate range and higherrates will provide greater residual grasscontrol.Rotational restrictions: If the soybean crop

is lost, soybeans, corn, peas, or snap beanscan be replanted. Alfalfa can be planted 4

101

STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

SOYBEAN

weeds

(burndown)

CORN

PRINCIPLESOF

PESTMNGM

T.


102

STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

SOYBEAN

weeds

(burndown)

CORN

PRINCIPLESOF

PESTMNGM

T.

months after application and small grainscan be planted after 4.5 months. Othercrops can be planted the following spring.

Synchrony XP (chlorimuron +thifensulfuron) + Express (tribenuron)+ 2,4-DRate: 0.375 oz/a Synchrony + 0.25 oz/a

Express + 8 oz/a 2,4-D ester.Adjuvants:Add a crop oil concentrate at

1% to the spray mixture.Timing:Apply in the fall or in the spring

45 days before planting.Remarks: Applying Synchrony, Express,

and 16 oz/a 2,4-D following corn harvest inthe fall has given excellent dandelion andwinter annual weed control in fields thatwill be no-till planted to soybeans the nextspring. Treatments made through cornstalks have performed well in killing dan-delions. If possible, wait 10 to 14 days afterharvest for the stalks to settle and weeds tobe exposed to the spray solution.Synchrony plus glyphosate (no 2,4-D or

Express) can be applied without delaybefore soybean planting. Use 0.25% surfac-tant and ammonium sulfate. This tank mixmay increase control of dandelion, horse-weed, and some other winter annual weedscompared to glyphosate alone. In addition,if a 0.75 oz/a rate is used in the spring,Synchrony will provide some residual con-trol of lambsquarters, pigweeds, smart-weeds, and ragweeds. If mixed with 2,4-Dester, planting must be delayed for 7 daysafter application.Rotational restrictions: Only soybeans can

be planted the spring following a Synchrony+ Express application.

Valor XLT (Valor SX + Classic premix)Valor XLT can only be applied south of

I-90 west of Madison and south of I-94 eastof Madison.Rate: 2.5 oz/a.Adjuvants: Add 1 to 2 pt/a crop oil con-

centrate or 0.25% nonionic surfactant.Ammonium sulfate at 8.5 to 17 lb/100 galmay also be added.Timing: Apply in the fall after soil temper-

ature is below 50°F or October 15 or in thespring either before planting or within3 days after planting.

Remarks: Valor XLT will provide burn-down control of several broadleaf weedsincluding dandelions in the fall and burn-down and limited residual control of lamb-squarters, horseweed, pigweed, velvetleaf,and common ragweed in the spring.Annual grasses and giant ragweed will alsobe suppressed. Burndown treatmentsshould include glyphosate or 2,4-D. Rateshigher than 2.5 oz/a and applications northof the interstate may lead to carryover torotational crops. This rate of Valor XLT isintended to be followed by a postemer-gence glyphosate application in RoundupReady soybean. Valor XLT can be tank-mixed with pendimethalin, Lorox, Senor, oradditional Valor SX for increased residualactivity in the spring. Do not tank-mix withDefine, Dual, Intrro, or Outlook. Do not useon soil with a pH greater than 7.6.Rotational restrictions: Barley and wheat

can be planted after 4 months; field cornand tobacco after 10 months; alfalfa, snapbeans, and peas after 12 months. Oats andpotato should not be planted for 30 months.

2,4-D EsterRate: 1 pt/a of a 3.8 lb/gal 2,4-D ester for-

mulation or equivalent.Adjuvants: Approved crop oil concen-

trates, agricultural surfactants and liquidfertilizers may be added to the spray mix-ture to improve control.Timing: Preplant—Apply 2,4-D ester no

less than 7 days before planting. Applica-tions of 1 qt/a require a 30-day wait beforeplanting.No-till: Apply before no-till soybean

planting for the suppression or control ofsmall, actively growing broadleaf weeds.This treatment can be used to controlbroadleaf weeds that aren’t effectively con-trolled by Gramoxone or glyphosate. Thistreatment may be tank-mixed with manyconservation-tillage soybean treatments forimproved broadleaf weed control.Remarks: There is some risk of soybean

injury, especially if heavy rains occur afterapplication. Do not apply 2,4-D beforeplanting unless you are prepared to acceptsoybean injury including possible standloss and/or yield reduction in some years.Plant soybeans 1 to 2 inches deep and makecertain the seed is adequately covered. Donot use on sandy soils with less than 1%


organic matter. Do not cultivate betweenherbicide application and soybean planting.Rotational restrictions: 2,4-D does not per-

sist in the soil for long, but certain labelsprohibit replanting other crops in the sameseason unless 2,4-D is labeled for preplantuse on that crop.

PREPLANT-INCORPORATED &PREEMERGENCE HERBICIDES

Authority Assist (Spartan + Pursuitpremix)Rates: 6 to 12 oz/a; reduced rates of 4 to 6

oz/a are recommended for early-seasonweed suppression when followed byglyphosate in Roundup Ready soybeans.Timing: Preplant incorporated—Apply and

incorporate into the top 2 inches of soil. Indry seasons, a preplant-incorporated treat-ment will provide better weed control thanpreemergence treatment.Preemergence—Apply between 45 days

before planting until within 3 days afterplanting.No-till: Authority Assist will provide

burndown activity on several annual grassand broadleaf weeds when applied withcrop oil, but a tank mix with glyphosate orGramoxone would typically be required forbroad-spectrum burndown of emergedweeds.Remarks: Authority Assist will control

many annual broadleaf weeds and willsuppress several annual grass species.Authority Assist can be tank-mixed withother preemergence grass herbicides toincrease grass control. The length of resid-ual activity will depend on the rate used.At reduced rates, it will provide early-sea-son broadleaf weed control and grass sup-pression when followed by glyphosate inRoundup Ready soybeans. Heavy rainsafter application or cold, wet soils mayincrease the risk of injury. The seed furrowmust be closed prior to application or cropinjury may result. Do not apply to crackingor emerged soybeans because severe injurywill occur. Do not apply to sands with lessthan 1% organic matter or to soils with apH greater than 7.5.Rotational restrictions: Soybeans can be

replanted at anytime after application;wheat can be planted after 4 months; barley

and tobacco can be planted after 9.5months; field corn, peas, and snap beanscan be planted after 10 months; alfalfa canbe planted after 12 months; sweet corn andoats can be planted after 18 months; andpotato can be planted after 26 months.

Authority FirstSee sulfentrazone + cloransulam premix

(page 109).

Authority MTZ (Spartan + Sencorpremix)Rates: 12 to 20 oz/a; reduced rates of 8 to

14 oz/a are recommended for early seasonweed suppression when followed byglyphosate in Roundup Ready soybeans.Timing: Preplant incorporated—Apply and

incorporate into the top 2 inches of soil. Indry seasons, preplant incorporated treat-ment will provide better weed control thanpreemergence treatment.Preemergence—Apply up to 30 days

before or within 3 days after planting.No-till: Apply up to 30 days before no-till

planting or apply preemergence after plant-ing. The addition of 1 qt/a of crop oil con-centrate or nonionic surfactant at 0.25% willincrease the burndown activity of Author-ity MTZ. If additional burndown activity isneeded, tank-mix with glyphosate,Gramoxone, or 2,4-D to control emergedweeds.Remarks: Authority MTZ will control

many annual broadleaf weeds and willsuppress several annual grass species.Authority MTZ can be tank-mixed withother preemergence grass herbicides toincrease grass control. The length of resid-ual activity will depend on the rate used.At the reduced rates, it will provide earlyseason broadleaf weed control when fol-lowed by glyphosate in Roundup Readysoybeans. Heavy rains after application orcold, wet soils may increase the risk ofinjury. The seed furrow must be closedprior to application or crop injury mayresult. Do not apply to cracking or emergedsoybeans because severe injury will occur.Do not apply to sands with less than 1%organic matter or to soils with a pH greaterthan 7.5.

103

STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

SOYBEAN

weeds

(pre/ppi)CO

RNPRINCIPLES

OF

PESTMNGM

T.


Rotational restrictions: Soybeans can bereplanted anytime after application; wheatand barley can be planted after 4 months;field corn and peas after 10 months; alfalfa,potato, and tobacco after 12 months; andsnap beans, peas, sweet corn, and oats after18 months.

Boundary 6.5EC(Dual Magnum + Sencor premix)Rate: 1.5 to 1.8 pt/a when followed by a

postemergence herbicide program or 1.2 to3 pt/a in a one-pass program.Timing: Preplant incorporated—Apply and

incorporate into the top 2 inches of soilwithin 14 days before planting.Preemergence—Apply after planting, but

before weeds and crop emerge.No-till: Boundary can be preplant surface

applied up to 30 days before planting orpreemergence after planting. Higher ratesshould be used with early preplant applica-tions. Boundary can be tank-mixed withglyphosate, Gramoxone, and 2,4-D to con-trol emerged weeds.Remarks: Boundary controls many annual

grass and broadleaf weeds. When used atlower rates, it will provide early seasoncontrol; late emerging weeds should becontrolled with a sequential postemergenceherbicide. Boundary can be tank-mixedwith Python for added velvetleaf control;with FirstRate for added common andgiant ragweed and velvetleaf control; withCommand for added common ragweedand velvetleaf control; and with Prowl foraid with triazine-resistant weeds. Boundarymay injure soybeans because of the Sencorcomponent. The risk of soybean injuryincreases when soybeans are planted lessthan 1.5 inches deep or when heavy rainsfollow application. Use should be avoidedon soils with less than 0.5% organic matter,on soils with a pH of 7.5 or higher, and infields where residues of atrazine exist. Donot use on sand regardless of organic mat-ter or on loamy sand with less than 2%organic matter. Limit the rate of Boundaryto 1.5 pt/a on soils with a pH above 7.Check the label for a list of metribuzin-sen-sitive soybean varieties. Boundary can bemixed with liquid fertilizer or impregnatedonto certain dry fertilizers for simultaneousapplications.

Rotational restrictions:Alfalfa and winterwheat can be planted 4.5 months afterapplication; barley, corn, peas, and springwheat after 8 months. Most other crops canbe planted after 12 months, except rootcrops, which are 18 months.Define SC (flufenacet)Rate: 8 to 14 oz/a.Timing: Preplant-incorporated—Apply

within 2 weeks before planting and incor-porate into the top 1 to 2 inches of soil.Preemergence—Apply after planting and

before weed emergence.No-till: Preplant surface applications can

be made within 2 weeks before planting.For improved annual weed burndown,tank-mix Define with glyphosate,Gramoxone, or 2,4-D.Remarks: Define controls several annual

grasses. However, the labeled rate in soy-bean is too low to provide season-longgrass control, except when the 14 oz/a rateis used on coarse-textured soils. Soybeansshould be planted 1 inch deep.Rotational restrictions: Corn and soybeans

can be planted anytime after application.Potatoes can be planted after 1 month; cab-bage and carrots after 4 months; and alfalfa,barley, beans, oats, peas, sweet corn, andwheat after 12 months.

Dual II Magnum(s-metolachlor + safener)Rate: 1 to 2 pt/a.Timing: Preplant-incorporated—Apply

within 14 days before planting, blendingthe herbicide into the top 2 inches of soilduring seedbed preparation. In dry sea-sons, preplant-incorporated applicationswill provide better annual weed controlthan preemergence applications.Preemergence—Apply after planting, but

before weeds and soybeans emerge.No-till: Apply 1.67 to 2.0 pt/a of s-meto-

lachlor. This treatment can be split withone-half applied early and the remainderapplied at planting. When soybeans will beplanted within 7 days, make a single appli-cation either ahead of or at planting. Ifweeds are present at the time of treatment,include Gramoxone or glyphosate in thespray mixture for improved annual weedburndown. On sands, loamy sands, orsandy loams, apply 1.33 pt/a within14 days before planting.

104

STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

SOYBEAN

weeds

(pre/ppi)CO

RNPRINCIPLES

OF

PESTMNGM

T.


Remarks: S-metolachlor provides good toexcellent control of foxtails and otherannual grasses, but fails to control vel-vetleaf and several other annual broadleafweeds. To broaden the spectrum of weedscontrolled, it can be tank-mixed with Com-mand, Lorox, Pursuit, Sencor, or trifluralin.Preplant-incorporated applications of2 pt/a s-metolachlor provide reasonableyellow nutsedge control, but preemergenceapplications provide only limited control.On soils with an organic matter contentbetween 6% and 20%, use up to 2.5 pt/a. Itis not labeled for use on peat or muck soils.Soybean injury is not a serious problem. S-metolachlor can be mixed with liquid fertil-izer for simultaneous application and pre-plant-incorporated applications can also beimpregnated onto certain dry fertilizers.Rotational restrictions: S-metolachlor will

not persist into the fall or the followinggrowing season.

FirstRate (cloransulam)Rate: 0.6 oz/a if less than 3% organic mat-

ter and 0.75 oz/a if greater than 3% organicmatter.Timing: Preplant-incorporated—Apply

within 2 weeks before planting for bestresults and incorporate into the top 1 to3 inches.Preemergence—Apply after planting and

before weed emergence, within 2 days ofplanting is best.No-till: Preplant surface applications can

be made within 2 weeks before planting.FirstRate has foliar activity to control cer-tain emerged broadleaf weeds. Add theadjuvants listed for postemergence applica-tions to obtain burndown activity.Gramoxone, glyphosate, and 2,4-D can betank-mixed with FirstRate to enhance burn-down. Apply FirstRate within 2 weeks ofplanting in no-till.Remarks: FirstRate controls several

broadleaf weeds including common andgiant ragweed (if not ALS resistant), vel-vetleaf, pigweed, lambsquarters, andsmartweed. FirstRate will not control blacknightshade and will require a tank-mixpartner or sequential herbicide treatmentfor control. Tank-mixing FirstRate withDual II Magnum, Intrro, or Outlook wouldprovide both grass and black nightshadecontrol. FirstRate’s control may be reduced

if applied to soil with greater than 5%organic matter. Do not apply if steady windspeed exceeds 10 miles per hour.Rotational restrictions: Do not plant wheat

until 3 months after application; alfalfa,field corn, oats, peas, and snap beans until9 months after application; and potatoesand sweet corn until 18 months after appli-cation. Tobacco can be transplanted10 months after a 0.3 oz/a rate, but requires30 months after higher rates. Crops notlisted on the label require a 30-month rota-tional interval.Gangster (FirstRate + Valor co-pack)Rate: 1.8 oz/a (0.3 oz/a FirstRate + 1.5

oz/a Valor) to 3.6 oz/a (0.6 oz/a FirstRate+ 3.0 oz/a Valor).Timing: Preemergence—Apply from 14 days

before planting to 3 days after planting.Remarks: Gangster will provide preemer-

gence control of many annual broadleafweeds. The length of residual activity willdepend on the rate used. At lower rates, itwill provide early season broadleaf controland could be followed with a broad spec-trum postemergence herbicide. At higherrates, grasses may be the only weeds thatrequire postemergence treatment. TheGangster co-pack contains Gangster FR,which has a label that is nearly identical toFirstRate, and Gangster V, which has a labelthat is nearly identical to Valor. Review theinformation under FirstRate and Valor fordetails and precautions about these prod-ucts. Although the Gangster FR labeldescribes postemergence applications, donot apply this co-pack postemergence orserious injury will result.Rotational restrictions: Each label has rota-

tional restrictions listed. Follow the mostrestrictive interval. Wheat can be planted at3 months after application; field corn, oats,peas, and snap beans after 9 months; andsweet corn and potato after 18 months.Many other crops require longer intervals.

Intrro (alachlor)Rate: Preplant-incorporated—2.5 to 3 qt/a.Preemergence—2 to 3 qt/a; 2 qt/a when

followed by glyphosate.Timing: Preplant-incorporated—Apply to

dry soil within 7 days before planting,blending the herbicide into the top 1 to 2inches of soil during seedbed preparation.

105

STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

SOYBEAN

weeds

(pre/ppi)CO

RNPRINCIPLES

OF

PESTMNGM

T.


106

STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

SOYBEAN

weeds

(pre/ppi)CO

RNPRINCIPLES

OF

PESTMNGM

T.

In dry seasons, preplant-incorporated treat-ment will provide better annual weed con-trol than preemergence treatment.Preemergence—Apply after planting, but

within 5 days after the last tillage for weedcontrol.No-till: For improved annual weed burn-

down, tank-mix glyphosate or Gramoxonewith 2.5 to 3 qt/a.Remarks: Intrro provides good to excel-

lent control of foxtails and other annualgrasses but fails to control velvetleaf andseveral other annual broadleaf weeds. Tobroaden the spectrum of weeds controlled,Intrro can be tank-mixed with Command,Lorox, Pursuit, or Sencor. Preplant-incorpo-rated Intrro at 3 lb/a of active ingredientprovides reasonable yellow nutsedge con-trol on mineral soils as well as peat or mucksoils. Preemergence-applied Intrro providesonly limited control of yellow nutsedge. Tocontrol black or hairy nightshade, use aminimum of 2.5 lb/a active Intrro on coarsesoils and 3 lb/a active Intrro on medium-and fine-textured soils. Intrro provides bet-ter annual weed control on peat or mucksoils than other soil-applied herbicides.Soybean injury from Intrro isn’t a seriousproblem. Certain dry fertilizers can beimpregnated with Intrro where the herbi-cide/fertilizer mixture will be incorporatedinto the soil before planting.Rotational restrictions: Alfalfa, corn, dry

beans, small grains, and soybeans can beplanted the following season.

Lorox (linuron)Rate: 1 to 2 lb/a of Lorox DF.Timing: Preemergence—Apply after plant-

ing, but before soybeans emerge.No-till: Preplant treatments of Lorox DF

can be surface-applied where soybeans willbe planted into a cover crop or previouscrop residue. If small weed seedlings arepresent, add 1% crop oil concentrate to thespray mixture. For larger weeds, Lorox canbe tank-mixed with Gramoxone,glyphosate, or 2,4-D for improved annualweed burndown.Remarks: Lorox provides good control of

most annual broadleaf weeds but only par-tially controls cocklebur and can missgrasses. Lower rates of Lorox can be tank-mixed with Dual II Magnum, Intrro, orOutlook to improve grass control. Lorox is

ineffective on peat or muck soils. Risk ofsoybean injury increases markedly onsandy soils. Do not use Lorox on sand,loamy sand, or any soil with less than 1%organic matter. Plant soybeans at least 1.75inches deep. Even on medium and heavysoils, heavy rainfall following applicationcan leach Lorox to the soybean root zonecausing foliar burn and stand reduction.Applications to areas with residual atrazinemay cause serious soybean injury.Rotational restrictions: Crops can be planted

4 months following Lorox application.

Outlook (dimethenamid-P)Rate: 10 to 21 oz/a.Timing: Preplant-incorporated—Blend the

herbicide into the top 1 to 2 inches of soilwithin 14 days before planting. In dry sea-sons, preplant-incorporated treatment willprovide better annual weed control thanpreemergence treatment. Preplant-incorpo-rated applications are not recommended oncoarse soils with less than 1.5% organicmatter.Preemergence—Apply after planting, but

before weeds emerge. If application delaysoccur, Outlook may be applied from the 1to 3 trifoliate stage.No-till: Usually a split application where

one-half of the herbicide is applied earlyand the remainder applied at planting pro-vides better weed control. When soybeanswill be planted within 7 days, make a sin-gle application either ahead of or at plant-ing. If weeds are present at the time oftreatment, include Gramoxone orglyphosate in the spray mixture forimproved annual weed burndown. Earlypreplant treatment is not recommended oncoarse-textured soils.Remarks: Outlook provides good to excel-

lent control of foxtails, crabgrass, and fallpanicum, but has no effect on quackgrass. Itfails to control velvetleaf and several otherannual broadleaf weeds. To broaden thespectrum of weeds controlled, Outlook canbe tank-mixed with Command, Lorox,Prowl, Pursuit, Python, Sencor, or triflu-ralin. Preplant-incorporated Outlook at 20oz/a provides reasonable yellow nutsedgecontrol, but preemergence applications pro-vide only limited control. Adjust the rateaccording to either soil cation exchangecapacity or soil texture and organic matter


107

STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

SOYBEAN

weeds

(pre/ppi)CO

RNPRINCIPLES

OF

PESTMNGM

T.

content. Use 21 oz/a of Outlook on all soilswith greater than 8% organic matter. Out-look generally doesn’t injure soybeans, butlong periods of saturated soil may suppressearly season soybean growth. Outlook canbe impregnated onto certain dry fertilizersfor simultaneous application.Rotational restrictions: Small grains can be

planted 4 months after application andthere are no restrictions the year afterapplying Outlook.

Prowl H2O (pendimethalin)Rate: 1.5 to 3.0 pt/a.Timing: Preplant-incorporated—Apply to

dry soil within the several weeks beforeplanting. Incorporate into the top 1 to 2inches of soil within 7 days of application.Preplant-surface—Apply up to 15 days

before planting or 45 days before planting ifPursuit is applied postemergence. Do notapply after planting.No-till: Pendimethalin can be tank-mixed

with 2,4-D, glyphosate, or Gramoxone forburndown or with several other residualherbicides to broaden the spectrum ofcontrol.Remarks: Pendimethalin provides good to

excellent annual grass control, but does notadequately control velvetleaf, wild mus-tard, common ragweed, smartweed, cockle-bur, or black nightshade. To broaden thespectrum of weed control, it can be tank-mixed with Command, Dual II Magnum,Intrro, Pursuit, or Sencor. Pendimethalin isineffective on peat or muck soils. Soybeaninjury doesn’t appear to be a problemexcept when applied to wet soils or in areassubject to prolonged flooding. Injury symp-toms are stunted soybean plants withswollen stems and inhibited secondaryroots. Pendimethalin can be impregnatedonto certain dry fertilizers for simultaneousapplication.Rotational restrictions: Pendimethalin gen-

erally doesn’t persist into the following sea-son, but winter wheat or winter barleyshould not be planted within 120 days afterapplication.

Prefix (Dual Magnum + Flexstarpremix)Rates: 2.0 to 2.5 pt/a. In southern Wiscon-

sin (south of Hwy 18 west of Madison andsouth of I-94 east of Madison), the maxi-mum rate is 2.5 pt/a. The maximum is2 pt/a in the region south of I-94 and Hwy29, excluding the counties of Adams, Clark,Marathon, Marquette, Portage, Shawano,Waupaca, Waushara, and Wood counties.Timing: Preplant incorporated—Apply and

incorporate into the top 2 inches of soilwithin 7 days after application. In dry sea-sons, preplant-incorporated treatment willprovide better weed control than preemer-gence treatment.Preemergence—Apply after planting, but

prior to weed emergence.No-till:Apply up to 15 days before no-till

planting or apply preemergence after plant-ing. Tank-mix with glyphosate, Gramox-one, or 2,4-D to control emerged weeds.Remarks: Prefix will control many annual

grass and broadleaf weeds. The 2 pt/a rateis intended to provide early season residualcontrol prior to a postemergenceglyphosate or conventional herbicide treat-ment. The length and degree of control willdepend on the soil texture and organic mat-ter. Full season control of many weeds maybe possible on coarse-textured soil. If themaximum rate of Prefix was soil-applied,do not apply Flexstar postemergence.Rotational restrictions: Soybeans or snap

beans can be planted anytime after applica-tion; small grains can be planted after 4.5months; field and sweet corn and peas after10 months; and alfalfa, potato, and tobaccoafter 18 months.

Pursuit (imazethapyr)Rate: 4 fl oz/a Pursuit or equivalent.Timing: Preplant-incorporated—Apply to

dry soil and blend into the top 1 to 2 inchesof soil up to 45 days before planting.Preemergence—Apply after planting, but

before soybeans emerge.No-till: Pursuit may be tank-mixed with

2,4-D, Gramoxone, or glyphosate forimproved annual weed burndown. Formaximum residual grass control, includealachlor, Dual II Magnum, Outlook, orProwl in the spray mixture.


Remarks: Pursuit controls numerousannual broadleaf weeds and provides someannual grass control. However, it is usuallytank-mixed with a soil-applied herbicidesuch as Dual II, Intrro, Outlook, Prowl, ortrifluralin to broaden control. Do not tank-mix with Command. Do not apply Pursuitmore than once per season or the same yearas other imazethapyr-containing herbi-cides. Pursuit is ineffective on peat or mucksoils. Risk of soybean injury from Pursuit isminimal but it occasionally causes internodeshortening and a reduction in fine root hairs.Rotational restrictions: Do not plant wheat

until 3 months after application; alfalfa, edi-ble beans, peas, or rye until 4 months afterapplication; conventional field corn or seedcorn until 8.5 months after application; bar-ley or tobacco until 9.5 months after appli-cation; oats, popcorn, sorghum, or sweetcorn until 18 months after application; orpotatoes until after 26 months. All othercrops should not be planted for 40 monthsafter Pursuit application.

Pursuit Plus(Pursuit + Prowl premix)Rate: 2.5 pt/a.Timing: Preplant-incorporated—Apply

within 45 days before planting. Incorporateinto the top 1 to 2 inches of soil within 7days of application.Preplant-surface—Apply up to 45 days

before planting, but not after planting.No-till:Add nonionic surfactant at 0.25%

to the spray mixture and 1 to 2 qt/a liquidnitrogen fertilizer to burndown manyannual weeds including cocklebur, pig-weeds, smartweed, and velvetleaf.Gramoxone, glyphosate, or 2,4-D can beadded to burndown other annual weedsnot controlled by Pursuit.Remarks: This combination provides

good annual weed control but is ineffectiveon peat or muck soils. For broader spec-trum control, include FirstRate or Sencor.Additional grass control can be obtained bymixing extra Prowl with Pursuit Plus. Pur-suit Plus generally doesn’t injure soybeans.This herbicide combination can be impreg-nated onto certain dry fertilizers for simul-taneous application.

Rotational restrictions: Pursuit Plus maypersist and cause damage to susceptiblecrops the following season. It has the samerestrictions as Pursuit except alfalfa cannotbe planted until 9.5 months after application.

Python (flumetsulam)Rate: 0.8 to 1.33 oz/aTiming: Preplant incorporated—Apply and

incorporate in to top 2 to 3 inches of soilwithin 30 days before planting. The lowerrates within each soil texture category needto be applied within 14 days of planting.Preemergence—Apply after planting, but

before soybeans crack or weeds emerge.No-till: If weeds are present at the time of

treatment, include Gramoxone, glyphosate,or 2,4-D in the spray mixture for annualweed burndown.Remarks:At lower labeled rates Python

controls lambsquarters, pigweed, and vel-vetleaf. Higher labeled rates controlsmartweed and nightshade. Some commonand giant ragweed will escape control, evenat higher rates. Python can be used as a pre-emergence treatment to control broadleafweeds prior to a glyphosate treatment inRoundup Ready soybeans. Do not use onpeat or muck soils. Soybeans have showngood tolerance to Python.Rotational restrictions: Field and seed corn

can be replanted anytime. Do not plantalfalfa, dry beans, small grains, or peas for4 months after application; tobacco until9 months after application; or potatoes until12 months after application. Sweet cornshould not be planted until 18 months afterapplication, with the exception of the spe-cific hybrids listed on the label or supple-ments that can be planted after 10.5 months.Crops not listed on the label require a26-month rotational interval.

Sencor (metribuzin)Rate: 0.33 to 0.66 lb/a of Sencor DF.Timing: Preemergence—Apply after plant-

ing, but before soybeans emerge.No-till: Sencor may be tank-mixed with

either Gramoxone or glyphosate forimproved annual weed burndown.

108

STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

SOYBEAN

weeds

(pre/ppi)CO

RNPRINCIPLES

OF

PESTMNGM

T.


109

STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

SOYBEAN

weeds

(pre/ppi)CO

RNPRINCIPLES

OF

PESTMNGM

T.

Remarks: Sencor provides excellent con-trol of annual broadleaf weeds but onlypartial control of annual grasses. It can betank-mixed with Command, Dual II Mag-num, Intrro, Outlook, or Prowl to broadenthe spectrum of control. Sencor is ineffec-tive on peat or muck soils. Risk of soybeaninjury increases markedly on lighter-tex-tured soils and on soils with a pH of 7.5 orhigher. Do not use Sencor on sand regard-less of organic matter content, on loamysand or sandy loam with less than 1%organic matter, or on any soil with less than0.5% organic matter. Plant soybeans 1.5inches deep. Even on medium and heavysoils, heavy rainfall following applicationcan leach Sencor to the soybean root zonecausing foliar burn and stand reduction.Applications to areas with residual atrazinemay cause serious soybean injury. Addi-tionally, the use of an organophosphateinsecticide on the same ground mayincrease the risk of soybean damage. Certaindry fertilizers may also be impregnatedwith this herbicide.Rotational restrictions: Alfalfa, barley,

corn, potatoes, and wheat can be planted4 months after application; peas after 8months; and beans and oats after 12months.

SonicSee sulfentrazone + cloransulam premix

(this page).

Sulfentrazone + cloransulampremixRate: 6.45 to 8 oz/a; reduced rates of 3 to

4 oz/a are recommended for early seasonweed suppression when followed byglyphosate in Roundup Ready soybeans.Timing: Preplant incorporated—Apply

within 14 days and incorporate into the top1 to 3 inches of soil.Preemergence—Apply at planting or

within 3 days after planting.No-till: Preplant surface applications can

be made before planting and this premixwill provide burndown activity on certainbroadleaf weeds in addition to residualactivity if 0.125 to 0.25% nonionic surfac-tant and ammonium sulfate at 2.5 lb/a areadded. It can be mixed with glyphosate,Gramoxone, or 2,4-D to broaden the spec-trum of control.

Remarks: This premix will provide pre-emergence control of many annualbroadleaf weeds. The length of residualactivity will depend on the rate used. Atlower rates, it will provide early seasonbroadleaf weed control when followed byglyphosate in Roundup Ready soybeans. Atfull rates, annual grasses will be sup-pressed, but will likely need to be con-trolled postemergence. The seed furrowmust be closed prior to applying this pre-mix or crop injury may result. Do not applyto cracking or emerged soybeans becausesevere injury will occur. Do not apply tosands with less than 1% organic matter. Donot apply if steady wind speed exceeds 10miles per hour.Rotational restrictions:Wheat can be

planted after 4 months; field corn after 10months (if organic matter is greater than1.5% and soil pH is less than 7); alfalfa,small grains, and dry beans after 12months; and sweet corn and potato after 18months. Several other crops cannot beplanted for 30 months.

TrifluralinRate: 1 to 2 pt/a of 4 lb/gal formulation

or equivalent.Timing: Preplant-incorporated—Apply to

dry soil within the several weeks beforeplanting. Incorporate into the top 2 to 3inches of soil within 24 hours after applica-tion. Prompt incorporation is important.Remarks: Trifluralin provides good to

excellent annual grass control, but does notcontrol black nightshade, cocklebur, wildmustard, common ragweed, smartweed, orvelvetleaf. Trifluralin can be tank-mixedwith Command or metribuzin. It is ineffec-tive on peat or muck soils. Soybean injurydoesn’t appear to be a problem except whentrifluralin is applied to wet soils or in areassubject to prolonged flooding. Trifluralincan cause stunted soybean plants withswollen crowns and inhibited secondaryroots. It can be mixed with liquid fertilizersor impregnated onto certain dry fertilizersfor simultaneous application.Rotational restrictions: Rotational grass

crops can be planted 12 months followingapplication. There is some danger that tri-fluralin may persist and damage suscepti-ble crops the following season. Risk of suchcarryover appears greater when the subse-quent sensitive crop is no-till planted.


Valor SX (flumioxazin)Rate: 2 to 3 oz/a.Timing: Preplant or preemergence—Apply

within 3 days after planting. Do not applypreplant incorporated.No-till: Valor can be tank-mixed with

glyphosate, Gramoxone, Synchrony, or2,4-D to increase the speed of burndown orto provide residual annual weed controlincluding seedling dandelion. To obtain thefull burndown activity from Valor, include1 to 2 pt/a crop oil concentrate.Remarks: Valor controls several small-

seeded broadleaf weeds and provides someannual grass suppression. Broadleaf weedsthat should be controlled at the 2 oz/a rateinclude lambsquarters, horseweed, night-shade, and pigweeds. Valor at 2.5 oz/ashould control most common ragweed andwaterhemp, but the rate should beincreased to 3 oz/a on fine-textured soils.Valor is not labeled to control weeds onsoils with greater than 5% organic matter.Valor can be tank-mixed with FirstRate,Lorox, Pursuit Plus, or Python for addi-tional broadleaf control or Command 3MEor pendimethalin for grass control. Due tothe risk of injury, do not use Valor as atank-mix partner with or apply to fieldstreated with Define, Dual II Magnum,Intrro, or Outlook. Valor may injure soy-beans if soils are cold and wet. To minimizethe risk of injury, plant soybeans at least 1.5inches deep. Do not incorporate Valor orapply if soybeans are cracking. Rain splat-ter may cause speckling of soybean plants.Rotational restrictions:At Valor rates up to

3 oz/a, field corn can be planted 1 monthafter application; tobacco and wheat can beplanted after 2 months; barley, snap anddry beans, and sweet corn can be plantedafter 4 months; and alfalfa and oats can beplanted after 5 months if tilled.

POSTEMERGENCE HERBICIDES

Assure II (quizalofop)Rate: 7 to 10 fluid oz/a.Adjuvants: Add either crop oil concentrate

at 1% or nonionic surfactant at 0.25% to thespray mixture.Timing: Soybean—Apply any time after

emergence until soybean pod set or up to80 days before harvest.Weeds—Apply 7 oz/a to 4-inch green fox-

tail and yellow foxtail and 8-inch giant fox-tail. Apply 5 oz/a to 6-inch wild proso mil-let and 12-inch shattercane. Apply 8 oz/a to6-inch crabgrass and 8-inch wirestemmuhly; 9 oz/a to 4-inch woolly cupgrass;and 10 oz/a to 10-inch quackgrass.Remarks: Assure II controls annual grasses

and perennial grasses like quackgrass andwirestem muhly. Control of quackgrass andwirestem muhly is usually evident the sea-son after application. Assure II can be tank-mixed with glyphosate to control volunteerRoundup Ready corn. Use 4 oz/a for12-inch tall corn, 5 oz/a for 18-inch tallcorn, and 8 oz/a for 30-inch tall corn. Add0.125% surfactant if the glyphosate formu-lation contains an adjuvant. If not, add0.25% nonionic surfactant. Soybean injuryfromAssure II is not a problem.Assure II can be tank-mixed with

Basagran, Classic, Flexstar, Harmony, andSynchrony, but grass control may bereduced. This antagonism can be reducedby increasing the Assure II rate or by apply-ing Assure II in a separate application. Insequential applications, apply Assure II 1day before or 7 days after the broadleaf her-bicide.Rotational restrictions: Do not rotate to

crops other than soybeans within 120 daysafter Assure II application.

Basagran (bentazon)Rate: 1 to 2 pt/a.Adjuvants: Add 1 qt/a of crop oil concen-

trate in the final spray mixture. Where vel-vetleaf is the primary weed problem, 2 to 4qt/a of 28% nitrogen solution or 2.5 lb/a ofspray grade ammonium sulfate may besubstituted for crop oil concentrate. If com-mon lambsquarters and/or common rag-weed are present with velvetleaf, use cropoil concentrate plus a nitrogen additive. Do

110

STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

SOYBEAN

weeds

(post)CO

RNPRINCIPLES

OF

PESTMNGM

T.


not apply Basagran in liquid fertilizerexcept as specified with 28% nitrogen orammonium sulfate.Timing: Soybean—Applications are gener-

ally made from the unifoliate to second tri-foliate leaf stage, but all stages are tolerant.Weeds—See label for weed size and rate

required for control.Remarks: Basagran provides fair to excel-

lent control of many annual broadleafweeds. Redroot pigweed and commonlambsquarters are only partially controlled,especially when treated late. Velvetleaf andcocklebur control is excellent. Basagranprovides good suppression of yellownutsedge and fair burndown Canada this-tle. It can be tank-mixed with other poste-mergence soybean herbicides. Soybeans arequite tolerant of Basagran but slight leafyellowing, bronzing, speckling, or burnmay occur. Soybeans generally outgrowthis condition within 10 days. Soybean leafburn increases when using nitrogen solu-tion, but new soybean growth is normaland crop vigor is not reduced. BecauseBasagran has contact action, weeds must bethoroughly covered with spray. Do notapply if wind exceeds 10 miles per hour.Rotational restrictions: None.

Cadet (fluthiacet)Rate: 0.4 oz/a in glyphosate mixtures,

0.5 oz/a with other mixtures, or 0.6 to0.9 oz/a if applied alone.Adjuvants: Add nonionic surfactant at

0.25% or crop oil concentrate at 1 to 2 pt/ato the spray solution. 28% nitrogen solutionat 1 to 2 qt/a or ammonium sulfate at 1 to2 lb/a may be added. If mixed with a fullyloaded glyphosate, only add ammoniumsulfate as required for glyphosate.Timing: Soybeans—Apply from first trifoli-

ate to full flower stages.Weeds—At the 0.9 oz/a rate, apply before

lambsquarters and waterhemp exceed2 inches, before pigweed exceeds 4 inches,and before velvetleaf exceeds 36 inches.Remarks: Cadet may cause temporary

speckling of soybean leaves. Cadet hasexcellent activity on velvetleaf and controlsplants up to 36 inches tall at 0.6 oz/a or atlower rates in tank mixtures. At the0.9 oz/a rate, it is labeled to control lambs-quarters, waterhemp, jimsonweed, and pig-weed, but these weeds are only listed as

suppressed at lower rates. Cadet has con-tact activity and requires good spray cover-age with a minimum of 15 gallons per acrespray volume and 20 psi spray pressure. Itis an option when targeting velvetleaf aloneor to improve the control of other broadleafherbicides. Do not apply if wind speedexceeds 10 miles per hour. Cadet can beused on field, silage, seed, and sweet corn.Rotational restrictions: Corn or soybeans

can be replanted anytime if the crop is lost.Other crops should not be planted until thefollowing year.

Classic (chlorimuron)Rate: 0.5 to 0.75 oz/a if soil pH is less

than 7.0 or 0.25 to 0.33 oz/a when tank-mixed with Harmony GT.Adjuvants: Add nonionic surfactant at

0.25% to the spray mixture. If droughty,crop oil concentrate at 1.0% (0.5% in Classic+ Harmony GT tank mixtures) of spray canbe used instead of surfactant. For velvetleafcontrol, add 2 to 4 qt/a of 28% nitrogensolution or 2 to 4 lb/a of spray gradeammonium sulfate, with surfactant or cropoil concentrate.Timing: Soybean—Apply after the first tri-

foliate leaf stage, but 60 days before soy-bean harvest.Weeds—See label for weed size and rate

required for control.Remarks: Classic controls several annual

broadleaf weeds, but lambsquarters andnightshade escape control. Tank-mixingClassic at 0.25 to 0.33 oz/a with HarmonyGT will control lambsquarters and improvevelvetleaf control over that provided byClassic alone. Tank-mixing Classic withFlexstar, lactofen, or Ultra Blazer will con-trol nightshade and waterhemp andimprove control of common ragweed. Tank-mixing Classic with a half rate of Pursuit(use 0.125% surfactant plus nitrogen) willcontrol nightshade. Tank-mixing Classicwith FirstRate will control common andgiant ragweed. Classic can be tank-mixedwith postemergence grass herbicides.Classic at 0.25 to 0.33 oz/a can also be tank-mixed with glyphosate when treatingRoundup Ready soybeans to improve yel-low nutsedge control. Ammonium sulfateis recommended in all Classic plusglyphosate tank mixtures. Surfactant at

111

STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

SOYBEAN

weeds

(post)CO

RNPRINCIPLES

OF

PESTMNGM

T.


0.25% should be added when theglyphosate formulation allows for thisaddition.Temporary yellowing and/or retardation

of soybean growth may occur within 5 to7 days after Classic treatment. STS (sulfony-lurea tolerant) soybean varieties show no orminimal injury after treatment even whencrop oil concentrate is used. Do not applyClassic to soybeans that are under stressfrom weather extremes or injury fromanother herbicide. Use Classic spray prepa-rations within 24 hours of mixing or prod-uct degradation may occur.Rotational restrictions: Classic may persist

and cause damage to susceptible crops thefollowing growing season especially if thesoil pH exceeds 7.0. Small grains can beplanted 3 months after treatment; alfalfa,field corn, processing sweet corn, drybeans, and peas can be planted 9 monthsafter treatment.

CobraSee lactofen (page 116).

Extreme(Pursuit + glyphosate premix)Use only on Roundup Ready soybean

varieties.Rate: 3 pt/a.Adjuvants:Add nonionic surfactant at

0.125% to the spray mixture plus ammoniumsulfate at 8.5 to 17 lb per 100 gal of spray.Timing: Soybean—Apply before bloom

and 85 days before harvest.Weeds—In general, apply before weeds

are 8 inches tall. The label lists specificweed heights for control. The maximumsize for crabgrass, foxtail, fall panicum, andwoolly cupgrass is at least 12 inches talland barnyardgrass is 6 inches tall. The max-imum size for lambsquarters, nightshade,pigweed, common and giant ragweed,smartweed, and waterhemp is at least 6inches and velvetleaf is 5 inches.Remarks: Extreme will provide good con-

trol of most annual grasses and broadleafweeds and will suppress perennial weeds.This premix has excellent postemergenceactivity and will provide residual control ofmany weeds. The greatest benefit of theresidual activity may be in row soybeanswhere the soybean canopy is slower toclose, when Extreme is applied very earlyin drilled soybean, or when drilled soy-

beans have a poor stand. Extreme may betank-mixed with Outlook to enhance resid-ual grass control. The risk of injury withExtreme is low, but it may cause stunting.Be cautious to avoid drift onto corn or otherplants during application. Extreme can alsobe applied before emergence of conven-tional soybeans as a burndown treatmentand can be tank-mixed with 2,4-D or Prowl,if applied before planting.Rotational restrictions: Do not plant wheat

until 3 months after application; alfalfa, edi-ble beans, peas, and rye until 4 monthsafter application; conventional field andseed corn until 8.5 months after application;barley and tobacco until 9.5 months afterapplication; oats and sweet corn until 18months after application; and potatoes until26 months. Allow 40 months before plant-ing all other crops.

FirstRate (cloransulam)Rate: 0.3 oz/a.Adjuvants:Add 0.125 to 0.25% of nonionic

surfactant. Ammonium sulfate at 2 lb/a or2.5% of 28% nitrogen solution or crop oilconcentrate at 1.2% may be added to thespray mixture. Always include a nitrogensource when treating velvetleaf. Injury mayincrease when a nitrogen source is appliedwith crop oil concentrate.Timing: Soybean—Apply before 50%

flowering.Weeds—Apply before horseweed,

smartweed, and velvetleaf exceed 6 inches;before common ragweed exceeds 8 inches;and before cocklebur and giant ragweedexceed 10 inches.Remarks: FirstRate controls several

broadleaf weeds and is excellent on com-mon and giant ragweed (if not ALS resis-tant) and cocklebur. To control commonlambsquarters and black nightshade,FirstRate will need to be tank-mixed or fol-low a preemergence herbicide that controlsthese weeds. Labeled tank-mix partnersinclude most postemergence broadleaf andgrass herbicides. Follow rates and adjuvantrecommendations of the tank-mix partner.FirstRate may antagonize Assure II andFusion’s activity, so sequential applicationsare recommended. Do not apply if steadywind speeds exceed 10 miles per hour. Soy-bean stunting from FirstRate seems to beminimal or temporary.

112

STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

SOYBEAN

weeds

(post)CO

RNPRINCIPLES

OF

PESTMNGM

T.


Rotational restrictions: Do not plant wheatuntil 3 months after application; alfalfa,field corn, oats, peas, and snap beans until9 months after application; and potatoesand sweet corn until 18 months after appli-cation. Tobacco can be transplanted 10months after a 0.3 oz/a rate, but requires 30months after higher rates. Crops not listedon the label require a 30-month rotationalinterval.

Flexstar (fomesafen)Rate: 1.0 to 1.3 pt/a. In southern Wiscon-

sin (south of Highway 18 if west of Madi-son and south of I-94 if east of Madison),the maximum rate is 1.3 pt/a. The maxi-mum rate is 1 pt/a Flexstar in most of theregion south of I-94 from Minnesota to EauClaire and south of Highway 29 from EauClaire to Green Bay plus Door andKewaunee counties. Flexstar is not regis-tered for use in Adams, Clark, Marathon,Marquette, Portage, Shawano, Waupaca,Waushara, and Wood counties or in north-ern Wisconsin.Adjuvants: Add nonionic surfactant at

0.25 to 0.5% or crop oil concentrate at 0.5 to1% to the spray mixture. Also add either1 to 2.5 gal of 28% nitrogen solution or8.5 lb of ammonium sulfate per 100 gal ofspray mixture.Timing: Soybean—Apply before bloom.

Weeds—The maximum leaf stage is 2 to6 leaves depending on broadleaf speciesand rate. See label for specific weeds.Remarks: Flexstar controls many annual

broadleaf weeds. Some lambsquarters andvelvetleaf may escape control. Tank mixeswith Basagran, Classic, FirstRate,glyphosate, Harmony GT, Pursuit, Raptor,Resource, and Synchrony are labeled. Flexs-tar can be tank-mixed with all of the poste-mergence grass herbicides, but it mayreduce the activity of the grass herbicide.Treated soybeans almost always show someleaf speckling, crinkling, and bronzing,especially on the youngest leaves. Soybeansgenerally outgrow this condition and cropvigor is not reduced. Because Flexstar hascontact action, weeds must be thoroughlycovered with spray. Use 15 to 20 gal/a ofwater and 30 to 60 psi pressure through flatfan or hollow cone nozzles.

Rotational restrictions: Small grains can beplanted 4 months after application, andbeans, corn, and peas can be planted10 months after application. Other cropsshould not be planted until 18 months aftertreatment. Flexstar can only be used inalternate years.

Fusilade DX (fluazifop-p)Rate: Apply 4 to 6 oz/a.Adjuvants: Add 0.25% crop oil concentrate

plus any adjuvants required by theglyphosate formulation.Timing: Soybean—Apply from emergence

until soybean bloom.Weeds—Apply before volunteer Roundup

Ready corn is 12 inches tall.Remarks: Fusilade DX has a supplemental

label recommending a tank mixture withglyphosate to control volunteer RoundupReady corn in Roundup Ready soybeans.With favorable soil moisture and weatherconditions, the 4 oz/a rate can be used.Fusilade DX can be used for annual grasscontrol in conventional soybeans, but otherpostemergence grass herbicides are recom-mended. Fusilade DX is rainfast in 1 hour.Rotational restrictions: Do not replant

grass crops like corn or small grains for60 days.

Fusion (Fusilade + fenoxaprop premix)Rate: 8 fluid oz/a.Adjuvants: Add crop oil concentrate at 0.5

to 1% or nonionic surfactant at 0.25 to 0.5%to the spray mixture. Use crop oil concen-trate at 1% when treating perennial grasses.The Fusion label also permits the additionof 28% nitrogen solution at up to 4% to thespray mixture or up to 4 lb/a ammoniumsulfate if required by a tank-mix partner.Timing: Soybean—Apply before bloom.Weeds—Apply 8 fluid oz/a to 2- to 4-inch

green and yellow foxtail, field sandbur andwoolly cupgrass, 2- to 6-inch fall panicum,2- to 8-inch giant foxtail, and 1- to 4-inchcrabgrass. Fusion at 6 fluid oz/a controls 4-to 8-inch wild proso millet, 6- to 12- inchshattercane, and 12- to 24-inch volunteercorn. Apply up to 14 oz/a as rescue treat-ments of giant foxtail, wild proso millet,and woolly cupgrass up to 16 inches tall.Remarks: Fusion controls annual grasses.

Two separate applications of Fusion, timed2 to 3 weeks apart, control perennialgrasses like quackgrass and wirestem

113

STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

SOYBEAN

weeds

(post)CO

RNPRINCIPLES

OF

PESTMNGM

T.


muhly. Fusion can be tank-mixed withglyphosate to control volunteer RoundupReady corn. Use 4 oz/a of Fusion plus0.25% crop oil concentrate if the corn is lessthan 12 inches tall. If the corn is 12 to 24inches tall, use 6 oz/a. Fusion can be tank-mixed with most broadleaf herbicides, butantagonism may reduce grass control. Tocompensate, the Fusion rate can beincreased 4 oz/a in tank mixtures. Whenyellow foxtail, barnyardgrass, woolly cup-grass, sandbur, or crabgrass are problemweeds, applying Fusion sequentially topostemergence broadleaf herbicides is rec-ommended. In sequential applications,apply Fusion 2 or 3 days before thebroadleaf herbicide or about 7 days afterthe broadleaf herbicide, when the grass hasgrown a new leaf. Do not apply Fusion tograsses that are stressed from weatherextremes or injury from another herbicide.Soybean injury from Fusion is not a problem.Rotational restrictions: Do not plant rota-

tional grass crops such as corn, sorghum, orsmall grains within 60 days after Fusionapplication.

GlyphosateRate: Broadcast—0.75 to 1.5 lb ae/a per

application for a total of 2.25 lb ae/a perseason in-crop. Use only on RoundupReady soybean varieties.Preharvest—Apply 0.75 to 3 lb ae/a

according to weed species (Touchdown islimited to 0.78 lb ae/a in Roundup Readysoybeans).Adjuvants:Ammonium sulfate at 8.5 to

17 lb/100 gal of spray mixture is recom-mended when treating drought-stressedplants or larger, hard-to-control weeds.Check the label to see if the glyphosate for-mulation requires additional surfactant.Glyphosate conversion table




Timing: Broadcast—Apply from soybeanemergence to full flower (R2 stage). Treatup to 8-inch annual weeds with 0.75 lbae/a of glyphosate. Larger weeds andperennials require higher rates.Preharvest—Apply at least 7 days before

normal soybean harvest, but only after soy-bean pods have lost all their green color.For best dry-down of weeds, wait 14 to 21days after application before harvestingsoybeans.Remarks: Broadcast—Roundup Ready soy-

beans are resistant to postemergence-applied glyphosate, but only use formula-tions labeled for such use. Glyphosate con-trols emerged grass and broadleaf weeds,but has no residual control. Glyphosate canbe tank-mixed with Assure II, Fusilade DX,Fusion, or Select Max to control volunteerRoundup Ready corn. (See the remarks sec-tion of those herbicides for adjuvant recom-mendations.) In drilled soybeans with theirearlier canopy closure, a single glyphosateapplication often provides season-long con-trol. We have had good results treatingdrilled soybeans at the 2-trifoliate leaf stage(when weeds are 2 to 6 inches) with 0.56 lbae/a glyphosate. Row soybeans mayrequire a second application. Be very cau-tious to avoid glyphosate drift onto corn orother plants during application.Preharvest—Glyphosate can be applied to

actively growing weeds as a preharvestcleanup for the control of perennial weedssuch as quackgrass (0.75 to 1.5 lb ae/a),Canada thistle (1.5 to 2.25 lb ae/a),bindweeds (2.25 to 3 lb ae/a), and hempdogbane (3 lb ae/a). Apply in 10 to 20gal/a of water and adjust nozzle height forgood weed coverage. If applying by air,mix up to 0.75 lb ae/a of glyphosate in 3 to5 gal/a of water. Do not apply if weedshave been damaged by frost. Perennialweeds should only be treated if at leasttwo-thirds of the plants’ leaves are greenand physiologically active. Touchdown islimited to 1 qt/a as a preharvest treatmenton Roundup Ready soybeans, but 6 qt/acan be applied in conventional soybeans.Rotational restriction: Glyphosate formu-

lations have no rotational restrictions forWisconsin field crops except for a 30-dayinterval before tobacco.

114

STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

SOYBEAN

weeds

(post)CO

RNPRINCIPLES

OF

PESTMNGM

T.


Gramoxone Inteon (paraquat)Preharvest: Gramoxone is registered as a

“harvest aid” or desiccant for soybeans. Itis not intended to hasten crop maturitysince this would result in immature, lowgrade soybeans. The primary purpose ofGramoxone is to dry weed growth that ispresent in mature soybeans.Rate: 5.5 to 11 fl oz/a (or 8 to 16 fl oz/a

Gramoxone Inteon).Adjuvants: Add nonionic surfactant at

0.125% or 1% crop oil concentrate to thespray mixture.Timing: Soybean—Apply when plants are

mature, at least 65% of the seed pods havereached a mature brown color, or whenseed moisture is 30% or less. Apply at least15 days before harvest.Remarks: Paraquat use allows faster com-

bine speed and reduces green weed foliagein the harvested crop. This treatment willdesiccate black nightshade leaves butberries will remain on the treated plant.Mature cocklebur is quite tolerant ofparaquat. Use a minimum of 20 gal/a ofwater with ground application and 5 gal/awhen paraquat is applied aerially. Avoidparaquat application when uniform cover-age cannot be obtained or excessive spraydrift may occur.Rotational restrictions: None.

Harmony SG (thifensulfuron)Rate: 0.125 oz/a on non-STS soybeans.

Apply up to 0.5 oz/a when tank-mixedwith glyphosate on STS/RR soybeans.Adjuvants: Add nonionic surfactant at

0.125 to 0.25% or crop oil concentrate at0.5% to the spray mixture. The higher rateof surfactant increases risk of soybeaninjury, particularly under hot, humid condi-tions. The oil addition is preferred underdry, cool conditions but also increases therisk of soybean injury. Also include 2 to 4qt/a of 28% nitrogen solution or 1 to 2 qt/aof 10-34-0 in the spray mixture. Sprayablegrade ammonium sulfate at 2 to 4 lb/a mayalso be used.With glyphosate tank mixtures on

STS/RR soybeans, add 4.25 to 17 lb/100 galof ammonium sulfate. Also add 0.125 to0.25% nonionic surfactant if the glyphosateformulation is not pre-loaded.

Timing: Soybean—Apply after the first tri-foliate leaf, but 60 days before harvest.Weeds—Harmony controls up to 4-inch

common lambsquarters, 8-inch pigweeds,6-inch velvetleaf, and 6-inch smartweeds.Remarks: Harmony controls several

broadleaf weeds, but does not control blacknightshade. Tank-mixing Harmony with ahalf rate of Pursuit (use 0.125% surfactantplus nitrogen) will control nightshade. Har-mony can be tank-mixed with postemer-gence grass herbicides, Basagran, Classic,Flexstar, or lactofen. Harmony can be tank-mixed with glyphosate to increase lamb-squarters control in Roundup Ready soy-beans. In STS/RR soybeans, the specialhigh rate is labeled for lambsquarters andwild buckwheat control. Temporary yel-lowing and/or reduction of soybeangrowth may occur within 5 to 7 days afterHarmony treatment. Such injury occursmost frequently during hot, humid weather.STS (sulfonylurea tolerant) soybean vari-eties show no or minimal injury after treat-ment even when crop oil concentrate isused. Do not apply Harmony to soybeansthat are under stress from weather extremesor injury from another herbicide. Do nottank-mix Harmony with organophosphateinsecticides or apply Harmony within14 days before or after such insecticide use.Rotational restrictions: Any rotational crop

can be planted 45 days after treatment.

Ignite (glufosinate)Only use on Liberty Link soybean vari-

eties.Rate: 22 oz/a.Adjuvants: The Ignite formulation con-

tains surfactants. Do not add additionalsurfactants.Timing: Apply between dawn and 2 hours

before sunset.Soybeans—Apply after emergence but

before the bloom stage.Weeds—Apply before barnyardgrass,

crabgrass, fall panicum, and yellow foxtailexceed 3 inches, and before giant and greenfoxtail, wild proso millet, and woolly cup-grass exceed 6 inches. Apply before pig-weed and velvetleaf exceed 3 inches; beforelambsquarters exceeds 4 inches; and beforenightshade, common and giant ragweed,and smartweeds exceed 6 inches.

115

STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

SOYBEAN

weeds

(post)CO

RNPRINCIPLES

OF

PESTMNGM

T.


Remarks: Ignite is a nonselective, contactherbicide that controls many annual weedsand will burn the top growth of perennialweeds. Ignite can be tank-mixed with mostpostemergence herbicides to enhance weedcontrol. Ignite lacks residual activity so asecond application can be made if needed.To avoid needing a second application, apreemergence residual herbicide often aidsin making a single application of Ignite suc-cessful. Liberty Link varieties have goodtolerance to Ignite, but slight speckling ofleaves may occur. Apply in a minimum of15 gallons per acre as thorough spray cov-erage is required. Do not apply if windspeeds exceed 10 mph. Ignite is rainfast in 4hours.Rotational restrictions: Small grains can be

planted 70 days after application and othercrops can be planted after 180 days.

LactofenRate: 6.0 to 12.5 fluid oz/a.Adjuvants: Phoenix—The Phoenix formu-

lation contains a premixed adjuvant. Add0.125 to 0.25% nonionic surfactant. Use thehigh concentration when weeds are at theirmaximum labeled size. Crop oil concen-trate can be used at 1 pt/a if droughty.Cobra—With reduced rates of 6 to

10 oz/a, add 1 pt/a crop oil concentrate.With a full rate, add crop oil concentrate at0.25 to 1% to the spray mixture. Refer tolabel for recommendations and rates basedon relative humidity. Alternatives to cropoil include nonionic surfactant at 0.25%during high humidity or 28% nitrogensolution at 4% plus 0.5% crop oil concen-trate during low humidity. Crop oil concen-trate is the preferred additive for the con-trol of taller weeds.Timing: Soybean—Apply at the 1- to

2-trifoliate-leaf stage to ensure good spraycoverage of weeds. Do not apply lactofenwithin 45 days of soybean harvest or pastthe R6 stage.Weeds—The full rate of lactofen controls

up to 8-leaf common ragweed and 6-leafgiant ragweed, pigweed, black nightshade,cocklebur, and waterhemp.Remarks: Lactofen provides good control

of black nightshade, pigweeds, ragweeds,and waterhemp, but only suppresses com-mon lambsquarters. Lactofen will burn offabove-ground portions of some perennial

weeds but since underground portionsaren’t killed, regrowth will occur. Reducedrates of lactofen are labeled to mix withClassic and Synchrony to control blacknightshade and with Classic, Harmony, andPursuit to enhance common ragweed con-trol. Lactofen can also be tank-mixed withAssure II, Basagran, FirstRate, glyphosate,Raptor, Resource, or Select Max. Lactofen-treated soybeans almost always show someleaf burning, crinkling, and bronzing, espe-cially on the youngest leaves. Soybeansgenerally outgrow this condition. Injury isgreatest with crop oil concentrate andincreases when adding nitrogen solution orammonium sulfate. New soybean growth isnormal and crop vigor is not reduced. Donot apply lactofen to soybeans that areunder stress from weather extremes.Because lactofen has contact action, weedsmust be thoroughly covered with spray.Use 20 to 30 gal/a of water with Cobra or15 to 20 gal/a of water with Phoenix.Apply at 40 to 60 psi pressure through flatfan or hollow cone nozzles spaced 20inches apart.Rotational restrictions: None.

Outlook (dimethenamid-P)Timing: Outlook can be applied from the

1 to 3 trifoliate stage for residual grass con-trol. See Outlook on page 106.

PhoenixSee lactofen (this page).

Poast Plus (sethoxydim)Rate: 1.5 pt/a.Adjuvants: Add 1 qt/a of crop oil concen-

trate. When controlling volunteer corn orcrabgrass, include 2 to 4 qt/a 28% nitrogensolution or 2.5 lb/a ammonium sulfatewith crop oil concentrate.Timing: Soybean—Apply anytime, but

75 days before harvest.Weeds—Poast Plus controls up to 8-inch

foxtails, fall panicum, barnyardgrass andwoolly cupgrass, 6-inch large and smoothcrabgrass, 18-inch shattercane, and 20-inchvolunteer corn. Poast Plus at 0.75 pt/a con-trols up to 10-inch wild proso millet.Remarks: Poast Plus controls annual

grasses and perennial grasses like quack-grass and wirestem muhly. Poast Plus canbe tank-mixed with most postemergencebroadleaf herbicides, but grass control may

116

STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

SOYBEAN

weeds

(post)CO

RNPRINCIPLES

OF

PESTMNGM

T.


be reduced. This antagonism can beavoided by applying Poast Plus 1 day beforeor 7 days after the broadleaf herbicide. Soy-bean injury is not a problem. Do not applyPoast Plus to grasses that are stressed fromweather extremes or injury from anotherherbicide. Do not apply if wind exceeds10 miles per hour.Rotational restrictions: Soybean and alfalfa

can be planted anytime after application.Other crops can be planted after 30 days.

Pursuit (imazethapyr)Rate: 4 fl oz/a Pursuit or equivalent.Adjuvants: Add nonionic surfactant at

0.25% to the spray mixture or 1% crop oilconcentrate. Also include 1 to 2 qt/a ofeither 28-0-0, 32-0-0, or 10-34-0 fertilizersolution in the spray mixture. Spray gradeammonium sulfate at 2.5 lb/a may be sub-stituted for liquid fertilizer.Timing: Soybean—Apply before bloom

and 85 days before harvest.Weeds—Apply before weeds are more

than 3 inches tall. Cocklebur, pigweeds,and shattercane can be controlled up to8 inches tall.Remarks: Pursuit controls many grass and

broadleaf weeds. Common lambsquartersusually escapes postemergence treatment,but can be controlled by adding a half rateof Harmony (use nonionic surfactant, notcrop oil concentrate as the adjuvant). Pur-suit can be tank-mixed with Basagran,FirstRate, Flexstar, lactofen, or Ultra Blazerto broaden the spectrum of broadleaf weedcontrol. For improved control of volunteercorn and grassy weeds, tank-mix withAssure II, Fusion, Poast Plus, or Select Max.However, the effectiveness of the grass her-bicide may be reduced due to antagonismfrom Pursuit. Pursuit can be tank-mixedwith glyphosate on Roundup Ready soy-beans or with Outlook for residual grasscontrol. Risk of soybean injury from Pursuitis minimal but it may shorten internodes.Rotational restrictions: Do not plant wheat

until 3 months after application; alfalfa, edi-ble beans, peas, or rye until 4 months afterapplication; conventional field corn andseed corn until 8.5 months after application;barley or tobacco until 9.5 months afterapplication; oats, popcorn, sorghum, orsweet corn until 18 months after applica-

tion; or potatoes until 26 months. Allow 40months after Pursuit application beforeplanting all other crops.

Raptor (imazamox)Rate: 4 oz/a when following a preemer-

gence grass herbicide or 5 oz/a when allherbicide applications are postemergence.Adjuvants:Add nonionic surfactant at

0.25% to the spray mixture, 1% crop oil con-centrate, or 1% methylated seed oil. Alsoinclude 1 to 2 qt/a of either 28-0-0 or 10-34-0 fertilizer solution in the spray mixture.Spray grade ammonium sulfate at 2.5 lb/amay be substituted for liquid fertilizer.Timing: Soybean—Apply before bloom

and 85 days before harvest.Weeds—Apply before foxtails and fall

panicum exceed 6 inches, barnyardgrassexceeds 5 inches, and wild proso milletexceeds 4 inches. Apply to broadleavesbefore lambsquarters, nightshade, rag-weeds, and smartweeds exceed 5 inchesand cocklebur, pigweeds, and velvetleafexceeds 8 inches.Remarks: Raptor controls many annual

grasses and broadleaf weeds. Common rag-weed may require a tank mix for completecontrol. Without a prior preemergencegrass herbicide treatment, Raptor may notadequately control barnyardgrass, crab-grass, wild proso millet, or woolly cup-grass. If Raptor is tank-mixed with a post-emergence grass herbicide, grass weed con-trol may be reduced. This antagonism canbe avoided by applying the grass herbicide3 days before or 7 days after the applicationof Raptor. Raptor may be tank-mixed withFirstRate to increase control of commonand giant ragweed. Cobra, Flexstar, or UltraBlazer tank mixtures may increase controlof waterhemp and ragweed. Tank-mixingbroadleaf herbicides with Raptor may alsoreduce its grass control. Raptor may betank-mixed with Outlook for residual grasscontrol. There is a risk that Raptor maycause temporary chlorosis and shorteningof internodes.Rotational restrictions: Do not plant wheat

until 3 months after application; barley untilafter 4 months; field and sweet corn untilafter 8.5 months; and alfalfa, oat, pea, andpotato until 9 months after application. Manyother vegetable crops are also listed on thelabel with a 9-month rotational interval.

117

STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

SOYBEAN

weeds

(post)CO

RNPRINCIPLES

OF

PESTMNGM

T.


Resource (flumiclorac)Rate: 4 to 12 oz/a.Adjuvants: Add 1 qt/a crop oil concen-

trate when applying Resource alone. Checkthe Resource label for adjuvant require-ments when tank-mixing.Timing: Soybean—Do not apply within

60 days of harvest.Weeds—Apply the following rates for vel-

vetleaf: 4 oz/a when 6 leaves or less, 6 oz/awhen 8 leaves, 8 oz/a when 10 leaves, and12 oz/a when 30 inches tall.Remarks: Resource is highly effective on

velvetleaf. It is less effective on otherbroadleaf weeds, but will suppress smalllambsquarters, cocklebur, common ragweed,and pigweed. Resource can be tank-mixedat 2 to 4 oz/a with postemergence broadleafherbicides or glyphosate for added vel-vetleaf control. Resource may cause tempo-rary speckling of soybean leaves, but plantsquickly outgrow this injury.Rotational restrictions: Corn or soybean

can be replanted if crop fails. Other cropscan be planted after 30 days.

Roundup formulationsSee glyphosate (page 114).

Select Max (clethodim)Rate: 9 oz/a. Use 16 oz/a when annual

grasses are at the maximum height listedfor control. Apply 12 oz/a for quackgrassand wirestem muhly.Adjuvants: Add nonionic surfactant at

0.25% or crop oil concentrate at 1 qt/a tothe spray mixture. Also add ammoniumsulfate at 2.5 lb/a or 2 qt/a 28% nitrogensolution.Timing: Soybean—Apply 60 days before

harvest.Weeds—Apply to 6-inch crabgrass and

field sandbur; 8-inch green foxtail, yellowfoxtail, fall panicum, and woolly cupgrass;12-inch giant foxtail; 10-inch wild prosomillet; 8-inch quackgrass and wirestemmuhly; and 18-inch shattercane.Remarks: Select Max controls annual

grasses and two separate applicationstimed 2 to 3 weeks apart will control heavyinfestations of quackgrass. Select Max doesnot injure soybeans. Select Max at 6 oz/acan be tank-mixed with glyphosate to con-trol Roundup Ready corn up to 12 inchestall. Higher rates can be used to control

taller corn. Add nonionic surfactant if theglyphosate formulation is not preloadedwith surfactant. Add 8.5 to 17 lb/100 galammonium sulfate to all glyphosate tankmixtures.Select Max can be tank-mixed with

broadleaf herbicides, but grass control maybe reduced. Increased rates should be usedwith Pursuit and Raptor tank mixtures.This antagonism can be avoided by apply-ing Select Max 1 day before or 7 days afterthe broadleaf herbicide. When tank-mixing,check the label for specific adjuvant optionsfor the mixture. If regrowth of perennialgrasses occurs, make a second applicationof Select Max. Do not apply if wind isgreater than 10 miles per hour.Rotational restrictions: Soybean, alfalfa,

potato, and other labeled crops can beplanted anytime. Do not plant other rota-tional crops until 30 days after application.

Sequence (Dual Magnum +glyphosate premix)Use only on Roundup Ready varieties.Rate: 2.5 to 3.5 pt/a.Adjuvants: Ammonium sulfate may be

added at 8.5 to 17 lb/100 gal.Timing: Soybean—Apply from emergence

through the third trifoliate stage.Weeds—Sequence at 2.5 pt/a provides

0.7 lb ae/a glyphosate and is effective onmost annual weeds if treated before the 6-inch height. The label has specific rates forindividual weed heights.Remarks: Sequence will provide good

control of most annual grasses andbroadleaf weeds and will control manyperennial weeds. The s-metolachlor compo-nent will provide residual annual grasscontrol, which may be beneficial in rowsoybeans or when applied early in drilledsoybeans. It can be tank-mixed with Fusionor Fusilade DX to control volunteerRoundup Ready corn. Sequence may causesome slight leaf crinkle or leaf spotting, butthe soybeans should rapidly outgrow thissymptom. Be cautious to avoid drift ontocorn or other plants during application. Donot apply if a preemergence application ofmetolachlor was previously made.Rotational restrictions: If the soybean crop

is lost, soybeans, corn, peas, or snap beanscan be replanted. Alfalfa can be planted 4

118

STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

SOYBEAN

weeds

(post)CO

RNPRINCIPLES

OF

PESTMNGM

T.


months after application and small grainscan be planted after 4.5 months. Othercrops can be planted the following spring.

Synchrony XP(Harmony + Classic premix)Rate:Apply 0.375 oz/a on non-STS soy-

beans. Apply up to 1.125 oz/a when tank-mixing with glyphosate on STS/RR soy-beans.Adjuvants: On STS (sulfonylurea tolerant)

varieties, add crop oil concentrate at 1% tothe spray mixture. On conventional vari-eties, add nonionic surfactant at 0.25% tothe spray mixture. In addition, add either2 to 4 qt/a of 28% nitrogen solution, 1 to 2qt/a of 10-34-0, or 2 to 4 lb/a of ammoniumsulfate. On STS/RR soybeans, add 0.25%nonionic surfactant when mixed withglyphosate plus ammonium sulfate at 4.25to 17 lb/100 gal.Timing: Soybean—Apply after the first tri-

foliate leaf stage and 60 days before harvest.Weeds—Apply before pigweed, cocklebur,

and other broadleaf weeds exceed 4 inches.Remarks:At 0.375 oz/a, only pigweed,

cocklebur and sunflower are listed as con-trolled. Lambsquarters, smartweed, andvelvetleaf control can be improved with theaddition of 0.06 oz/a Harmony SG; commonragweed and velvetleaf control can beimproved with 0.15 oz/a FirstRate; andwaterhemp, common ragweed, nightshade,and velvetleaf control can be improvedwith 1 pt/a Flexstar. Synchrony will notcontrol nightshade by itself. Non-STS soy-bean varieties may be slightly stunted bySynchrony, but STS varieties have good tol-erance. On STS/RR soybeans, Synchrony atup to 1.125 oz/a can be tank-mixed withglyphosate, which may improve control ofspecific broadleaf weeds and yellownutsedge if not being controlled byglyphosate alone. This rate should only beused south of I-90 between LaCrosse andMadison and south of I-94 between Madi-son and Milwaukee. Synchrony should notbe tank-mixed with Poast Plus unlessapplied to an STS variety.Rotational restrictions: Soybeans can be

replanted anytime after application. Smallgrains can be planted after 3 months;alfalfa, dry and snap beans, field corn,sweet corn, peas, and tobacco after 9months; and potatoes after 30 months.

TouchdownSee glyphosate (page 114).

Ultra Blazer (acifluorfen)Rate: 1.0 to 1.5 pt/a.Adjuvants: Add nonionic surfactant at

0.125 to 0.25%, crop oil concentrate at 1 to2 pt/a, 2 to 4 qt/a of 28% nitrogen solution,or 2.5 lb/a ammonium sulfate to the spraymixture.Timing: Soybean—Apply in the 1- to

2-trifoliate-leaf stage to ensure good spraycoverage of weeds. Apply 50 days beforeharvest.Weeds—The maximum leaf stage is 2 or

4 leaves for most weeds listed for control.See label for size and rate required for spe-cific weeds.Remarks: Ultra Blazer controls pigweed,

common ragweed, and black nightshadebetter than Basagran, but is less active onvelvetleaf and cocklebur. It will burn theabove-ground portions of perennial weedssuch as common milkweed, Canada thistle,and field bindweed, but since undergroundportions are not killed, regrowth will occur.Ultra Blazer can be tank-mixed withBasagran, Classic, FirstRate, glyphosate,Harmony, Pursuit, Raptor, Resource, andthe postemergence grass herbicides. Soy-beans treated with Ultra Blazer almostalways show some leaf speckling, crinkling,and bronzing, especially on the youngestleaves. Soybeans generally outgrow thiscondition. Do not apply Ultra Blazer to soy-beans that are under stress from weatherextremes or injury from another herbicide.Because Ultra Blazer has contact action,weeds must be thoroughly covered withspray. Use 10 to 20 gal/a of water and aminimum of 40 psi pressure through flatfan or hollow cone nozzles spaced 20inches apart. Do not apply if wind exceeds15 miles per hour.Rotational restrictions: Soybeans can be

planted anytime, small grains after 40 days,and all other crops after 100 days.

119

STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

SOYBEAN

weeds

(post)CO

RNPRINCIPLES

OF

PESTMNGM

T.


120

STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

SOYBEAN

weeds

(post)CO

RNPRINCIPLES

OF

PESTMNGM

T.

Table 3-2. Rate equivalents of soybean herbicide premixes

Herbicide Rate/acre Provides the equivalent of:

Authority Assist 6 oz 5 oz Spartan 4L + 2 fl oz Pursuit 2SAuthority First/Sonic 3 oz 3.7 fl oz Spartan 4L + 0.28 oz FirstRate 84DFAuthority MTZ 12 oz 4.3 fl oz Spartan 4L + 4.3 oz Sencor 75DFBoundary 6.5EC 1.5 pt 1.03 pt Dual II Magnum 7.64EC + 5 oz Sencor 75DFCanopy EX 29.5DF 1.1 oz 1.0 oz Classic 25DF + 0.15 oz Express 50SGCanopy 75DF 2.25 oz 1.9 oz Sencor 75DF + 1 oz Classic 25DFEnlite 2.8 oz 2 oz Valor SX + 0.3 oz Classic 25DF + 0.5 oz Harmony SGEnvive 2.5 oz 1.4 oz Valor SX + 0.9 oz Classic 25DF + 0.14 oz Harmony SGExtreme 2.17SC 3 pt 4 fl oz Pursuit 2S + 0.56 lb ae glyphosateFusion 2.56EC 8 fl oz 8 fl oz Fusilade DX 2EC + 6.7 fl oz Option II 0.67ECGangster (co-pack) 2.4 oz 2 oz Valor 51DF + 0.4 oz FirstRate 84DFPrefix 2 pt 1.1 pt Dual II Magnum 7.64EC + 1 pt FlexstarPursuit Plus 2.9EC 2.5 pt 4 fl oz Pursuit 2S + 2 pt Prowl 3.3ECSequence 5.25EC 2.67 pt 1 pt Dual II Magnum 7.64EC + 0.75 lb ae glyphosateSynchrony XP 28.4DF 0.375 oz 0.32 oz Classic 25DF + 0.05 oz Harmony 50SGValor XLT 2.5 oz 1.5 oz Valor SX + 1 oz Classic 25DF


121

STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

SOYBEAN

weeds

(post)CO

RNPRINCIPLES

OF

PESTMNGM

T.

Table 3-3. Forage and grain harvest intervals for soybean herbicidesa

Product Forage harvest interval Grain harvest interval

Assure II Not permitted 80 daysAuthority Assist Not permitted No restrictionsAuthority First/Sonic Not permitted 65 daysAuthority MTZ Not permitted No restrictionsBasagran 30 days 30 daysBoundary 40 days No restrictionsCadet Not permitted 60 daysClassic Not permitted 60 daysDefine SC Not permitted No restrictionsDual II Magnum No restrictions No restrictionsEnlite Not permitted No restrictionsEnvive Not permitted No restrictionsExtreme Not permitted 85 daysFirstRate 14 days 65 daysFlexstar Not permitted Treat before bloomFusilade DX Not permitted Treat before bloomFusion Not permitted Treat before bloomGangster Not permitted 65 daysGlyphosate—broadcastb 14 days 14 daysGlyphosate—preharvest 25 days 7 daysGramoxone Inteon—harvest aid Not permitted 15 daysHarmony SG Not permitted 60 daysIgnite Not permitted 70 daysIntrro Not permitted No restrictionsLactofen (Cobra/Phoenix) Not permitted 45 daysLorox Not permitted No restrictionsOutlook Not permitted No restrictionsPoast Plus 75 days 75 daysPrefix Not permitted No restrictionsProwl H2O No restrictions No restrictionsPursuit Not permitted 85 daysPursuit Plus Not permitted 85 daysPython Not permitted 85 daysRaptor No restrictions No restrictionsResource Not permitted 60 daysSelect Max Not permitted 60 daysSencor 40 days No restrictionsSequence—preplant 30 daysSequence—postemergence Not permitted 90 daysSynchrony XP Not permitted 60 daysTrifluralin No restrictions No restrictionsUltra Blazer Not permitted 50 daysValor SX Not permitted No restrictionsValor XLT Not permitted No restrictionsaLabels may have changed after this table was prepared. Consult current labels to verify the information.bFor broadcast postemergence applications to Roundup Ready soybeans.


STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

SOYBEAN

weeds

(post)CO

RNPRINCIPLES

OF

PESTMNGM

T.

Table 3-4. Rainfree period and adjuvants required for postemergence soybean herbicides

Hours to ————————————Recommended adjuvants————————————Herbicide be rainfast Nonionic surfactant Crop oil concentrate Nitrogen additivea

Assure II 1 0.25% or 1%Basagranb 4 1 qt/a or 28% N at 2–4 qt/a orAMS at 2.5 lb/aCadet 4 0.25% or 1–2 pt/a plus 28% N at 1–2 qt/a orAMS at 1–2 lb/a

may be addedClassic 1 0.25% or 1% if hot, dry Also add 28% N at 2–4 qt/a orAMS at

2–4 lb/a for velvetleafCobrac 0.5 0.25% if high or 0.25–1.0% or 28% N at 1 gal/a

relative humidity or AMS at 2–4 lb/a plus NIS or COCExtreme 1 0.125% plus AMS at 2.5 lb/a or 28% N at 1–2 qt/aFirstRate 2 0.125–0.25% or 1.2% Add 28% N at 2.5% orAMS at 2 lb/a

when using nonionic surfactantFlexstar 1 0.25–0.5% or 0.5–1.0% plus 28% N at 2.5% orAMS at 10 lb/100 galFusilade DX 1 0.25%Fusion 1 0.25–0.5% or 0.5–1.0% 28% N at up to 4% may be addedGlyphosate 2–6 Check label to see if AMS at 8.5–17 lb/100 gal may be added

surfactant is neededGramoxone Inteon 0.5 0.25% or 1%—preharvestHarmony SG 1 0.25–0.5% or 0.5% if cool, dry plus 28% N at 2–4 qt/a or 10-34-0 at 1–2 qt/a

orAMS at 2–4 lb/aIgnite 4Phoenix 1 0.125–0.25%Poast Plus 1 1 qt/a 28% N at 2–4 qt/a orAMS at 2.5 lb/ad

Pursuit 1 0.25% or 1% COC orMSO plus 28% N or 10-34-0 at 1–2 qt/a orAMS at2.5 lb/a

Raptor 1 0.25% or 1% COC orMSO plus 28% N or 10-34-0 at 1-2 qt/a orAMS at2.5 lb/a

Resource 1 1 qt/aSelect Max 1 0.25% or 1 qt/a plus AMS at 2.5 lb/aSynchrony XP 1 0.25% if non-STS or 1% if STS variety plus 28% N at 2–4 qt/a or 10-34-0 at 1–2 qt/a

variety or AMS at 2–4 lb/aUltra Blazer 4 0.125–0.25% or 1–2 pt/a or 28% N at 2–4 qt/a orAMS at 2.5 lb/aaAMS = ammonium sulfate; COC = crop oil concentrate; MSO = methylated seed oil; NIS = nonionic surfactant.bAdd crop oil concentrate for lambsquarters and common ragweed control, add a nitrogen additive for velvetleaf control, or add both if allthree weeds are present.cAdjust adjuvant type and rate based on relative humidity (RH). See label for recommendations.dAdd a nitrogen additive plus crop oil concentrate when controlling volunteer corn or large crabgrass.

122


SOYBEAN INSECTMANAGEMENT

Insecticides suggested in this section areintended as a guide to assist you in select-ing chemical insect control options. Whilesuggestions provide an overview of prod-uct registrations for specific field cropinsect pests, this guide is not intended as anexhaustive label source. Product inclusionor omission does not imply endorsementby UW Extension. Proper and safe insecti-cide use requires great care and strictadherence to the most current label direc-tions. Label changes and occasional-usecancellations may have occurred since thewriting of this publication.A number of the products listed in this

section are restricted-use insecticides. Wediscuss restricted-use pesticides in thebeginning of this publication. Refer toappendix table 1 for a list of pesticides thatcurrently require certification to be applied.It is possible that additional insecticideswill be classified before the next growingseason. Contact your county Extensionagent for additional information on insecti-cide restriction.Insecticides help control insect pests, but

they also can kill beneficial insects such ashoney bees as well as predators and para-sitic wasps that are important in biologicalcontrol. Notify beekeepers before usinginsecticides and apply only between 4 p.m.and nightfall—when bees are least likely tobe actively foraging. Treatment of legumecrops while they are in blossom could

result in substantial bee losses. See the dis-cussion on reducing insecticide hazards tobees in “Forage Insect Management” formore suggestions.

INSECT PESTS

Bean leaf beetleBean leaf beetle population densities

have increased in the Midwest followingrecent mild winters. Although pod feedinghas been noted as far north as Chippewacounty, defoliation and disease transmis-sion (bean pod mottle virus) are of moreconcern in the southernmost counties.Adult beetles are 5 mm long, about the

size of lady beetles. Wing covers are typi-cally light yellow with a black margin andfour black spots. Variations include crimsonwing covers with spots or light yellowwing covers with no spots. There is alwaysa black triangle behind the “neck” region(prothorax). Beetles readily drop from theplant if they detect disturbance.Adults overwinter under leaf debris near

soybean fields. Once they become active inthe spring, the beetles feed on wildlegumes, alfalfa, and clover. As soybeansbegin to emerge, beetles leave these alter-nate hosts and concentrate on soybeanseedlings. Thus, the earliest planted fieldsare at greatest risk from feeding damageand virus transmission. Bean leaf beetleschew round holes between the major leaflet

123

STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

SOYBEAN

CORN

PRINCIPLESOF

PESTMNGM

T.

5% 10% 20% 30% 40% 50%

Use this guide to help determine the extent of defoliationby leaf-feeding insects.


124

STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

SOYBEAN

insectsCO

RNPRINCIPLES

OF

PESTMNGM

T.

veins. This damage is easily distinguishedfrom caterpillars and grasshoppers whichchew ragged, irregular holes.Adults lay eggs in the soil next to soy-

bean stems. Larvae hatch about 1 weeklater and feed on roots and stems. Theirroot feeding is not believed to be of eco-nomic importance. First-generation adultsappear in July, peaking during the late veg-etative and early reproductive stages ofsoybean growth. Second-generation adultscan be found from late August to mid-Sep-tember where they feed on leaves andpods. This second generation can cause sig-

nificant crop damage. Beetles may clipdeveloping pods from the plant or graze onthe outer layer of the pod leaving only athin layer of tissue. Diseases can enter thesedamaged areas and the seeds will be discol-ored, shrunken, and moldy.Growers should scout for overwintered

beetles beginning shortly after soybeansemerge. Count the number of beetles oneach plant sampled. Examine 5 feet of rowin each of five locations throughout thefield. Divide the total number of beetlesfound by 25 to estimate the number perfoot of row. Also estimate the percent ofleaf defoliation using the guide on the pre-vious page. Check again when first-cropalfalfa harvest is underway, as the activitymay force beetles to move to soybeans.Consult table 3-5 for guidance on when totreat. Before bloom, soybeans can tolerateup to 40% defoliation.Scout for second-generation bean leaf

beetle adults during August and Septemberby walking 100 feet in from the edge of thefield. Scout each field and each varietywithin a field separately as beetles some-times prefer one variety over another.Scouting is no longer necessary after podsreach the R7 stage (yellow pod).In 30-inch row soybeans, place a 3-foot-

wide strip of cloth (stapled to two dowelrods) on the ground between the rows.Slide the cloth under the plants, disturbing

Table 3-5. Early-season bean leaf beetle economicthresholds in soybeans

Crop value Treatment cost/acre (insecticide plus application)($/bu) $6 $7 $8 $9 $10 $11

———————beetles/planta———————Growth stage—VC

$5.00 2.4 2.8 3.2 3.6 4.0 4.4$6.00 2.0 2.3 2.7 3.0 3.4 3.7Growth stage—V1$5.00 3.7 4.4 5.0 5.6 6.2 6.8$6.00 3.1 3.6 4.1 4.7 5.2 5.7Growth stage—V2$5.00 5.9 6.8 7.8 8.8 9.8 10.7$6.00 4.9 5.7 6.5 7.3 8.1 8.9aFor beetles per foot of row, multiply number by 7.6Source: Marlin Rice, Iowa State University, 2000.

Table 3-6. Second-generation bean leaf beetle economic thresholdsin reproductive stage soybean*

Crop value ——————Treatment cost/acre (insecticide plus application)——————($/bu) $7 $8 $9 $10 $11 $12 $13 $14 $15

————————————beetles/foot of row————————————$5.00 5.5 6.3 7.1 7.9 8.7 9.5 10.3 11.0 11.8$6.00 4.6 5.2 5.9 6.5 7.2 7.8 8.5 9.2 9.9$7.00 3.9 4.4 5.0 5.6 6.1 6.7 7.3 7.8 8.4$8.00 3.5 4.0 4.5 5.0 5.5 6.0 6.5 7.0 7.5

————————————— beetles/sweep—————————————$5.00 3.5 4.0 4.5 5.0 6.5 7.2 7.7 8.3 8.7$6.00 2.9 3.3 3.7 4.1 5.4 6.0 6.4 6.9 7.3$7.00 2.4 2.8 3.1 3.5 3.8 4.2 4.5 4.9 5.2$8.00 2.2 2.5 2.8 3.2 4.1 4.5 4.8 5.2 5.5*Economic thresholds are based on a row spacing of 30 inches and a plant population of eight plantsper foot of row. For narrow-row soybean (8-inch rows) and a plant population of three plants per footof row, multiply the above economic thresholds by 0.70.Source: Marlin Rice, Iowa State University, 2000.


125

STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

SOYBEAN

insectsCO

RNPRINCIPLES

OF

PESTMNGM

T.

the plants as little as possible. Shake theplants vigorously over the cloth. Count thebeetles on the cloth. Repeat this procedurefour times for each 20 acres in the field.Determine the average number of beetlesper foot of row.In narrow-row soybeans, a sweep net will

be easier to use than a drop cloth. Take 20sweeps in each 20 acres across the field.Consult table 3-6 for guidance on when

to treat. Between bloom and pod fill, plantscan tolerate 20% defoliation. Be sure toassess defoliation on the entire plant, notjust the top leaves. If the average number ofbean leaf beetles equals or exceeds the eco-nomic threshold, an insecticide applicationis necessary to prevent economic yield loss.Pod damage can also be incorporated

into second-generation bean leaf beetlethresholds, with 5–10% of the pods show-ing bean leaf beetle feeding. Pod clipping istypically worse during dry weather as bee-tles move from feeding on leaves to feedingon pods. Inspect dropped pods for signs offeeding damage (as opposed to abortioncaused by drought stress).If the beetle population is less than the

economic threshold, scout the field again 5days later. Stop scouting when beetlecounts start to decline, soybean pods beginto turn yellow, or the field is sprayed.Treatment thresholds for the prevention

of bean pod mottle virus are not available.(Scouting techniques and treatment timing

courtesy of Marlin Rice, Iowa State University.)

GrasshoppersGrasshoppers could be a problem during

dry years. If young hoppers are numerousin grassy areas, such as fencerows androadsides adjacent to soybeans, spray suchareas before grasshoppers spread throughthe soybean field. If blooming weeds arepresent, notify nearby beekeepers beforeusing an insecticide and only applybetween 4 p.m. and nightfall—when beesare least likely to be foraging and exposed.Insecticidal control is most effective whenused before grasshoppers are fully grown.

Green cloverwormsGreen cloverworms and other caterpil-

lars, as well as corn rootworm beetles, willchew soybean leaves in July and August. Todate, the green cloverworm is the onlymember of this group of potential concern

in Wisconsin. This caterpillar (approxi-mately 1.25 inches long when full grown) islight green and has two, thin white stripesrunning down each side of its body. Sub-stantial defoliation can result if populationsare heavy.

Potato leafhopperLarge populations of potato leafhopper

can pose a threat to soybean fields. The soy-bean’s hairy leaves and stems usually pro-tect it from leafhopper damage. But duringyears with abnormally high leafhopperpopulations or in fields with varieties thatare less hairy, fields must be sampled tomake sure the crop is not threatened. Dam-age appears as yellowish patches on theleaves, and leaf crinkling and cupping areusually noted. The crinkling and cuppinglook similar to herbicide injury. Extensivefeeding by potato leafhopper can stuntplants.You will have to examine the leaves and

stems to take whole-plant counts on plantsthat are 1 foot or less in height. Take sam-ples in several areas of a field. For plantstaller than 1 foot, use a 15-inch diametersweep net to sample the fields. Researchindicates this is more accurate than takingwhole plant samples. To complete onesweep, move the net in one continuousstraight line motion through the top 15inches of the foliage of the row from oneside of your body through the foliage in therow to the other side of your body. Con-tinue this process until 20 sweeps havebeen taken in an area, and take no less thanfive sets of 20 sweeps in a field to estimatethe population density. For solid-seededbeans, cover the same area that you wouldfor 30-inch rows.If an average of two leafhoppers are

found per plant in fields with less than fourtrifoliate leaves per plant, control may beneeded. If there are six leafhoppers perplant on flowering plants, control may beneeded. For a pod that is 3⁄4 inch long onone of the four uppermost nodes of themain stem, 13 leafhoppers or more perplant may cause economic injury. Examinethe leaves carefully to see if the leafhoppersare able to get through the hairs and feedon leaves before deciding to treat.


126

STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

SOYBEAN

insectsCO

RNPRINCIPLES

OF

PESTMNGM

T.

Leafhopper sampling data indicate thatthe number of leafhoppers recovered persweep represents half the actual numberper plant, regardless of row spacing. Forexample, if you have taken your five sets of20 sweeps and have an average of two persweep, you should assume an actual aver-age of four leafhoppers per plant. Whendeciding on treatment, use the estimatedactual number of insects per plant.

Seedcorn maggotSeedcorn maggots overwinter as pupae.

Adult flies emerge in late spring around thetime that soybean fields are being planted.Females lay eggs in fields with high levelsof organic matter. Decaying weeds andcrop residue, or application of livestockmanure will make a field more attractive toegg-laying flies. The eggs hatch within aweek. These white, tapered, legless mag-gots attack germinating seeds, feeding onthe cotyledons.Seedlings may emerge with brown feed-

ing scars on the cotyledons or they mayhave no cotyledons (such shoots are called“snakeheads”). Damage typically occurs infields with an abundance of organic matter(manure or decaying plant matter) andtends to be worse when cold, wet weatherslows germination.There are no economic thresholds or pre-

dictive tools for identifying fields certain tohave economic damage. Preventativeplanter-box seed treatment (e.g., KernelGuard Supreme) or commercial seed treat-ments (e.g., Cruiser Maxx, Gaucho 600) areavailable when planting soybeans to fieldswith high organic matter.

Soybean aphidAphid identification and life cycleSoybean aphids (Aphis glycines) are about

1⁄16-inch long and green to yellowish-greenin color. They are the only aphid speciesknown to infest and reproduce on soybeanin the United States. Early in the growingseason, populations are found predomi-nately on the underside of new leaves. Asthe season progresses, colonies can befound on leaves within the canopy, movingto stems and petioles when populations arehigh.

The soybean aphid life cycle is complex,with both sexual and asexual phases,depending on the time of year and the hostplant. They overwinter in the egg stage onbuckthorn, the aphid’s only known over-wintering host. From spring to late summerthe aphids are all female and give birth tolive females, allowing for explosive popula-tion growth. In the spring, winged femalesmigrate from buckthorn to soybeans, where12 to 15 generations can be produced. Dur-ing the summer, both winged and winglessforms can be found on soybeans. Thewinged aphids fly to other soybean fieldsto colonize. In the fall, male and femalewinged aphids migrate back to buckthornwhere mating and egg-laying occurs.Aphids use piercing-sucking mouthparts

to remove plant sap. Feeding damageresults in stunting and yield loss. They alsotransmit several soybean viruses as theyprobe and feed between infected and unin-fected plants. In addition, they excrete asugary substance, referred to as “honey-dew.” Late in the summer, affected plantsmay take on a sooty appearance if aphidpopulations are high as mold grows on theexcrement.Summer migrants (winged females) seem

to prefer late-planted soybeans over early-planted soybean fields. Expect higher infes-tations on soybeans planted after early Junecompared to soybeans planted between lateApril and mid-May.Natural enemies (predators and parasitic

wasps) are an important component of soy-bean aphid management. Predators such aslady beetles (larvae and adults), greenlacewings (larvae), and minute pirate bugs(nymphs and adults) consume soybeanaphids. Parasitic wasps lay eggs insideaphids. The developing wasp larva kills thehost from within. The adult wasp emerges,leaving behind a hollowed-out shellreferred to as an aphid “mummy.” Para-sitized aphids are tan to dark brown andstick to the underside of soybean leaves.Another natural control agent is a fungalpathogen that can cause an epidemic in thesoybean aphid population.

Soybean aphid treatment decisions

Results of university field trials and labo-ratory and greenhouse studies continue tohelp refine recommendations on soybean


127

STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

SOYBEAN

insectsCO

RNPRINCIPLES

OF

PESTMNGM

T.

aphid economic injury levels, treatmentthresholds, insecticide efficacy, and soybeanhost plant resistance to the aphid. Treat-ment decision guidelines are summarizedas follows:1. Avoid treating soybean aphids when they

first appear in a field. Insecticide appli-cations to control low and nondamag-ing soybean aphid populations will alsokill beneficial insects, allowing surviv-ing aphids and migrants to more read-ily repopulate the field. Soybean aphidsreproduce much faster than lady beetlesand other beneficial insects. Thus, earlyseason treatments can lead to higherpopulations than if the field had notbeen sprayed.

2. Scout fields weekly to determine the rateof population increase. Begin intensivescouting no later than the mid-vegeta-tive stages of soybean growth, typicallyaround mid- to late-June. Count thenumber of aphids present on 20 to 30plants per field. Examine the entireplant for aphids, paying close attentionto the upper leaves and stems whereaphids congregate. Be sure to sampleplants from throughout the field toobtain a representative sample. Calcu-late the average number of aphids perplant based on the total number ofplants sampled. The UW Nutrient andPest Mangement program has devel-oped a handy card to help with scout-ing and counting. The Visual Guide forSoybean Aphid Scouting is available bycalling 608-265-2660 or download acopy at ipcm.wisc.edu/pubs/pest/SBA-count2004.htm.Continue monitoring throughout poddevelopment as aphids move downstems and colonies become distributedthroughout the canopy.Regular field visits are critical as popu-lations can increase to economicallydamaging levels within 7 days. How-ever, keep in mind that the presence ofsoybean aphids does not mean thatpopulations will necessarily reach dam-aging levels. A number of factors play arole in regulating populations: naturalenemies (predators and parasiticwasps), temperature (aphids reproducefastest between 68° and 77°F), plantingdate, aphid fungal disease, soybean

growth stage, degree of plant stress(e.g., drought), and, possibly, soybeanvariety. Regular scouting will helpdetermine how these factors are influ-encing aphid growth rates under yourfield conditions. Monitor soybeanaphids until they begin to decline natu-rally in mid- to late August.

3. Treat when approximately 80% of thefield has reached an average of 250aphids per plant AND the population isactively increasing. University trialshave found that the best control andyield response occurs when plants aretreated between beginning bloom (R1)and full pod (R4). At later stages ofgrowth (R5 and beyond), plants can tol-erate more aphids per plant; however,how many more has not yet been deter-mined. We do know that once podshave reached full seed (R6), it is too lateto protect yield and treatment is notrecommended. For pictures anddescriptions of soybean growth stages,see Reproductive Soybean DevelopmentStages and Soybean Aphid Thresholds(www.plantpath.wisc.edu/soyhealth/pdf/sbrthresholds05.pdf).These recommendations build in a7-day lead time that allows time toschedule treatment, purchase product,or deal with weather delays when soy-bean aphid populations are activelyincreasing.Research and scouting updates are

posted regularly during the growing sea-son in theWisconsin Crop Manager newslet-ter (ipcm.wisc.edu/wcm). For more infor-mation about regional aphid populationdevelopments, contact your county Exten-sion agent. Other valuable sources of infor-mation include the University of WisconsinSoybean Plant Health web site(www.plantpath.wisc.edu/soyhealth) andthe North Central Soybean Research Pro-gram web site (www.ncsrp.com).

Stink bugsTwo species of stink bugs—the green

stink bug (Acrosternum hilare) and brownstink bugs (Euschistus spp.)—may be foundin Wisconsin soybean fields in August.Stink bugs feed in clusters on plants alongfield edges, becoming quite noticeable as


128

STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

SOYBEAN

insectsCO

RNPRINCIPLES

OF

PESTMNGM

T.

plant leaves turn yellow. Occasionally pop-ulations may be high. Stink bugs arebelieved to migrate into the state each year.The chief distinction between the two

species is their color. Stink bug adults havea shield shaped body, with pointed “shoul-ders.” Green stink bug adults are brightgreen with black bands on their antennae;adult brown stink bugs are a speckledbrown. Nymphs are rounder than adults,roughly resembling a beetle. Green stinkbug nymphs are multicolored (black, green,yellow, and red markings), while brownstink bugs nymphs are copper-brown.Both nymphs and adults have piercing-

sucking mouthparts which they use to pen-etrate the pod and suck plant fluids. Punc-tures can be found as small brown or blackspots. Young seeds may be deformed,undersized, and possibly aborted underheavy stink bug pressure; older seeds canbe discolored or shriveled. Feeding damagemay also indirectly delay plant maturity.In early August, as soybean pods begin to

fill, scout five different areas of the fieldtaking 20 samples at each location. Usesweep nets for drilled narrow-row beans.For wide-row plantings, place a light-col-ored cloth between rows and shake plantsto dislodge bugs from the canopy. Countboth nymphs and adults in the sampletotal. Calculate stink bugs per sweep (orper row foot) based on the average of allsamples taken throughout the field.Stink bug thresholds in seed beans are

lower than in grain soybeans. In wide-rowplantings, thresholds range from 1 to3 bugs/foot of row. For narrow-row plant-ings, the threshold is 20 bugs/100 sweepsfor seed beans and 40 bugs/100 sweeps forgrain soybeans.

Thistle caterpillar(painted lady butterfly)The painted lady, an orange and brown

mottled butterfly, is noted for periods ofgreat abundance followed by periods ofgreat scarcity, probably due to natural con-trol. It is strongly migratory, explaining itsappearance in northern areas such as Wis-consin. The butterfly causes no damage tocultivated crops.The larval stage, called the thistle cater-

pillar, is usually first noticed feeding onthistles. Subsequent generations occurringin late-July and August can be found in

soybeans in large enough numbers to causeconcern. The spiny caterpillars have a mot-tled yellowish-green and black body with ayellow stripe running the length. Thespines are also yellowish.Thistle caterpillars form a loose silk web-

bing in the upper three or four leaveswhere they feed. The black granular-appearing material found in the webbing isfecal matter (frass). Most of the defoliationoccurs during the last two stages of larvaldevelopment, when larvae are 3⁄4 to 11⁄4inches long.Soybeans are almost always in the repro-

ductive stages of development when popu-lations become damaging. At that stage,plants can withstand 20% defoliation with-out an economic loss in yield. In the vegeta-tive stage (prebloom), plants can withstandup to 30% defoliation before the yield lossis economically damaging.

Two-spotted spider miteAlthough uncommon, two-spotted spider

mite can become serious during hot dryweather. Adults are tiny (less than 1⁄60 inch),yellow-green, with eight legs and darkspots on either side of their oval bodies.Magnification (a 10X hand lens) is oftennecessary to clearly see spider mite adults,nymphs and eggs on the underside ofleaves. Eggs are round, white to light yel-low, and laid on the underside of leaves. Innorthern states populations overwinter asadult females in sheltered field marginareas. Most years, adequate rainfall and afungal pathogen keep the spider mites incheck. During outbreaks, however, spidermites reproduce quickly with multipleoverlapping generations. Eggs hatch in 2 to4 days, nymphs develop in 2 to 4 days, andadults can live up to 21 days. Each genera-tion is completed in 4 to 14 days, with thefastest developmental rates occurring whentemperatures exceed 91°F.Spider mites damage plants by piercing

the cells and sucking sap. Mites often goundetected until damage is severe in partbecause of their tiny size and becauseplants are drought stressed. Initially, leavesare discolored with tiny white or yellowspecks (stippling). Leaves turn from yellowto bronze and may fall off under heavyinfestations. Webbing is often found on theundersides of leaves. Damage is often more


129

STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

SOYBEAN

insectsCO

RNPRINCIPLES

OF

PESTMNGM

T.

severe along field edges where mites havemigrated from adjacent fields, grasses, andweeds, or in drier areas of the field.Check the upper, middle, and lower

canopy for damage as well as for the pres-ence of live mites and webbing on theundersides of leaves. Estimate the percent-age of soybean leaf surface damaged (stip-pling, discoloration). Tap plants onto awhite sheet of paper to dislodge mites fromthe plant. If present, you will see blackspecks moving slowly on the white surface.If mite injury is evident within the field,there is a potential for economically dam-aging populations within 1–2 weeks. Moni-tor the entire field to determine whetherspot treatment or whole field treatment isappropriate.No specific economic threshold has been

developed for two-spotted spider mite insoybeans. Treatment may be warranted if:■ mites are present between bloom (R1)

and pod fill (R5),■ 15% or more leaf area on plants are dis-

colored and stippled with leaves yel-lowing,

■ live mites are present, and■ hot, dry weather is expected to continue.

Refer to the chart below for treatmentdecision guidelines for the Upper Midwestsoybean growing region.Treatment may be delayed if cooler tem-

peratures and high humidity are expected.Although rainfall reduces the risk of dam-aging spider mite populations, thunder-storms alone cannot be relied upon to elim-inate infestations, particularly if rainsarrive after establishment of large mitepopulations and are followed by continuedhot, dry conditions.The most effective natural enemy of two-

spotted spider mite is a fungal pathogenwhich thrives under relatively cool temper-atures (less than 85°F), with at least 90% rel-ative humidity. At least 12–24 hours of suchconditions are believed necessary for exten-sive spread of the disease, and spider mitepopulations may decline rapidly inresponse to fungal disease activity. Infectedmites have a dark discolored, waxy orcloudy appearance and mite death occurswithin 1 to 3 days of infection.

Table 3-7. Treatment decision guidelines for two-spotted spider mites(Excerpted from Ohio State University and Michigan State University.)

Presence of mites Damage Assessment

Barely detected on leaves in drylocations or on edges of fields.

Barely detectable Treatment not necessary.

Easily detected on leaves in drylocations or on edges of fields.Difficult to find within field.

Foliage is green, but stipplinginjury is detectable on under-sides of leaves of some plants.

Treatment not necessary, butkeep monitoring.

All plants are infested. All plants exhibit some stip-pling, even on healthy leaves.Some speckling and discol-oration of lower leaves. Fieldmargins and dry areas havemost damage.

Rescue treatment is warranted,especially if many immaturesand eggs are present.

All plants heavily infested. Discolored and wilted leaveseasily found throughout thefield. Severe damage evident.

Effective rescue treatment maysave field.

Extremely high numberspresent.

Field discolored, leaves dryingdown. Significant foliage andstand loss.

Rescue treatment may not savefield. However, new growth mayappear if treated.


130

STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

SOYBEAN

insectsCO

RNPRINCIPLES

OF

PESTMNGM

T.

Table 3-8. Suggestions for insect control in soybeans

Amount ofInsect Insecticidea product/acre Remarks, precautions

Bean leaf beetle See the economic threshold tables (tables 3-5 and 3-6) in the discussion about bean leafbeetles for recommendations on treatment timing.Alias 4F 1.5 oz Do not apply within 7 days of harvest. Do not

exceed 4.5 fl oz/a (0.14 lb ai/a) per season.Ambush 2E 3.2–6.4 fl oz Do not apply within 60 days of harvest. Do

not exceed 0.4 lb ai/a per season.Asana XL 5.8–9.6 oz Do not apply within 21 days of harvest. Do

not feed or graze livestock on treated plants.Do not exceed 0.2 lb ai/a per season.

Baythroid XL 1.6–2.8 oz Do not apply within 45 days of harvest. Donot exceed 11.2 oz/a per season.

Cobalt 19–38 oz Allow at least 14 days before applying a sec-ond application of Cobalt or another productcontaining chlorpyrifos. Do not apply within30 days before harvest. Do not graze or feedtreated foliage to livestock.

Cruiser 5FS seed treatment For use in commercial seed treaters only, orcertified retail treatment locations. May bepackaged with compatible and registeredseed treatment fungicides (e.g., CruiserMaxxPak). (1.28 oz/100 lb seed)

Delta Gold 1.5EC 1.5–1.9 oz Do not apply within 21 days of harvest. Donot exceed 0.1 lb ai/a per season. Do notallow livestock to graze treated forage or feedtreated hay to livestock.

dimethoate 1.0 pt Do not apply within 21 days of harvest. Donot feed or graze within 5 days of last appli-cation.

Endigo 3.5–4.4 oz Do not apply within 30 days of harvest. Donot exceed a total of 9.0 fl oz/a of Endigo ZCor 0.06 lb ai of lambda-cyhalothrin–containingproducts, or 0.125 lb ai of thiamethoxam-con-taining products per growing season.

Furadan 4F 0.25–0.5 pt Do not apply within 21 days of harvest. Donot make more than 2 foliar applications perseason. Do not graze or feed treated foliage tolivestock.

Gaucho 600 seed treatment For protection of planted seeds from damagecaused by over-wintering bean leaf beetles.For use in commercial seed treaters only.(1.6–3.2 oz/100 lb seed)

Hero 2.6–6.1 oz Do not apply within 21 days of harvest. Donot exceed 0.4 lb ai/a per season. Do notgraze or harvest treated soybean forage,straw, or hay for livestock feed.

Lorsban Advanced 1.0–2.0 pt Do not apply more than 6 pt/a (3 lb ai/a) perseason. Do not apply within 28 days of harvest.

Mustang Max 2.8–4.0 oz Use higher recommended rate for increasedpest pressure, increased residual control, orlater-season applications. Do not graze orfeed treated forage or straw to livestock. Donot exceed 0.15 lb ai/a per season. Do nottreat within 21 days of harvest.

aMultiple trade names listed within a row indicate products with the same active ingredient(s). (continued)bDo not apply to blossoming soybeans if bees are foraging.


131

STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

SOYBEAN

insectsCO

RNPRINCIPLES

OF

PESTMNGM

T.

Orthene 90S 0.83–1.1 lb Do not apply within 14 days of harvest.Penncap-Mb 2.0–3.0 pt Do not apply within 20 days of harvest. Make

no more than 2 applications per season.Pounce 3.2 EC 2.0–4.0 oz Do not apply within 60 days of harvest. Do

not exceed 0.4 lb/a per season.Proaxis 1.92–3.2 oz Do not apply within 45 days of harvest. Do

not graze or harvest treated soybeans for for-age, straw or hay for livestock feed. Do notexceed 0.03 lb ai (0.48 pt)/a per season.

Sevin XLR Plus 1.0–2.0 pt Do not apply within 21 days of harvest.Warrior II, 0.96–1.6 oz Do not graze or harvest treated soybeans forSilencer 1EC 1.92–3.2 fl oz forage, straw, or hay for livestock feed. Do

not apply within 30 days of harvest. Do notexceed 0.06 lb ai/a per season.

Cutworms Asana XL 5.8–9.6 oz Do not apply within 21 days of harvest. Donot feed or graze livestock on treated plants.Do not exceed 0.2 lb ai/a per season.


Cobalt 13.0–26.0 oz Allow at least 14 days before applying a sec-ond application of Cobalt or another productcontaining chlorpyrifos. Do not apply within30 days before harvest. Do not graze or feedtreated foliage to livestock.




Lorsban Advanced 1.0–2.0 pt Do not apply more than 6 pt/a (3 lb ai/a) perseason. Do not apply within 28 days of harvest.

Mustang Max 1.28–4.0 oz Do not graze or feed treaeted forage or strawto livestock. Do not exceed 0.15 lb ai/a perseason. Do not treat within 21 days of harvest.

Pounce 3.2EC 2.0–4.0 fl oz Do not apply within 60 days of harvest. Donot exceed 0.4 lb ai/a per season.

Proaxis 1.92–3.2 oz Do not apply within 45 days of harvest. Donot graze or harvest treated soybeans for for-age, straw or hay for livestock feed. Do notexceed 0.03 lb ai (0.48 pt)/a per season.

Warrior II, 0.96–1.6 oz Do not graze or harvest treated soybeans forSilencer 1EC 1.92–3.2 fl oz forage, straw, or hay for livestock feed. Do


Table 3-8. Suggestions for insect control in soybeans (continued)


(continued)

Bean leaf beetle(cont.)


132

STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

SOYBEAN

insectsCO

RNPRINCIPLES

OF

PESTMNGM

T. Grasshoppers Treat when migration from adjacent areas begins and populations are heavy (more than30% defoliation before bloom or 20% between bloom and pod fill).Asana XL 5.8–9.6 oz Do not apply within 21 days of harvest. Do





dimethoate see labelEndigo 3.5–4.5 oz Do not apply within 30 days of harvest. Do

not exceed a total of 9.0 fl oz/a of Endigo ZCor 0.06 lb ai of lambda-cyhalothrin–containingproducts, or 0.125 lb ai of thiamethoxam-con-taining products per growing season.

Furadan 4F 0.25–0.5 pt Do not apply within 21 days of harvest. Donot make more than 2 foliar sprays per sea-son. Do not graze or feed treated foliage tolivestock.


Lorsban Advanced 1.0–2.0 pt Use lower rate for young nymphs. Do notapply more than 6 pt/a (3 lb ai/a) per season.Do not apply within 28 days of harvest. Do notgraze or feed treated foliage to livestock.

Mustang Max 3.2–4.0 oz Do not graze or feed treaeted forage or strawto livestock. Do not exceed 0.15 lb ai/a perseason. Do not treat within 21 days of harvest.


no more than 2 applications per season.Proaxis 3.2–3.84 oz Do not apply within 45 days of harvest. Do


Sevin XLR Plus 1.0–3.0 pt Do not apply within 21 days of harvest.Warrior II, 1.6–1.92 oz Do not graze or harvest treated soybeans forSilencer 1EC 3.2–3.84 fl oz forage, straw, or hay for livestock feed. Do






133

STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

SOYBEAN

insectsCO

RNPRINCIPLES

OF

PESTMNGM

T.Green cloverworm Usually requires 12 or more half-grown worms per foot of row and 15% defoliation duringpod-set and pod-fill stages to warrant treatment.Ambush 2E 3.2–6.4 fl oz Do not apply within 60 days of harvest. Do

not exceed 0.4 lb ai/a per season.Asana XL 2.9–5.8 oz Do not apply within 21 days of harvest. Do







Intrepid 2F 4.0–8.0 fl oz Do not apply within 7 days of harvest for hayor forage, or within 14 days for seed. Do notmake more than 4 applications per year orexceed 64 fl oz/a (1 lb ai/a) per season.

Lorsban Advanced 0.5–1.0 pt Do not apply more than 6 pt/a (3 lb ai/a) perseason. Do not apply within 28 days ofharvest. Do not graze or feed treated forageto livestock.

Mustang Max 2.8–4.0 oz Do not graze or feed treated forage or strawto livestock. Do not exceed 0.15 lb ai/a perseason. Do not treat within 21 days of harvest.


no more than 2 applications per season.Pounce 3.2EC 2.0–4.0 fl oz Do not apply within 60 days of harvest.Proaxis 1.92–3.2 oz Do not apply within 45 days of harvest. Do


Sevin XLR Plus 1.0–2.0 pt Do not apply within 21 days of harvest.Tracer 1.0–2.0 fl oz Do not apply within 28 days of harvest. Do

not feed treated forage or hay to meat ordairy animals. Do not exceed more than 6 floz/a (0.18 lb ai/a) per season.



(continued)


134

STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

SOYBEAN

insectsCO

RNPRINCIPLES

OF

PESTMNGM

T.

Warrior II, 0.96–1.6 oz Do not graze or harvest treated soybeanSilencer 1EC 1.92–3.2 fl oz forage, straw, or hay for livestock feed. Do


Soybean aphid Alias 4F 1.5 oz Do not apply within 7 days of harvest. Do notexceed 4.5 fl oz/a (0.14 lb ai/a) per season.

Asana XL 5.8–9.6 oz Do not apply within 21 days of harvest. Donot feed or graze livestock on treated plants.Do not exceed 0.2 lb ai/a per season.

Baythroid XL 2.8 oz Do not apply within 45 days of harvest. Donot exceed 11.2 oz/a per season.


Cruiser 5FS seed treatment For use in commercial seed treaters only, orcertified retail treatment locations. May bepackaged with compatible and registeredseed treatment fungicides (e.g., CruiserMaxxPak). (1.28 oz/100 lb seed)


dimethoate 1.0 pt Do not apply within 21 days of harvest.Endigo 2.5–3.5 oz Do not apply within 30 days of harvest. Do

not exceed a total of 9.0 fl oz/a of Endigo ZCor 0.06 lb ai of lambda-cyhalothrin–containingproducts, or 0.125 lb ai of thiamethoxam-con-taining products per growing season.

Furadan 4F 0.25–0.5 pt Do not apply within 21 days of harvest. Donot make more than 2 foliar applications perseason. Do not graze or feed treated foliage tolivestock.

Gaucho 600 seed treatment For use in commercial seed treaters only.(1.6–3.2 oz/100 lb seed)


Lorsban Advanced 1.0–2.0 pt Do not apply more than 6 pt/a (3 lb ai/a)per season. Do not apply within 28 days ofharvest. Do not graze or feed treated forageto livestock.


Orthene 90S 0.56–1.1 lb Do not apply within 14 days of harvest.




Green cloverworm(cont.)


135

STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

SOYBEAN

insectsCO

RNPRINCIPLES

OF

PESTMNGM

T.Penncap-Mb 1.0–3.0 pt Do not apply within 20 days of harvest. Makeno more than 2 applications per season.

Pounce 3.2 EC 4.0–8.0 oz Do not exceed 0.4 lb ai/a per season. Do notapply within 60 days of harvest. Do not grazeor feed treated forage or hay.




Stink bugs Treat when adult bugs or nymphs reach 1–3 bugs/foot of row during pod fill,40 bugs/100 sweeps for grain soybean, or 20 bugs/100 sweeps for seed beans.Asana XL 5.8–9.6 oz Do not apply within 21 days of harvest. Do








Orthene 90S 0.56–1.1 lb Do not apply within 14 days of harvest.Penncap-Mb 1.0–3.0 pt Do not apply within 20 days of harvest.Proaxis 3.2–3.84 oz Do not apply within 45 days of harvest. Do





Amount ofInsect Insecticidea product/acre Remarks, precautionsSoybean aphid(cont.)

(continued)


136

STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

SOYBEAN

insectsCO

RNPRINCIPLES

OF

PESTMNGM

T. Thistle caterpillar Treat if defoliation reaches 30% before bloom or 20% between bloom and pod fill.Ambush 2E 3.2–6.4 fl oz Do not apply within 60 days of harvest. Do

not exceed 0.4 lb ai/a per season.Asana XL 5.8–9.6 oz Do not feed or graze livestock on treated field

Do not exceed 0.20 lb ai/a per season. Do notapply within 21 days of harvest.





Pounce 3.2EC 2.0–4.0 fl oz Do not apply within 60 days of harvest. Donot exceed 0.4 lb ai/a per season.


Sevin XLR Plus 1.5 qt Do not apply within 21 days of harvest.Warrior II, 0.96–1.6 oz Do not graze or harvest treated soybeanSilencer 1EC 1.92–3.2 fl oz forage, straw, or hay for livestock feed. Do


Two-spotted Treat as needed on field margins or entire field.spider mite dimethoate 1.0 pt Do not apply within 21 days of harvest. Do

not feed or graze within 5 days of last appli-cation.

Cobalt 13.0–26.0 fl oz Wait at least 14 days before making a secondapplication of Cobalt or another product con-taining chlopyrifos. Do not apply within 30days of harvest. Do not graze or feed treatedfoliage to livestock.

Endigo 4.0–4.5 oz For suppression only, not control. Do not applywithin 30 days of harvest. Do not exceed atotal of 9.0 fl oz/a of Endigo ZC or 0.06 lb aiof lambda-cyhalothrin–containing products,or 0.125 lb ai of thiamethoxam-containingproducts per growing season.



(continued)


137

STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

SOYBEAN

insectsCO

RNPRINCIPLES

OF

PESTMNGM

T.

Hero 10.3 oz Do not apply within 21 days of harvest. Donot exceed 0.4 lb ai/a per season. Do notgraze or harvest treated soybean forage,straw, or hay for livestock feed.

Lorsban Advanced 1.0 pt Do not apply more than 6 pt/a per season.Do not apply within 28 days of harvest. Donot graze or feed treated forage to livestock.A second application 3–5 days after the initialspray may be needed to control newlyhatched nymphs. In this case, alternate to anon-chlorpyrifos product that is effectiveagainst mites (e.g., dimethoate).

Proaxis 3.84 oz For suppression only, not control. Do not applywithin 45 days of harvest. Do not exceed0.03 lb ai/a per season. Do not graze or har-vest treated soybean forage, straw, or hay forlivestock feed.

Warrior II, 1.92 oz For suppression only, not control. Do not applySilencer 1EC 3.84 oz within 30 days of harvest. Do not exceed

0.06 lb ai/a per season. Do not graze or har-vest treated soybean forage, straw, or hay forlivestock feed.

aMultiple trade names listed within a row indicate products with the same active ingredient(s).bDo not apply to blossoming soybeans if bees are foraging.


Amount ofInsect Insecticidea product/acre Remarks, precautionsTwo-spottedspider mite (cont.)


SOYBEANDISEASE MANAGEMENT

Soybeans grown in Wisconsin are subjectto attack by several disease-causing organ-isms. Growers should learn to identify themajor soybean diseases in order to distin-guish them from poor plant health due toinsects, adverse weather and soil condi-tions, herbicide injury, and nutrient defi-ciencies. Solutions to disease problems aregenerally quite different compared withsolutions to insects, weeds, and other prob-lems. Soybean diseases can be controlled orreduced by planting resistant or tolerantvarieties, using a crop management systemthat fits your farming operation, and usingagricultural chemicals—generally fungicides.

RESISTANT OR TOLERANTVARIETIESThe use of disease-resistant or tolerant

varieties is a practical and economical con-trol for soybean diseases in Wisconsin.However, no soybean variety is resistant toall diseases. Carefully evaluate the majordiseases on your farm and consider diseasereactions when selecting soybean varieties.Disease reaction of soybean varieties candiffer from year to year because themicroorganisms that cause plant diseasecan change genetically and attack varietiesthat were formerly resistant. Soybean vari-eties also may have different reactionswhen grown under different cultural prac-tices and weather conditions. Consult thepublicationWisconsin Soybean Variety Testsfor information on specific varieties.

CROP MANAGEMENTThe use of crop rotation and clean tillage

are very powerful disease-control tools.Many fungal and bacterial pathogens ofsoybeans survive between cropping sea-sons in soybean crop debris. Once this cropresidue is thoroughly decayed, these dis-ease-causing organisms die out. Therefore,

crop rotation and tillage programs that per-mit residue decomposition before the nextcrop is planted will help reduce diseasessuch as brown stem rot, sclerotinia stem rot(white mold), pod and stem blight, anthrac-nose, stem canker, Septoria brown spot,Cercospora leaf spot (purple seed stain),bacterial blight and several other fungaland bacterial leaf diseases, and the soybeancyst nematode. Soil populations of the soy-bean cyst nematode can be minimized bycrop rotation with nonhost crops.Very few of the fungi and bacteria that

attack soybeans infect other crop plants.Rotations with corn, small grains, or mostforages deprive soybean pathogens of ahost on which to infect, reproduce, andcarry over between soybean crops.Adequate, balanced soil fertility also can

be important in reducing disease losses.Less-than-adequate phosphorus or potashcan result in increased losses from Septoriabrown spot, soybean cyst nematode, sev-eral root rots, and pod and stem blight.Healthy, vigorous plants are more tolerantof diseases and better able to produce anear-normal yield despite diseases.

FUNGICIDESFungicides can be used to control soy-

bean diseases.Fungicidal seed treatment for soybeans

may be beneficial under the following con-ditions.■ If you will be doing early planting in

cold, wet soils.■ Reduced till and no-till fields.■ If germination is below 80% or there are

other indications of low seed vigor.Seed invaded by disease-producingorganisms such as Phomopsis (pod andstem blight fungus) is more likely torespond to seed treatment.

138

STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

SOYBEAN

CORN

PRINCIPLESOF

PESTMNGM

T.


■ If the field is known to be heavilyinfested with soybean root-invadingfungi such as Pythium, Rhizoctonia, orPhytophthora.Select the seed treatment fungicide to

match pathogen pressure—soil type,tillage, soil moisture and temperature, andseed health will influence the degree ofpressure.Follow the label for application rates and

instructions. Apply fungicide seed treat-ments before applying a Rhizobium; inocu-lum and plant seed immediately.Foliar fungicides can be used to lower

losses due to leaf diseases and pod andstem blight. Pod and stem blight mayreduce yield, but its major effect is throughseed infection (Phomopsis seed decay) thatresults in reduced seed germination andlower seedling vigor. Evaluations in Wis-consin reveal that foliar-applied fungicidesreduce seed infection and improve germi-nation. Foliar-applied fungicides for thecontrol of leaf diseases and pod and stemblight have improved yields in Wisconsintests, but this result has been inconsistent.Soybean seed producers should consider

the use of foliar fungicides to improve seedquality. The following factors should beconsidered before foliar fungicides areused.■ Potential risk. The diseases controlled by

fungicide sprays are important whenwarm, wet weather prevails during thepod-fill stage. If, at bloom, the 30-dayoutlook is for warm, wet weather, thesediseases will be active and fungicidesprays will be beneficial. Most productlabels suggest two sprays, one at earlypod development (upper pods 0.50 to0.75 inch long) and a second spray 14 to21 days later. However, if the weatherhas been dry since the first applicationand the forecast is for continued dryweather, do not spray a second time.One application when upper pods are0.75 to 1.0 inch long has been effectivein Wisconsin trials.

■ Was the field planted to soybeans the previ-ous year? If you grow soybeans for twoor more consecutive years, diseaseseverity potential will be higher than ifyou rotate crops.

■ No-till or minimum tillagewill increasethe potential of disease if soybeans areplanted consecutive years.

■ Early-maturing varieties usually suffergreater losses from diseases controlledby foliar fungicides than full-seasonvarieties.

■ Benefits of improved seed quality from dis-ease control may be an important con-sideration for applying fungicides toseed-production fields.

■ High yields (50 bu/a or more) should beanticipated if fungicide application is tobe economical.

■ Treatment cost versus expected benefit.Each treatment costs about $20 to $30/afor the chemical, wetting agent, andapplication.

■ A dense canopy of weedswill impede themovement of the fungicide to soybeanpods and foliage.Follow label instructions for application

rates and additional application instructions.Soil-applied fungicides can be used for

control of Phytophthora root rot. Ridomil2EC and Ridomil 5G are the only productsregistered for this purpose. Consider thefollowing if you are thinking of usingRidomil 2EC or Ridomil 5G:■ Potential risk. Ridomil should be consid-

ered for fields with a history of frequentPhytophthora root rot. This disease cancause significant yield loss even with-out extensive plant death. Soils withhigh water-holding capacity are usuallyat greatest risk.

■ Soybean variety. Ridomil performance isgreatly affected by a variety’s level ofresistance or tolerance to Phytophthoraroot rot. Varieties that are highly toler-ant have performed best with Ridomiluse in Wisconsin research trials. Vari-eties with full resistance respond less toRidomil treatment. Ridomil should notbe applied to a fully susceptible or lowtolerant soybean variety.

139

STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

SOYBEAN

diseasesCO

RNPRINCIPLES

OF

PESTMNGM

T.


140

STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

SOYBEAN

diseasesCO

RNPRINCIPLES

OF

PESTMNGM

T.

SOYBEAN DISEASES

Phytophthora root rotPhytophthora root rot may be found on

soybeans grown on any soil type, but soilswith poor internal drainage are especiallyprone to Phytophthora problems. Youngplants are very susceptible and die quickly,the resulting gaps in rows are the only evi-dence the disease is present. Older plantsare killed more gradually or plant vigor isreduced throughout the growing season.Initial leaf symptoms are a progressive yel-

lowing and wilting of leaves from the bot-tom to the top of the plant. The dead leavesgenerally remain attached for a week ormore. Dead or dying plants have a browndiscoloration of the stem progressingupward from the soil line.Variety selection and field monitoring.

Planting resistant varieties provides thehighest level of protection against individ-ual races of Phytophthora. So if the fungusexists in your fields, you’ll need to knowwhich races are prevalent. To determinewhich races are present in a field, plant sev-eral varieties that differ in reported resis-

Fungicide Sample formulations

Pathogens controlled

RemarksRhiz. Pyth. Phyt. Phom.

captan many ■ ■ ■ Protects against seed rot.carboxin +captan

Vitavax-captan ■ ■ ■ Protects against seed rot; provides systemic protection ofseedlings to disease caused by Rhizoctonia. Carboxin con-trols seedborne phase of Phomopsis (pod and stem blight).Phomopsis can lower germination and seedling vigor.

carboxin +thiram

Vitavax-200 ■ ■ ■ Protects against seed rot; provides systemic protection ofseedlings to disease caused by Rhizoctonia. Carboxin con-trols seedborne phase of Phomopsis (pod and stem blight).Phomopsis can lower germination and seedling vigor.

fludioxonil Maxim 4FS ■ ■ Protects against Rhizoctonia and seed-borne Phomopsis. Usewith Apron XL for broad-spectrum disease protection.

fludioxonil +mefenoxam

Apron Maxx RFC,Apron Maxx RTA,Apron Maxx Bean Pak,Cruiser Maxx Pak,Warden RTA

■ ■ ■ ■ Protects against seed rot and seedling death caused byPhomopsis, Phytophthora, Pythium, and Rhizoctonia.

mefenoxam Apron XL-LS ■ ■ Improves stands by controlling seed rot and seedling deathcaused by Phytophthora and Pythium. Has systemic activity.Will enhance performance of soybean varieties with low tomoderate resistance (tolerance) to Phytophthora.

metalaxyl Allegiance ■ ■ Improves stands by controlling seed rot and seedling deathcaused by Phytophthora and Pythium. Has systemic activity.Will enhance performance of soybean varieties with low tomoderate resistance (tolerance) to Phytophthora.

PCNB +ethazole

Terraclor Super-x,Terra-Coat L-205N

■ ■ ■ Protects against seed rot caused by Pythium and Rhizoctonia.

thiram many ■ ■ ■ Protects against seed rot; suppresses seedborne fungi.trifloxystrobin+ metalaxyl

Trilex AL ■ ■ Provides seed and seedling protection against seedbornefungi causing seed decay and the soilborne pathogensRhizoctonia solani and Pythium spp.

Abbreviations: Rhiz. = Rhizoctonia, Pyth. = Pythium, Phyt. = Phytophthora, Phom. = Phomopsis.aFollow label instructions for application rates and additional application instructions. Apply fungicide seed treatments before applying aRhizobium inoculum and plant seed immediately.

Table 3-9. Fungicides for treating soybean seeds for protection against Rhizoctonia, Pythium,Phytophthora, and Phomopsisa


141

STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

SOYBEAN

diseasesCO

RNPRINCIPLES

OF

PESTMNGM

T.

tance. This test is especially importantwhen planting a variety in a specific fieldfor the first time. Races of the pathogen candiffer from field to field. Also, new racescan become prevalent and a soybean vari-ety that has shown no Phytophthora rootrot in past years can become very diseased.For this reason, it’s important to monitorthe performance of varieties with race-spe-cific resistance. Be aware that many soy-bean varieties have the same source ofresistance to Phytophthora root rot. Consultthe publicationWisconsin Soybean VarietyTests for information on specific varieties.Resistant varieties: Soybean varieties con-

tain different genes for resistance. Eachgene confers resistance to specific races ofPhytophthora. No one variety is resistant toall races. This form of resistance results in avery high level of control. Resistant vari-eties perform well across a wide range ofenvironments; however, the appearance ofa new race can result in severe disease.Tolerant varieties:Many soybean varieties

are not highly resistant to specific races ofPhytophthora but vary in the degree of sus-ceptibility to all races. Varieties with a lowlevel of susceptibility frequently arereferred to as tolerant. Highly tolerant vari-eties can perform very well against Phy-tophthora root rot. However, performanceof tolerant varieties can drop when condi-

tions are highly favorable for this disease.Tolerance can be supplemented by use ofappropriate cultural practices, formulationsof seed treatment fungicides that containmefenoxam or metalaxyl, and Ridomil soiltreatment.Cultural practices. Phytophthora root rot is

most effectively suppressed by avoidingsusceptible varieties. The ability of varietiesto resist Phytophthora root rot can beenhanced by the following cultural practices.■ Improve soil drainage.■ Avoid tillage practices or other field

activities that enhance soil compaction.■ Ridge soil around the base of plants

during cultivation to promote rootgrowth from the lower stem. This maysuppress Phytophthora root rot whenthe root rot phase predominates. Thelower soil moisture in the ridges createsa less favorable environment for Phy-tophthora activity.

Chemical control. For early Phytophthoraroot rot control, treat seed with Apron 25W;treat only varieties with moderate to hightolerance. For longer control, apply Ridomil2E in the furrow, over the row, or broadcastor apply Ridomil 5G in the furrow or in aband over the row.

Table 3-10. Fungicides for foliar and soil application for soybeana

Fungicide Formulation Groupb

Cercosporablight &leaf spot

Downymildew

Frogeyeleaf spot

Phytoph-thoraroot rot

Pod andstemblightc

Powderymildew

Sclerotiniastem rot

(white mold)

Septoriabrownspot

azoxystrobin Quadris 11 ■ ■ ■ ■

basic coppersulfate

Cuprofix Disperss,Cuprofix Ultra 40

M1 ■■

■■

■■

■■

■■

chlorothalonil Bravo 500 M5 ■ ■ ■ ■ ■

mefenoxam Ridomil Gold GR,Ridomil Gold 4EC

4 ■■

pyraclostrobin Headline 11 ■ ■ ■ ■

thiophanate-methyl

Topsin M 4.5FL,Topsin M 70WP,Topsin MWDG

1 ■

■■

■

■■

■

■■

■

■■

aFollow label instructions for application rates, time of application, and additional application instructions.bGroup codes indicate modes of action; use fungicides with different group codes to reduce the risk of disease resistance.cControl of seed infection by PSB pathogen.


142

STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

SOYBEAN

diseasesCO

RNPRINCIPLES

OF

PESTMNGM

T.

Brown stem rotBrown stem rot (BSR) can reduce grain

yield by 10 to 25%. Symptoms do notappear until after pod development hasbegun. The insides of stems turn brownand leaves gradually yellow, wilt, and die.The symptoms begin in August and earlySeptember, depending on the relativematurity of the variety. Due to the timing,brown stem rot is often confused with earlymaturity. Yield loss due to brown stem rotis greatest when the soybean crop isplanted early and in narrow rows. Brownstem rot resistant varieties and/or longercrop rotations may be most critical in thissituation.Crop management. Crop rotation can be

used to control brown stem rot. However, ifgrowing susceptible varieties, you shouldhave at least 2 years of a non-host cropbetween soybean crops. Rotating soybeanand corn on alternate years can result inyield loss due to brown stem rot. Corn andsmall grains are excellent non-host crops.Current research indicates that foragelegumes, peas, and snap beans are not asso-ciated with increased severity of brownstem rot. The risk of brown stem rotdeclines as soil pH increases to 7.0 orabove.Resistant varieties. Both public and pri-

vate soybean varieties are available withmoderate to high levels of resistance tobrown stem rot. Consult the publicationWisconsin Soybean Variety Tests for informa-tion on specific varieties. Watch for foliarsymptoms associated with “resistant” vari-eties. These symptoms may be caused by abreakdown of resistance by the BSRpathogen or a different pathogen.Integration of rotation and resistant varieties.

The movement to more integrated agricul-tural systems to reduce production costsmakes an alternating soybean and cornrotation a seemingly desirable system.However, only 1 year of corn between soy-bean crops results in minimal suppressionof the brown stem rot fungus. Preliminary

results from experiments in Iowa and Wis-consin suggest that varieties that are highlyresistant to brown stem rot reduce inocu-lum in the soil, but to a lesser degree than ayear of corn. Thus, use of varieties resistantto brown stem rot may take on addedimportance as the time interval betweensoybean crops is shortened. Althoughplanting a variety resistant to brown stemrot would be the most effective manage-ment option, another option is to plantresistant and susceptible soybean varietieson an alternating basis each time soybeansare planted in rotating corn or other non-host of the brown stem rot fungus. Brownstem rot is more severe in no-till fields thanin conventional till. Therefore, longer croprotations and/or resistant varieties shouldbe considered if using no-till systems forsoybean production.

Leaf diseasesLeaf diseases such as downy mildew,

bacterial blight, powdery mildew, andbrown spot are present in most soybeanfields but generally do not cause significantyield losses. Frogeye leaf spot and Cer-cospora leaf spot, diseases normally foundin the South, are becoming more prevalentin Wisconsin. Hot, humid weather favorsdevelopment of these diseases.Yield losses from leaf diseases may occur

more frequently if soybeans are plantedafter June 1, especially if downy mildew orpowdery mildew develop. Under certainenvironmental conditions these diseasescan occur early in the growing season andcause premature defoliation and subse-quent yield losses. Early development ofbrown spot may indicate other health prob-lems are present. Crop rotation, fall plow-ing to bury soybean debris, or applicationof foliar fungicides at early podding canreduce the incidence of leaf diseases.


143

STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

SOYBEAN

diseasesCO

RNPRINCIPLES

OF

PESTMNGM

T.

Soybean rustSoybean rust is a rapidly spreading fun-

gal disease that was first detected in theUnited States in 2004. Soybeans are suscep-tible to rust infection at all growth stages.Infected plants have fewer pods, fewerseeds per pod, and poorly filled seeds.Yield losses are predicted in the UpperMidwest, but the extent may be less thanpreviously anticipated.Symptoms. Symptoms first appear in the

lower canopy with tiny gray spots formingon the undersides of leaves, often clusterednear leaf veins. As the disease progresses,the spots rapidly increase in size andbecome visible on the upper side of the leafas well as on petioles, stems, and pods.Spots change color, going from gray to tanto reddish-brown or black. Leaves turn yel-low and drop prematurely. Early rustsymptoms may be mistaken for downymildew, brown spot, bacterial pustule, orfrogeye leafspot.There is no evidence that the soybean

rust fungus will survive Wisconsin winters.As a result, the pathogen must be blownnorthward to reinfest fields each year. Dis-ease development is favored by long peri-ods of leaf wetness (at least 8 hours), highrelative humidity (75 to 80%), and tempera-tures between 59°F and 86°F. At highertemperatures, disease development slowsor stops. Spores can be produced 10 daysafter infection and are continually releasedas long as environmental conditions arefavorable.Scouting. Early detection and a rapid

response are critical to soybean rust man-agement. Scout fields frequently, concen-trating on early planted fields and earlymaturing varieties, and in fields that aresubject to prolonged dews. Begin monitor-ing at soybean emergence and continue ona weekly schedule. Use a hand lens tocheck lower leaves where rust symptomsare likely to show first. If soybean rust hasbeen reported in a neighboring state,increase scouting frequency to twice aweek. Check the North American SoybeanRust Alert System(www.usda.gov/soybeanrust/) frequentlyto track development and movement ofrust in other states. You may also call theUniversity of Wisconsin, Plant Pathogen

Detection Clinic's toll-free number (1-866-787-8411 or 1-866-RUST411) for a recordedmessage on soybean rust movement.To confirm diagnosis, select leaves repre-

senting the range of symptoms. Place theleaves between layers of cardboard andpaper towels and place in a sealable plasticbag. Keep them cool until mailing andrecord as much field history information aspossible. Send to the Plant Disease Diag-nostics Clinic, Department of Plant Pathol-ogy, University of Wisconsin-Madison, 1630Linden Drive, Madison, WI 53706- 1598.There will not be a fee for soybean rustdiagnosis in 2006.Crop management. Use proven crop man-

agement practices that provide the greatestsoybean yield potential for your farm.Modifying crop management practices inthe absence of rust may reduce yields. Plantsoybeans as early as practical. If soybeanrust does occur, yield loss is likely to be lesswhen rust is diagnosed at later growthstages. Cultural practices such as widerrows and reduced plant populations couldpotentially decrease the severity of rust bydecreasing the length of time leaves remainwet. Wider row width may also be benefi-cial for sprayer movement in the field andbetter coverage of leaves throughout thecrop canopy. However, it is not known howmuch of an impact these practices will haveon soybean rust. Growers should considerthe impact of all diseases before changingcultural practices.Fungicides are the only in-season control

practices that are effective against soybeanrust. Method of control is considered eitherpreventive (sometimes called protectant) orcurative:■ Preventive fungicides prevent fungi from

infecting and/or penetrating host tis-sue. These fungicides must be in placebefore plants are infected, or they willnot control the disease. The strobilurinclass of fungicides (azoxystrobin, pyra-clostrobin, trifloxystrobin, etc) are allpreventive fungicides.

■ Curative fungicides (triazoles) inhibit orstop the development of infections thatare already established. These fungi-cides are also able to slow diseasedevelopment by limiting the pathogen's


ability to produce new spores. This“post-infection activity” makes triazolesthe fungicide of choice if soybean rust isestablished at low levels in a field. It isimportant to remember that triazoles donot have unlimited curative activity andare most effective when applied toplants with less than 10% infection inthe lower canopy. Triazole fungicidesmay also be applied as a preventive,before disease infection.Up to two fungicide treatments may be

necessary depending on when rust arrivesand at what crop stage the first applicationis made. Refer to table 3-11 for a current listof products registered for use on soybeanrust. Be sure to read and follow fungicidelabels for pre-harvest intervals and sprayintervals for special disease situations. Dueto resistance concerns, avoid making suc-cessive applications of strobilurins or tria-zoles. For treatments to be most effective,leaves, stems, and pods should be thor-oughly covered. Ensure adequate leaf cov-erage by selecting nozzles that deliver fineto medium droplets (200–350 microns) andthat are designed to promote canopy pene-tration. Use spray pressures between 40-70psi and outputs over 15 gal/a (5 gal/a foraerial application). Always follow labeldirections.For the latest soybean rust information,

contact your local county Extension agentor visit the University of Wisconsin’sSoybean Plant Health site atwww.plantpath.wisc.edu/soyhealth/.

Soybean cyst nematodeThe soybean cyst nematode (SCN) was

first discovered in southeastern Wisconsinin 1980. Currently, this destructive root-infecting pathogen should be considered athreat in all soybean growing regions ofWisconsin.Soybean cyst nematodes are microscopic

roundworms that reside in the soil and liveby extracting nutrients from soybean roots.Common foliar symptoms are yellowingand eventual premature death. SCN-dam-aged plants usually are stunted and nodu-lation is often disrupted. Plant death mayoccur, but usually does not. Symptoms canbe confused with other crop productionproblems such as nutrient deficiencies,injury from agricultural chemicals, soil

compaction, and other soybean disorders.SCN populations can also interact with andintensify these disorders, and vice versa.If high populations of SCN are present,

plants show symptoms often before flower-ing. However, symptoms may not appearuntil pod set if low soil populations of SCNexist. SCN-infected plants commonly occurin oval-shaped patches that vary in sizeand increase each year soybeans areplanted in an infested field. The affectedarea generally expands in the direction oftillage.A laboratory soil analysis usually is nec-

essary to determine the presence of SCN.However, you can diagnose SCN in thefield by observing the cysts on the soybeanroot. Initially, the cysts are white, but theyturn brown with time. The cysts areapproximately the size of a pin head. Becareful not to confuse them with nodulescaused by nitrogen-fixing bacteria.Sampling for soybean cyst nematode. A soil

analysis test can be used to confirm a sus-pected nematode problem or to eliminateSCN as one of several possible causes ofpoor plant growth. Soil samples can betaken anytime of the year.There are several ways to take a soil sam-

ple for nematode analysis. The following isa general guide:1. Use a soil probe or narrow-bladed

trowel or shovel. Take samples close toplants at a depth of 8 to 10 inches. Dis-card the upper 2 inches of soil, espe-cially if it is dry. Be sure to include plantroots.

2. Submit one sample for a 10-acre field orfor a suspected area within the field.Sample soil and roots from 12 to 20plants and mix into one sample; 1 to 2pt of soil is adequate. Sample fromplants in the margins of suspected areasand not from their centers.

3. Place samples in sturdy plastic bags,fasten the open end securely, and accu-rately label samples. Keep the samplesfrom becoming dry and overheated.Mail samples early in the week to avoiddelays in transit.Laboratories will report the number of

nematodes per unit of soil, usually per 100cc of soil, or per gram of dry root. Growersand crop consultants may use these lab

144

STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

SOYBEAN

diseasesCO

RNPRINCIPLES

OF

PESTMNGM

T.


STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

SOYBEAN

diseasesCO

RNPRINCIPLES

OF

PESTMNGM

T.

Table 3-11. Fungicides registered for foliar soybean diseases in Wisconsin

Trade name Active ingredient Chemical family FRACa Rate/a Remarks

Alto 100 SL cyproconazole triazole 3 2.75–5.5 fl oz Do not exceed 11 fl oz/a Alto 100 SL or 0.072 lbai/a of cyproconazole-containing products perseason. Do not apply within 30 days of harvest.Do not graze forage within 14 days after anapplication or use soybean forage or hay aslivestock feed if making more than one applica-tion at the 5.5 fl oz/a rate.

Bravo chlorothalonil chloronitrile M5 1.0–2.0 pt Labeled for suppression of rust. Wait at leastWeather Stik 14 days between treatments and do not exceed

three applications per season. Do not applymore than 6 pt/a. Do not feed treated hay orthreshing to livestock. Do not harvest for grainwithin 6 weeks of last treatment.

Cuprofix Ultra 40 Copper sulfate inorganic M1 0.75–3.0 lb See label for use instructions.Domark 230 ME tetraconazole triazole 3 4.0–5.0 fl oz Do not apply after R5 growth stage. Do not

exceed 10 fl oz/a per season or make more thantwo applications per season. Do not graze orfeed treated forage or hay to livestock.

Echo 720 chlorothalonil chloronitrile M5 1.0–2.5 pt Do not feed treated soybean hay or threshing toEcho 90 DF 1.25–2.0 lb livestock. Do not harvest for grain within 42Echo Zn 2.0–3.5 pt days of last treatment.Folicur 3.6 F tebuconazole triazole 3 3.0–4.0 fl oz Applications may not be made within 21 days of

harvest. Do not apply more than 12 fl oz/a perseason or exceed three applications per season.

Headline pyraclostrobin strobilurin 11 6.0–12.0 fl oz Do not exceed 24 fl oz/a per season. Do notmake more than one application of Headlinebefore alternating to a labeled fungicide with adifferent mode of action (not Group 11). Do notharvest for grain within 21 days of last treatment.

Laredo EC myclobutanil triazole 3 4.0–8.0 fl oz Do not make more than two applications ofmyclobutanil-containing products to soybeansper season. Do not apply more than 0.25 lb ai/amyclobutanil per year. Do not feed treated for-age and hay to livestock. Do not harvest forgrain within 28 days of last treatment.

Proline 480 SC prothioconazole triazole 3 2.5–3.0 fl oz Applications may not be made within 21 days ofharvest. Do not apply more than 9 fl oz/a perseason or exceed three applications per season.

Quadris azoxystrobin strobilurin 11 6.2–15.5 fl oz Do not apply more than 1.5 lb ai/a per seasonof products containing azoxystrobin. Do notmake more than one application of 15.5 fl oz/aof Quadris (0.25 lb ai/a) to soybean forage andhay. Do not apply within 14 days of grain har-vest. May be applied the day of harvest for for-age or hay.

Quadris Xtra azoxystrobin methoxyacrylate 3, 11 4.0–6.8 fl oz Do not apply more than 13.6 fl oz/a per season.+ cyproconazole + triazole Do not apply within 30 days of harvest of soy-

bean (bean). Do not graze forage within 14days of an application. Do not apply more than0.072 lb ai/a per season of products containingcyproconazole or 1.5 lb ai/a of products con-taining azoxystrobin. Do not use soybean for-age or hay as livestock feed if applying QuadrisXtra more than once at 6.8 fl oz/a rate.

(continued)

145


STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

SOYBEAN

diseasesCO

RNPRINCIPLES

OF

PESTMNGM

T.

Quilt azoxystrobin strobilurin 3, 11 14.0–20.5 fl oz Do not apply more than 42 fl oz/a per season+ propiconazole + triazole of Quilt. Do not exceed a total of 0.34 lb ai/a of

products containing propiconazole and 1.5 lbai/a of products containing azoxystrobin peryear. Do not apply within 21 days of harvest.

Stratego propiconazole triazole 3, 11 10.0 fl oz Applications may not be made within 21 days+ trifloxystrobin + strobilurin of harvest. Do not apply more than three times

per season. Do not exceed 30 fl oz/a per sea-son. Do not apply more than two sequentialapplications of Stratego or any other Group 11fungicide without alternating with a fungicidefrom another group.

Tilt propiconazole triazole 3 4.0–6.0 fl oz Apply up to the R6 growth stage. Do not applymore than 12 fl oz/a of Tilt per year. Do notapply more than 0.34 lb ai/a of products con-taining propiconazole per year.

Topsin M 70 WP thiophanate- thiophanates B1 0.5–1.0 lb Do not apply more than 2 lb/a product (1.4 lbTopsin MWDG methyl ai) per season. Do not graze or feed treatedTopsin MWSB vines or hay to livestock.a FRAC codes indicate the modes of action for each fungicide; multiple applications of fungicides from the same group increases the chancesfor the fungus developing resistance.

Table 3-11. Fungicides registered for foliar soybean diseases in Wisconsin (continued)

Trade name Active ingredient Chemical family FRACa Rate/a Remarks

146

Table 3-12. Risk assessment of soybean cyst nematode by soilpopulation and soil type

Egg count range Potential yield lossRisk per 100 cc soil for SCN susceptible variety

None 0 NoneLow 1–500 0–10% silt or clay soil

5–20% sandy soilsModerate 500–2000 10–20% silt or clay soils

10–40% sandy soilsHigh 2000–5,000 20–50% all soilsVery High >5,000 30–70%

10–20% expected yield loss for resistant varietiesaaSoybean varieties with CystX resistance should be superior to other forms of SCN resistance in fieldswith very high SCN populations in soil.


results to determine SCN damage potential(table 3-12). Nematode analysis laboratoriesare listed in table 2-15 on page 89.Crop management. To keep soil popula-

tions of SCN at non-damaging levels, rotatesoybeans with crops such as small grains,corn, alfalfa, and most vegetables (exceptpeas, snap beans, lima beans, and dry-edi-ble beans). The SCN can increase rapidly ifsoybeans are frequently planted in thesame field.Two years of field studies indicate that

you can expect higher populations of SCNif planting in areas of fields with soil pHlevels above 7.0 as compared to areas withpH levels of 5.9 to 6.5. Damage is usuallymore severe in sandy soils, but will occur inall types of soil.Resistant varieties. SCN-resistant soybean

varieties are becoming available. However,control should start with crop rotationwhich delays development of damaginglevels of SCN and greatly enhances the per-formance of resistant soybean varieties.Sample soils to determine population levelsof SCN. Resistant varieties should beplanted in fields with more than 1,000 SCNeggs/250 cc of soil. Consult the publicationWisconsin Soybean Variety Tests for informa-tion on specific varieties.

Diaporthe pod and stem blightPod and stem blight is a conspicuous dis-

ease of maturing soybeans. Plants areinfected throughout the season, but con-spicuous symptoms do not appear until2 to 3 weeks before maturity. Symptoms aresmall, black fruiting bodies that look likespecks on maturing soybean stems andpods. Severe infection by the Diaporthefungus does not always mean a reductionin yield, but it generally results in reducedquality of seed for market or future plant-ing. This is the Phomopsis seed decayphase of pod and stem blight. Infected seedmay show no detectable symptoms or canbe in some stage of decay. Visibly infectedseeds are a discolored brown, shriveled,and often covered with white mold. Thisdisease is favored by warm, wet weatherduring late pod fill.Control. Diaporthe pod and stem blight

can be controlled or reduced by integratingone or more of the following practices: usepathogen-free seed, plant later, practice

crop rotation, deep-plow soybean debris,harvest as early as possible, and apply reg-istered fungicides at early podding (see sec-tion on fungicides). Resistant varieties arenot known, but early-maturing varietiesgenerally are more susceptible. Seed treat-ments are useful when Phomopsis-infectedseed must be sown. Plant-disease diagnos-tic laboratories can examine seed lots todetermine approximate amounts of infec-tion that may be present in seed. Narrow-row production does not increase pod andstem blight (Phomopsis seed decay).

Sclerotinia stem rot(white mold)Sclerotinia stem rot (also called white

mold) is characterized by dying plants inwhich the stems are covered with whitemycelium and hard black structures calledsclerotia. Sclerotia also form inside infectedstems. Sclerotinia stem rot can be confusedwith Phytophthora root rot. Close inspec-tion of affected plants is very important.Sclerotinia stem rot is favored by cool tomoderate temperatures and high humidi-ties in the crop canopy, especially duringthe flowering phase of crop development.The risk of Sclerotinia stem rot is greatest

when soybeans are grown in high-yieldenvironments. Narrow-row production,early planting, plant populations greaterthan 200,000 plants per acre, irrigation, andhigh soil fertility are management practicesthat increase the risk of Sclerotinia stem rot.Variety selection is critical under theseconditions.Control. Sclerotinia stem rot management

recommendations are based on the amountof disease that has been present in the fieldand on the relative resistance or susceptibil-ity of the soybean variety planted. Refer totable 3-13 for specific recommendations.Soybean varieties differ in susceptibility

to Sclerotinia stem rot. Complete resistanceto Sclerotinia is not available. Disease reac-tions of soybean varieties are greatly influ-enced by environmental conditions. Consultthe publicationWisconsin Soybean VarietyTests for information on specific varieties.The Sclerotinia stem rot fungus survives

for years in the absence of a favorable host.Two years of a non-host crop reduces, butdoes not eliminate the risk of Sclerotiniastem rot. Corn and small grains are excel-

147

STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

SOYBEAN

diseasesCO

RNPRINCIPLES

OF

PESTMNGM

T.


148

STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

SOYBEAN

diseasesCO

RNPRINCIPLES

OF

PESTMNGM

T.

lent non-host crops to rotate with soybean;sunflowers, lima beans, and snap beans arehosts and increase the potential of Sclero-tinia stem rot in soybean. Many broadleafweeds also are host. Thus, control ofbroadleaf weeds in the non-host crop yearis critical.Topsin 70W and Topsin 4.5F are regis-

tered on soybean and are moderately effec-tive for control of Sclerotinia stem rot ifapplied when flowers are present on thelower half of stems.Herbicides containing lactofen (Cobra,

Phoenix) will suppress white mold if appliedat or before first bloom. Check the label forrates and adjuvant recommendations.Sclerotia of Sclerotinia sclerotiorum are

long-lived in soil but are subject to attackby many soil organisms. One commerciallyavailable biological control product, Con-

tans WG, is labeled to control Sclerotiniastem rot in agricultural soils. Contans WGis applied in water to the soil surface, usu-ally during preplanting or post-harvest onthe stubble of a previously diseased crop.Contans WG can be sprayed just ahead ofthe tillage equipment. It should be incorpo-rated within 24 hours after spraying, ide-ally immediately after spraying. ContansWG can be incorporated with irrigation onsandy soils and some peat soils. It may betank-mixed and applied with herbicidessuch as trifluralin or glyphosate. Do notmix Contans with any other fungicide.Read and follow label directions. The moretime between treatment and the typicalonset of disease, the better.

Table 3-13. Management recommendations for Sclerotinia stem rot (white mold)

Field history (% disease) Management recommendationsa,b

0% Plant pathogen-free seed. Maintain current row width and plant population.Avoid crops that are susceptible to white mold in the rotation.

<5% If disease is…—present in pockets:Avoid planting susceptible soybean varieties. Maintaincurrent row width and plant population. Rotate out of soybeans for at least1 year.—spread throughout field: Plant partially resistant varieties. Maintain currentrow width, but reduce plant population if planting less-resistant varieties.Rotate out of soybeans for at least 1 year.

5–25% If soybean variety is…—partially resistant:Maintain current row width and plant population.Rotate out of soybeans for at least 1 year.—moderately susceptible:Widen row width to 15 to 30 inches and lower seed-ing rate accordingly. Rotate out of soybeans for at least 1 year. Consider treatingseed fields with a fungicide at flowering.

25–50% Select partially resistant varieties. Maintain current row width but lower theplant population. Rotate 1–2 years out of soybeans. Consider treating field witha fungicide at flowering.

>50% Plant varieties with as much resistance as possible. Narrow row spacing maybe acceptable for varieties with good resistance. If planting 30-inch rows,plant at 125,000 seeds/a. Rotate 2–3 years out of soybeans. Fungicide treatmentnecessary for susceptible varieties grown for seed—apply when flowers arepresent on lower half of stems.

aVariety resistance rankings: resistant = <5% mortality, high yield; partially resistant = 5–25% mortality,high yield; moderately susceptible = 26–50% mortality, variable yield; susceptible = 26–50% mortality, low yield;highly susceptible = >50% mortality, low yield.bOptimum seeding rates for fields with a high risk for white mold: 180,000 plants/a for 7.5- and 15-inch rowsand 125,000 plants/a for 30-inch rows.Source: Soybean Plant Health, University of Wisconsin. www.plantpath.wisc.edu/soyhealth.


Alfalfa mosaic virusAlfalfa mosaic virus (AMV) was detected

in soybean for the first time in 1999. MostAMV inoculum is introduced into soybeanfields by aphids that acquire the virus fromforage legumes. Transmission occursthroughout the season. Infected leaves mayhave a bright yellow mosaic or the leafveins may turn yellow but the rest of theleaf remains the normal green color.Control. No genes with resistance have

been reported. Soybeans planted early inthe season appear to be less affected by thedisease.

Bean pod mottle virusBean pod mottle virus (BPMV) was first

detected in Wisconsin in 1999. Bean leafbeetles feed on infected forage legumes andtransmit the virus to soybeans throughoutthe season. Young leaves in the uppercanopy exhibiting light green to yellowmottling. Some leaves become puckeredand distorted. Stems remaining green afterpods have matured retain petioles after leafblades drop. The virus survives in insectsover the winter.Control. Tolerant varieties are reported,

but varieties are not characterized for reac-tion to BPMV. Management of bean leafbeetle is key to control of virus (see theinsect section for recommendations). Delayplanting until mid-May to avoid feeding byoverwintered bean leaf beetles.

Soybean mosaic virusThe soybean mosaic virus occurs in Wis-

consin, but yield loss has not been docu-mented. Infected leaves develop a mosaicof light and dark green areas and chlorosismay develop between the dark green areas.Leaf surfaces become raised or blisteredand leaf margins may be wavy or curldownward. Most infected plants areslightly stunted, have fewer pods, andmature later. Infected seed, a major sourceof inoculum, may be discolored. Aphidsfeed on infected plants and transmit SMVto healthy plants throughout the season.Control. Plant virus-free seed. Varieties

appear to differ in susceptibility but theyare not characterized for reaction to SMV.Soybeans planted early in the seasonappear to be less affected by the disease.

Tobacco streak virusTobacco streak virus (TSV) is widespread

in Wisconsin but yield loss is not known.This disease was detected in soybean forthe first time in 1999. Infected leavesacquire a mild mosaic coloring of yellowand green. Leaf and flower buds may beexcessively proliferous. Maturity is delayedin infected plants and plants remain green.Most TSV inoculum is introduced into soy-bean fields as infected seed. Thrips transmitTSV to healthy plants season-long.Control. Varieties appear to differ in reac-

tion to TSV although genes with resistanceto the virus have not been reported. Soy-beans planted early in the season appear tobe less affected by the disease.

149

STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

SOYBEAN

diseasesCO

RNPRINCIPLES

OF

PESTMNGM

T.


150

STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

SOYBEAN

diseasesCO

RNPRINCIPLES

OF

PESTMNGM

T.


FORAGE & PASTUREPEST MANAGEMENT

4

STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

SOYBEAN

CORN

PRINCIPLESOF

PESTMNGM

T.

A3646-09, IV. Forages:A3646/05, IV. Forages 10/14/08 4:48 PM Page 151

FORAGE & PASTUREWEED MANAGEMENT

Wisconsin has millions of acres of har-vested forages and pastures that serve asthe base of our strong livestock enterprises.Weeds can cause serious losses in foragesand pastures unless management practicesare in place to contain them. This sectionwill discuss weed management in legumeforages and then in grass pastures.

FORAGE LEGUMESWeed management tools are much more

limited in forage crops compared to graincrops. The only opportunity to use mechan-ical methods of weed management is dur-ing seedbed preparation before establish-ment. As a result, growers rely uponherbicides and competition from foragelegumes to suppress weeds. After the seed-ing year, though, weeds are seldom a prob-lem as long as the stand remains vigorousand dense. Weedy fields usually occurwhen stands decline, a sign that major ren-ovation is required. Weeds can be sup-pressed with mowing/grazing; however,weed species can affect feed quality andpalatability. Herbicide use is common innewly seeded stands, but rare in estab-lished stands. Legume establishment with acover crop is discussed in the small grainssection of this manual.

ESTABLISHING FORAGELEGUMES WITHOUT A COVERCROP (DIRECT SEEDING)Historically, small-seeded legumes in

Wisconsin have been sown with a smallgrain cover crop; currently, most growersestablish forage legumes without a com-panion crop. (See the small grains sectionfor details about weed management whenlegumes are seeded with cereals.) Whiledirect seeding can enhance yields in theestablishment year, small-seeded legumesgrow slowly, leaving the soil surfaceexposed and subject to erosion. Don’t use

this establishment practice where youexpect soil erosion. In these cases considerplanting with a no-till drill or using a tem-porary cover crop as discussed later.Because small-seeded legumes are poorcompetitors until they are well established,adequate weed control in the seeding phaseis essential.The postemergence herbicides available

in forages make it possible to practice theIPM principle of “treat as needed.” If nopreplant-incorporated herbicide is used,scout fields weekly after planting. Considerusing the appropriate herbicide or herbi-cide combination if weed pressure is mod-erate to high. There is no need to treat ifweed pressure is light.The impact of weeds on forage quality

varies from field to field, weed to weed,and year to year, but is primarily affectedby the weeds present and their density andgrowth stage when harvested. Table 4-1compares the relative seriousness of com-mon annual and perennial weeds in for-ages. These rankings are based on labora-tory analyses and feeding studies withanimals done by several midwestern uni-versities.Some of these species may not be particu-

larly objectionable in terms of forage value,but may present other problems. For exam-ple, pigweed and lambsquarters may benutritious but can also accumulate nitrates,especially in nitrogen-rich soils and whenrain follows a prolonged dry period. Cock-lebur and nightshade are in the “serious”category because they frequently containpoisonous compounds. Pennycress impartsa garlicky flavor to milk.The herbicides listed in table 4-2 control

many weeds in direct-seeded legume estab-lishment. Most treatments have little effecton perennial weeds, and special controlmeasures for such species should be usedwhile the field is in other crops.

152

STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

weeds

SOYBEAN

CORN

PRINCIPLESOF

PESTMNGM

T.


STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

weeds

SOYBEAN

CORN

PRINCIPLESOF

PESTMNGM

T.

153

Table 4-2. Legume tolerance and herbicide effectiveness on weeds commonly found inlegumes seeded without a cover cropa

PoastEptam Treflan Buctril Butyrac Glyphosateb Plus Pursuit Raptor Select

Type of application PPI PPI POST POST POST POST POST POST POSTMode of action group 8 3 6 4 9 1 2 2 1Labeled crops al, bf, cl al al al, bf al, bf, cl al, bf, cl al, cl al, clc al, bfLegume tolerance F/G G F/G G E E G G EGrassesBarnyardgrass G/E G/E P N E G/E G G G/EFoxtails G/E G/E P N E E G G/E EQuackgrass P N N N E G P/F F G

BroadleavesCommon chickweed F P P P E N G G NCommon lambsquarters F F/G G/E G/E G/E N F/G G NCommon ragweed F N G/E G/E E N F F NEastern black nightshade P P F/G F E N E E NPennycress P N G/E F E N G/E G/E NPigweeds F/G G/E F G/E E N E E NShepherd’s purse P N E F E N G/E G/E NSmartweeds P P G P G/E N G G NVelvetleaf F/G N G G/E G/E N G/E G/E NWild mustard P/F N G F/G E N G/E G/E NWild radish P/F N G F E N G G N

AbbreviationsType of application: PPI = preplant incorporated, POST = postemergence.Labeled crops: al = alfalfa; bf = birdsfoot trefoil; cl = clover.Legume tolerance and control ratings: E = excellent; G = good; F = fair; P = poor; N = none.

aAdapted from Extension publication Alfalfa Management Guide (NCR547), 2004.bIf broadcast spraying, apply only to Roundup Ready alfalfa or severe crop injury will occur.cOnly labeled for clover grown for seed.

Table 4-1. Impact of common weeds on forage quality

——————————————Relative seriousness——————————————Serious Moderate Slight

Annual weeds cocklebur green foxtail common ragweedEastern black nightshade pennycress pigweedsgiant foxtail shepherd’s pursegiant ragweed velvetleafsmartweeds lambsquartersyellow foxtail wild mustard

Perennial weeds curly dock Canada thistle dandelionhoary alyssum quackgrass and white cockleyellow rocket other grasses


Buctril (bromoxynil)Rate: Buctril—1.0 to 1.5 pt/a.

Buctril 4EC—0.5 to 0.75 pt/a.Adjuvants: Do not add surfactants or

other additives to the spray mixture.Timing: Postemergence, forages—Treat

when alfalfa has at least four trifoliateleaves.Weeds—Treat when annual broadleaves

are 2 inches or less in height and have nomore than four leaves.Remarks: Buctril is a postemergence, con-

tact herbicide that controls many commonbroadleaf weeds in alfalfa in either directseeding or with a companion crop. Use thelower rate to control Eastern black night-shade, lambsquarters, pennycress, andshepherd’s purse, and the higher rate tocontrol wild mustard, pigweed, wildradish, ragweed, and velvetleaf.Serious alfalfa injury may occur if the

temperature exceeds 70°F within 3 daysafter application. Several factors influencethe injury potential of Buctril. The mostimportant seem to be (1) stage of alfalfagrowth (seedlings with less than four trifo-liate leaves are very sensitive), (2) presenceof atrazine and/or Eptam residues (theyenhance Buctril injury), (3) temperatureand relative humidity (hot, humid condi-tions present a greater risk than hot, dryconditions), and (4) other causes of stress(healthy alfalfa is least affected by Buctril).Do not treat alfalfa stressed by moisture

shortage or excess, insect injury, or othercauses. Use spray volumes of at least20 gal/a, flat fan nozzles, and 30 psi pres-sure. Do not add surfactant or other addi-tives to the spray mixture.Buctril can be tank-mixed with Pursuit to

improve control of pigweed, chickweed,and nightshade. Fields treated with Buctrilalone may be harvested 30 days after appli-cation and the forage used for any purpose.Fall-treated alfalfa cannot be harvesteduntil 60 days after application.Rotational restrictions: Crops can be

planted 30 days after application.

Butyrac 200 (2,4-DB)Rate: 1 to 3 qt/a. Check the label for spe-

cific rates according to weed species andsize.Adjuvants: Do not add surfactants or

other additives to the spray mixture.

Timing: Postemergence, forages—Treat any-time after legume emergence.Weeds—Treat when annual broadleaf

weeds are 3 inches or less in height.Remarks: Butyrac 200 is a water-soluble

amine liquid that contains 2 lb ae/gal. Itcontrols many annual broadleaf weeds, butis weak on smartweed and some mustardsand does not control grasses. Some sup-pression of perennial broadleaf weeds canbe expected.Butyrac 200 can be applied to spring and

summer-seeded alfalfa or birdsfoot trefoil.Do not apply Butyrac after the first cuttinghas been taken.The legume should be actively growing

and free of stress, and no rainfall shouldoccur within 7 to 10 days to reduce risk ofcrop injury. Legume seedlings may showtemporary stunting, particularly if higherrates are applied during hot, humid condi-tions. Forage grasses planted with thelegume will not be harmed by Butyrac.Treated seedling forage cannot be harvestedor grazed for 60 days after application.Butyrac can be tank-mixed with Buctril,

Poast Plus, Pursuit, Raptor, or Select.Rotational restrictions: The label gives no

information on planting rotation crops.

Eptam (EPTC)Rate: Eptam 7-E—3.5 to 4.5 pt/a.

Eptam 20-G—15 to 20 lb/a.Timing: Preplant-incorporated—Apply

Eptam to a smooth, dry seedbed just beforeplanting and immediately incorporate to adepth of 2 to 3 inches to prevent herbicideloss through evaporation. Where possible,simultaneously apply and incorporateEptam in one operation.Remarks: Eptam provides good control of

annual grasses and many annual broadleafweeds. Eptam may be used to establishalfalfa, birdsfoot trefoil, and clovers. Usethe lower rate on lighter textured soils.Eptam is generally ineffective on peat ormuck soils. To control only annual grasses,2.25 pt/a may be used. The high rate par-tially suppresses yellow nutsedge andquackgrass, but complete control of anyperennial weed should not be expected.Eptam does not control smartweed, blacknightshade, or perennials such as Canadathistle and bindweeds.

154

STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

weeds

SOYBEAN

CORN

PRINCIPLESOF

PESTMNGM

T.


Incorporate with a tillage implement,working the field in two different direc-tions. Weed control is dependent uponthorough and immediate incorporation.Much of the herbicide will evaporate if it isnot incorporated within minutes afterapplication.Temporary stunting of the small-seeded

legume and sealing of the first leaves mayoccur. Injury is likely if Eptam was appliedduring cool wet weather, at high rates, or ifit was poorly incorporated. Do not seedbromegrass, fescue, ryegrass, orchardgrass,timothy, or small grain since these will bekilled. Do not apply Eptam if atrazine hasbeen applied within 12 months as severeinjury may result. Eptam can be mixed withliquid fertilizer solution or impregnated ontodry fertilizer for simultaneous application.Rotational restrictions: Other crops can be

planted any time after the first harvest.

GlyphosateIf broadcasted, use only on Roundup Ready

alfalfa varieties.Rate:Apply 0.75 lb ae/a following plant-

ing for annual and perennial weed control.For established stands with large perennialweeds, rates up to 1.5 lb ae/a can be effectivein the late summer to early fall. Currently,several products containing glyphosatehave the supplemental label to be appliedin Roundup Ready alfalfa.Adjuvants: Ammonium sulfate at 8.5 to 17

lb/100 gal of spray mixture is recom-mended if using hard water. Additionalsurfactant is rarely needed.Timing: Apply glyphosate when weeds

are at the proper height (check the label),generally 4 to 6 inches tall. Glyphosate canbe applied after any cutting if needed.Remarks: Glyphosate kills a wide range of

grass and broadleaf weeds. RoundupReady alfalfa has excellent tolerance toglyphosate. In Roundup Ready alfalfa,apply glyphosate when the weed popula-tion justifies treatment. In direct seedings,this occurs approximately 30 to 40 daysafter seeding. If oats are planted as a tem-porary cover crop, apply glyphosate whenoats are approximately 6 inches tall to killoats and weeds. Treated fields can be har-vested 5 days after application. Amaximumof 4.64 lb ae/a (132 fl oz/a of Original Maxand Roundup WeatherMax) can be appliedper year, with no more than 1.5 lb ae/a per

application. The supplemental label indi-cates that up to 10% of the purchased seedmay not have the Roundup Ready geneand recommends applying glyphosatewhen alfalfa has three to four trifoliateleaves to eliminate susceptible plants. Thecurrent one-time technology fee per 60-lbbag or Roundup Ready alfalfa seed is $125for producers east of the Rocky Mountains.Due to the ruling of a recent court case,Roundup Ready alfalfa cannot be plantedin the United States. Fields previouslyplanted with Roundup Ready alfalfa canstill be harvested and sold as long as spe-cific regulations are followed. ConsultUSDA-APHIS for further information(www.aphis.usda.gov/biotechnology/alfalfa.shtml).Rotational restrictions: None.

Poast Plus (sethoxydim)Rate: Apply 18 to 24 fluid oz/a of Poast

Plus to control annual grass weeds. Use36 fluid oz/a of Poast Plus to kill volunteergrains that emerge following barley, oat,rye, or wheat harvest.Adjuvants:Add 1 qt/a of a crop oil con-

centrate for all Poast Plus applications. Ifquackgrass is present, also add 2 to 4 qt/aof 28% liquid nitrogen or 2.5 lb/a of ammo-nium sulfate.Timing: Postemergence, forages—Treat at any

stage of alfalfa, clover, or trefoil growth.Weeds—Treat when annual grasses are

4 to 8 inches tall and actively growing.Remarks: Poast Plus gives excellent con-

trol of annual grasses in newly seededalfalfa, clover, and birdsfoot trefoil. For bestcontrol, treat before the first mowing.Apply Poast Plus in 5 to 20 gal/a of spraysolution using 40 to 60 psi pressure. Do notuse flood jet nozzle tips. Treat volunteerwinter cereals when they are 4 inches talland before tillering has started; treat only inthe fall as control will be unacceptable withspring applications. Poast Plus is rainfastwithin 1 hour after application. Alfalfa andbirdsfoot trefoil can be harvested 7 daysafter treatment if the forage is greenchopped or ensiled, and 14 days after treat-ment if harvested as dry hay. For clover,dried forage cannot be harvested for 20days. In alfalfa only, Poast Plus can be tank-mixed with Pursuit or Raptor to broadenthe spectrum of weeds controlled.

155

STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

weeds

SOYBEAN

CORN

PRINCIPLESOF

PESTMNGM

T.


Poast Plus can also be applied to kill oatsused as a temporary companion crop. In thissystem, oats are seeded with the legumebut are then killed after having protectedthe soil from water or wind erosion andalso having displaced most annual weeds.Apply Poast Plus when the oats are 4 to 6inches tall.Rotational restrictions: Do not plant other

crops to be harvested for 30 days afterapplication unless Poast Plus is registeredfor use on that crop.

Pursuit (imazethapyr)Rate: 3 to 6 fl oz/a of Pursuit. See label

for rates needed for specific weed species.Adjuvants: In most situations when apply-

ing Pursuit to newly seeded alfalfa orclover, add a nonionic surfactant to thespray solution (1 qt/100 gal). If weeds arelarge and growing conditions are dry, con-sider using a crop oil concentrate (5 qt/100gal) or a methylated seed oil (4 qt/100 gal)instead of a surfactant. For all applications,also add 28% liquid nitrogen (1.25 to 2.5gal/100 gal) or ammonium sulfate (12 to 15lb/100 gal) to the spray solution.Timing: Postemergence, forages—Treat

when alfalfa or clover has at least two fullyexpanded trifoliate leaves.Weeds—Treat when annual weeds are 1 to

3 inches tall or rosettes are 1 to 3 incheswide.Remarks: Pursuit controls many annual

broadleaf and several annual grass weeds.It can be applied to seedling or establishedalfalfa and clover, but the spectrum ofweeds controlled does not include many ofthe weeds found in older stands. Unlikeother postemergence treatments in alfalfaor clover, Pursuit continues controllingweeds as they germinate after applicationbecause it persists several months in thesoil. To increase the spectrum of weeds con-trolled, Pursuit may be tank-mixed withBuctril, Butyrac, Poast Plus, or Select.Pursuit will be safer to alfalfa and more

effective on weeds if environmental condi-tions favor plant growth. Thus if air tem-peratures stay at or below 40°F for 10 ormore hours, delay Pursuit application untilat least 48 hours after the temperature risesabove 40°F or until weeds are activelygrowing. Following application, alfalfa maybe temporarily stunted. Plants usuallyrecover in 5 to 10 days.

Do not apply Pursuit within 30 days ofharvest. Do not apply Pursuit preplantincorporated or preemergence.Pursuit kills weeds by blocking the ALS

enzyme and is considered to have a highrisk of allowing resistant weeds to develop.However, using Pursuit in alfalfa may lowerthe risk of resistant weeds appearingbecause most escaping individuals thatmight be resistant would be clipped beforegoing to seed, thus preventing a shift toresistant biotypes in the seed bank.Rotational restrictions: If a Pursuit-treated

field needs to be replanted, do not plant thefield to alfalfa for 4 months following appli-cation. Soybeans and imidazolinone-resistant/tolerant corn (Clearfield corn) canbe replanted anytime after a Pursuit appli-cation in alfalfa. See appendix table 2 foradditional plant back information.

Raptor (imazamox)Rate:Apply 4 to 6 fl oz/a. Adjust the rate

according to the specific weeds present andtheir size as indicated on the label. In gen-eral, the 4 oz/acre rate controls sensitiveannual grass and broadleaf species that areno taller or wider than 3 inches.Timing:Apply Raptor to new seedings

when alfalfa has two or more trifoliateleaves.Adjuvants: In most situations when apply-

ing Raptor to newly seeded alfalfa, add anonionic surfactant to the spray solution(1 qt/100 gal). If weeds are large and grow-ing conditions are dry, consider using acrop oil concentrate (4 qt/100 gal) or amethylated seed oil (4 qt/100 gal) insteadof a surfactant. For all applications, alsoadd 28% liquid nitrogen (2.5 gal/100 gal) orammonium sulfate (12 to 15 lb/100 gal) tothe spray solution.Remarks: Raptor can be used as a post-

emergence herbicide in newly seeded orestablished alfalfa. The general use guide-lines and performance are similar to thoseof the closely related herbicide Pursuit. Theprimary differences between Raptor andPursuit is that Raptor is more effective oncommon lambsquarters and grasses, has nopreharvest interval, and has a shorter rota-tional interval for most vegetable crops.Both provide excellent control of pigweedand mustard species and very good controlof chickweeds, foxtails, barnyardgrass,nightshades, and smartweeds. Raptor isweak on ragweeds, but at the maximum

156

STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

weeds

SOYBEAN

CORN

PRINCIPLESOF

PESTMNGM

T.


labeled rate of 6 fl oz/a, it suppresses com-mon and giant ragweed as well as dande-lion, Canada thistle, and quackgrass.As with Pursuit, there is a slight risk of

alfalfa injury from Raptor, but the crop nor-mally recovers within a few days. Raptorpersists after application and will controlsensitive weeds that germinate for severalweeks after application if a timely rainplaces the active ingredient in the zone ofweed seed germination. Raptor could betank-mixed with Buctril, Butyrac, PoastPlus, or Select. The comments on resistantweed development for Pursuit also pertainto Raptor.Rotational restrictions: Following a Raptor

application, soybeans can be planted any-time. Wait 3 months before planting alfalfaand wheat, 8.5 months for corn, and 9months for most vegetable crops.

Select (clethodim)Rate: Apply 6 to 16 fl oz/a of Select to

control annual grasses.Adjuvants:Add 1% v/v of crop oil con-

centrate to the spray solution. If difficult-to-control grass species are present, the labelsuggests adding 1 to 2 qt/a of liquid nitro-gen or 2.5 to 4.0 lb/a of ammonium sulfateto improve control.Timing: Postemergence, forages—Treat at

any stage of alfalfa growth.Weeds—Treat when annual grasses are

2 to 6 inches tall and actively growing.Remarks: Select can be used to control

grasses during the establishment of alfalfaand birdsfoot trefoil grown for hay, silage,green chop, or direct grazing. Select is notlabeled for use in clovers. Always use acrop oil concentrate with Select. ApplySelect in 5 to 20 gal/a of spray solutionusing 30 to 60 psi pressure. Do not useflooding nozzle tips. To control volunteercereals in summer-seeded alfalfa, treat inthe late summer or early fall when the cere-als are 4 to 6 inches tall.Select can also be used to kill oats planted

as a temporary companion crop. In this sys-tem, oats are seeded with alfalfa to protectthe soil from erosion and to displace mostannual weeds. Apply Select when the oatsare 4 to 8 inches tall.Injury to alfalfa or birdsfoot trefoil is not

expected from Select applications. Foragetreated with Select can be harvested, fed, orgrazed 15 days after application. Select canbe tank-mixed with Pursuit or Butyrac

(2,4-DB) in new seedings for broadleafweed control, but do not do so unless thefeeding, grazing, and harvesting restrictionon these labels can be observed. Read thelabel carefully as restrictions can varybetween companies.Rotational restrictions: Do not plant rota-

tional crops until 30 days after application.

Treflan (trifluralin)Rate: 1 pt/a on coarse, 1 to 1.5 pt/a on

medium and 1.5 pt/a on fine textured soils.Timing: Preplant-incorporated—Apply Tre-

flan prior to planting and incorporatewithin 24 hours to a depth of 2 to 3 inches.Remarks: Many brands of trifluralin are

marketed for use in soybeans and vegetablecrops. However, it appears that only TreflanHFP has a supplemental label to allow tri-fluralin to be used in new seedings ofalfalfa. This supplemental label must be inthe possession of the user at the time ofapplication to fields being seeded to alfalfa.Treflan gives excellent control of annualgrasses and pigweed, but has little effect onragweed, velvetleaf, and weeds in the mus-tard family. Because it is very active ongrasses arising from seed, do not seed for-age grasses such as orchardgrass orbromegrass with the alfalfa because theywould be killed. Treflan will not controlquackgrass or wirestem muhly arising fromrhizomes. Treflan can be simultaneouslyapplied with liquid fertilizer or impreg-nated onto dry fertilizer. It kills weeds bystopping cell division and has a low risk ofallowing resistant weeds to develop.Rotational restrictions: Peas, potatoes, and

soybeans can be planted anytime after aTreflan application. Wild proso millet, corn,sorghum, oats, and any other grass cropmixtures can be planted 1 year after aspring application or 14 months after a fallapplication.

157

STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

weeds

SOYBEAN

CORN

PRINCIPLESOF

PESTMNGM

T.


SUMMER SEEDINGSMost growers who seed alfalfa in the

summer find that fewer weeds germinate atthis time of the year and therefore preplant-incorporated herbicides are not needed.Summer annuals that germinate in latesummer (velvetleaf, pigweed, crabgrass,and wild proso millet) typically do notgrow very tall and die with the first frost,so treatments are usually not necessary.However, winter annuals like shepherd’spurse and pennycress need careful moni-toring. They develop into the rosette stagein late summer and early fall and then arequick to flower the following spring. Theseweeds may reduce forage quality in the sec-ond year, therefore we recommend scout-ing fields routinely every other week intothe early fall to see if a postemergence treat-ment is needed.When summer seedings follow wheat

harvest, volunteer wheat is often a seriousweed problem. This is less likely if fieldsare moldboard plowed before seedingalfalfa. When fields are disked, chiselplowed, or no-till seeded, winter wheatoften germinates and competes vigorouslywith the alfalfa, especially the followingspring. If volunteer wheat threatens alfalfaestablishment, apply Poast Plus or Selectwith an appropriate additive when wheatis 4 to 6 inches tall and actively growing.Do not wait until the spring or early sum-mer to treat as control will be much moredifficult. Poast Plus and Select also kill vol-unteer oats, but these will die during thewinter and seldom require treatment.

WEED MANAGEMENTIN ESTABLISHED FORAGELEGUMESRemoving weeds from forage crops sel-

dom increases total yield because theweeds are harvested along with the crop.However, since weeds are often less palat-able and lower in protein and digestibilitythan forages, controlling weeds canimprove forage quality.Some believe that weed control may pro-

long the productive life of forage stands bypreventing competitive weeds such asquackgrass and dandelions from crowdingout the forage. However, if weeds are theonly stress present, they seldom affect for-age stand density. Other factors have been

found to play a more important role indetermining stand life. These include coldwinters, frequent cutting schedule, and dis-ease and insect problems.Established stands of forage legumes

compete effectively with many annual andperennial weeds. If weeds appear, inade-quate soil fertility, low soil pH, poor soildrainage, plant diseases, or other factorshampering legume growth may be thecause. Winter annual weeds such as shep-herd’s purse and pennycress may become aproblem if conditions the previous fall weresuitable for their establishment. Someperennial weeds, such as white cockle, yel-low rocket, dandelions, hoary alyssum, andquackgrass, persist despite legume compe-tition. These weeds can be kept fromspreading by harvesting the infestedlegume before weed seeds are produced. Ifseed does mature before the legume isready for harvest, the forage should beensiled as this will kill many weed seeds.Base herbicide selection decisions in

established legumes on the weed species tobe controlled and forage stand density. Foralfalfa, treat only if the field has an average of55 stems or a minimum of 4 to 5 crowns persquare foot. For stands with fewer stems orcrowns present, we recommend rotating toanother crop. Use table 4-3 to help selectthe appropriate treatments for the weedcomplex found in each field. For a sum-mary of harvest and grazing intervals fol-lowing herbicide use in forages, refer toappendix table 4 at the end of this manual.

Butyrac 200 (2,4-DB)Rate: Apply 1 to 3 qt/a to seedling

weeds. The lower rate is effective on smallpigweed, pennycress, lambsquarters, andwild mustard. Smartweed and curly dockare suppressed at the 3 qt/a rate.Adjuvants: Do not add surfactants or

other additives to the spray mixture.Timing: Postemergence—Treat when weeds

are actively growing. Winter annuals likepennycress should be treated in the fall.Remarks: Butyrac can be applied to estab-

lished alfalfa only. Alfalfa should behealthy and actively growing for greatestselectivity. Some stem twisting and leafmalformation may occur, but plants usuallyoutgrow these symptoms. Alfalfa can beharvested 30 days after Butyrac applicationin established stands.

158

STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

weeds

SOYBEAN

CORN

PRINCIPLESOF

PESTMNGM

T.


Rotational restrictions: The label gives noinformation on rotational crop plant backintervals.

GlyphosateRate: Roundup Ready alfalfa—Apply 0.75

lb ae/a for annual and perennial weed con-trol in the spring. For established standswith large perennial weeds, rates up to 1.5lb ae/a can be effective in the late summerto early fall. Several products containingglyphosate have the supplemental label tobe applied in Roundup Ready alfalfa.Pasture renovation—See comments on

glyphosate in the pasture renovation section(page 168).Adjuvants: Ammonium sulfate at 8.5 to 17

lb/100 gal of spray mixture is frequentlyrecommended when applying glyphosate,especially if hard water is being used.Additional surfactant is rarely needed.

Timing: Only broadcast treatments toRoundup Ready alfalfa. Apply glyphosatewhen weeds are at the proper height orgrowth stage. Fall applications will give thebest results for perennial broadleaf weeds.Quackgrass can be controlled with eitherspring or fall applications. If annual weedsappear and are dense enough to warranttreatment, apply when they are 4 to 6inches tall. Glyphosate can be applied afterany cutting if needed.Remarks: See earlier comments regarding

glyphosate use in Roundup Ready alfalfa inthe Direct Seeding section (page 149).Although no new seedings are allowed dueto the recent injunction, previously plantedalfalfa can be grown and sold given the fol-lowing three conditions: (1) pollinators maynot be added to the field, (2) follow USDA-APHIS established best practices to clean-

159

STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

weeds

SOYBEAN

CORN

PRINCIPLESOF

PESTMNGM

T.

Table 4-3. Legume tolerance and herbicide effectiveness on weeds commonlyfound in established legume stands

Butyrac Glyphosatea Poast Plus Pursuit Raptor Select Sencor Velpar

Mode of action group 4 9 1 2 2 1 5 5Labeled crops al al, bf, cl al, bf al, bf,b cl al, clc al, bf al alLegume tolerance G E E G G E F/G GAnnual weedsCommon chickweed P E N G G N E EField pennycress F/G E N E E N G/E G/EFoxtail species N E E G G/E E F FShepherd’s purse G E N G/E G/E N E E

Perennial weedsBroadleaf plantain F/G G/E N F F N P F/GCanada thistle N G/E N P P/F N P NCommon dandelion N G N P/F P/F N G/E G/ECurly dock P/F — N P — N F FHemp dogbane N E N P — N P NHoary alyssum F — N — — N F/G GPerennial sowthistle N E N G G N P PQuackgrass N E F/G P/F P/F F/G F/G F/GWhite cockle N F/G N P P N G FWirestem muhly N E F/G P P F/G P FYellow nutsedge N F N F F N F FYellow rocket N G/E N F/G F/G N G G/E

AbbreviationsLabeled crops: al = alfalfa; bf = birdsfoot trefoil; cl = clover.Legume tolerance and control ratings: E = excellent; G = good; F = fair; P = poor; N = none.

aIf broadcast spraying, apply only to Roundup Ready alfalfa or severe injury will occur.bLabeled for use only when these species are used as a cover crop.bLabeled only for clover grown for seed.


ing equipment, and (3) Roundup Readyalfalfa must be clearly identified if it ismoved off-farm.Fall applications of glyphosate are

encouraged to control dandelion, whitecockle, yellow rocket, and other perennialbroadleaf weeds.Rotational restrictions: None.

Poast Plus (sethoxydim)Rate: To control annual grasses in the

summer, use 1.5 pt/a of Poast Plus. Forquackgrass suppression, apply 2.25 pt/a ofPoast Plus.Adjuvants:Add 1 qt/a of a crop oil con-

centrate for all Poast Plus applications. Ifquackgrass or wirestem muhly is present,also add 2 to 4 qt/a of 28% liquid nitrogenor 2.5 lb/a of ammonium sulfate.Timing: Postemergence—Treat when

annual grasses are 4 to 8 inches tall andactively growing. Treat when quackgrassand wirestem muhly are 6 to 8 inches talland actively growing.Remarks: Poast Plus can be spring-

applied to suppress quackgrass andwirestem muhly before first cutting or usedin the summer to control annual grassesthat appear following the second or thirdcutting in older (thinner) establishedalfalfa, clover, and birdsfoot trefoil stands.Forage grasses will be stunted or killed.Poast Plus gives less control if grassyweeds are under stress, especially fromdrought, or if they have been mowed previ-ously. The legume can be harvested 7 daysafter Poast Plus application if the forage isgreen chopped or ensiled, and 14 days afterapplication if harvested as dry hay. Use 40to 60 psi pressure, 5 to 20 gal/a spray solu-tion, and flat fan or hollow cone nozzles toapply Poast Plus.Rotational restrictions: Do not plant other

crops to be harvested for 30 days afterapplication unless Poast Plus is registeredfor use on that crop.

Pursuit (imazethapyr)Rate: 3 to 6 fl oz/a of Pursuit or equivalent.Adjuvants:Add a crop oil concentrate

(5 qt/100 gal) or, under dry conditions, usea methylated seed oil (MSO, 4 qt/100 gal)in the spray solution. For all applications,also add 28% liquid nitrogen (1.25 to2.5 gal/100 gal) or ammonium sulfate(12 to 15 lb/100 gal) to the spray solution.

Timing:Apply in the spring or fall to dor-mant established alfalfa/clover or after acutting before regrowth exceeds 3 inches.Remarks: Use of Pursuit in established

alfalfa/clover will be limited as most com-mon weeds are perennials. Where annualslike shepherd’s purse, pennycress, chick-weed, eastern black nightshade, or giant orgreen foxtail appear in established stands,Pursuit could be an appropriate herbicidechoice.Good herbicide coverage is essential for

adequate weed control; weeds cut duringharvest may not receive much Pursuit andbe inadequately controlled. Up to 6 fl oz/aof Pursuit could be applied in establishedalfalfa and these rates would be necessaryto suppress perennial weeds like dandelionor quackgrass. There is a 30-day restrictionon harvesting or grazing alfalfa/cloverafter applying Pursuit. No more than 4oz/a of Pursuit can be applied during thelast year of the stand.Rotational restrictions: Alfalfa and clovers

can be planted 4 months after a Pursuitapplication. Soybeans and imidazolinoneresistant/tolerant corn (Clearfield corn) canbe planted anytime after a Pursuit applica-tion. See appendix table 2 for additionalplant back information.

Raptor (imazamox)Rate:Apply 4 to 6 fl oz/a. Adjust the rate

according to the specific weeds present andtheir size as indicated on the label. In gen-eral, the 4 oz/a rate controls sensitiveannual grass and broadleaf species that areno taller (or wider in the case of rosette-forming weeds like shepherd’s purse) than3 inches.Timing: Apply Raptor in the spring or fall

to established dormant or semidormantalfalfa or after any cutting before alfalfa has3 inches of growth/regrowth. Do not applyRaptor after the second or later cuttings theyear before rotating to corn to be able tocomply with the plant back interval.Adjuvants: In most situations when apply-

ing Raptor to established alfalfa, add a cropoil concentrate (4 qt/100 gal) or under dryconditions, use a methylated seed oil (MSO,4 qt/100 gal) in the spray solution. For allapplications, also add 28% liquid nitrogen(2.5 gal/100 gal) or ammonium sulfate(12 to 15 lb/100 gal) to the spray solution.

160

STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

weeds

SOYBEAN

CORN

PRINCIPLESOF

PESTMNGM

T.


Remarks: Raptor can be used as a post-emergence herbicide in established alfalfa.See comments on Raptor in the section ondirect seedings. Most weeds in establishedstands are perennials. Raptor is weak onsuch species, but it will suppress yellowrocket, dandelion, Canada thistle, andquackgrass. Raptor will not control whitecockle. Older alfalfa stands sometimes haveshepherd’s purse, pennycress, or foxtailsfor which Raptor will be effective. Raptorpersists after application and will controlsensitive weeds that germinate for severalweeks after application if adequate rainfallis received to move the herbicide into thesoil. Raptor has no preharvest interval(PHI).Rotational restrictions: Following a Raptor

application, soybeans can be planted any-time. Wait 3 months before planting alfalfaand wheat, 8.5 months for corn, 9 monthsfor most vegetable crops, and 26 months forred beets and sugar beets.

Select (clethodim)Rate: To control annual grasses in the

summer, use 8 to 10 fl oz/a of Select. Tosuppress quackgrass or wirestem muhly,apply 8 to 16 fl oz/a.Adjuvants:Add 1% v/v of crop oil con-

centrate to the spray solution. If difficult-to-control grass species are present, the labelsuggests adding 1 to 2 qt/a of liquid nitro-gen or ammonium sulfate at 2.5–4.0 lb/a toimprove control.Timing: Postemergence—Treat when annual

grasses are 2 to 6 inches tall and whenperennials are 4 to 8 inches tall.Remarks: Select can be spring-applied to

suppress quackgrass or wirestem muhlybefore first cutting or used in the summerto control annual grasses that appear fol-lowing the second or third cutting in older(thinner) established alfalfa or birdsfoot tre-foil grown for hay, silage, green chop, ordirect grazing. A single application usuallyresults in a nearly quackgrass-free first cut-ting, but some quackgrass regrowth oftenappears later in the season. Forage grassesin treated fields will be stunted or killed bySelect. Forage treated with Select can beharvested, fed or grazed 15 days afterapplication. Select can be used in alfalfaand birdsfoot trefoil, but not in clovers.See previous section on Select for addi-

tional comments about its use.

Rotational restrictions: Do not plant othercrops for 30 days after application.

Sencor (metribuzin)Rate: Sencor rates are based upon the

weeds to be controlled. For pennycress,shepherd’s purse, and cheatgrass/downybrome, apply 0.5 to 0.67 lb/a of Sencor DF(dry flowable). For white cockle, yellowrocket, and tansy mustard, use 0.67 to1.33 lb/a of Sencor DF. For dandelion andquackgrass suppression, use 1.33 lb/a ofSencor DF. This rate reduces competitionfrom curly dock and will seriously injuremost forage grasses. Use the lower rates onsandy loam and loamy sand soils but donot apply on sandy soils.Timing: Pre-greenup—Sencor can be early

spring-applied to alfalfa established for atleast 1 year. Do not apply Sencor during theseeding year nor the year after seeding. Itmust be applied to dormant alfalfa anytimein early spring after the snow has melted,when the ground is not frozen and beforenew legume growth appears. If green for-age shoots are present, injury will occur.Remarks: Sencor controls many annual

and several perennial weeds. Sencor maybe applied to alfalfa mixed with foragegrasses, but some injury to the grassesshould be expected. Stresses such asdrought, disease, low fertility, overcutting,or insects may increase the likelihood ofcrop injury. Alfalfa may not be harvested orgrazed for 28 days after application.Sencor is also labeled for impregnation

onto dry fertilizer for simultaneous applica-tion. To reduce risk of injury to alfalfa thathas broken dormancy, apply Sencor on dryfertilizer when the alfalfa is less than3 inches tall and the foliage is dry.Sencor DF is a dry flowable formulation

with 75% active ingredient and is availablein water soluble packets (Sencor Solupak)that are dropped unopened into water inthe spray tank. Sencor is also available in aliquid formulation (Sencor 4L).Sencor gives good to excellent control of

dandelions. Light infestations of dande-lions do not warrant treatment. Dandelionsare palatable to livestock and their nutritivevalue similar to that of alfalfa. However,dandelions may reduce the amount oflegume harvested and increase the timeneeded to dry the forage. Do not apply Sen-cor if the alfalfa stand is not sufficient to fill

161

STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

weeds

SOYBEAN

CORN

PRINCIPLESOF

PESTMNGM

T.


the voids left by the weed control. Theeffect of Sencor is often apparent for morethan one season.Rotational restrictions: If cropping plans

change after Sencor application, soybeans,corn, alfalfa, potatoes, and forage grassesmay be planted in treated fields 4 monthsafter application. Barley and wheat may beplanted 8 months after Sencor application.Do not apply additional Sencor to any ofthese rotational crops during the same year.Other crops can be planted 12 months afterthe initial application except root crops likebeets and onions which require an18-month waiting period.

Velpar (hexazinone)Rate: Use 0.67 to 1.0 lb/a of Velpar DF on

coarse to medium soils with 1% or lessorganic matter. Use 1 to 2 lb/a on mediumto heavy soils with 1 to 5% organic matter.The lower rates control weeds such aschickweed, buttercup, shepherd’s purse,pennycress, and yellow rocket. Apply1.33 to 2.0 lb/a to soils with more than 5%organic matter. Usually 1.33 lb/a is neededto suppress dandelions, quackgrass, andwhite cockle but lower rates have givenacceptable suppression, especially onmedium- and light-textured soils.Timing: Pre-greenup—Apply to dormant

alfalfa or before new alfalfa growth exceeds1 to 2 inches. Treating taller alfalfa willresult in crop injury. Do not treat if groundis snow-covered or frozen.Remarks: Velpar can be used in alfalfa

fields beginning the year after establish-ment. However, the weed infestation theyear after seeding seldom justifies suchapplications. If such a treatment is needed,Velpar can only be used when the root sys-tem is well established. This usually meansthat the alfalfa was direct seeded (without acompanion crop) and grew vigorously inthe seeding year. Use no more than 1 lb/aof Velpar in stands less than 12 months old.Velpar is similar in performance to Sen-

cor. Do not treat stressed stands or alfalfa-grass mixtures. Do not use in sands, poorlydrained soils, or exposed subsoil areas. Vel-par may be mixed with dry bulk fertilizerfor simultaneous application.Add Velpar to a water-filled tank and mix

thoroughly. Use at least 20 gal/a of spraysolution to apply. Do not overlap, and turnoff sprayer when starting, turning or stop-

ping to avoid crop injury. Do not graze orfeed treated forage or hay for 30 days afterapplication. Velpar DF is a water dis-persible formulation with 75% active ingre-dient. Velpar is also available in a solubleliquid formulation. See the general com-ments about dandelions in alfalfa in theprevious section on Sencor. Velpar Alfamaxand Alfamaxgold are new products thatcombine hexazinone with diuron to pro-vide burndown and residual control ofweeds. These have not been evaluated inWisconsin.Rotational restrictions: Corn may be

planted 12 months after treatment providedthe field is deep disked or plowed beforeplanting; other crops can be planted 2 yearsafter Velpar application.

WEED AND BRUSH CONTROLIN GRASS PASTURESProper fertilization, grazing, and weed

management all play an important role ingood pasture management. Low soil fertil-ity or excessive grazing weakens produc-tive forage species and allow weeds toinvade. Management of weeds before theyflower can be effective at reducing or eveneliminating populations.Several management options exist in pas-

tures, but most producers rely on mowing,grazing, or herbicides. While mowing canprevent seed production if conductedbefore plants flower, herbicides are usuallymore effective and less expensive. In addi-tion, several herbicides or herbicide combi-nations can be used to control unwantedbrush in pastures. Which herbicide to usewill depend upon the susceptibility of themost prevalent weeds in the pasture (seetable 4-4). Recommended rates of herbi-cides typically do not damage foragegrasses, but will kill existing foragelegumes such as clovers and birdsfoot tre-foil. If these forage legumes are desirable,avoid using herbicides or spot treat to mini-mize herbicide contact with these plants.Herbicides labeled for pastures are not

harmful to livestock when properlyapplied. However, treatment of poisonousweeds may make these species more palat-able to grazing livestock or cause accumu-lation of toxic substances in nonpoisonousweeds. As a general recommendation, donot graze treated pastures for 1 to 2 weeks

162

STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

weeds

SOYBEAN

CORN

PRINCIPLESOF

PESTMNGM

T.


after application. Otherwise follow thegrazing restrictions as described on the her-bicide label. We also suggest a 1- to 2-weekinterval without grazing before applyingherbicides in pastures. This will helpensure that the weeds are not stressed fromgrazing and trampling when treated.For details about the effectiveness of her-

bicides registered for use on invasiveweeds growing in CRP fields, refer toappendix table 4 at the end of this book.

Ally/Escort (metsulfuron)Rate: Rates vary between 0.1 and 1.0 oz/a

depending upon targeted weed species.Apply 0.3 oz/a as a broadcast treatment tocontrol multiflora rose. Rates of 0.1 to 0.2oz/a control wild carrot, musk thistle, but-tercup, and curly dock. For spot treatments,mix 1 oz of product/100 gal of water (plussurfactant) and wet foliage to the point justbefore runoff. Higher rates (0.5 to 1.0 oz/a)are recommended to control difficult weedspecies. (Please consult the label.)

Adjuvants:Add a nonionic surfactant at0.5 to 1.0 qt/100 gal of spray solution.Timing: Postemergence—Treat multiflora

rose soon after the bushes are fully leafedout and other weeds when they are in therosette to bud growth stages and activelygrowing, or in the fall to resprouting greentissue.Remarks: Ally and Escort are sulfonylurea

herbicides that control blackberries, bulland plumeless thistles, burdock, chick-weed, dandelion, horsenettle, mullein, mul-tiflora rose, plantain, wild parsnip, andyarrow. Thorough coverage of leaves andstems assures best results, but avoid over-application or grass injury will occur. Symp-toms in treated weeds begin to appear 2 to 3weeks after application. If desired, theseproducts can be tank-mixed with 2,4-D,Banvel, or Weedmaster.Apply metsulfuron in 10 gal/a or more of

water within 24 hours of preparation orproduct degradation may occur. Do not usemore than 40 psi when applying and do not

163

STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

weeds

SOYBEAN

CORN

PRINCIPLESOF

PESTMNGM

T.

Table 4-4. Herbicide effectiveness on weeds commonly found in pastures*

Ally/Weed species Escort Crossbow Curtail Dicamba Forefront Glyphosate Milestone Stinger Weedmaster 2,4-D

Biennials

Burdock G/E G/E G G G/E G G/E G/E G G/E

Carrot, wild E G G G G G/E F P G/E G/E

Parsnip, wild E G G F G G/E F F G/E G/E

Thistle, bull G G/E G/E G/E G/E G/E E G/E G/E G/E

Thistle, musk G/E G/E G G/E E G/E E G/E G/E G/E

Thistle, plumeless G/E G/E G/E G/E G/E G/E E G/E G/E G/EPerennials

Blackberry spp. G G — F — G — P F/G FButtercup spp. E G/E — G — G/E — — G FChicory E F/G G F/G — G/E — G/E G/E G/E

Chickweed, giant G/E G — F/G — G/E — — F/G PDock spp. G/E G/E F F/G G/E G/E G G G/E F/GGoldenrod spp. G/E F/G F F/G F/G G P/F P G F/GHorsenettle G G — F — G — N G PKnapweed, spotted F G G G E G/E E G/E G/E FMilkweed, common N F — F — G — P F/G PNettle, stinging — G/E — F — G/E — — G F/GRose, multiflora G/E G — F/G F/G G F P F P/FSowthistle, perennial F F/G G F/G — G — F F/G PThistle, Canada F/G F G F G/E G/E E G/E F/G F

* This summary table is based on observations in Wisconsin and other North Central states.Abbreviations E=excellent; G=good; F=fair; P=poor; N=none; — = no information.


use hollow cone nozzles. Make only oneapplication per year. Follow all label direc-tions to avoid spray drift and for sprayercleanup after application.There is no grazing restriction following

application, even for lactating dairy ani-mals. Nevertheless, a 10- to 14-day removalperiod is suggested.Smooth brome, bluegrass, timothy, and

native grasses like bluestems are tolerant ofAlly and Escort if they have been estab-lished for 6 months or more. Fescue shouldbe established for at least 24 months beforeapplying metsulfuron and may cause seed-head suppression if applied in spring. Donot use these products in ryegrass pastures.Forage legumes are sensitive to metsul-furon and are usually killed in treatedareas, therefore, avoid broadcasting treat-ments if these legumes are important.Rotational restrictions: Metsulfuron

residues persist in the soil for severalmonths to years after application. Do notrotate or overseed any crop or forage intotreated areas within 34 months unless afield bioassay test as described on the labelhas been conducted.

Banvel/ClaritySee dicamba (page 165).

Crossbow (triclopyr + 2,4-D ester)Rate: For most brush species use 1.5 gal/a

when broadcast spraying, or 1.0 to 1.5%(vol/vol) mixture for foliar applications tosingle plants or small areas. The broadcastrate varies from 1 to 4 qt/a for herbaceousbroadleaf weeds. Check the label for therate to use on specific weeds.Timing: Postemergence—Plants must be

fully leafed out and actively growing whentreated with foliar sprays. Crossbow canalso be applied as a cut stump treatment todeciduous trees most of the year.Remarks: Crossbow is a prepackaged mix

of triclopyr (Garlon) and 2,4-D ester andcontrols many herbaceous and brushweeds including alder, ash, burdock, wildcarrot, cherry, goldenrod, multiflora rose,sumac, and willow. It can be applied withconventional boom sprayers as a broadcasttreatment, as a foliar spray to individualbrush plants, or as a cut stump treatment.Crossbow contains 2 lb ae 2,4-D and 1 lb aetriclopyr/gal and is formulated to have low

volatility. Follow label precautions to pre-vent spray or vapor drift to sensitive vege-tation.Do not graze lactating dairy cows in pas-

tures treated with Crossbow until the nextgrowing season. While there is no grazingrestriction for other livestock, we recom-mend a 10- to 14-day removal period. Iflivestock will be marketed, remove the ani-mals from these pastures at least 3 daysbefore slaughter the year Crossbow is used.

Curtail (clopyralid + 2,4-D)Rate: 2 to 6 pt/a. Use lower rates on

annual and biennial weeds and higher rateson Canada thistle.Adjuvants:Adjuvants are not normally

needed with Curtail.Timing: Treat biennial weeds when they

are in the rosette growth stage. Treat peren-nials when the basal leaves are fully devel-oped and up to the bud stage. Later appli-cations to perennials may also be done ifsoil moisture is adequate and plants areactively growing.Remarks: Curtail contains 0.38 lb ae of

clopyralid and 2.0 lb ae of 2,4-D per gallon.Both active ingredients are formulated asamines. Thus, there is minimal risk ofvapor drift with Curtail. When applied at4 to 6 pt/a, Curtail gives the same amountof clopyralid as 8 to 12 fl oz of Stinger andthe same amount of 2,4-D as 1.0 to 1.5 qt of2,4-D (products with 3.8 lb ae per gallon).The primary use of Curtail in pastures

will be to control thistles and spotted knap-weed. Curtail is not an effective brush her-bicide. The label recommends the 4 pt/arate for light to moderate Canada thistleand knapweed infestations when plants areactively growing and 6 pt/a for denseinfestations or when dry weather or otherstresses have reduced the growth ofCanada thistles. For biennial thistles, use2 pt/a when plants are in the rosette stageand 3 pt/a if bolting has occurred butbefore plants reach the bud stage.For best results, treat when weeds are

actively growing. Drought, heat and coldstress may reduce weed control andincrease crop injury. The grazing restrictionfor lactating dairy cattle is 14 days. Animalsmust be removed from treated pasturesbefore being slaughtered unless 2 weekshas passed since treatment. If animals areto be moved into areas with sensitivebroadleaf plants, feed animals untreated

164

STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

weeds

SOYBEAN

CORN

PRINCIPLESOF

PESTMNGM

T.


forage for at least 7 days before movingthem. While there is no grazing restrictionfor other livestock, we suggest a 10- to 14-day interval for all animals. Grass hay can-not be harvested for 30 days after applica-tion. Curtail is rainfast within 6 hours afterapplication.

DicambaRate: Apply 0.5 to 1.0 pt/a Banvel or

Clarity to control weeds such as wild buck-wheat, chickweed, chicory, curly dock,common ragweed, giant ragweed, redrootpigweed, shepherd’s purse, and velvetleaf.The 1 pt/a rate burns down the topgrowthof field bindweed, Canada thistle, perennialsowthistle, and leafy spurge. Rates of 1 to2 qt/a will control weeds such as wild car-rot, goldenrod, knapweed, whorled milk-weed, poison ivy, and yarrow.Adjuvants: Including a nonionic surfactant

at 0.25 to 0.50% (v:v) of spray solution canprovide additional control, particularly fordifficult-to-control weeds.Timing: Postemergence—Apply dicamba to

young, actively growing weeds before theyblossom. If perennials regrow, treat asneeded. In newly seeded grass pastures, donot apply dicamba until the grasses havethree to five leaves.Remarks: Dicamba controls many hard-

to-kill broadleaf weeds and several brushspecies. Follow label directions and adjustapplication rates according to the weedsthat need to be controlled. High rates ofdicamba may cause temporary injury tosensitive pasture grasses. Avoid drift ofdicamba onto desirable plants or cropinjury will occur. Soybeans, tobacco, vegetablecrops, and most ornamentals are particularlysensitive to dicamba.Pastures treated with up to 1 pt/a of

dicamba should not be grazed by dairy ani-mals for 7 days or harvested for hay for 37days after treatment. Pastures treated withup to 1 qt/a of dicamba should not begrazed by dairy animals for 21 days or har-vested for hay for 51 days after treatment.Pastures treated with up to 2 qt/a ofdicamba should not be grazed by dairy ani-mals for 40 days or harvested for hay for 70days after treatment. There is no waitingperiod between treatment and grazing fornon-lactating animals, but a 10- to 14-dayperiod is suggested. Meat animals shouldnot graze in treated pastures 30 days beforeslaughter.

Forefront (aminopyralid + 2,4-D)Rate: 24 to 42 fl oz/a. If spot treating, up

to 84 fl oz/a may be applied IF no morethan half the area is sprayed.Adjuvants: Anonionic surfactant is recom-

mended at 0.25 to 0.5% (v/v).Timing: Postemergence—Applications

should be made before bud to early bloomstage or treat regrowth following mowingor grazing in the fall.Remarks: Aminopyralid is particularly

active on plants in the Asteraceae (thistles,knapweeds) and Fabaceae (legumes) fami-lies, but many species appear to be fairlytolerant, especially established grasses.DowAgrosciences has added 2,4-D tobroaden the range of broadleaf weeds thatare controlled by this herbicide (e.g.,goldenrod spp.). Soil activity of amino-pyralid lasts for several months; if appliedin the fall, it can carryover into the nextyear. Treated areas should not be harvestedfor 7 days after application. To minimize riskof damage to sensitive plants, wait at least 3days before transferring animals fed sprayedforage.Rotational restrictions: Do not rotate to

any crop for 1 year; a soil bioassay isrequired before planting broadleaf crops.

GlyphosateRate: Varies with species and method of

application. See label for details.Adjuvants:Ammonium sulfate at 8.5 to

17 lb/100 gal of spray mixture is frequentlyrecommended, especially if using hardwater. Additional surfactant is rarelyneeded.

Timing: Postemergence—Treat perennialbroadleaves in the late bud to early flowerstage or treat regrowth following mowingor grazing. Treat brush species when leavesare fully expanded and plants are activelygrowing.Remarks: Glyphosate is available in vari-

ous brand names. Not all products arelabeled for use in pastures; check the labelbefore using. Products may also vary inglyphosate concentration, type and amountof surfactants, and approved use rates.Spot application of glyphosate in pas-

tures is very appropriate for treating local-ized weed problems such as Canada thistleor multiflora rose which often occur inpatches. No more than 10% of any acreshould be spot-treated at one time. Addi-

165

STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

weeds

SOYBEAN

CORN

PRINCIPLESOF

PESTMNGM

T.


tional applications can be made in the samepasture at 30-day intervals. Glyphosate isnonselective and will kill all treated vegeta-tion; reseed the area with a desirable mix-ture of forage species. Foliar sprays ofglyphosate kill these brush species: alder,elms, honeysuckle, multiflora rose, oaks,poison ivy, sumac, and willow. Symptomsof injury may not appear for several weeks.Glyphosate can also be used in pastures

in wiper applicators. An 8- to 12-inch heightdifference between the weeds and pasturespecies is required. This approach is usefulto suppress tall herbaceous broadleafweeds such as chicory, goldenrod, giantragweed, bull thistle, and plumeless thistlein pastures with birdsfoot trefoil or clover.For both spot treatment and selective

equipment applications, remove domesticlivestock before treating and do not grazeor harvest for 14 days.

Milestone (aminopyralid)Rate: 3 to 7 fl oz/a. If spot-treating, up to

14 fl oz/a may be applied IF less than 50%of the area is treated.Adjuvants: For postemergence applica-

tions, a nonionic surfactant should beadded at 0.25 to 0.5% (vol/vol).Timing: Postemergence—Applications

should be made before bud to early bloomstage for annual and biennial weeds, whileperennials should be treated at either thebud stage or in the fall to actively growingplants that have been mowed or grazed.Milestone also has pre-emergent activityfor several months.Remarks: This herbicide is particularly

active on plants in the Asteraceae (e.g. this-tles, knapweeds) and Fabaceae (legumes)families, but many broadleaf plants appearto be fairly tolerant and established grassesare very tolerant. Soil activity lasts for sev-eral months; if applied in the fall, can carry-over into the next year. While this producthas no grazing restrictions, avoid transfer-ring animals fed treated forage for 3 days to pre-vent damage to sensitive plants.Rotational restrictions: Do not rotate to

any crop for 1 year; a soil bioassay isrequired before planting broadleaf crops.

Overdrive (dicamba + diflufenzopyr)Rate: 4 to 8 oz/a.Adjuvants: Use a nonionic surfactant at

1 qt/100 gal of spray solution (0.125%, v/v)or methylated seed oil at 1.5 to 2 pt/a.Remarks: The product contains diflufen-

zopyr and dicamba. The Overdrive labellists many weeds common in pastures andnoncrop areas, including biennial thistles,bindweeds, burdock, buttercups, Canadathistle, curly dock, goldenrod, horsenettle,spotted knapweed, white cockle, wild car-rot, and wild parsnip.The recommended rates of Overdrive in

pastures are 4 to 8 oz/a. Annual broadleafweeds and biennials in the rosette stagewill be controlled at lower rates than peren-nials. Overdrive must be applied with anonionic surfactant or methylated seed oil(MSO). Consider using MSO when treatinghard-to-kill weeds or when plants areunder moisture or temperature stress. Thisproduct has no harvesting or grazingrestrictions.

Spike (tebuthiuron)Rate: Varies with brush species and

method of application. See label for details.Timing: Can be applied most of the year.Remarks: Spike is a persistent, nonselec-

tive herbicide registered for brush controlin pastures and non-cropland areas. TheSpike 20P formulation is the only formula-tion clearly registered for use in pastures.Spike 20P is a pelleted formulation with20% active ingredient. The label recom-mends killing individual plants by spread-ing Spike evenly over the area under thetarget plant at a rate of 0.75 oz of Spike pel-lets in 100 sq ft (equivalent to 20 lb/a).However, the most logical way to distributethe pellets is at the base of individual plants.This approach gives excellent control ofmultiflora rose when 0.25 oz of Spike pelletsare distributed around three to six bushes.All vegetation in the treated area will bekilled for 2 years or more. Spike can beapplied anytime the ground is not frozen,but plants will only be killed once rainfallmoves the herbicide into the root zone.Treated brush will die over a period of sev-eral weeks to months. Use great care toavoid injury to nearby sensitive vegetationand to prevent movement into surface orground water. (The Spike label has a ground

166

STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

weeds

SOYBEAN

CORN

PRINCIPLESOF

PESTMNGM

T.


water advisory statement.) Susceptiblebrush species include black locust, box-elder, maple, mulberry, multiflora rose, oak,willow, and many more. There is no grazingrestriction following application, but haycannot be harvested from treated pasturesfor 12 months.

Stinger (clopyralid)Rate: Apply 0.33 to 1.0 pt/a.Adjuvants: Surfactants and other additives

are not normally added to the spray mixture.Timing: Postemergence—Applications

should be made before bud to early bloomstage for annual and biennial weeds, whileperennials should be treated at either thebud stage or in the fall to actively growingplants that have been mowed or grazed.Stinger also has pre-emergent activity forseveral months.Remarks: Stinger is particularly active on

plants in the Asteraceae family such as this-tles and knapweeds. A single application ofStinger may not eradicate Canada thistle,but it often reduces the infestation for sev-eral years. Stinger can be tank-mixed with2,4-D or dicamba for a more economicaltreatment. Stinger will kill treated foragelegumes such as trefoil and clovers.While there is no grazing restriction for

pastures, we recommend at least a 7-dayrestriction be followed for pastures. Do notmove livestock from treated areas onto sen-sitive broadleaf crop areas until they havegrazed for 7 days on an untreated pasture.Otherwise urine and manure may containsufficient Stinger to injure sensitivebroadleaf crops.Stinger is relatively soluble and decom-

poses slowly in the soil. The label has aground water advisory statement and theproduct must not be used in sites vulnera-ble to groundwater contamination. Followlabel guidelines for sprayer cleanup anddrift prevention.

Weedmaster (dicamba + 2,4-D)Rate: Apply 1 pt/a of Weedmaster to con-

trol buttercup, lambsquarters, pigweed,and smartweed. Use 2 pt/a to control bur-dock, chicory, curly dock, dandelions, gold-enrod, mustards, bull thistle, musk thistle,and plumeless thistle. Apply 2 qt/a to con-trol elderberry, honeysuckle, nettle, night-

shade, poison ivy, and tansy ragwort and tosuppress field bindweed, Canada thistle,perennial sowthistle, and leafy spurge.Adjuvants: Do not add surfactants or

other additives to the spray mixture.Timing: Postemergence—Treat when weeds

are actively growing. Do not treat newlyseeded areas.Remarks:Weedmaster is a prepackaged

formulation of dicamba + 2,4-D for use inpastures. The product contains 1 lb ae ofdicamba and 2.8 lb ae/gal of 2,4-D amine.Use appropriate precautions to avoid driftto nearby sensitive vegetation. This productwill kill forage legumes such as clover andtrefoil.No grazing restrictions exist for nonlac-

tating animals, but lactating dairy cattlecannot graze treated fields for 7 days aftertreatment or meat animals within 30 daysof slaughter. Treated grass may be har-vested for hay 37 days after application.

2,4-D for herbaceousweed controlRate: Apply 2 pt/a of 2,4-D amine or

ester (forms containing 3.8 lb acidequiv/gal) to control annual broadleafweeds, 2 to 4 pt/a to control biennials andperennial broadleaves.Adjuvants: Do not add surfactants or

other additives to the spray mixture.Timing: Postemergence—Treat annual

broadleaves when they are seedlings; bien-nials like bull, musk, and plumeless thistlesin the rosette stage; and actively growingperennial broadleaf weeds in the bud stage.Remarks: Repeated application of 2,4-D

amine or ester for 2 or 3 years will effec-tively control most nonwoody broadleafweed populations in grass pastures. Eitherfall or spring applications control biennialthistles in the rosette stage if they areactively growing when sprayed. After thebiennials have formed a flower stalk, theyare more tolerant to these herbicides. Sev-eral years of treatment may be necessary tosatisfactorily control hard-to-kill perennialweeds.The 2,4-D amines are water-soluble liq-

uids and 2,4-D esters are emulsifiable con-centrates. Both formulations are sold undervarious trade names and at various concen-trations of acid equiv/gal. Ester formula-tions have greater potential to volatilizeand drift than amine formulations. Read

167

STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

weeds

SOYBEAN

CORN

PRINCIPLESOF

PESTMNGM

T.


the label carefully to avoid application dur-ing conditions that will promote vapordrift. Formulations of 2,4-D ester are alsoavailable in low-volatile forms that reducethe potential for vapor drift.Most labels state that pastures treated

with 2,4-D should not be grazed by dairycattle for 7 days after treatment and thatmeat animals must be removed fromtreated areas 3 days before slaughter unlessmore than 2 weeks have elapsed since treat-ment. Do not cut treated grass for haywithin 30 days after application. Read thelabel carefully for specific rates, grazingrestrictions, and application precautions.

2,4-D Ester for brush controlRate: Varies with brush species and

method of application. See label for details.Adjuvants: Do not add surfactants or

other additives to the spray mixture.Timing: Postemergence—Apply 2,4-D ester

in late spring or early summer when brushis in full leaf and actively growing.Remarks:With foliar sprays, wet foliage

to the point of runoff. Some formulationsspecify adding oil to the spray mixture.Low volatile esters are preferred, especiallynear susceptible crops. Esters of 2,4-D aloneare not effective on all brush species. Someretreatment is usually required for com-plete kill. Cut brush that is more than 6 to 8feet tall and treat the cut surface orregrowth. Esters of 2,4-D are available asemulsifiable concentrates and generallycontain 3.8 lb acid equiv/gal. Keep dairycattle off treated pastures for at least 7 days.

PASTURE RENOVATIONNo-till pasture renovation with herbi-

cides is attracting interest in several areasof Wisconsin. It is best suited to fields onhillsides where tilling the soil may allowexcessive erosion to occur. Success dependson timely rains to stimulate the germina-tion of the forage seeds. The following her-bicides aid in no-till pasture renovation. Besure broadleaf weeds have been controlledbefore interseeding legumes into pastures.After the legume is established, there are noselective herbicides available for broadleafweed control. Where biennial thistles arepresent, treat for at least 2 years before ren-ovation to reduce their abundance.See table 4-5 for a summary of harvest

and grazing intervals following herbicideuse in pastures.

GlyphosateRate: Varies with species and method of

application, but typically ranges from 0.5 to1.1 lb ae/a. See the label for details.Adjuvants:Ammonium sulfate at 8.5 to

17 lb/100 gal of spray mixture is frequentlyrecommended, especially if using hardwater. Additional surfactant is rarelyneeded.Timing: Preplant—Apply to actively grow-

ing vegetation before planting desirablespecies.Remarks: Several brands of glyphosate

are registered for pasture renovation andcan be used to control Canada thistle,quackgrass, and other perennial weedsbefore reseeding forages, grasses, andlegumes. Treated areas can be tilled beforeseeding or planted with no-till seeders. Ero-sion on hillsides may occur as glyphosatekills all treated vegetation. No grazing orharvesting restrictions exist unless morethan 2.25 lb ae/a is applied. If this rate isexceeded, wait 8 weeks following treatmentbefore grazing or harvesting hay.

168

STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

weeds

SOYBEAN

CORN

PRINCIPLESOF

PESTMNGM

T.


Gramoxone (paraquat)Rate: Apply 0.7 to 1.3 pt/a Gramoxone

Max or 1 to 2 pt/a Gramoxone Inteon. Usethe high rate to suppress smooth bromeand orchardgrass. Increase both theGramoxone rate and the volume of wateras the density and size of vegetation to betreated increases.Adjuvants:Add nonionic surfactant at 1 to

2 pt/100 gal of spray solution.Timing: Preplant—Apply preplant or at

the time of seeding in the spring or earlysummer.Remarks: Gramoxone suppresses the

competition of existing sod and emergedbroadleaf weeds and grasses to facilitateseeding grasses and/or forage legumessuch as alfalfa, clovers, and birdsfoot trefoilinto existing pastures without tillage.

Apply in at least 20 gal/a of water and treatonly closely grazed or mowed pastures thatare no more than 2 to 3 inches tall at thetime of spraying.The burn-down action of Gramoxone

facilitates the no-till seeding (pasture seed-ing) of more desirable forage legumes andgrasses. No-till seeding with Gramoxone ismore successful in bluegrass pastures thanin pastures containing large amounts ofquackgrass. Quackgrass recovers morerapidly after treatment than bluegrass andmay compete vigorously with legumeseedlings. Gramoxone will not kill peren-nial weeds such as dandelions. In fieldsinfested with broadleaf weeds, use 2,4-D ordicamba in the fall before renovation.Allow at least 42 days between treatmentand first grazing.

169

STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

weeds

SOYBEAN

CORN

PRINCIPLESOF

PESTMNGM

T.

Table 4-5. Harvest and/or grazing restrictions for herbicides registeredfor use in forages and pasturesa

Interval betweenType of application and

Herbicide Use(s) animal grazing or harvest Comments

Ally/Escort pastures all 0 days No grazing restrictions.Buctril alfalfa all 30 days Do not harvest summer-seeded alfalfa

treated with Buctril until 60 daysfollowing application.

Butyrac 200 alfalfa, trefoil all 60 days: new seedings30 days: establishedstands

Crossbow pastures lactating dairy next season Remove livestock from treated areas atother 0 days least 3 days before slaughter during year

of treatment. See label for restrictions ifharvesting grass as hay or if using highrates.

Curtail pastures lactating dairy 14 days Do not harvest hay for 30 days afterother 0 days application. Remove meat animals 7 days

before slaughter.Dicamba pastures lactating dairy 7 days: <1 pt/a No waiting period between treatment

21 days: 1–2 pt/a and grazing for nonlactating animals.40 days: 2–4 pt/a Remove meat animals from treated areas

30 days before slaughter. If hay is to beharvested and fed to dairy animals, seelabel for restrictions.

Eptam alfalfa, clovers, trefoil all — No restrictions on the label.Forefront pastures all 7 days: harvested Before transferring animals from treated

areas areas to areas planted with sensitive0 days: grazed areas broadleaf crops, graze them for 3 days on

untreated pastures.aLabels may have changed after this table was prepared. Consult current labels to verify the information. (continued)


170

Glyphosateb spot treatment or all 14 days With spot treatments, do not treat moreselective equipment in than 1⁄10 of any acre.forage grasses andlegumespasture renovation all 8 weeksalfalfa, preharvest all 36 hours Only for fields being rotated to another

crop.alfalfa, Roundup Ready all 5 days

Gramoxone Inteon pasture renovation all 42 daysMilestone pastures all 0 days Before transferring animals from treated

areas to areas planted with sensitivebroadleaf crops, graze them for 3 dayson untreated pastures.

Overdrive pastures all 0 days No grazing restrictions.Plateau pastures all 7 days: hay No grazing restrictions on the label.Poast Plus alfalfa, clovers, trefoil all 14 days: dry hay

20 days: dried cloverPursuit alfalfa all 30 daysRaptor alfalfa all 0 daysSelect alfalfa, trefoil all 15 daysSencor alfalfa all 28 daysSpike pastures all 0 days No grazing restrictions on the label;

do not harvest hay from treated pasturesfor 12 months.

Stinger pastures all 0 days No grazing restrictions on the label.Do not use hay or straw for compostingor mulch on broadleaf crops.

Treflan alfalfa all — No restrictions on the label.Velpar alfalfa all 30 daysWeedmaster pastures lactating dairy 7 days Allow 37 days between application and

other 0 days hay harvest. Remove meat animals fromtreated areas 30 days before slaughter.

2,4-D pastures dairy 7 days 2,4-D labels vary. See specific label ofother 3–7 days product used. Do not harvest grass for

hay within 30 days of application.aLabels may have changed after this table was prepared. Consult current labels to verify the information.bDifferences in restrictions exist on some brands of glyphosate. Verify what restrictions apply to your brand before using it.

Table 4-5. Harvest and/or grazing restrictions for herbicides registeredfor use in forages and pasturesa (continued)

Interval betweenType of application and


STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

weeds

SOYBEAN

CORN

PRINCIPLESOF

PESTMNGM

T.


FORAGE & PASTUREINSECT MANAGEMENT

171

STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

insectsSO

YBEANCO

RNPRINCIPLES

OF

PESTMNGM

T.

Insecticides suggested in this section areintended as a guide to assist you in select-ing chemical insect control options duringthe season. This book provides an overviewof product registrations for specific fieldcrop insect pests; it is not intended as anexhaustive insecticide label source. Productinclusion or omission does not implyendorsement by University of WisconsinExtension. Remember, certain insecticidesare produced by different manufacturersand directions for use, rate, and method ofapplication may vary by formulation.Therefore, always read the insecticide labelcompletely before using the material.Insecticides are often interchangeably

referred to by their common and tradenames. Trade names such as Mustang Maxare capitalized, while common chemicalnames, zeta-cypermethrin in this example,are not.A number of the products listed in this

section are restricted-use insecticides. Wediscuss restricted-use pesticides in thebeginning of this publication. Refer toappendix table 1 for a list of pesticides thatcurrently require certification to be applied.It is possible that additional insecticideswill be classified before the next growingseason. Contact your county Extensionagent for additional information on insecti-cide restriction.

REDUCING INSECTICIDEHAZARDS TO BEESInsecticides help control insect pests, but

they also can kill beneficial insects such ashoney bees. Notify beekeepers before usinginsecticides and apply only between 4 p.m.and nightfall—when bees are least likely tobe actively foraging. Never spray alfalfa orclover when in blossom. Some insecticides,such as Penncap-M (micro-encapsulatedmethyl parathion) and dimethoate, statethat applications should not be made dur-ing bloom. Failure to heed this warning is ause inconsistent with the label and, there-fore, a violation of the law.Insecticides in table 4-6 can be applied to

non-blooming alfalfa with minimal beehazard, provided there are no bloomingclover or weeds in the alfalfa field. Theseinsecticides must not be allowed to driftinto bee yards or onto adjacent weeds ordomestic crops that are in bloom, otherwisesubstantial bee losses could occur.

Table 4-6. Timing of insecticideapplications to avoid bee deathsa

Do not apply on blooming crops or weedsDimethoateFuradanImidanSevin

Apply only during late eveningLannateMalathion

aIf temperatures are unusually low following treat-ment, residues on the crop may remain toxic to beesup to 20 times as long as during reasonably warmweather. If abnormally high temperatures occur dur-ing late evening or early morning, bees may activelyforage on the treated crop during these times.


Do not spray blooming alfalfa. If insectsare damaging blooming alfalfa, harvest thealfalfa and, if necessary, spray the newgrowth to control the insects. However,before spraying the stubble, check for thepresence of blossoming plants. Duringsome years, heavy populations of blossom-ing white clover appear in alfalfa stubbleshortly after harvest of the first crop. Beesforaging on these blossoms will be killed ifstubble is sprayed for alfalfa weevils insuch fields. Select an effective insecticidethat is the least toxic to bees.Avoid spraying ditch banks, fencerows,

and roadsides when plants there are inbloom.Advance notificationWisconsin beekeepers

may request a 24-hour advance notice ofapplications of certain pesticides madewithin a 1.5 mile radius of their bee yards.The insecticides involved are those whichare labeled “Highly Toxic to Bees” or whichcontain the active ingredient methomyl(e.g., Lannate). Beekeepers desiringadvance notification must provide theirrequest in writing to the landowner or per-son controlling the use of the land on whichpesticides may be applied either by groundor aerially. All requests expire at the end ofeach calendar year.

ALFALFA INSECTSConsult Extension publication Alfalfa

Insect Pests (A2156) for color photos anddescriptions of major alfalfa insect pests.The publication is available from countyExtension offices.

Alfalfa blotch leafminerThe alfalfa blotch leafminer was first

detected in plant samples from northwest-ern Wisconsin in Burnett and Sawyer coun-ties during the fall of 1996. By midsummer1997 it was reported in several fields ineastern and central Wisconsin. The insect isnative to Europe and was first reported inNorth America in the northeastern UnitedStates in 1968.Description of life stages Adults are small,

black, hump-backed flies that emerge fromoverwintering pupae located on the surfaceof the soil. The first indication of their pres-ence is the appearance of numerous pin-holes (from a few to over 100) in theleaflets. These holes are mostly signs ofadult feeding but can also serve as egg-lay-ing sites. Females lay one to three eggs peralfalfa leaflet. Maggots that hatch fromthese eggs are small and yellow and feedwithin the leaf. The resulting tunnel usuallystarts at the base of the leaflet and widenswith movement toward the tip of the leaf,resulting in the “blotch” appearance. Whenfully grown they crawl out of the leaves,drop to the ground, and pupate. A secondgeneration of flies emerge in about 1 week(mid-July), and is followed by a third gen-eration in late August.Damage Punctures and blotches result in

leaf deterioration and possible defoliation.Leaf damage lessens quality while leaf-drop reduces yield. Significant yield lossshould only occur if damaged leaves dropfrom the plant or are shaken from the hayduring harvesting.

172

STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

insectsSO

YBEANCO

RNPRINCIPLES

OF

PESTMNGM

T.

Table 4-7. Periods to scout for insect pests of forages

Insect pest Spring growth Second growth Third growth New seeding

Alfalfa blotch leafminer yes yes yes yesAlfalfa caterpillar no yes yes noAlfalfa weevil yes new growth only no seldomAphids yes yes yes yesBlister beetlesa no yesb yesb yesb

Cutworms yes yes yes yesGrasshoppers seldom seldom seldom seldomPlant bugs no yes yes yesPotato leafhopper no yes yes yesSpittlebug nymphs yes no no yesaBlister beetles in hay can be toxic to horses.bWhen abundant, blister beetles make fresh-cut forage distasteful.


173

FORAGES

&PASTURES

insectsSTO

REDGRAIN

INSECTSPERENNIAL

WEEDS

SMALL

GRAINSAPPENDIX

SOYBEAN

CORN

PRINCIPLESOF

PESTMNGM

T.

Control Biological control is well-estab-lished in the northeastern United States andhas greatly reduced the threat posed by thispest. Cutting schedule can be used to reduceincidence of damage. In Canada, harvest ofthe first crop normally controls the firstgenerations. The second and third genera-tions may not correspond as closely withcutting schedules, this can result in moreextensive injury in the second and thirdcuttings. As is true for the alfalfa weevil,cooler weather favors alfalfa developmentover that of the insect, while warm weathermay require alteration of cutting schedules.Chemical control can be effective if appliedduring the “pinhole” stage, but treatmentwill not pay unless leaf drop is extensive.Treatment may be justified when 30 to 40%of the leaflets exhibit pinhole feedinginjury.

Alfalfa caterpillarLarvae are dark green with a narrow

white stripe along each side of the bodythrough which runs a thin red line. Whenfully grown they are 1.5 inches long. Thisinsect is seldom of concern to alfalfa pro-duced in the Midwest, and treatment is notsuggested unless populations reach 10 ormore per sweep.The adult stage attracts the most atten-

tion because swarms of these sulfur-yellowbutterflies can be seen flying over alfalfafields during mid- to late summer.

Alfalfa weevilAlfalfa weevil larvae are slate-colored

when small, but bright green when fullgrown (3⁄8 inch). There is a white stripedown the back, and the head is black. Theychew and skeletonize leaves. If larval popu-lations are large, the entire plant may bedefoliated, giving the field a grayish cast.Although larvae are present from May wellinto the summer, peak feeding activity fallsoff by mid-June.When full grown, the larvae spin silken

cocoons on the plants, within the curl offallen dead leaves, or within litter on theground. They change into adults in 1 to2 weeks. The adults are dark gray to brownsnout beetles measuring 3⁄16 inch in length.There is a distinct dark shield-like mark onthe back. After feeding a short time, mostadults leave the field and enter a restingperiod that lasts until fall. Adults then

return to the alfalfa field and lay a few eggsbefore the onset of cold temperatures. Thisegg laying is insignificant; most eggs arelaid during the following spring.Although most of the feeding damage is

done by larvae, at times adult damage issignificant. Larvae and adults can continueto feed on new growth of the second crop.Populations can be great enough to killplants and, as a result, fields can be lost.Begin checking alfalfa fields for signs of

weevil feeding in mid-May. This usuallygives sufficient warning of developingproblems. Since peak larval activity typi-cally occurs from mid-May to early June,check fields every few days. However, pop-ulation peaks vary from year to year, mak-ing it difficult to predict the extent of activ-ity and exact time when peak populationswill occur. Therefore, it is important toperiodically check with your county Exten-sion office for updates on the alfalfa weevilsituation.Control measures should be imple-

mented when 40% of the plant tips of thefirst crop show obvious signs of damage.This does not mean 40% defoliation, butthat 40% of the plants are beginning toshow signs of feeding activity. If this occurswithin 7 to 10 days of the suggested harvestdate for your area, harvest the hay as soonas possible and watch the stubble for signsof weevil damage to new growth of the sec-ond crop. Early cutting will save the cost ofan insecticide application. If you cannotharvest, spray as soon as possible. If 40%tip damage is found more than 10 daysahead of the suggested harvest date, thefield should be sprayed as soon as possible.Harvesting too early could be detrimentalto alfalfa stands. Growers may not be ableto harvest fast enough to stay ahead of theweevil in years of high alfalfa weevil abun-dance. In these cases, growers may have tospray the most heavily infested fields andharvest those with lighter infestations.If a field is harvested early because of

alfalfa weevil problems, or if substantialdamage has occurred with a standard har-vesting schedule, the stubble must bechecked carefully for signs of damage tonew growth of the second crop. Some fieldsmay fail to green-up because adults andlarvae are consuming new crown buds asfast as they are formed. Check the stubble,the soil surface around alfalfa plants, and


under leaf litter for larvae and adults. Ifyou find them and if there is no sign ofregrowth in 3 or 4 days after harvest, spraythe stubble as soon as possible. Treatment isalso suggested if feeding damage is appar-ent on 50% of the new growth.If you find no larvae or adults, lack of

regrowth is due to other factors. Rememberthat dry weather will often delay growth ofthe new crop.Economic treatment threshold popula-

tions which include the presence of adultweevils require an insecticide that islabeled for control of both adult weevilsand larvae. Check product labels to selectan insecticide that is effective on bothstages or does not distinguish between thetwo.

AphidsTwo types of aphids can be found on

alfalfa: the soft, green pea aphids or thespotted alfalfa aphids, which are yellowand faintly dark spotted. Aphids congre-gate on stems and leaves and suck plantsap. This causes stunting and yellowing ofalfalfa. If aphids are abundant, treat beforethese symptoms occur. Pea aphids cancause significant damage when numbersexceed 100 per sweep, particularly if soilmoisture is below plant requirements.

GrasshoppersOccasionally, grasshoppers are abundant

enough to concern farmers. No treatment issuggested until populations reach 20/sq ydin field margins or 8/sq yd within alfalfafields. Treat while grasshoppers are stillsmall.

Plant bugsPlant bugs that are particularly important

to alfalfa production are the tarnished plantbug, the rapid plant bug, and the alfalfaplant bug. The adult tarnished plant bug is1⁄4 inch long and brown. Nymphs are greenwith black spots on the back. Adult alfalfaplant bugs are 3⁄8 inch long and are lightgreen. Nymphs are green with red eyes.Rapid plant bug adults resemble the alfalfaplant bugs but are dark brown with yellowmargins. Nymphs are red tinged.Plant bugs extract plant sap with their

tube-like mouthparts. In high populations,this can result in stunted alfalfa growth orcrinkled, puckered leaves. On alfalfa less

than 3 inches tall, treat if there are threeplant bug adults and/or nymphs persweep; on taller alfalfa, treat when there arefive or more adults and/or nymphs persweep.Insecticide applied within 7 to 10 days of

harvest is unlikely to increase alfalfa yieldand quality. In addition, preharvest inter-vals restrict insecticide use during this time.The best solution for such fields is to har-vest early.Note that while plant bug feeding can

stunt plants and cause crinkling and puck-ering of leaves, these alfalfa growth aberra-tions also have been found in the absenceof plant bugs.

Potato leafhopperPotato leafhoppers are small (1⁄8 inch),

green, wedge-shaped insects. Adults andnymphs look similar except that adultshave wings and nymphs are wingless.Leafhopper nymphs can be distinguishedfrom other small green insects by their side-ways movement when disturbed. Potatoleafhoppers feed on alfalfa by insertingtheir beaklike mouthparts (proboscis) intoleaves and tapping into the food-conduct-ing tissue (phloem) to extract plant sugars,minerals, and other compounds. As theyfeed, they inject a toxin into the plant toinhibit water and nutrient transport. Feed-ing damage results in plant stunting, andthe yellowing of the leaves in a tell-taleV-shaped pattern starting at the leaf tip.Serious infestations of leafhoppers will alsoreduce the yield and protein content of theplants.Potato leafhoppers are mid- to late-sea-

son alfalfa pests that migrate to Wisconsinfrom southern areas. First-crop alfalfa har-vested at the proper time escapes damage.However, monitor subsequent crops forleafhoppers. New seedings must also be

174

Table 4-8. Treatment thresholds forpotato leafhoppers on alfalfa (Treatwhen leafhopper densities reach these thresholds.)

Alfalfa Leafhoppers/stem height (inches) net sweep (average)

3 0.26 0.58–11 1.012–14 2.0

STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

insectsSO

YBEANCO

RNPRINCIPLES

OF

PESTMNGM

T.


175

FORAGES

&PASTURES

insects

monitored carefully and sprayed at thresh-old. Failure to do so can reduce yieldthroughout the life of the stand due tostress caused by leafhoppers during estab-lishment.Because potato leafhopper populations

vary from year to year and we cannot pre-dict populations within a given year, fieldsmust be monitored weekly to accuratelydetermine damage potential. Both nymhsand adults feed on alfalfa and should becounted together when scouting fields. Usea 15-inch diameter insect sweep net to takesamples. A total of 100 sweeps should betaken throughout the field. Walk an M-shape through the field, taking 20 consecu-tive sweeps in each of five randomlyselected areas. To obtain an accurate popu-lation estimate, sample when plants are dryand avoid field edges. Cold, wet, or windyconditions may temporarily knock adultsand nymphs from plants, resulting in aninaccurate sweep count. As you sample,keep a running total of the number ofleafhoppers caught at each location anddivide the total by 100. Refer to table 4-8 fortreatment thresholds.Economic thresholds are based on the

average number of leafhoppers per sweepand on plant height. Taller plants have

higher treatment thresholds because theycan withstand more damage and will beharvested sooner than shorter plants.

SpittlebugsSpittlebug nymphs appear in early May

in extreme southern Wisconsin. These soft,orange or green bugs can be found in whitespittle masses in leaf axils, and later in theclumps of new growth at tips of stems.They suck plant sap and stunt but do notyellow the alfalfa. Treat if there is an aver-age of at least one spittlebug per stem.

INSECT PESTS OFBIRDSFOOT TREFOIL,CLOVER, AND PASTUREGrasshoppers and spittlebugs occasion-

ally cause problems in clover fields.Grasshoppers are occasionally a problem

in pastures. Treat when nymphs are abun-dant and before migration into row crops isextensive. Apply sprays while grasshop-pers are small. Notify nearby beekeepers atleast 48 hours before you use an insecticideif blossoming weeds or other plants arepresent. Do not allow sprays to drift intobee yards or onto blooming crops or weeds.Use the insecticides listed in table 4-9 to

control insect pests of birdsfoot trefoil,clover, and pastures.

STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

SOYBEAN

CORN

PRINCIPLESOF

PESTMNGM

T.

Table 4-9. Insecticide suggestions for birdsfoot trefoil, clover, and pasture

Amount ofInsect Insecticidea product/acre Remarks, precautionsb

BIRDSFOOT TREFOIL INSECTSAlfalfa plant bug, Mustang Max 2.8–4.0 oz Amaximum of 0.025 lb ai/a may be applied per cutting,Tarnished plant bug, with up to 0.075 lb ai/a applied per season. Applications mayPlagiognathus plant bug be made up to 3 days before cutting or grazing and up to

7 days before harvesting seed. Allow at least 7 days betweenapplications.

Grasshoppers Mustang Max 2.8–4.0 oz See remarks for Mustang Max above.Potato leafhoppers Sevin XLR Plus 2 pt Do not apply within 7 days of harvest or grazing.

Mustang Max 2.24–4.0 oz See remarks for Mustang Max above.CLOVER INSECTSGrasshoppers malathion 1–2 pt Refer to label for preharvest interval information. Use only

when air temperature is above 60°F.Mustang Max 2.8–4.0 oz See remarks for Mustang Max above.

Potato leafhoppers Mustang Max 2.24–4.0 oz See remarks for Mustang Max above.Sevin XLR Plus 2 pt Do not apply within 7 days of harvest or grazing.

aAll insecticides in this table are to be applied to the plant foliage. (continued)bNotify nearby beekeepers before you use insecticides and apply only between 4 p.m. and nightfall when bees are least likely to be exposed.Do not treat clover during bloom. Treatment of clover fields that contain blossoming weeds or other plants can result in severe bee losses.


Table 4-10. Insecticide suggestions for alfalfa


Alfalfa blotch Baythroid XL 2.0–2.8 oz Do not apply within 7 days of harvest.leafminer Cobalt 19.0–38.0 fl oz Do not graze or cut within 14 days at 19–26 oz/a rate or within

21 days at higher rates. Do not exceed four applications perseason of Cobalt or other chlorpyrifos-containing products orapply more than once per cutting or apply within 10 days oflast treatment.

Furadan 4F 1.0–2.0 pt Do not apply more than once per year. Do not apply within 14days of harvest at the low rate; do not apply within 28 days ofharvest at the high rate. Apply only to fields planted to purestands of alfalfa. Do not move bees into fields within 7 days ofapplication. Do not apply in proximity of waterfowl or onfields where waterfowl are known to repeatedly feed.

Imidan 70WP 1.0–1.33 lb Do not apply within 7 days of harvest. Apply only once percutting.

Lorsban Advanced 2.0 pt Do not cut or graze within 21 days application. No more thanfour applications per year or more than one application percutting.

Warrior II, 1.92 oz Do not apply more than 0.12 lb ai/a per season. Do not applySilencer 1EC 3.84 oz within 1 day of harvest for forage or within 7 days of harvest

for hay. See label for resistance statement.

STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

insectsSO

YBEANCO

RNPRINCIPLES

OF

PESTMNGM

T.

176

(continued)

PASTURE INSECTSArmyworms (pasture) Mustang Max 2.8–4.0 oz Amaximum of 0.025 lb. ai/a may be applied per cutting.

For hay, a maximum of 0.10 lb ai/a per season may be applied.For forage and hay, allow at least 7 days between treatments.For straw and seed screenings, wait at least 17 days betweentreatments and do not apply within 7 days of harvest.

Sevin XLR Plus 1.0–1.5 pt Do not apply within 14 days of harvest or grazing.Tracer 1.0–2.0 fl oz No preharvest interval restrictions for forage. Do not harvest

hay or fodder for 3 days. Do not allow cattle to graze treatedarea until spray has dried. Do not apply more than 6 fl oz/a(0.186 lb ai/a) per season.

Warrior II 1.28–1.92 oz Do not cut grass to be dried and harvested for hay until 7 daysafter last application. Do not exceed 0.09 lb ai/a per season.

Grasshoppers Mustang Max 2.8–4.0 oz See remarks for Mustang Max in pasture armyworms.(rangeland) Sevin XLR Plus 0.5–1.0 pt May be harvested or grazed the same day as treatment.

Do not apply more than 2 pt/a per year.Warrior II 1.28–1.92 oz Do not cut grass to be dried and harvested for hay until 7 days

after last application. Do not exceed 0.09 lb ai/a per season.aAll insecticides in this table are to be applied to the plant foliage.bNotify nearby beekeepers before you use insecticides and apply only between 4 p.m. and nightfall when bees are least likely to be exposed.Do not treat clover during bloom. Treatment of clover fields that contain blossoming weeds or other plants can result in severe bee losses.

Table 4-9. Insecticide suggestions for birdsfoot trefoil, clover, and pasture (continued)



FORAGES

&PASTURES

insectsSTO

REDGRAIN

INSECTSPERENNIAL

WEEDS

SMALL

GRAINSAPPENDIX

SOYBEAN

CORN

PRINCIPLESOF

PESTMNGM

T.

Table 4-10. Insecticide suggestions for alfalfa (continued)


aAll insecticides in this table are to be applied to the plant foliage. (continued)Multiple trade names within a row indicates products containing the same active ingredient(s).bNotify nearby beekeepers before you use insecticides and apply only between 4 p.m. and nightfall when bees are least likely to be exposed.Do not treat alfalfa during bloom. Treatment of fields that contain blossoming weeds or other plants can also result in severe bee losses.

177

Alfalfa caterpillar Ambush 2E 3.2–12.8 oz Do not apply more than 0.2 lb ai/a per cutting. No waitingperiod to harvest if application rate is 0.1 lb ai/a or less. Forrates greater than 0.1 lb ai/a, do not apply within 14 days ofharvest.

Baythroid XL 1.6–2.8 oz Do not apply within 7 days of harvest.Cobalt 13.0–26.0 fl oz Do not graze or cut within 7 days at 13 oz/a rate or within

14 days at rates up to 26 oz/a. Do not exceed four applicationsper season of Cobalt or other chlorpyrifos-containing productsor apply more than once per cutting or apply within 10 days oflast treatment.

Mustang Max 2.24–4.0 oz Amaximum of 0.025 lb ai/a may be applied per cutting, withup to 0.075 lb ai/a applied per season. Applications may bemade up to 3 days before cutting or grazing and up to 7 daysbefore harvesting seed. Allow at least 7 days between applica-tions.

Pounce 3.2EC 2.0–8.0 oz Do not apply more than 0.2 lb ai/a per cutting. No waitingperiod to harvest if application rate is 0.1 lb ai/a. For ratesgreater than 0.1 lb ai/a, do not apply within 14 days of harvest.

Proaxis 1.92–3.2 oz Do not apply within 1 day of harvest for forage or within 7days of harvest for hay. Do not apply more than 0.06 lb ai(0.96 pt)/a per season.

Sevin XLR Plus 2.0 pt Do not apply within 7 days of harvest.Warrior II, 0.96–1.6 oz Do not apply more than 0.12 lb ai/a per season. Do not applySilencer 1EC 1.92–3.2 oz within 1 day of harvest for forage or within 7 days of harvest

for hay.Alfalfa weevil Note: If adult weevils are also causing economic damage, select an insecticide labeled for control of adults. The

labels for Furadan and Lorsban list adults as well as larvae. Technically, Ambush, Imidan, Penncap-M andPounce could be used at rates suggested below for control of adults since they list alfalfa weevil.Ambush 2E 6.4–12.8 oz Do not apply more than 0.2 lb ai/a per cutting. No waiting

period to harvest if application rate is 0.1 lb ai/a or less. Forrates greater than 0.1 lb ai/a, do not apply within 14 days ofharvest.

Baythroid XL 1.6–2.8 oz Do not apply within 7 days of harvest.Cobalt 19.0–38.0 fl oz Do not graze or cut within 14 days at 19–26 oz/a rate or within


dimethoate 0.5–1.0 pt Do not apply within 10 days of harvest.Furadan 4F 0.5–2.0 pt Do not apply more than once per season. Do not apply within

(larvae) 7 days of harvest at 0.5 pt rate; within 14 days of harvest at1.0–2.0 pt 1.0 pt rate; or within 28 days of harvest at 2.0 pt rate. Apply(adults) only to fields planted to pure stands of alfalfa. Do not move

bees into fields within 7 days of application. Do not apply inproximity of waterfowl or on fields where waterfowl areknown to repeatedly feed.


STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

insectsSO

YBEANCO

RNPRINCIPLES

OF

PESTMNGM

T.

178


Lorsban Advanced 1.0–2.0 pt Do not cut or graze treated alfalfa within 14 days afterapplication at rate of 1 pt/a; or within 21 days at higher rates.No more than four applications per year or more than oneapplication per cutting.


Pounce 3.2EC 4.0–8.0 oz Do not apply more than 0.2 lb ai/a per cutting. No waitingperiod to harvest if application rate is 0.1 lb ai/a or less. Forrates greater than 0.1 lb ai/a, do not apply within 14 days ofharvest.


Warrior II, 1.28–1.92 oz Do not apply more than 0.12 lb ai/a per season. Do not applySilencer 1EC 2.56–3.84 oz within 1 day of harvest for forage or within 7 days of harvest

for hay.Aphids Ambush 2E 3.2–12.8 oz Do not apply more than 0.2 lb ai/a per cutting. No waiting


Baythroid XL 2.8 oz Do not apply within 7 days of harvest.Cobalt 13.0–26.0 fl oz Do not graze or cut within 7 days at 13 oz/a rate or within

14 days at rates up to 26 oz/a. Do not exceed four applicationsper season of Cobalt or other chlorpyrifos-containing productsor apply more than once per cutting or apply within 10 days oflast treatment.


(blue alfalfa 7 days of harvest at 0.5 pt rate; within 14 days of harvest ataphid) 1.0 pt rate; or within 28 days of harvest at 2.0 pt rate. Apply0.5–2.0 pt only to fields planted to pure stands of alfalfa. Do not move(pea aphid) bees into fields within 7 days of application. Do not apply in

proximity of waterfowl or on fields where waterfowl areknown to repeatedly feed.

Lorsban Advanced 0.5 pt Do not cut or graze within 7 days application at 0.5 lb ai/a.No more than four applications per year or more than one percutting.




for hay.



(continued)

Alfalfa weevil(cont.)


FORAGES

&PASTURES

insectsSTO

REDGRAIN

INSECTSPERENNIAL

WEEDS

SMALL

GRAINSAPPENDIX

SOYBEAN

CORN

PRINCIPLESOF

PESTMNGM

T.

Armyworms Ambush 2E 3.2–12.8 oz Do no apply more than 0.2 lb ai/a per cutting. No waitingperiod to harvest if application rate is 0.1 lb ai/a or less. Forrates greater than 0.1 lb ai/a, do not apply within 14 days ofharvest.



Lorsban Advanced 1.0–2.0 pt Do not cut or graze within 14 days of application at 1.0 lb ai/aor within 21 days of application at higher rates. No more thanfour applications per year or more than one per cutting.


Pounce 3.2EC 2.0–8.0 oz Do no apply more than 0.2 lb ai/a per cutting. No waitingperiod to harvest if application rate is 0.1 lb ai/a. For ratesgreater than 0.1 lb ai/a, do not apply within 14 days of harvest.


Sevin XLR Plus 2.0–3.0 pt Do not apply within 7 days of harvest.Tracer 1.0–2.0 fl oz No preharvest interval restrictions for forage. Do not harvest

hay or fodder for 3 days. Do not allow cattle to graze treatedarea until spray has dried. Do not apply more than 6 fl oz/a(0.186 lb ai/a) per season


for hay.Cutworms Ambush 2E 3.2–12.8 oz Do not apply more than 0.2 lb ai/a per cutting. No waiting





Mustang Max 2.24–4.0 oz Amaximum of 0.025 lb ai/a may be applied per cutting, withup to 0.075 lb ai/a applied per season. Applications may bemade up to 3 days before cutting or grazing and up to 7 daysbefore harvesting seed. Allow at least 7 days betweenapplications.



aAll insecticides in this table are to be applied to the plant foliage. (continued)Multiple trade names within a row indicates products containing the same active ingredient(s).bNotify nearby beekeepers before you use insecticides and apply only between 4 p.m. and nightfall when bees are least likely tobe exposed. Do not treat alfalfa during bloom. Treatment of fields that contain blossoming weeds or other plants can also resultin severe bee losses. 179


STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

insectsSO

YBEANCO

RNPRINCIPLES

OF

PESTMNGM

T.




for hay.Grasshoppers Baythroid XL 2.0–2.8 oz Do not apply within 7 days of harvest.

Cobalt 7.0–13.0 fl oz Do not graze or cut within 7 days. Do not exceed four applica-tions per season of Cobalt or other chlorpyrifos-containingproducts or apply more than once per cutting or apply within10 days of last treatment.


7 days of harvest. Apply only to fields planted to pure standsof alfalfa. Do not move bees into fields within 7 days of appli-cation. Do not apply in proximity of waterfowl or in fieldswhere waterfowl are known to repeatedly feed.




Sevin XLR Plus 1.0–3.0 pt Do not apply within 7 days of harvest.Warrior II, 1.28–1.92 oz Do not apply more than 0.12 lb ai/a per season. Do not applySilencer 1EC 2.56–3.84 oz within 1 day of harvest for forage or within 7 days of harvest

for hay.Plant bugs Ambush 2E 6.4–12.8 oz Do not apply more than 0.2 lb ai/a per cutting. No waiting




dimethoate 0.5–1.0 pt Do not apply within 10 days of harvest.Lorsban Advanced 1.0–2.0 pt Do not cut or graze within 14 days of application at 1.0 lb ai/a

or within 21 days of application at higher rates. No more thanfour applications per year or more than one per cutting.



180

(continued)

Cutworms (cont.)


FORAGES

&PASTURES

insectsSTO

REDGRAIN

INSECTSPERENNIAL

WEEDS

SMALL

GRAINSAPPENDIX

SOYBEAN

CORN

PRINCIPLESOF

PESTMNGM

T.




Sevin XLR Plus 2.0–3.0 pt Do not apply within 7 days of harvest.Warrior II, 1.28–1.92 oz Do not apply more than 0.12 lb ai/a per season. Do not applySilencer 1EC 2.56–3.84 oz within 1 day of harvest for forage or within 7 days of harvest

for hay.Potato leafhopper Ambush 2E 3.2–12.8 oz Do not apply more than 0.2 lb ai/a per cutting. No waiting


Baythroid XL 0.8–1.6 oz Do not apply within 7 days of harvest.Cobalt 7.0–13.0 fl oz Do not graze or cut within 7 days. Do not exceed four applica-

tions per season of Cobalt or other chlorpyrifos-containingproducts or apply more than once per cutting or apply within10 days of last treatment.

dimethoate 0.5–1.0 pt Do not apply within 10 days of harvest.Furadan 4F 1.0–2.0 pt Do not apply more than once per year. Do not apply within 14

days of harvest at 1 pt/a rate; do not apply within 28 days ofharvest at 2 pt/a rate. Apply only to fields planted to purestands of alfalfa. Do not apply in proximity of waterfowl or onfields where waterfowl are known to repeatedly feed. Do notmove bees into fields within 7 days of application.




Pounce 3.2EC 4.0–8.0 oz Do not apply more than 0.2 lb ai/a per cutting. No waitingperiod to harvest if application rate is 0.1 lb ai/a. For ratesgreater than 0.1 lb ai/a, do not apply within 14 days of har-vest.




Plant bugs (cont.)

aAll insecticides in this table are to be applied to the plant foliage. (continued)Multiple trade names within a row indicates products containing the same active ingredient(s).bNotify nearby beekeepers before you use insecticides and apply only between 4 p.m. and nightfall when bees are least likely tobe exposed. Do not treat alfalfa during bloom. Treatment of fields that contain blossoming weeds or other plants can also resultin severe bee losses.

181


182

STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

insectsSO

YBEANCO

RNPRINCIPLES

OF

PESTMNGM

T.

Sevin XLR Plus 2.0 pt Do not apply within 7 days of harvest.Warrior II, 0.96–1.6 oz Do not apply more than 0.12 lb ai/a per season. Do not applySilencer 1EC 1.92–3.2 oz within 1 day of harvest for forage or within 7 days of harvest

for hay.Spittlebugs Ambush 2E 6.4–12.8 oz Do not apply more than 0.2 lb ai/a per cutting. No waiting




Imidan 70WP 1.33 lb Do not apply within 7 days of harvest. Apply only once percutting.

Lorsban Advanced 1.0 pt Do not cut or graze within 14 days of application at 1.0 pt ai/a.No more than four applications per year or more than one percutting.


Pounce 3.2EC 4.0–8.0 oz Do not apply more than 0.2 lb ai/a per cutting. No waitingperiod to harvest if application rate is 0.1 lb ai/a. For ratesgreater than 0.1 lb ai/a, do not apply within 14 days of harvest.



for hay.aAll insecticides in this table are to be applied to the plant foliage. Multiple trade names within a row indicates products containing thesame active ingredient(s).bNotify nearby beekeepers before you use insecticides and apply only between 4 p.m. and nightfall when bees are least likely to be exposed.Do not treat alfalfa during bloom. Treatment of fields that contain blossoming weeds or other plants can also result in severe bee losses.



Potato leafhopper(cont.)


FORAGE DISEASEMANAGEMENT

183

FORAGES

&PASTURES

STORED

GRAININSECTS

PERENNIALWEEDS

SMALL

GRAINSAPPENDIX

SOYBEAN

CORN

PRINCIPLESOF

PESTMNGM

T.

Many disease-causing organisms attackforages in Wisconsin. Any approach toplant disease control requires identificationand knowledge of the cause and its lifecycle, the effect of environment on diseasedevelopment, and the potential control pro-cedures available. Economic and environ-mental factors often determine the controlprocedures employed for these various dis-eases. Control strategies can be an integra-tion of the following methods: plantingresistant or tolerant varieties, proper cropmanagement, and agricultural chemicals(mostly fungicides).Variety selection is key to disease man-

agement in forages and small grains. Referto Extension publication Perennial ForageVariety Update for Wisconsin (A1525) for spe-cific disease resistance ratings. This publi-cation is updated each year with new testdata for each variety.

ALFALFA LEAF AND STEMDISEASESAlthough leaf and stem diseases occur in

almost every alfalfa field, their severity isdependent on periods of wet weatherand/or heavy dews. Although leaf andstem diseases may reduce alfalfa yields,their main effect is reducing the nutritionalvalue of the forage. Severe leaf disease cancause excessive leaf drop—the leaves ofalfalfa plants contain much more proteinand are more digestible than the stems.Except for anthracnose, alfalfa varieties

have not been characterized for reaction toleaf and stem diseases. While there are noalfalfa varieties available with documentedresistance, observations indicate that vari-eties differ in reaction to leaf-infectingpathogens. An important cultural practicethat can minimize losses due to leaf andstem diseases is harvesting the crop at thebud stage or no later than 10% flower.Many leaf diseases increase dramatically

Table 4-11. Probability and occurrence of alfalfa diseases in stands ofdifferent ages

—Harvest (established stand)— —————————Year——————————Disease 1st 2nd 3rd 4th Seeding 1st 2nd 3rd 4th

Anthracnose —a ++ +++ ++ ++ +++ +++ +++ +++Aphanomyces root rot ++ +++ +++ +++ +++ ++ ++ ++ ++Bacterial wilt + + +++ +++ — + ++ +++ +++Common leaf spot ++ +++ +++ +++ +++ +++ +++ +++ +++Downy mildew +++ + + +++ +++ ++ ++ ++ ++Fusarium crown root rot +++ +++ +++ +++ — + ++ ++ +++Fusarium wilt + ++ +++ +++ — + ++ +++ +++Phytophthora root rot ++ +++ +++ +++ +++ ++ ++ ++ ++Pythium root rot — — — — +++ + + + +Spring black stem +++ ++ — +++ ++ +++ +++ +++ +++Summer black stem — ++ +++ + +++ +++ +++ +++ +++Verticillium wilt +++ + ++ +++ — + ++ +++ +++aProbability of occurrence and/or severity: —= none, + = low, ++ = moderate, +++ = high.


184

PERENNIALWEEDS

STORED

GRAININSECTS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

diseasesSO

YBEANCO

RNPRINCIPLES

OF

PESTMNGM

T.

after the first flower stage. Also, leaf andstem diseases can be more severe whenalfalfa is seeded with a companion crop.Leaf diseases common to Wisconsin arecommon leaf spot, downy mildew, Stem-phylium leaf spot and Lepto leaf spot.Spring black stem and summer black stemresult in leaf loss, but, as their names imply,are diseases of stems and crowns. Anthrac-nose is a disease of stems and crowns.

ALFALFA SEEDLING DISEASESStand establishment failure due to

seedling diseases has become more com-mon in Wisconsin. Aphanomyces, Pythium,Phytophthora, and Rhizoctonia are the soilfungi considered to be major causes. Seed-ing failures are more commonly reported infields with soils that become waterloggedfor 7 to 14 days. In addition, many reportsare associated with direct seeding. How-ever, this may be because the developmentof plants established by direct seeding aremore easily monitored than plants seededwith a companion crop such as oat. Oftenseeding failures are blamed on the compan-ion crop from such factors as lodging.Phytophthora/Aphanomyces-resistant

alfalfa varieties are available and should beplanted in fields that periodically havewaterlogged soils. Alfalfa varieties rangefrom highly susceptible to highly resistantto Phytophthora and Aphanomyces. Noinformation is available on variety reac-tions to Pythium and Rhizoctonia. Fungi-cides offer some control in the earlyseedling phase (table 4-12).

ALFALFA ROOTAND CROWN DISEASESRoot and crown diseases play a major

role in establishment and stand longevityproblems in Wisconsin. Often, low soil fer-tility, winter injury, and soil insects worktogether with disease organisms to reducealfalfa stands. Stand losses can be mini-mized by planting varieties that are resis-tant to several diseases and using cropmanagement practices that minimize stresson stands. Crop rotation is of little value forcontrol of most alfalfa diseases becausemost pathogens survive indefinitely in thesoil or are introduced with forage debris inseed. However, good management prac-tices can prolong the productivity and lifeof plants that survive the initial infection.1. Select disease-resistant varieties. ConsultExtension publication Perennial ForageVariety Update for Wisconsin (A1525) forspecific ratings.

2. Maintain good soil fertility to promoteextensive lateral root developmentabove the diseased region of the rootand to extend the life of the plant.

3. Avoid untimely cuttings that might stressthe plants. Heavy rains immediatelyafter cutting often result in severe PRRinfections. Do not cut, for example,between September 1 and October 15.

4. Control leaf-feeding insects, which canstress plants making them more suscep-tible to root and crown diseases.

5. Improve surface and subsurface drainageby tilling and land-leveling, if practical,to reduce root and crown diseases.

Table 4-12. Products registered for disease control in alfalfa seedlings andother forage legumes

PathogensFungicide Product formulations controlled Comments

captan many Pythium, Protects against seed rot.Phytophthora,Rhizoctonia

mefenoxam Apron XL LS (seed treatment) Pythium, Systemic activity protects againstRidomil Gold EC Phytophthora seed rot and early seedling blight.(soil application at planting)

thiram many Pythium, Protects against seed rot.Phytophthora,Rhizoctonia


185

FORAGES

&PASTURES

diseasesSTO

REDGRAIN

INSECTSPERENNIAL

WEEDS

SMALL

GRAINSAPPENDIX

SOYBEAN

CORN

PRINCIPLESOF

PESTMNGM

T.

Bacterial wiltBacterial wilt often appears in the second

or third year of the stand and can reducestands considerably if susceptible varietiesare grown. Fortunately, most alfalfa vari-eties have good resistance to bacterial wilt,but this can differ greatly among varieties.

Fusarium wiltFusarium wilt, caused by the fungus

Fusarium oxysporum f. sp. medicaginis, is eco-nomically damaging throughout Wiscon-sin, but is especially a problem in sandyloam soils.Because the pathogen survives indefi-

nitely in the soil, crop rotation is not aneffective control. Planting resistant alfalfavarieties is the only practical control. Manyvarieties have resistance to Fusarium wilt.

Verticillium wiltThe Verticillium wilt fungus invades the

plant’s vascular system and reduces theflow of water and nutrients to stems andleaves. Infected alfalfa plants may be killedduring the growing season or over winter.Verticillium wilt becomes more apparentafter the second year of a stand. It is impor-tant for growers and agricultural consul-tants to be able to recognize Verticilliumwilt and to use methods to limit its spread.The following measures minimize the

chances of introducing the fungus to anarea and spreading the disease betweenand within fields.1. Resistant varieties.Alfalfa varieties dif-fer in reaction to Verticillium wilt. Care-fully select alfalfa varieties with resistanceto the prevalent diseases in your area.

2. Harvesting suggestions: (a) harvest recentseedings first and (b) harvest fields atthe hard-bud or early flower stage.Early harvest can limit some yield andquality losses caused by Verticilliumwilt and can slow the spread of the wiltfungus in a field.

Phytophthora root rotPhytophthora root rot (PRR) is a major

cause of alfalfa stand depletion. PRR cankill individual plants scattered throughoutthe field, all plants in irregularly shapedpatches, or entire fields. The disease is mostsevere in fields with poor internal drainageor fields where soils become saturated byexcessive rainfall or irrigation.

Alfalfa varieties with high levels of PRRresistance are available to Wisconsin grow-ers. Growers should be aware that alfalfavarieties rated PRR resistant vary greatly inextent of resistance.PRR is often most severe in the seeding

year. Seeding failures often occur if suchfields are immediately replanted; occasion-ally alfalfa varieties with some level ofresistance can fail in the seedling stage ofgrowth. Apron (fungicide) seed treatmentsupplements inherent resistance to PRR.

Aphanomyces/Phytophthoraroot rot complexAphanomyces is an important water mold

fungus contributing to poor alfalfa estab-lishment and growth in wet soils.Aphanomyces interacts with Phytophthora tocause a destructive disease complex. Resis-tance to both pathogens is needed toimprove alfalfa production in many wetsoils in Wisconsin.Aphanomyces causes poor plant growth,

stunting and yellowing, but seldom killsplants. Roots may be somewhat yellow andlack laterals and nodules, but it does notcause distinct root lesions like Phytophthoradoes. When diagnosing, check culturalpractices such as seed bed preparation, Rhi-zobium inoculum, and planting depth. Ifyou’ve eliminated cultural practices andyou answer yes to the following questions,then Aphanomycesmay be the cause.—Have you eliminated a possible

atrazine or other herbicide carryover?—Does red clover or trefoil grow well in

the site?—Did you plant a variety with a high

level of resistance to Phytophthora, and was ittreated with mefenoxam (Apron) fungicide?Soils may be tested for Aphanomyces

potential through your county Extensionagent, or by the Plant Disease DiagnosticClinic, Room 283, Russell Labs, Universityof Wisconsin-Madison, Madison, WI 53706.Submit a representative 1 pint soil sample,along with a $30 fee to cover costs of theassay. The test requires 2 weeks to complete.Alfalfa varieties are available with com-

bined resistance to Aphanomyces and Phy-tophthora root rots. Consult Extensionpublication Perennial Forage Variety Update(A1525) for reported resistance of alfalfavarieties to Aphanomyces and Phytoph-thora root rots. Note, though, that race 2 of


186

PERENNIALWEEDS

STORED

GRAININSECTS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

diseasesSO

YBEANCO

RNPRINCIPLES

OF

PESTMNGM

T.

Aphanomyces is present in Wisconsin. Mostvarieties rated as resistant to this diseaseare resistant to race 1, not race 2. However,race 2-resistant alfalfa varieties are becom-ing available, with more being developed.

General root and crown rotAgeneral root and crown rot is caused by

a complex of fungi that persist in the soil;infection results in slow regrowth andstand decline. The disease is very commonin older stands but can occur in poorlymanaged younger stands. Although theoutside of infected roots may not exhibitmuch rot, the core of the root and crowntissues will be rotted and have a brown-black discoloration. Infected plants aremore susceptible to attack by other diseasesand winter injury. Alfalfa varieties that arerated to have good winterhardiness gener-ally show less root and crown rot. Crownand root rot can be reduced in all alfalfavarieties by maintaining high soil fertility(especially potassium), a soil pH of 6.8 to7.0, controlling leaf diseases, and not over-grazing or cutting stands between Septem-ber 1 and October 15.

RED CLOVER DISEASESRed clover, like alfalfa, has diseases that

attack leaves, stems, and roots, reducingyield, quality, and stand life. The prevalentleaf and stem diseases can be controlled byplanting resistant or tolerant varieties. Cut-ting the crop at late bud or early bloom alsocan help minimize leaf and stem diseases.Root rots of red clover cause depletions ofstands. Stand decline can be reduced byplanting varieties with good winterhardi-ness and maintaining high soil fertility(especially potassium).

Crown and root rotsCrown and root rots can cause serious

stand decline in red clover. Several soilfungi can be the cause of this problem.Infected plants often are stunted or wilted.The roots of these plants are rotted (darkbrown-black) on the outside and in the cen-tral core of the plants. The disease is mostdamaging when the rot progresses into thecrown. Infected plants are prone to winter-kill. Winter injury in turn can lead to severeroot and crown rot. Varieties such as Arling-ton or Marathon that have good resistanceto northern anthracnose and powdery

mildew are strongly recommended. Suchresistance also increases winter survival,making them better able to combat theeffects of root and crown rot. Root and crownrot also can be reduced by maintaininggood soil fertility (especially potassium).

Northern anthracnoseNorthern anthracnose can reduce yields

and quality of red clover in stands of allages. Resistant varieties are available.

Powdery mildewPowdery mildew forms a white powdery

mass of mold on the upper surface of theleaves. Most newer varieties are resistant topowdery mildew.

VirusesViruses in red clover are recognized by a

green-and-yellow mosaic pattern thatdevelops on leaves. Viral symptoms can beconfused with symptoms of nutrient defi-ciencies. Red clover varieties differ in reac-tion to bean yellow mosaic virus. Reactionto other viruses is not known.

DISEASES OFFORAGE GRASSESCommon diseases of forage grasses are

leaf rust, stem rust, leaf spot, and root rot.Rusts are recognized by round, brightorange pustules that rupture the leaf tissues(leaf rust) or oblong, reddish-brown pus-tules that rupture stem tissues (stem rust).Leaf spot diseases differ from the rusts inthat they do not rupture the plant tissues.Most leaf spots are characterized by brownto black spots that are bordered by a yellowhalo. Root rots cause brown to black rootsthat are reduced in number and size. A dis-ease called ergot can develop in the headsof forage grasses. Long, hard, black fungalstructures are scattered in the heads andreplace the grain where they form. Theseergot bodies can cause health problems ifconsumed by livestock.Ergot can be reduced by cutting forage

grasses early and clipping wild grassesalong the edges of fields. Rust and leaf spotdiseases can be reduced by harvesting thecrop as early as possible and planting resis-tant or tolerant varieties. Consult Extensionpublication Perennial Forage Variety Updatefor Wisconsin (A1525) for variety reactionsto diseases.


STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNPRINCIPLES

OF

PESTM

NGMT.

SMALL GRAINS PEST MANAGEMENT

5

A3646/09, V. Small Grains (6.5) 10/14/08 4:50 PM Page 187

SMALL GRAINS WEED MANAGEMENT

A sound weed management programoften uses supplementary mechanicalweeding to maximize the effectiveness ofan herbicide treatment. However, smallgrains are sown in narrow rows, makingcultivation after planting impossible. Con-sequently, cultural practices such as croprotation, adapted varieties, adequate fertil-ization, crop competition, and clean seedwill maximize weed control. Fewer herbi-cide alternatives are available for weed con-trol in small grains than for most othercrops. Therefore, the small grain producermust use all possibilities in an integratedapproach for effective weed management.

Fall-seeded small grains are very compet-itive with weeds. Winter wheat, for exam-ple, seldom needs an herbicide treatment.The exception is with winter annual weedslike shepherd’s purse and pennycress thatemerge with wheat in the fall. Check fieldsregularly after seeding and be ready to treatif and when needed.

Many producers apply nitrogen to winterwheat and often ask about using liquid fer-tilizer as the carrier to simultaneouslyapply the herbicide. This “weed and feed”approach would save a trip over the field,but has two serious limitations. First, nitro-gen is most effective when applied early inthe spring, often before green-up, whilemost herbicides are applied betweenFeeke’s stages 4 and 8. Postponing the fer-tilizer application creates a major delay thatwill reduce small grain yield. The otherconcern is that liquid fertilizers applied atthese growth stages may result in leaf burnto the cereal, especially if applied underhot, humid conditions. This risk is particu-larly high for herbicides like Harmony thatrequire a surfactant in the spray solution.Thus, we discourage applying herbicides inliquid fertilizer in small grains.

It’s important to measure the growth stageof cereals before using postemergence herbi-cides. Figure 5-1 shows this relationshipand includes the Feeke’s scale which givesa numerical value to 11 developmentalstages.

For a summary of harvest and grazingintervals following herbicide use in smallgrains, refer to table 5-2.

SMALL GRAINS WITH A LEGUME SEEDING

Spring-seeded small grains often havealfalfa seeded with them. This greatly limitsthe use of herbicides. If weeds are abun-dant, harvesting the small grain as silage isan excellent practice because it kills weedsbefore they produce seeds, harvests weedswhile they still have relatively good feedvalue, and greatly increases the likelihoodof successfully establishing the legume.Interest in frost-seeding red clover intowinter wheat is growing in Wisconsin. Aswith alfalfa seeded into oats, weeds areusually not an important factor after frostseeding, but in situations where broadleafweeds are abundant, two herbicide optionsare available.

Buctril (bromoxynil)Rate: 1.0 to 1.5 pt/a (consult the label to

determine rate for specific weed species).Adjuvants: Do not add surfactants or

other additives to the spray mixture.Timing: Postemergence—Treat when small

grains have several leaves and up to theboot stage, when alfalfa has at least four tri-foliate leaves, and when weeds are small.

Remarks: This product can be used insmall grains alone or with an underseedingof alfalfa but not on red clover or any otherlegume. Buctril controls many broadleafweeds that may occur in companion cropseedings, particularly shepherd’s purse,pennycress, wild mustard, and wild radish.

188

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

weeds

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNPRINCIPLES

OF

PESTM

NGMT.


STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

weeds

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNPRINCIPLES

OF

PESTM

NGMT.

189

Figure 5-1. Herbicide application periods at various growth stages of small grains(using Feeke’s scale) Adapted and used with permission from Michigan State University Extensionpublication Weed Control Guide for Field Crops (E-434)

l l l l l l l l l l l l l1 2 3 4 5 6 7 8 9 10 10.1 10.5 11

FEEKE’S SCALE

SEEDLING ——————TILLERING—————— ——————STEM EXTENSION—————— —HEADING— RIPENING

————jointing———— ——boot——

flowering

last leafjustvisiblesecond

nodevisiblefirst

nodeof stemvisible

leafsheathsstronglyerected

leafsheathslengthentillers

formedtilleringbeginsone

shoot

winterdormant

MCPA, 2,4-D

Banvel/Clarity

Harmony Extra & Harmony (oats)Affinity BroadSpec (oats)

Orion

Harmony Extra & Harmony (wheat & barley)Huskie (wheat & barley)

Affinity BroadSpec (wheat)

Starane

Buctril

Stinger

Rage D-Tech

ligule oflast leafjust visible

in“boot”


STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

weeds

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNPRINCIPLES

OF

PESTM

NGMT.

190

Cereals registered B,W B,O,W All O B,O,W B,O,W B,W All B,O,W All B,O,W All AllMode of action group 2 4 6 27 2 2 6, 27 4 2, 4 4, 14 4 4 4Can be underseeded? No No Alfalfa No No No No Alfalfa, No No No No No/Yesa

red cloverCereal crop tolerance G/E F/G G G/E G/E G/E G/E G G G G/E E GAnnual grass weeds N N N N N N N N N N N N NAnnual broadleaf weeds

Common chickweed G G P G G F G/E F G P G P FCommon ragweed G G G F/G G F G G G F G/E G/E G/EGiant ragweed P G F/G F/G P P G G F F — G/E GLambsquarters G/E G/E G/E E G/E E E G G G/E P N EPennycress E F G E E E E E G E F/G P EPigweed E G/E F/G E E E G/E G G E P N EPrickly lettuce G G F — G F G/E G/E F G G G/E G/EShepherd’s purse E F E E E E G/E E G G — P ESmartweeds G G/E G E G G G/E P G F — F PWild buckwheat G G/E G/E P G F G/E F G F F/G F/G FWild mustard E F G G E E G/E G/E G G F/G N G/EWild radish F/G F G — F/G F G/E G/E — G — N G/E

Perennial broadleaf weedsCanada thistle G F P P G P F F P P P G/E FField bindweed P F P P P P F F P F F/G P FPerennial sow thistle F F/G N — F P G F F F P F F

Abbreviations

Cereals registered: B=barley, O=oats, W=wheatControl ratings: E=excellent, G=good, F=fair, P=poor, N=none, — = no information

aSome brands of 2,4-D amine allow application in underseeded small grains. We do not recommend it because the risk of legume injury is very high.

Apply Buctril in at least 20 gal/a of water.Applications of Buctril to underseeded oatsmay result in serious alfalfa injury if thetemperature on the day of application or inthe 3 days after application exceeds 70°F.Temperatures above this limit will be morelikely to cause serious injury if the relativehumidities are high on the day of treat-ment. See additional comments on Buctriluse in the following section, “Small GrainsWithout a Legume Seeding.”

MCPARate: Apply 0.33 to 0.5 pt/a of MCPA

amine (forms containing 4 lb acidequiv/gal). When using products contain-ing other than 4 lb acid equiv/gal, adjustrates accordingly to apply 0.17 to 0.25 lb/aacid equivalent.

Adjuvants: Do not add surfactants orother additives to the spray mixture.

Timing: Postemergence—Treat when smallgrain is tillered and has four or more leavesbut before the jointing stage. The legumeshould be 2 to 3 inches tall.

Remarks: Never use the ester formula-tions of MCPA in companion crop seedingsas the legume will be killed. Legume standsof alfalfa; trefoil; or red, alsike, white, or

Table 5-1. Crop registration,tolerance, and herbicideeffectiveness on weedscommonly found insmall grains Affin

ityBro

adSp

ec

Banvel/

Clarit

y

Buctril

Callis

to

Harmon

y Extra

Harmon

y

Huskie

MCPA am

ine

Orion

Rage D-Tech

Starane

Sting

er

2,4-Damine


ladino clover are usually not severelyinjured at this rate or time of application.MCPA amine labels caution that the prod-uct should not be used unless some legumeinjury can be tolerated. Some brands ofMCPA do not carry label directions for useon small grain undersown with a smallseeded legume. Using brands without labeldirections for this use is illegal.

A well-developed small grain and weedcanopy of leaves is necessary to provide aprotective “umbrella” over the legumeseedlings to minimize herbicide contactwith the legume. Sometimes, under idealgrowing conditions, legume seedlings growalmost as rapidly as the small grain andsuch a protective canopy never develops.Do not apply MCPA when legumeseedlings are as tall or nearly as tall as thesmall grain or when the oat and weedcanopy does not cover the alfalfa seedlings.Excessive exposure to the herbicide treat-ment will almost certainly result in severelegume damage. Use less than 6 gal/a ofwater and low pressure when applyingMCPA to reduce risk of legume injury.Broadleaf weeds are more easily controlledas seedlings than when they begin toflower.

Buctril vs. MCPAThe factors to consider in choosing

between these two products are tempera-ture and relative humidity at and after timeof treatment, degree of protection to thelegume by the small grain and weedcanopy, the specific weed species present,and the growth stage of the alfalfa andcereal. For example, Buctril is most indi-cated when lambsquarters, smartweeds orwild buckwheat are present, temperaturesare 70°F or less, and alfalfa has 4 or moretrifoliate leaves. MCPA would be the betterchoice if pigweed is the dominant weed,temperatures exceed 70°F, humidities arehigh, and the oats and weeds protect thealfalfa seedlings.

SMALL GRAINS WITHOUT A LEGUME SEEDING

Affinity BroadSpec (Harmony + Express premix)

Rate: Use 0.4 to 1.0 oz/a in wheat orbarley; 0.4 oz/a in oats. Rates of 0.4 to0.6 oz/a must be tank-mixed with otherherbicides.

Adjuvants: Add nonionic surfactant at2 pt/100 gal of spray solution. See label forsurfactant rates when mixing other herbi-cides with Affinity BroadSpec. Ammoniumsulfate at 2 lb/a or 2 qt/a of nitrogen fertil-izer may also be added.

Timing: Postemergence—Apply from the2 leaf stage, but before the flag leaf is visi-ble in wheat and barley. Apply from the3 leaf stage but before the jointing stage inoats.

Weeds: Treat annual weeds before theyare 4 inches tall or wide. Treat 4- to 8-inchCanada thistle in the spring.

Remarks: Affinity BroadSpec is a premixof a 1:1 ratio of Harmony and Express,which provides a higher rate of Expressthan in Harmony Extra. Affinity BroadSpeccontrols many species of mustards, includ-ing wild mustard, shepherd’s purse, andpennycress, and also pigweed, lambsquar-ters, henbit, and smartweeds. Wild buck-wheat should be controlled with a 0.8 oz/arate. Common ragweed control is inconsis-tent and giant ragweed is not adequatelycontrolled. To ensure adequate control ofcommon ragweed, tank-mix with 2,4-D.When treating Canada thistle, tank-mix0.8 oz/a with 2,4-D or dicamba. Buctril andStarane are also labeled for tank mixtures.2,4-D is a likely partner as Affinity Broad-Spec will improve wild buckwheat andsmartweed control compared to 2,4-Dalone. The effect of Affinity BroadSpec onweeds is rapid, but symptoms appearslowly, especially if cool weather followsapplication.

Apply in at least 5 gal/a of water withflat fan nozzle tips and in at least 10 gal/awith flood jet tips. Nitrogen fertilizer maybe used as the carrier instead of water.Allow at least 45 days following applica-tion before harvest. Do not feed forage orhay to livestock. Straw from treated smallgrains may be used for bedding or feed.

191

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

weeds

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNPRINCIPLES

OF

PESTM

NGMT.

ne


Rotational restrictions: Wheat and barleycan be replanted anytime after application,soybeans can be planted after 7 days, andcorn can be planted after 14 days. Anyother crop can be planted 45 days after anapplication of Affinity BroadSpec, exceptcanola or beets, which require a 60-dayinterval.

Banvel/Clarity See dicamba (this page).

Buctril (bromoxynil)Rate: Apply 1.0 to 1.5 pt/a.Adjuvants: Do not add surfactants or

other additives to the spray mixture.Timing: Postemergence—Base timing on the

stage of weed growth but do not treat smallgrains in or beyond the boot stage.

Weeds—Apply when weeds in winterwheat have no more than 8 leaves or whenweeds in spring-seeded cereals have4 leaves and when weeds in either seedingtime are no more than 2 inches tall.

Remarks: Buctril controls manybroadleaves commonly found in smallgrains, especially shepherd’s purse, penny-cress, lambsquarters, wild radish, wildmustard, and yellow rocket seedlings. Thistreatment only controls seedling weedswhen spray coverage is thorough and uni-form. It will not control perennial weedslike Canada thistle. Apply Buctril with flatfan nozzles using at least 10 gal/a of waterand 30 psi pressure.

Buctril can be applied to wheat, barley,rye, and oats and tank-mixed with MCPAor 2,4-D for any of these cereals. It can betank-mixed with dicamba, Express, or Har-mony Extra only for use in winter andspring wheat. Do not apply if crops areunder stress or if the weeds are protectedby a crop canopy. Treated areas cannot begrazed for 45 days.

Rotational restrictions: Corn can beplanted anytime after Buctril application.Other crops can be planted the followingyear.

Callisto (mesotrione)Rate: 6 oz/a preemergence or 3 oz/a

postemergence.Adjuvants: For postemergence applica-

tions, add crop oil concentrate at 1% ornonionic surfactant at 0.25%. The additionof 28% nitrogen solution at 2.5% or ammo-nium sulfate at 8.5 lb/100 gal may increaseweed control, but may increase the risk ofinjury.

Timing: Preemergence—Apply after plant-ing oats and before weed emergence.

Postemergence—Apply to oats beforeweeds exceed 5 inches in height. Do notapply within 50 days of harvest.

Remarks: Callisto has a supplementallabel allowing these applications. Callistocontrols many annual broadleaf weeds andcannot be used on oats underseeded withalfalfa. A preemergence application shouldprovide greater crop safety than postemer-gence applications. Tank-mixing emulsifi-able concentrate formulations of other pes-ticides with postemergence applications arenot recommended because of the risk ofinjury. Only one Callisto application can bemade per year.

Rotational restrictions: Small grains can beplanted 120 days after application. Alfalfa,soybeans, potatoes, and tobacco can beplanted after 10 months. Other crops can-not be planted until 18 months after treat-ment.

DicambaRate: Apply 2 to 4 oz/a of either Banvel

or Clarity in wheat or spring oats; 2 to3 oz/a in spring barley.


Timing: Postemergence—Apply to winterwheat in spring after winter dormancy andbefore joint stage or to spring-sown wheat oroats in the 2- to 5-leaf stage, and to spring-seeded barley in the 2- to 4-leaf stage.

Weeds—Treat when weeds are in the 2- to3-leaf stage and rosettes are less than 2inches across.

Remarks: Carefully monitor crop develop-ment and treat only at recommendedgrowth stages. Later application may injuresmall grains and reduce yield. Dicambacontrols many broadleaf weeds and is par-ticularly effective on smartweed and wildbuckwheat. This herbicide will also kill

192

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

weeds

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNPRINCIPLES

OF

PESTM

NGMT.


legumes—never use it on small grainundersown with a legume seeding. Sincemost of Wisconsin’s small grain is grownwith an undersown legume, use of dicambaor dicamba combinations in small grain(especially oats) will be very limited.

Dicamba is weak on weeds in the mus-tard family and very effective on wildbuckwheat and smartweed. Dicamba canbe tank-mixed with 2,4-D, MCPA, Buctril,Express, or Harmony Extra in winter wheatand winter barley to broaden the spectrumof weeds controlled. In spring-seeded bar-ley, Buctril, Express, Harmony Extra, orMCPA can be tank-mixed with dicamba; inspring-seeded oats, only MCPA can betank-mixed with dicamba. Oats are moretolerant to dicamba than wheat and barley.Do not treat barley unless some injury isacceptable.

Crop staging and proper application tim-ing are critical to avoid injuring smallgrains with dicamba. Do not use even lowrates of dicamba after the small grain hasdeveloped beyond the recommendedgrowth stage. Be particularly cautious withearly developing wheat varieties like Madi-son and Wakefield.

Rotational restrictions: Corn can beplanted anytime after dicamba application.Other crops can be planted after harvest.

Harmony Extra SG (Harmony SG + Express premix)

Rate: Use 0.45 to 0.9 oz/a in wheat andbarley; 0.45 to 0.6 oz/a in oats. (Rates ofnew Harmony Extra SG are 50% higherthan the original Harmony Extra.)

Adjuvants: Add a nonionic surfactant at2 pt/100 gal of spray solution. See label forsurfactant rates when mixing other herbi-cides with Harmony Extra.

Timing: Postemergence—Apply HarmonyExtra to wheat or barley with 2 leaves butbefore the flag leaf is visible. Treat oats afterthe crop has 3 leaves but before the jointingstage.

Weeds—Treat annual weeds after emer-gence and before they are 4 inches tall orwide; treat 4- to 8-inch Canada thistle in thespring.

Remarks: Harmony Extra, a premix ofHarmony SG and Express, controls manyspecies of mustards, including wild mus-tard, shepherd’s purse, pennycress, and

wild radish, and also pigweed, lambs-quarters, henbit, kochia, and smartweed.Common ragweed control is inconsistentand giant ragweed is not adequately con-trolled. To ensure adequate control of wildradish or common ragweed, mix BuctrilMCPA, or 2,4-D with Harmony Extra.When treating Canada thistle, mix 2,4-Dwith Harmony Extra. If appropriate,dicamba can also be tank-mixed with Har-mony Extra.

Do not apply more than 0.6 oz/a of Har-mony Extra to oats, nor more than 0.9 oz/ato wheat and barley. Small grain varietiesvary in tolerance to Harmony Extra. Do notuse this product in the oat varieties Ogle,Porter, or Premier.

Apply Harmony Extra in at least 5 gal/aof water with flat fan nozzle tips and in atleast 10 gal/a with flood jet tips. Nitrogenfertilizer may be used as the carrier insteadof water. Follow label instructions carefullyto prevent drift and to properly clean thesprayer after treatment. Tank mixes withdicamba may reduce control of somebroadleaf weeds and combinations withBuctril may reduce Canada thistle control.Do not harvest within 45 days of applica-tion. Do not graze or harvest small grain forsilage. Straw from treated small grains maybe used for bedding or feed.

Rotational restrictions: Any crop can beplanted 60 days after applying HarmonyExtra.

Harmony SG (thifensulfuron)Rate: Use 0.45 to 0.9 oz/a in wheat and

barley; 0.45 to 0.6 oz/a in oats.Adjuvants: Add a nonionic surfactant at

1 to 2 pt/100 gal of spray solution. See thelabel for surfactant rates when tank-mixingwith other herbicides.

Timing: Postemergence—Apply Harmonyafter wheat or barley is in the 2-leaf stagebut before the flag leaf is visible; treat oatswhen the crop is in the 3-leaf stage butbefore jointing.

Weeds—Treat when broadleaf weeds are 1to 4 inches tall.

Remarks: Harmony controls several com-mon annual broadleaves in winter wheat,barley, and oats. These include most weedsin the mustard family, pigweed, lambsquar-ters, chickweeds, smartweeds, mayweed,pineappleweed, and annual sowthistle. Ifmixed with other herbicides, it controls

193

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

weeds

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNPRINCIPLES

OF

PESTM

NGMT.


prickly lettuce and wild radish. Harmonycan be tank-mixed with 2,4-D, dicamba, orBuctril to broaden the spectrum of weedscontrolled. Small grain varieties vary insensitivity to Harmony; do not use thisproduct on the oat varieties Ogle, Porter, orPremier. Do not apply Harmony when thecereals are under environmental stress. Pro-longed cool weather or wide fluctuations intemperatures before, during, and afterapplication may result in temporary yel-lowing or crop stunting. The risk of cropinjury is greatest when the cereals are in the2- to 5-leaf growth stages.

Apply Harmony in 10 to 20 gal/a ofwater. Nitrogen fertilizer may be used asthe carrier instead of water. Read the labelfor instructions on using a fertilizer carrierand on cleaning the sprayer followingapplication.

Rotational restrictions: Wheat, barley, oats,and field corn may be planted anytime afterapplying Harmony. Any other crop may beplanted 45 days after application.

Huskie (pyrasulfotole + Buctril +safener premix)

Rate: 11 to 15 oz/a (11 oz/a is the stan-dard rate).

Adjuvants: Add 0.5 to 1 lb/a ammoniumsulfate or 1 to 2 qt/a of 28% nitrogen solu-tion. Nonionic surfactant at 0.25% may beadded if required by a tank-mix partner.

Timing: Postemergence—Apply from 1 leafup to flag leaf emergence.

Weeds—Treat actively growing weedsbefore they have more than 4 to 6 leaves orare more than 4 inches in diameter.

Remarks: Huskie controls many annualbroadleaf weeds and will suppress someperennial broadleaf weeds in wheat andbarley. If needed, Huskie can be tank-mixedwith other small grain herbicides. ApplyHuskie in 10 or more gallons of water peracre to achieve thorough spray coverage asthese ingredients primarily have contactactivity. Nitrogen fertilizer may be used asthe carrier instead of water when winterwheat is treated. Huskie is rainfast in1 hour. Do not graze or harvest forage for25 days after application or harvest grainfor 60 days after application.

Rotational restrictions: Small grains can bereplanted 7 days after application; soy-beans after 4 months; and alfalfa, drybeans, corn, and potato after 9 months. Afield bioassay is required before plantingcrops not listed on the label.

MCPARate: Apply 0.5 to 1.0 pt/a of MCPA

amine or MCPA ester (formulations con-taining 4 lb acid equiv/gal).


Timing: Postemergence—Apply in springafter grain has four leaves and before joint-ing stage. Do not apply in boot to doughstage.

Remarks: Apply MCPA when small grainis fully tillered (usually 4 to 8 inches tall).The risk of crop injury increases as the rateincreases. Apply MCPA with a minimum of10 gal/a of water. MCPA amine is solublein water while MCPA ester is an emulsifi-able concentrate. MCPA is sold under vari-ous trade names and at various concentra-tions of acid equivalence. Be sure to readand follow the guidelines on the label foryour brand of MCPA as there are oftenlabeling differences between manufactur-ers. Wheat, barley, oats, and rye grain fromfields treated with MCPA may be used forany purpose.

Rotational restrictions: The label gives noinformation on planting rotational crops.

Orion (florasulam + MCPA premix)Rate: 17 oz/a.Adjuvants: The addition of 0.2% nonionic

surfactant is suggested. Timing: Postemergence—Apply from 3-leaf

stage up to jointing. Applications fromjointing until boot stage may cause injury.

Weeds—Treat actively growing weedswhen 1 to 4 inches tall.

Remarks: Orion is labeled to control manymustards such as shepherd’s purse, fieldpennycress, and wild mustard as well ascommon chickweed, lambsquarters, pig-weed, common ragweed, wild buckwheat,and smartweeds. Apply in 8 or more gal-lons per acre. Orion is rainfast in 4 hours.Treated small grains can be grazed in 7 days.

194

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

weeds

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNPRINCIPLES

OF

PESTM

NGMT.


Rotational restrictions: Small grains can beplanted 14 days after application; corn canbe planted after 3 months; alfalfa, drybeans, potatoes, and soybeans can beplanted after 9 months; all other crops canbe planted after 12 months.

Rage D-Tech (Aim + 2,4-D premix)Rate: Apply 8 to 16 fl oz/a. Adjuvants: Add a nonionic surfactant at

0.25%. Ammonium sulfate at 2 to 4 lb/a ornitrogen fertilizer at 2 to 4 gal/100 gal ofspray solution may be added.

Timing: Postemergence—Apply Aim tosmall grains from 3-tillers to before jointing.

Weeds—Treat weeds before they exceed 4to 6 inches in height.

Remarks: Rage D-Tech controls manyannual broadleaf weeds such as lambsquar-ters, pigweed, and several mustard specieslike field pennycress, shepherd’s purse, andwild mustard and will suppress wild buck-wheat. Thorough coverage is important forcontrol. Rage D-Tech may be tank-mixedwith other herbicides. Rage D-Tech con-tains the ingredient in Aim, which is a con-tact herbicide and often causes speckling ofcrop leaves. Do not apply if small grainleaves are wet from dew or rain becauseinjury will be more severe.

Rotational restrictions: Most field cropscan be planted after 30 days. Many veg-etable crops should not be planted for 12months.

Starane (fluroxypyr)Rate: 0.67 pt/a.Adjuvants: Do not add surfactants or

other additives to the spray mixture.Timing: Postemergence—Apply Starane to

actively growing wheat, oats, or barleyfrom the 2-leaf growth stage up to andincluding flag leaf emergence. Treat at least40 days before harvest.

Weeds—Treat actively growing annualweeds before they exceed 8 inches inheight; treat hemp dogbane when it is 12 to18 inches tall.

Remarks: Starane controls severalbroadleaf weeds in wheat, oats, and barley.Susceptible species include hemp dogbane,chickweed, kochia, common ragweed, andbedstraw. Starane is particularly effectiveon hemp dogbane; fields with this weedcould be rotated to wheat and treated withStarane to reduce the infestation. This prod-

uct also suppresses pennycress, mustard,wild buckwheat, and field bindweed. Up to1.33 pt/a of Starane could be applied tothese latter weeds but it is probably betterto tank-mix Starane with other broadleafherbicides to improve and broaden thespectrum of control to include additionalweeds. Control will be reduced if weedfoliage is wet at the time of application.Never use Starane in fields underseededwith legumes as they would be killed.Starane is available as an emulsifiable con-centrate with 1.5 lb ae fluroxypyr/gal.

Rotational restrictions: Only wheat, barley,and oats can be replanted sooner than 120days after application. All other crops canbe planted after 120 days.

Stinger (clopyralid) Rate: 0.25 to 0.33 pt/a.Adjuvants: Do not add surfactants or

other additives to the spray mixture.Timing: Postemergence—Apply Stinger to

wheat, barley, or oats between the 3-leafbut before the boot stage.

Weeds—Treat Canada thistle in the rosetteto early bud stage and annual broadleaveswith 2 to 5 leaves.

Remarks: Stinger controls severalbroadleaf weeds in wheat, barley, and oats.It is weak on smartweed and does not con-trol weeds in the mustard family or lamb-squarters. Stinger is labeled for severalweeds in the composite family, includinggiant and common ragweed and Canadathistle. For Canada thistles, use 0.33 pt/aand treat as the cereal reaches the earlyboot stage. Never use Stinger in fieldsunderseeded with legumes. Weeds shouldbe actively growing when treated; do notadd a surfactant or crop oil to the spraysolution. Do not use in fields that will besummer seeded to alfalfa. Also avoid usingin areas where the groundwater is vulnera-ble to contamination due to very permeablesoils and/or a very shallow water table.Stinger can be tank-mixed with Buctril,dicamba, MCPA, or 2,4-D.

Rotational restrictions: Treated fields canbe planted to wheat, barley, oats, grasses, orfield corn anytime after application. Alfalfa,soybeans, dry beans, and sunflowers can beplanted 10.5 months after application. Do notplant other crops within 18 months unlessrisk of some crop injury is acceptable.

195

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

weeds

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNPRINCIPLES

OF

PESTM

NGMT.


196

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

weeds

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNPRINCIPLES

OF

PESTM

NGMT.

2,4-DRate: Apply 1.0 pt/a of 2,4-D amine or

0.67 pt/a of 2,4-D ester (forms containing3.8 lb acid equiv/gal) in wheat, rye, or bar-ley. Apply 0.5 to 1.0 pt/a of 2,4-D amine or0.5 pt/a of 2,4-D ester in oats.


Timing: Postemergence—Treat when cerealsare fully tillered (usually 4 to 8 inches tall)and before the jointing stage; never treat inthe boot or dough stages.

Weeds—Treat when annual broadleavesare 4 inches or less in height.

Remarks: When using forms of these her-bicides containing other than 3.8 lb acidequiv/gal, adjust rates accordingly. Apply2,4-D before the small grain reaches thejointing stage of development. Do not treatgrains in the boot to dough stage.

Susceptible broadleaf weeds are usuallycontrolled by the lower rates, but less sus-ceptible weeds require full dosage.

Smartweed and pennycress are best con-trolled by 2,4-D ester, but amine is lesslikely to injure small grains. 2,4-D aminesare usually water soluble liquids while2,4-D esters are emulsifiable concentrates.2,4-D is sold under various trade namesand at various concentrations of acid equiv-alence. Be sure to read and follow theguidelines on the label for your brand of2,4-D as there are often labeling differencesbetween manufacturers. Wheat, barley,oats, and rye grain from fields treated with2,4-D amine or ester may be used for anypurpose.

Rotational restrictions: Corn may beplanted 7 to 14 days after 2,4-D application;soybeans may be planted after 7 to 30 days;other crops can planted after 3 months.


STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

weeds

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNPRINCIPLES

OF

PESTM

NGMT.

Table 5-2. Harvest and/or grazing restrictions for herbicides registered for use in small grainsa

Interval between Type of application and


Affinity wheat, barley all 45 days Do not graze or feed wheat or barley as BroadSpec forage or silage

Buctril small grains all 45 days Do not harvest summer-seeded alfalfa treated with Buctril until following spring.

Callisto oats all 30 days for grazingor forage; 50 daysbefore harvest

Dicamba small grains non-lactating 0 days Do not harvest hay within 37 days after lactating 7 days treatment.

Glyphosateb small grains, — 7 days Apply only when grain is in hard dough preharvest stage (30% moisture or less)

Harmony Extra/ wheat, barley all 45 days Do not graze or feed wheat or barley as Harmony SG forage or silage.Huskie wheat, barley all 25 days for grazing

or forage; 60 days forgrain or straw

MCPA small grains all — Do not allow livestock to graze treated fields within 7 days of slaughter.

Orion small grains all 7 days for grazing;60 days before harvest

Rage D-Tech small grains dairy or meat 14 days for grazing Do not feed straw to livestock.Starane small grains all 7 days for grazing;

40 days before harvestStinger small grains all 7 days Do not harvest hay from treated grain

fields.2,4-D small grains all 2-week grazing

restrictionsmall grains, all 7 days before Do not feed straw to livestock. preharvest harvest

aLabels may have changed after this table was prepared. Consult current labels to verify the information.bThese are the restrictions on the Roundup and Touchdown labels and several other glyphosate products. Differences exist on some brands of glyphosate. Verify what restrictions apply to your brand before using it.

197


SMALL GRAINS INSECT MANAGEMENT

Insecticides suggested in this section areintended as a guide to assist you in select-ing chemical insect control options duringthe season. This book provides an overviewof product registrations for specific fieldcrop insect pests; it is not intended as anexhaustive insecticide label source. Productinclusion or omission does not implyendorsement by University of WisconsinExtension. Remember, certain insecticidesare produced by different manufacturersand directions for use, rate, and method ofapplication may vary by formulation.Therefore, always read the insecticide labelcompletely before using the material.

Insecticides are often interchangeablyreferred to by their common names andtrade names. Trade names such as Warriorare capitalized, while common chemicalnames, lambda-cyhalothrin in this example,are not.

A number of the products listed in thissection are restricted-use insecticides. Wediscuss restricted-use pesticides in thebeginning of this publication. Refer toappendix table 1 for a list of pesticides thatcurrently require certification to be applied.It is possible that additional insecticideswill be classified before the next growingseason. Contact your county Extensionagent for additional information on insecti-cide restriction.

INSECT PESTS OF SMALL GRAINS

AphidsAphids (primarily greenbug, bird cherry-

oat, and English grain aphid) damageplants indirectly by transmitting barley yel-low dwarf virus (BYDV) and directly bysucking the sap. Light or heavy infestationsof these small (less than 1⁄16 of an inch),green, soft-bodied insects may result insevere red-leaf damage of oats, but onlyheavy infestations cause yellowing and

eventual browning. Once the red-leaf dam-age or yellowing is noticeable, it is usuallytoo late to spray.

These aphids can also infect winter wheatin the fall. Winged, infected aphids fly tothe fields and then transmit the virus to theseedlings as they feed on them. The extentof BYDV infection of Wisconsin’s winterwheat is related to the number of aphidspresent during the summer, the percent ofthe aphid population that carry the virus,and planting date of wheat. The degree ofinfection and subsequent winter kill andyield reduction can be very high in fieldsplanted during August if the numbers ofinfected aphids are high. Delaying plantinguntil September 15 will avoid peak fallaphid flights. Wheat seed treatments of Gau-cho 600 (0.8 fl oz/hundredweight) and Cruiser5FS (0.75 to 1.33 fl oz/hundredweight) arelabeled for early season control of aphids andto reduce the potential spread of BYDV. Donot graze or feed livestock on treated areasfor 45 days after planting. Treated seed maybe obtained from seed dealers and/or seedtreatment service providers.

ArmywormsArmyworms can severely damage small

grain fields. Larvae, resulting from mothflights in late June and early July, cause theproblems. In July, these worms strip leavesand frequently clip off kernels and the headas the crop approaches maturity. By day,they hide on the soil surface and beneathclods. Detecting young larvae requires care-ful searching.

To guard against severe losses, check sev-eral areas of each field carefully. Checkthick lodged areas first because army-worms will often be most numerous here. Ifyou do not find worms in these areas, theodds are good that there are no problems inthe rest of the field. However, check thefield again in several days. If you findarmyworms in the lodged areas, check sev-

198

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

insectsAPPENDIX

FORAGES

&PASTURES

SOYBEAN

CORN

PRINCIPLESO

FPEST

MNGM

T.


199

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

insectsAPPENDIX

FORAGES

&PASTURES

SOYBEAN

CORN

PRINCIPLESO

FPEST

MNGM

T.

eral areas in the rest of the field. Treatmentis suggested if populations average three ormore per square foot.

GrasshoppersOccasionally, grasshoppers are abundant

enough to concern farmers. Insecticide useis not suggested until populations reach20/sq yard in field margins or 8/sq yard insmall grain fields. Apply treatments whilegrasshoppers are still small.

WirewormsWireworms are small (less than 1.5 inches

long), copper-colored larvae that attackunderground stems and kill plants in irreg-ular areas in oat fields. They are a problem

mainly on Spencer loam soils of centralWisconsin. Wheat seed treatments of Gau-cho 600 (0.13 to 0.26 fl oz/hundredweight)and Cruiser 5FS (0.19 to 0.25 fl oz/hundred-weight) are labeled for early season control ofwireworm in wheat. Treated seed may beobtained from seed dealers and/or seedtreatment service providers.

Table 5-4. Insecticide suggestions for small grains (check label for registered crops)


Aphids, Baythroid XL 1.8–2.4 oz Do not apply within 30 days of harvest. For aphids, use higher grasshoppers rate and increased water volume for applications after damage

has occurred. dimethoate 0.5–0.75 pt Labeled for control of greenbug aphids and grasshoppers in

wheat only.malathion 57% EC 1.5–2.0 pt Do not apply within 7 days of harvest. Mustang Max 3.2–4.0 oz Do not apply more than 0.125 lb ai/a per season.Penncap-Mc 2–3 pt Labeled for control of aphids (including greenbugs) and

grasshoppers in wheat, oat, and barley. Do not apply within15 days of harvest or grazing.

Proaxis 2.56–3.84 oz Labeled for wheat only. Do not apply more than 0.03 lb ai(0.48 pt)/a per season. Do not apply within 30 days of harvest.

Sevin XLR Plus 1–3 pt Grasshoppers only. Do not apply within 21 days of harvest forgrain.

Warrior II, 1.28–1.92 oz Do not apply within 30 days of harvest. Do not exceedSilencer 1EC 2.56–3.84 oz 0.06 lb ai/a per season. Best control obtained before aphids

begin to roll leaves. Once crop has started to boot, may pro-vide suppression only. Higher rates and increased coveragewill be necessary.

Armyworm Baythroid XL 1.8–2.4 oz Do not apply within 30 days of harvest. Do not exceed 4.8 oz/a per season.

Mustang Max 1.76–4.0 oz Do not apply more than 0.125 lb ai/a per season.Penncap-Mc 2–3 pt Do not apply within 15 days of harvest or grazing.Proaxis 2.56–3.84 oz Labeled for wheat only. Do not apply more than 0.03 lb ai

(0.48 pt)/a per season. Do not apply within 30 days of harvest.Sevin XLR Plus 2–3 pt For use on wheat only. Do not apply within 21 days of harvest.Tracer 1–3 fl oz Do not exceed 9 fl oz (0.28 lb spinosad) per acre per year. Do

not apply within 21 days of grain or straw harvest, or within14 days of harvest for forage or hay.

Warrior II, 1.28–1.92 oz Do not apply within 30 days of harvest. Do not exceedSilencer 2.56–3.84 oz 0.06 lb ai/a per season.

aAll insecticides in this table are to be applied to the plant foliage.bDo not allow sprays to drift into bee yards or onto adjacent blooming crops or weeds.cMixing Penncap-M (microencapsulated methyl parathion) with emulsifiable concentrates, organic solvents, or some surfactants mayincrease the potential hazard to applicators.

Table 5-3. Treatment thresholds for aphids to preventdirect plant damage (not disease reduction) andsubsequent grain yield loss

English grain aphid or Growth stage oat-bird cherry aphid Greenbug

Seedling 30 aphids/stem 20 aphids/stemBoot to heading 50 aphids/stem 30 aphids/stem


SMALL GRAINS DISEASE MANAGEMENT

Many disease-causing organisms attacksmall grains in Wisconsin. Any approach toplant disease control requires identificationand knowledge of the cause and its lifecycle, the effect of environment on diseasedevelopment, and the potential control pro-cedures available. Economic and environ-mental factors often determine the controlprocedures employed for these various dis-eases. Control strategies can be an integra-tion of the following methods: plantingresistant or tolerant varieties, proper cropmanagement, and agricultural chemicals(mostly fungicides).

Variety selection is key to disease man-agement in small grains. Refer to Extensionpublications Small Grain Varieties for Grainand Forage (A3397) and Wisconsin WinterWheat Performance Tests (A3868) for specificdisease resistance ratings. The publicationis updated each year with new test data foreach variety.

SMALL GRAIN DISEASES

Barley yellow dwarf (red leaf)Barley yellow dwarf of wheat or barley

and red leaf of oat are caused by the samevirus—barley yellow dwarf virus. Infectedwheat or barley plants show yellowedfoliage, stunted plants, and underdevel-oped heads. Infected oat plants also arestunted and have underdeveloped heads,but the foliage becomes red with slight yel-lowing—thus, the common name red leaf.

The barley yellow dwarf virus is trans-mitted by aphids. The virus overwinters inwild grasses and winter wheat; however,inoculum carried in from southern states byaphids appears to be more critical in dis-ease development. Volunteer oat plants,corn, and virus-carrying aphids serve asinoculum for infection of winter wheat inthe fall. Corn is another source of inoculumof the barley yellow dwarf virus.

To control red leaf, choose resistant vari-eties of oat. Most wheat varieties are sus-ceptible. Plant oat, barley, and spring wheatearly to avoid high populations of virus-laden aphids. Delay planting of winterwheat to avoid high aphid populations inthe fall. Generally, winter wheat plantedafter mid-September is less affected by bar-ley yellow dwarf virus. Encourage goodvegetative growth by seeding at appropri-ate rates and by using fertility managementtechniques.

ErgotErgot is an important disease in rye, triti-

cale, wheat and barley, but rare in oat.Some of the grain in an infected head isreplaced with a long, purple black, horn-like fungus structure that may reach 1 inchin length. Ergot causes little or no yield lossbut is toxic if fed to livestock. All varietiesof rye are susceptible. Information is notavailable on barley and wheat varieties.

Leaf rust and stem rustLeaf rust and stem rust occur on all small

grains grown in Wisconsin. Disease severitydiffers each year depending on weather con-ditions, varieties of small grains grown, andprevalent strain(s) of the rust fungi present.Small grain yields can be greatly reduced asa result of severe rust development.

There are several possible ways to controlor reduce rust in small grains. In mostyears, early planting effectively controlsstem rust of oat, and stem rust and leaf rustof spring wheat. Stem rust fungi do notoverwinter in Wisconsin, and inoculummust be introduced from states south ofWisconsin. The wheat leaf rust fungus canoverwinter on winter wheat if the cropdoes not freeze although this situationrarely occurs.

200

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

diseasesAPPENDIX

FORAGES

&PASTURES

SOYBEAN

CORN

PRINCIPLESO

FPEST

MNGM

T.


201

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

diseasesAPPENDIX

FORAGES

&PASTURES

SOYBEAN

CORN

PRINCIPLESO

FPEST

MNGM

T.

Leaf rust (crown rust) of oat survives onbuckthorn bushes; these serve as a sourceof inoculum each spring. Thus, early plant-ing has less of an impact on leaf rust devel-opment on oat. Destruction of buckthornbushes in the vicinity of oat fields can sup-press leaf rust of oat.

Rust diseases of small grains can be effec-tively controlled by planting rust-resistantvarieties. However, new races of the rustfungi frequently develop and infect vari-eties that were formerly resistant. Bewareof rust development in varieties rated asresistant.

Foliar-applied fungicides are registeredfor rust control in small grains (table 5-5).See product label for registered crops, rates,and timing of applications.

Powdery mildewPowdery mildew is caused by the fungus

Erysiphe graminis. White to light gray, powdery patches form on the leaves,sheaths, stems, and floral bracts. Blackspecks (cleistothecia) form in the mildewgrowth as the crop matures. When mildewgrowth is severe, infected leaves wither anddie early. The fungus overwinters on livingand dead plants.

To control powdery mildew, choose resis-tant varieties of small grains. If the diseaseis present on lower leaves and the plantsare reaching the boot stage, apply foliarfungicides (table 5-5).

ScabScab in wheat and barley, in its most con-

spicuous form, is a head blight, recognizedby the premature ripening or bleaching ofone or more spikelets of a grain head anytime after heading. The light yellow colorof diseased regions of a head show in sharpcontrast with the healthy green of theremaining portion of the head. A light pinkor salmon color may appear at the base ofinfected spikelets. Infected kernels are awhite, salmon, or reddish color, are badlyshrunken and wrinkled, and have a notice-ably rough, flaky seed coat. Sometimes thescab fungus girdles the stem below thehead, not allowing the head to develop.Stem tissues immediately below the headwill turn brown. Scab reduces yield andquality of wheat and barley.

The scab fungus produces mycotoxinsthat are harmful if scabby grain is fed toswine. Wheat (or barley) with 10% scabbykernels may contain mycotoxins whichcause vomiting, feed refusal, and reproduc-tive problems in swine. If seed from scabbyfields is planted, seed rot, seedling blight,crown rot, and root rot can cause loss ofstand and subsequent yield loss. The mostcommon scab fungus, Fusarium gramin-earum, is the same organism that can causeroot rot, stalk rot, and ear rot of corn. Thus,wheat or barley that is planted after corngenerally has a higher incidence and sever-ity of scab. If wheat or barley must followcorn, deep incorporation of corn debrisshould reduce the potential for scab devel-opment.

Septoria black stem of oatSeptoria black stem of oat appears as

oval, chocolate-brown spots on leaf bladesand sheaths. Small, black fruiting bodies ofthe fungus appear in the center of the spots.Stems under sheath spots are dark brownto black and are rotted. The rotted stemsare weakened, and severely infected plantswill lodge and make harvesting difficult.Infected kernels are purple to black. Oatvarieties differ in susceptibility.

Septoria leaf blotch of wheatSeptoria leaf blotch is caused by the fun-

gus Septoria tritici. Small, light green to yel-low spots on the leaves and sheaths enlargeand merge to form irregular, tan to reddishbrown blotches with gray-brown to ash-col-ored centers often partly surrounded by ayellow margin. Black specks (pycnidia)form in older lesions or at stem nodes.Affected leaves often turn yellow, wither,and die early. The fungus survives in livingand dead wheat plants, and in seed.

To control Septoria leaf blotch, rotatecrops. If planting wheat in fields that werecropped to wheat the previous year, deepincorporation of wheat residues offerssome control. Wheat varieties differ inresistance to Septoria leaf blotch. However,available levels of resistance will not pro-vide adequate control during moderate tosevere epidemics of Septoria leaf blotch.Foliar-applied fungicides are necessary ifweather and management practices create


202

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

diseasesAPPENDIX

FORAGES

&PASTURES

SOYBEAN

CORN

PRINCIPLESO

FPEST

MNGM

T.

an environment favorable for severe Septo-ria leaf blotch development. Apply foliarfungicides at the boot stage to protect theflag leaf of plants.

SmutSmut in small grains has greatly

increased in recent years and has been par-ticularly severe in oat. Plants infected witha smut fungus appear normal until theheads emerge. The grain in infected plantsis replaced by the smut fungus and appearsas a black powdery mass of spores. Thesmut fungi are carried with the seed and donot survive in the soil or plant debris.Planting seed from fields with smuttedplants the previous year will perpetuate theproblem. Do not confuse weathered black-ened heads with smut. Heads of smallgrains are often colonized by non-patho-genic fungi that make the heads black.However, the grain is present, in contrast tosmut that replaces the grain with its sootyblack spores. Although similar in appear-ance and biology, smut diseases of smallgrains are caused by different fungi. Theseinclude loose smut of wheat, loose smut ofbarley, loose smut of oat, covered smut ofoat, covered smut of barley and bunt, orstinking smut of wheat.

To control smut diseases of small grains,don’t plant seeds from fields heavilyinfested with smut. You can use seed fromfields with less than 1% smutted headswithout a significant risk of smut develop-ment. Small grain seed certified by the Wis-consin Crop Improvement Association hasbeen grown using procedures that controlsmut diseases. Plant resistant varieties.Many races of smut fungi of oat are presentin Wisconsin and more races may developthat attack oat varieties that are currentlyresistant.

Certain fungicide seed treatments effec-tively control smut diseases of small grains(table 5-5). Mechanical seed treatment isrecommended but not necessary. Followthe directions on the product label to assureproper treatment, handling, and use of seedtreated with fungicide. Fungicide-treatedseed cannot be used for food, feed, or oil.

Take-allTake-all is a root rot disease caused by a

soil-inhabiting fungus. Winter wheat ismost affected. Spring wheat, barley, and oatare the least susceptible. Symptoms of take-all include stunted plants and bleached-white heads. Lower stems show a black,rotted appearance and a rotted and sparseroot system.

To reduce the incidence and severity oftake-all, rotate crops and control wildgrasses such as quackgrass. Make sure lev-els of soil nitrogen are adequate. The NH3form of nitrogen suppresses take-all. Con-sider using nitrapyrin (N-Serve), a nitrogenstabilizer; it improves the effectiveness ofnitrogen fertilization. Delay winter wheatplanting to escape fall infection. Winterwheat planted after alfalfa may be at riskbecause of invasion by quackgrass. Take-allis seldom a problem in a rotation sequenceof soybean-winter wheat.


STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

diseasesAPPENDIX

FORAGES

&PASTURES

SOYBEAN

CORN

PRINCIPLESO

FPEST

MNGM

T.

Bumper 41.8 ECb propiconazole triazole 3 4 fl oz ■ ■ ■ ■ ■ For barley, oats, rye, and wheat. Can beapplied until the ligule of the flag leafemerges (Feeke’s growth stage 8) on bar-ley, rye, and oats. For wheat only, Bumpercan be applied until full head emergence(Feeke’s growth stage 10.5). Applicationsat later stages may leave illegal residues.Do not exceed 4 fl oz/a per season. Do notapply to oats within 40 days of harvest.Do not graze or feed livestock treatedwheat, barley or rye forage or cut thegreen crop for hay or silage. After harvest,the straw from these crops may be usedfor bedding or feed. Treated oat foragemay be grazed, and oat forage and haymay be fed to livestock.

Carambab metconazole triazole 3 10–14 fl oz ■c ■ ■ ■ ■ ■ For barley, oats, rye, triticale, and wheat.For control of head scab only, rates up to17 fl oz/a may be used under severe dis-ease pressure. The minimum retreatmentinterval is 6–8 days. There are no livestockfeeding restrictions.

Cuprofix Ultra 40 copper sulfate inorganic M1 1.0–1.25 lb ■ For barley, oats, and wheat. See label forDisperss use instructions.Cuprofix MX copper sulfate inorganic M1 2.5–4.75 lb ■ For barley, oats, and wheat. See label for Disperss use instructions.Dithane DF Rain- mancozeb dithio- M3 2.1 lb (DF) ■ ■ ■ ■ For triticale and wheat. Do not exceedshield, Dithane carbamate 1.6 qt (F-45) three applications during the season. F-45 Rainshield, 2.0 lb (M45) Do not apply after full head emergenceDithane M45 (Feekes growth stage 10.5) or within 26

days of harvest. Do not graze livestock intreated areas prior to harvest.

Folicur 3.6 Fb tebuconazole triazole 3 4.0 fl oz ■c ■ For barley and wheat. See label for appli-cation instructions. A maximum of 4 floz/a of Folicur 3.6 F may be applied percrop season. Do not apply within 30 daysof harvest. Straw may be fed or used forbedding. Do not graze or feed livestockgreen forage within 6 days after treatment.

Headlined pyraclostrobin methoxy- 11 6.0–9.0 fl oz ■ ■ ■ ■ For barley, rye, and wheat. Do not applycarbamate more than 0.29 lb a.i. pyraclostrobin/a per

season. Do not harvest barley hay or feedgreen-chopped barley within 14 days oflast application.

Fus.

head

scab

Rust

Pow

d.m

ildew

Sept

.lf.bl

otch

Glu

me

blot

chTa

nsp

ot

Chemical FRAC Amount ofProduct Common name family codea prod./a Remarks

Table 5-5. Fungicides for control of foliar diseases of small grains

Disease abbreviations: Fus. head scab = Fusarium head scab; powd. mildew = powdery mildew; Sept. lf. blotch = Septoria leaf blotch.a Fungicide group numbers indicate the modes of action: multiple applications of fungicides with same group number increases the chances for resistance.b To limit the potential for development of resistance, do not make more than two applications of Group 3 fungicides per season (Bumper, Caramba, Folicur, Proline, Prosaro, Quilt, Stratego, and Tilt).c Suppression only.d To limit the potential for development of resistance, do not make more than two applications of Group 11 fungicides per season(Headline, Prosaro, Quadris, Quilt, and Stratego).

203

(continued)


PRINCIPLESO

FPEST

MNGM

T.CO

RNSO

YBEANFO

RAGES&

PASTURESAPPENDIX

SMALL

GRAINSdiseases

PERENNIALW

EEDSSTO

REDGRAIN

INSECTS

Manzate ProStick mancozeb dithio- M3 2 lb ■ ■ ■ ■ For barley, oats, rye, triticale, and wheat.Manzate Flowable carbamate 1.6 qt Do not make more than three applications

during the season. Do not exceed 4.8 qt/aManzate Flowable or 6 lb/a Manzate Pro-stick per crop. Do not apply within 26days of harvest. Do not graze livestock intreated areas prior to harvest.

Penncozeb 75 DF mancozeb dithio- M3 1.0–2.0 lb ■ ■ ■ ■ For barley, oats, rye, triticale, and wheat.Penncozeb 80 WP carbamate 1.0–2.0 lb Do not make more than three applicationsPenncozeb 4FL 0.8–1.6 qt per season. Check label for maximum

applications rates and other restrictions. Proline 480 SCb prothioconazole triazole 3 see remarks ■c ■ ■ ■ ■ For barley and wheat. Barley rate: 2.8–5.7

fl oz/a. Wheat rate: 4.3–5.7 fl oz/a. Applyup to two times per year (only one treat-ment may be made at the 5.7 fl oz/a rate)and no more than 9.37 fl oz/a per year.Proline 480 SC may be applied up to thepoint where heads are in full flower(Feeke’s growth stage 10.52). Do not applywithin 32 days of barley harvest or within30 days of wheat harvest.

PropiMax ECb propiconazole triazole 3 2.0–4.0 fl oz ■c ■ ■ ■ ■ ■ For barley, oats, rye, triticale, and wheat.Do not apply more than 8 fl oz/a Propi-Max EC (0.22 lb ai) per season. If forage orhay will be harvested, do not exceed 4 floz/a (0.11 lb ai). Do not apply within 30days of harvest for forage, within 40 daysof harvest for grain and straw, or within45 days of harvest for hay.

Prosaro 421 SCb,d propiconazole triazole 3,11 7.0 fl oz ■c ■ ■ ■ ■ For barley and wheat. Apply up to two+ trifloxystrobin oximino- times per year. Do not exceed 8.2 fl oz/a

acetate Prosaro 421 SC per crop year. May beapplied up to the point where wheatheads are in full flower (Feeke’s growthstage 10.52). Do not apply within 30 daysof harvest. Straw may be fed or used forbedding. Do not graze or feed livestockgreen forage within 6 days after treatment.

Quadrisd azoxystrobin methoxy- 11 ■ ■ ■ ■ ■ For barley, triticale, and wheat. Applyacrylate only after jointing and up until full head

emergence (Feeke’s growth stages 6–10.5).Do not harvest treated barley or wheat forforage. Do not exceed 0.40 lb ai/a per sea-son of azoxystrobin-containing products.Do not apply within 14 days of harvest forhay or within 45 days of harvest for grainor straw.

Fus.

head

scab

Rust

Pow

d.m

ildew

Sept

.lf.bl

otch

Glu

me

blot

chTa

nsp

ot


Table 5-5. Fungicides for control of foliar diseases of small grains (cont.)

204

(continued)


STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

diseasesAPPENDIX

FORAGES

&PASTURES

SOYBEAN

CORN

PRINCIPLESO

FPEST

MNGM

T.

Quiltb,d propiconazole triazole 3,11 7.0–14.0 fl oz ■ ■ ■ ■ ■ For barley, triticale, and wheat. Do not + azoxystrobin methoxy- apply within 45 days of harvest for grain

acrylate and straw. Do not harvest wheat for for-age. Do not graze or feed livestock treatedforage or cut green crop for hay or silage.Do not apply more than 0.167 lb ai/a ofpropiconazole-containing products or 0.40lb ai/a of azoxystrobin-containing prod-ucts per season. Under certain environ-mental conditions, tank mixes with herbi-cides and/or fertilizer may cause cropinjury.

Strategob,d propiconazole triazole 3,11 7.0 fl oz ■ ■ ■ ■ ■ For barley and oats. Do not exceed + trifloxystrobin oximino- 14 fl oz/a (0.1183 lb ai) per season. Do not

acetate apply after full head emergence (Feeke’sgrowth stage 10.5) or within 40 days ofharvest. See label for grazing restrictions.

Tiltb propiconazole triazole 3 2–4 fl oz ■c ■ ■ ■ ■ ■ For barley, oats, rye, triticale, and wheat.Do not apply within 30 days of harvest forforage, within 40 days of harvest for grainand straw, or within 45 days of harvest forhay. Do not exceed 8 fl oz/a per season. Ifharvesting for forage or hay, do not exceed4 fl oz/a per season. Do not apply morethan 0.22 lb ai/a of propiconazole-contain-ing products per season.

Disease abbreviations: Fus. head scab = Fusarium head scab; powd. mildew = powdery mildew; Sept. lf. blotch = Septoria leaf blotch.a Fungicide group numbers indicate the modes of action: multiple applications of fungicides with same group number increases the chances for resistance.b To limit the potential for development of resistance, do not make more than two applications of Group 3 fungicides per season (Bumper, Caramba, Folicur, Proline, Prosaro, Quilt, Stratego, and Tilt).c Suppression only.d To limit the potential for development of resistance, do not make more than two applications of Group 11 fungicides per season(Headline, Prosaro, Quadris, Quilt, and Stratego).

Fus.

head

scab

Rust

Pow

d.m

ildew

Sept

.lf.bl

otch

Glu

me

blot

chTa

nsp

ot


Table 5-5. Fungicides for control of foliar diseases of small grains (cont.)

205


STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

diseasesAPPENDIX

FORAGES

&PASTURES

SOYBEAN

CORN

PRINCIPLESO

FPEST

MNGM

T.

Table 5-6. Seed treatment fungicides for small grainsa

Oat ——Wheat—— ——Barley——All Loose Loose Covered

Product Fungicide smuts smut Bunt smut smut Seed/seedling decay

Apron XL LS mefenoxam Barley, oat, rye, triticale, wheat.For protection against seed and seedling rot caused by Pythium ongrain crops.

Dividend Extreme difenoconazole ■ ■ Wheat. Protects againstDividend XL RTAb + mefenoxam ■ ■ Fusarium spp. that are associated

with “scabby” seed plus seed and seedling rots caused by Pythium.

Enhance carboxin + captan ■ ■ ■ ■ ■ Barley, oat, wheat.

Enhance Plus maneb + carboxin ■ ■ ■ ■ ■ Barley, oat, wheat.+ lindane

Manzate 200, mancozeb ■ ■ ■ Barley, oat, rye, wheat.Dithane M-45 ■ ■ ■

Penncozeb 75DF ■ ■ ■ ■

Maxim 4FS fludioxonil ■ ■ Barley, oat, rye, wheat. For control ofseed-borne and soil-borne fungi thatcause seed decay, damping-off, and seedling blights.

Raxil MD tebuconazole ■ ■ ■ ■ Barley, oat, wheat, triticale.Raxil XT + metalaxyl ■ ■ ■ ■ ■

Raxil-thiram tebuconazole ■ ■ Wheat. Protection against+ thiram Fusarium spp. that are associated

with “scabby” seed.

Vitavax 200 carboxin + thiram ■ ■ ■ ■ ■ Barley, oat, wheat.aThis table is intended as a reference guide. Chemicals, combinations, and labels change frequently—check current label for details.bAlso labeled for use on triticale.

206


STORED

GRAININSECTS

SMALL

GRAINSAPPENDIX

FORAGES

&PASTURES

SOYBEAN

CORN

PRINCIPLESO

FPEST

MNGM

T.

PERENNIAL WEEDMANAGEMENT

6

PERENNIALW

EEDS

A3646-09, VI. Perennial-app (6.5) 10/14/08 4:52 PM Page 207

PERENNIAL WEED MANAGEMENT

208

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNPRINCIPLES

OF

PESTM

NGMT.

Perennial weeds are less widespread thanannuals, but traditionally have been moredifficult to manage because they propagateby vegetative means as well as by seeds.Knowing how the plant propagates (i.e.,tubers, taproots, spreading roots, or rhi-zomes) is an important first step in design-ing an appropriate management program.For example, taprooted weeds like dande-lions are eliminated with moldboard plow-ing. This same tool will not eradicate weedswith spreading roots such as hemp dog-bane and Canada thistle or those with rhi-zomes like quackgrass and wirestemmuhly.

This section gives information on com-mon perennial weeds. Table 6-1 providesherbicide considerations on these and otherperennial species troublesome in someareas of Wisconsin. Few details regardingherbicide treatments are presented here;consult earlier sections of this bulletin foradditional information.

The advent of herbicide-resistant cropsopens new avenues for perennial weedmanagement. Herbicides that previouslywould kill the crop can now be used totackle difficult-to-control perennials at amore appropriate time of treatment andstill have the benefit of crop competitionafter application. Noticeable long-termreductions in perennial weed infestationshave been documented in both UWresearch trials and by farmers in productionfields.

QUACKGRASSQuackgrass is a persistent perennial

weed. Its extensive system of rhizomes(underground stems) and roots represents60 to 70% of the plant’s weight and con-tains abundant food reserves. Rhizomesenable quackgrass to resprout after mow-ing or cultivation. Quackgrass is quite sen-sitive to soil disturbance during the grow-

ing season and is most effectively managedby a combination of mechanical, chemical,and cultural control practices. Repeatedtillage or herbicide treatment controlsquackgrass by depleting food reserves andpreventing manufacture and accumulationof additional reserves. Tillage and cultiva-tion are most effective during periods ofwarm, dry weather because quackgrass rhi-zomes brought to the soil surface dry outand die. Late fall cultivation can also beeffective as freezing winter temperaturesalso help kill exposed quackgrass rhizomes.Herbicide recommendations vary accord-ing to the season in which control begins,the crop to be planted, and the product(s)to be used.

Accent (nicosulfuron),Beacon (primisulfuron),and Option (foramsulfuron) for corn

Accent, Beacon, and Option are post-emergence sulfonylurea herbicides thatselectively control quackgrass in corn. Theyare particularly well-suited for fields wherequackgrass appears in localized areas andwhere other herbicides are inappropriate ordifficult to use in a specific cropping sys-tem. These products translocate from thefoliage to the rhizomes and do not affectquackgrass through soil uptake. Injurysymptoms in quackgrass may appearslowly (7 to 10 days) and action may not becomplete until 30 days after application.Quackgrass that emerges after applicationand any escaping weeds can be controlledwith a cultivation 7 or more days aftertreatment.

Do not cultivate fields before applyingAccent, Beacon, or Option as this willreduce quackgrass control. Half-rate appli-cations of Accent or Beacon applied toactively growing quackgrass, followed by atimely cultivation has consistently given


acceptable quackgrass control. We expectsimilar results with Option. The effects of asingle application are usually evident fortwo or more seasons. The active ingredientsof Accent and Beacon are available in sev-eral premixed products and all provideacceptable quackgrass control.

Assure II (quizalofop),Fusion (fluazifop + fenoxaprop),Poast Plus (sethoxydim), and Select (clethodim) for soybeans

All of these “graminicides” (grass killers)are labeled for quackgrass control in soy-beans. They translocate from the treatedfoliage into the rhizomes. Assure is gener-ally more active on quackgrass than Fusion,Poast Plus, or Select. All of the productsreduce quackgrass below the economicthreshold and have effects that are evidentfor more than one season. Do not cultivate7 days before or after applying any of theseproducts, but cultivating 7 to 14 days lateroften improves overall weed control. Dryweather or other stress conditions willreduce quackgrass control.

Glyphosate before planting conventional varieties/hybridsand on Roundup Ready corn and soybean

Many brands of glyphosate can beapplied before planting most crops to killexisting vegetation. Glyphosate applied toactively growing quackgrass is rapidlytranslocated throughout the quackgrass rhi-zome system. Treat when quackgrass is 6 to8 inches tall (3- to 4-leaf stage) and activelygrowing in either the fall or spring. Wherepossible, treat in the fall rather than in thespring.

The rate to use for quackgrass controldepends upon the previous cropping sys-tem, level of tillage after application, sprayvolume, and the concentration ofglyphosate in the brand you select. In siteswhere row crops have been grown andtillage is practiced, 0.75 lb ae/a ofglyphosate in 10 gal/a or less of water isusually recommended. For no-till sites andold sods that will not be moldboardplowed, 1.5 lb ae/a is recommended.

Glyphosate can be applied directly toquackgrass in Roundup Ready soybeansand Roundup Ready corn. This method can

be used in untreated fields that were tilledbefore planting. Glyphosate offers littleadvantage in quackgrass control over selec-tive herbicides in corn and soybeans for theseason, but should give better long-termcontrol. When glyphosate is used forannual weed control in Roundup Readycrops, rates of 0.75 lb ae/a usually giveexcellent quackgrass control as well.

Symptoms of injury to quackgrass may notoccur until 7 to 10 days after application.Cool, cloudy weather after treatment slowsthe appearance of symptoms. The effects ofa single glyphosate application are usuallyevident for several seasons, especially infields that were tilled before plantingand/or row cultivated after planting.

Some brands of glyphosate can beapplied prior to the final alfalfa harvest inthe fall or spring to control quackgrassbefore rotating to another crop. Apply therecommended rate and wait 36 hours orlonger before harvesting. No other productcan be tank-mixed with glyphosate andtillage will usually be needed to enhancethe control of quackgrass and to kill peren-nial broadleaf species, including alfalfa,before the next crop is planted.

Poast Plus (sethoxydim)and Select (clethodim)for alfalfa and trefoil

These are the only grass-specific herbicidesapproved for use in alfalfa and trefoil.Symptoms develop slowly on quackgrass,but active growth ceases upon applicationand within 10 to 21 days the stems are eas-ily pulled from treated plants, indicatingthey are dying. Poast Plus and Select sup-press quackgrass significantly in the firstcutting of forages but the long-term effectsare less evident in alfalfa than in soybeansfollowed by tillage. Poast Plus (but notSelect) can also be used to suppress quack-grass in clovers.

WIRESTEM MUHLYUnlike most of our weeds, wirestem

muhly is native to North America. It hasincreased in importance in Wisconsin inrecent years. This is due to several factors,including less tillage, enhanced control ofother species, loss of diversity in crop rota-tions (especially less forages), and the pro-duction and spread of wirestem muhly

209

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNPRINCIPLES

OF

PESTM

NGMT.


seeds. Because wirestem muhly is a warm-season species, growth starts later in thespring than for quackgrass and other cool-season plants. Wirestem muhly rhizomesgrow near the surface, therefore shallowtillage can be effective in suppressing thisweed. Vigorous tillage done just as growthbegins in the spring has been observed toyield the best results.

Control in soybeansWirestem muhly is easily controlled with

postemergence applications of Assure II,Fusion, Poast Plus, or Select. Use a crop oilconcentrate and treat when wirestem is 6 to8 inches tall and actively growing. PlantingRoundup Ready soybean varieties andusing glyphosate as a postemergence treat-ment is another option. This may even bepractical in no-till systems becausewirestem emerges later and grows moreslowly in the spring than quackgrass.

Control in cornWirestem muhly control is very challeng-

ing in corn. Try to achieve effective sup-pression before planting corn with appro-priate control measures the prior season.Accent and Option applied to wirestem 4 to8 inches tall and the combination of Accentplus Beacon (half rate of each) give accept-able wirestem suppression. Lightningapplied postemergence in fields where animidazolinone resistant/tolerant cornhybrid (Clearfield corn) has been plantedalso effectively suppresses wirestem muhly.Planting a Roundup Ready corn hybrid andapplying glyphosate as a postemergencetreatment is another way to suppress wire-stem muhly. Two applications of Liberty inLiberty Link hybrids also show promise onthis weed. All treatments will give bettercontrol if the field is vigorously cultivated10 or more days after application.

Control in other cropsWirestem muhly is often an unnoticed

weed in alfalfa fields. Use a fall applicationof glyphosate the year before rotating fromalfalfa to corn or other crops. Plantingwheat in fields with wirestem muhly can beas effective as the tillage prior to seedingwheat will reduce the rhizome mass andwheat will compete very effectively withwirestem because it grows vigorously in

the spring. After wheat harvest, use a com-bination of glyphosate and tillage to furtherreduce the infestation.

YELLOW NUTSEDGEYellow nutsedge is a persistent perennial

weed that reproduces by seed and tubers(nutlets) produced on its rhizome system.Each nutsedge plant can produce nearly7,000 tubers in a single season. If not con-trolled, an acre may contain more than30,000,000 tubers in the upper 10 inches ofthe soil. The best control strategy is preven-tion, early detection, and removal. Whilemost tubers develop into new plants thenext year, many can remain dormant in thesoil for several years. Yellow nutsedge isusually found as isolated patches, in lowwet areas, and in soils with high amountsof organic matter. Populations can alsoestablish in upland mineral soils and infestentire fields.

Yellow nutsedge control is feasible insome crops, difficult in others, and nearlyimpossible in small grains and establishedforages. Tillage is an essential part of yel-low nutsedge management. While the bestcombination of tillage and chemical treat-ment may not always provide full-seasoncontrol, it should suppress nutsedge duringthe critical period of competition. Manysoil-applied herbicides lose much of theireffectiveness when applied to the highorganic matter soils where yellow nutsedgeis often found. Postemergence treatmentsare not affected by soil texture or organicmatter levels and are especially appropriatewhen nutsedge occurs in patches of fields.In no-till cropping systems, use postemer-gence strategies to suppress nutsedgebecause preplant incorporation cannot bedone and preemergence applications giveinconsistent control.

The following herbicide treatments pro-vide varying degrees of nutsedge control.Individual treatments may be used only onspecific field crops as listed.

Acetochlor, Alachlor, Dual II Magnum (s-metolachlor),and Outlook (dimethenamid-P) for corn and soybeans

These herbicides are chemically related.Acetochlor can only be used in corn but theothers are registered for use in corn and

210

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNPRINCIPLES

OF

PESTM

NGMT.


soybeans. All give adequate nutsedge sup-pression when applied as preplant-incorpo-rated treatments, but preemergence appli-cations will give adequate suppression onlyif abundant rainfall occurs within 5 to 8days of treatment. Dual often provides bet-ter late-season control of nutsedge than theother herbicides. Rates of these productswill usually be higher than those neededfor annual weeds. Alachlor and acetochlorare more active on yellow nutsedge inmuck soils than the other products in thisgroup.

Basagran (bentazon) for corn, soybeans, and dry or succulent beans

Basagran applied to actively growingnutsedge that is 6 to 8 inches tall providesgood to excellent suppression in corn, soy-beans, and dry or succulent beans. A repeatapplication may be made 7 to 10 days afterthe first application if necessary, or the fieldmay be cultivated 10 to 21 days after thefirst application. Do not apply when eitherthe crop or nutsedge has been exposed toprolonged drought or during periods ofunseasonably cold weather as poor weedcontrol will result. Do not cultivate fieldswithin 5 days before or after Basagran treat-ment. Basagran can be tank-mixed withseveral herbicides and is sold as a premixwith some other products for simultaneousapplication in corn and soybeans. Nutsedgesuppression is not usually affected by thesemixtures.

Classic (chlorimuron)for soybeans

Classic is the only sulfonylurea with sig-nificant activity on nutsedge in soybeans.Treat when nutsedge is 2 to 4 inches talland cultivate 14 or more days after treat-ment if needed.

Permit (halosulfuron)for corn

Permit is a sulfonylurea applied to cornas a postemergence treatment that givesexcellent nutsedge control. Use a crop oilconcentrate to assure maximum perfor-mance and apply Permit when nutsedge is4 to 12 inches tall. The label indicates that1.0 to 1.33 oz/a are needed to controlnutsedge and 0.67 oz/a to suppress it.However, our data show excellent control

even at the 0.67 oz rate. We suggest using0.67 to 1.0 oz/a and treating whennutsedge averages 8 to 10 inches tall. Bywaiting for nutsedge to reach this height,few additional plants should appear afterapplication. However, a timely row cultiva-tion is recommended to ensure full-seasoncontrol. The premixture of halosulfuronand dicamba (Yukon) also controls yellownutsedge.

PERENNIAL BROADLEAFCONTROL in glyphosate-resistant crops

The advent of Roundup Ready cropsopens a new opportunity to control severalperennial broadleaf species selectively inthe growing crop. This means we canobtain good to excellent suppression ofperennial weeds like hemp dogbane,Canada thistle, milkweed, Jerusalem arti-choke, field and hedge bindweed, andperennial sowthistle that can last for sev-eral seasons. We seldom expect such resultsfrom the alternatives available in conven-tional varieties or hybrids. Our research onglyphosate-resistant corn and soybeans hasled to the following suggestions to manageperennial broadleaf weeds in glyphosate-resistant crops.■ Plant the crop without tillage. Tillage

delays the development of perennialweeds while in a no-till system, theweed grows rapidly and reaches theideal growth stage for treatment soonerthan if tillage were done.

■ Delay the application until the budstage on the perennial broadleaf weedor until the weed is 24 to 30 inches tall,whichever occurs first. Apply theseguidelines to the most advanced plantsin the population.

■ The right time to treat perennialbroadleaves is often 5 to 7 weeks afterplanting when the soybeans are in theV-4 to V-6 growth stage. This is laterthan when annual weeds would nor-mally be treated. However, this latertiming (bud stage) is often the best timefor perennials because herbicide move-ment from the treated foliage to theroots is maximized.

211

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNPRINCIPLES

OF

PESTM

NGMT.


■ To avoid crop yield loss due to uncon-trolled annual weeds while waiting totreat perennial broadleaves, apply areduced rate (perhaps 50% of the rec-ommended rate) of a soil-active herbi-cide as a tank mixture with the burndown treatment before planting. Selectthe preemergence herbicide based onthe expected annual weed population.A reduced rate is not risky becauseescaping annual weeds will be killed bythe glyphosate application targeted tothe perennial weed.

■ In fields with perennial broadleafweeds where tillage has been done,apply a reduced rate of a PPI or PREherbicide. It may take longer for theperennial species to reach the floweringstage in these fields.

■ Application timing is more importantthan rate. Our research has shown thatapplying 0.75 lb ae/a of glyphosate toactively growing perennial weeds in thebud to early flower stage gives excellentcontrol the season of application withgreatly reduced weed populations thenext year.

■ Split applications of glyphosate are notnecessary. Control from a single treat-ment when perennial broadleaves beginto flower is as effective as repeatedtreatments. This means that no addi-tional trips through fields with peren-nial broadleaf weeds should be needed.

■ Uniform coverage of the weed foliage isimportant and difficult. As mentioned,weed height is seldom uniform in apopulation of perennial broadleaves.Select the appropriate nozzles andadjust the boom height to cover theweed foliage as uniformly as possible.Remember that boom height alsoaffects the risk of particle drift from thetarget area.

■ Monitor the population of the perenni-als in following years and use an appro-priate management program if/whenperennials again reach threshold levels.

CANADA THISTLE inconventional grain crops and pastures

Canada thistle infests croplands, pastures,fence rows, ditch banks, and roadsides. Ithas increased noticeably in recent years,particularly in our roadsides and reducedtillage fields. While infestations can startfrom seed, most shoots emerge from theextensive horizontal and vertical root sys-tem. Roots may penetrate to 10 ft deep andspread horizontally 15 ft or more. Singleplants form either male or female flowersand a patch of Canada thistle plants usuallyconsists of only one flower type. Canadathistle plants may vary in appearance fromone area to another. The degree of spini-ness, the extent of leaf lobing, leaf width,and flower color differ among plants. Forexample, in Wisconsin we have both purpleand white-flowered biotypes of Canadathistle.

Repeated mowing should at least preventCanada thistles from spreading to newareas and will probably reduce their area ofinfestation. Tillage is more effective thanmowing because it exposes roots to dryingor freezing conditions and also prevents thebuildup of food reserves in the roots. Real-ize however that tillage may spread theroots to previously uninfested parts of thefield. Combining mechanical and chemicalcontrols often gives the best results.

Dicamba (Banvel/Clarity/Status)and 2,4-D for corn and small grains

Even though dicamba and 2,4-D are sys-temic herbicides, a single application willnot kill the entire root system. This is espe-cially true in corn and small grains becausethe rates that can be safely applied and thetime of application will not give long-termcontrol of Canada thistle. Status containsdicamba and diflufenzopyr; it can be usedin corn and gives results equivalent todicamba alone on several perennialbroadleaf weeds.

Glyphosate between crops

An effective time to use glyphosate forCanada thistle control is after harvestingwheat or oats for grain or an early-season

212

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNPRINCIPLES

OF

PESTM

NGMT.


vegetable crop like peas or sweet corn. Thisallows treatment at an effective rate whenthe thistles have regrown and are activelytranslocating food reserves to the root system.

Stinger (clopyralid)for corn, small grains, and pastures

While Stinger can be applied in the samecrops as Banvel and 2,4-D and has the samemode of action, only a single application isneeded for good to excellent Canada thistlesuppression. The effects of a single treat-ment are usually evident for several years.The rate can be adjusted according to this-tle density. Apply higher rates in densethistle areas because there are more rootswith buds than in areas where infestationsare light to moderate. Apply Stinger whennearly all plants have emerged and Canadathistle is in the rosette to prebud stage(plants are usually 4 to 18 inches tall).

Stinger persists in the soil several monthsafter application. Follow rotational cropand drift control guidelines carefully. Therelatively high price of Stinger compared toother herbicides is often justified becausethe cost can be spread over several yearssince annual treatments are not neededand, usually only a small proportion of agiven field needs treating. Stinger can betank-mixed with 2,4-D or dicamba for amore economical treatment. A premixtureof Stinger and Garlon, sold as Redeem R&P,is a more economical option for Canadathistle control in pastures.

HEMP DOGBANE inconventional crops

Hemp dogbane has both vertical and hor-izontal roots. Plants often spread withinfields and from field to field because farm-ers inadvertently transport a piece of theperennial root to new locations, producingnew dogbane colonies.

Plants may flower but establishmentfrom seed is of minor importance. Studiesin Kansas found that plants originatingfrom seeds and grown for 2 years withoutcompetition formed vertical roots nearly 14ft deep and the horizontal roots extendedalmost 40 ft in diameter. Six to 8 weeks afterseed germination, hemp dogbane is consid-ered “established” because it can thenreproduce vegetatively from the root. Onceestablished, dogbane grows much more

rapidly than corn or soybeans, especially inno-till systems. We can use this to ouradvantage because most postemergencetreatments are more effective on largerrather than smaller plants and in no-tillfields the weed develops more rapidly thanin plowed fields. Thus plants can be treatedsooner in the season before significant croplosses from competition have occurred.

If possible, consider growing aglyphosate-resistant soybean variety orcorn hybrid in fields with hemp dogbane.The immediate and long-term effects of asingle application of glyphosate in either ofthese cropping systems will be superior tothe following alternatives.

Dicamba (Banvel/Clarity) and 2,4-D for corn and small grains

Dicamba and 2,4-D have very good activ-ity on hemp dogbane. They are more effec-tive on this weed at the rates we can use incorn and small grains than they are onCanada thistle. In a between-crops situa-tion, Iowa State researchers applied 1 lbai/a of 2,4-D and observed 97% dogbanecontrol 1 year after application. Universityof Illinois weed scientists observed a 60%reduction in dogbane infestation from a0.5 lb ai/a application of 2,4-D in corn with7 to 8 leaves and dogbane in the earlyflower stage.

Hemp dogbane is listed on many brandsof 2,4-D. However, labels require the use ofdrop nozzles once corn is more than 8inches tall. This is a serious problembecause it is often too early to treat the dog-bane effectively since some plants have notyet emerged and those that have aretranslocating very little material to theroots. When most hemp dogbane hasemerged and plants are in the bud stage,the weed is usually much taller than thecrop and drop nozzles will not give effec-tive control. Dogbane is more likely to be atthe proper growth stage when no-till cornis 6 to 8 inches tall than when conventionalor reduced tillage is used.

Even though these products are systemicherbicides, a single application will not killthe entire root system. Ester formulations of2,4-D are preferred over amine formula-tions but both are effective. In most cases,2,4-D and dicamba give similar results on

213

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNPRINCIPLES

OF

PESTM

NGMT.


Table 6-1. Summary of herbicides for perennial weed suppression in corn andsoybeans

Weed Time of application Corn Soybeans

Bindweeds Post dicamba Flexstarglyphosatea glyphosatea

Status Ultra Blazer2,4-D

Canada thistle Between crops glyphosate glyphosatePost dicamba Basagran + Ultra Blazer

glyphosatea glyphosatea

StatusStinger2,4-D

Hemp dogbane Between crops glyphosate glyphosatePost dicamba glyphosatea

glyphosatea

StaraneStatus2,4-D

(continued)

dogbane but occasionally 2,4-D is moreeffective. A tank mix of these products canbe applied. Distinct herbicide containsdicamba and diflufenzopyr; it can be usedin corn and gives results equivalent todicamba alone on several perennialbroadleaf weeds. Cultivation after treat-ment in corn will further weaken theplants. Cultivators with sweeps will bemore effective than those with points ornarrow shovels.

Starane (fluroxypyr)for small grains and corn (field or sweet)

Starane applied postemergence effec-tively controls hemp dogbane. The use ofStarane in small grains was described pre-viously. In field or sweet corn, applyStarane up to the V5 growth stage. Do notapply Starane once corn has six or morevisible leaf collars.

Glyphosatebetween crops

As with Canada thistle, a good opportu-nity to use glyphosate for hemp dogbanecontrol is after harvesting wheat or oats forgrain or an early-season vegetable crop likepeas or sweet corn. This allows treatmentwith an effective rate when the dogbanehas regrown and is actively translocatingfood reserves to the root system.

214

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNPRINCIPLES

OF

PESTM

NGMT.


215

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNPRINCIPLES

OF

PESTM

NGMT.

Table 6-1. Summary of herbicides for perennial weed suppression in corn andsoybeans (continued)

Weed Time of application Corn Soybeans

Dandelion Post dicamba ClassicIgniteb glyphosatea

Status SynchronySteadfastStinger2,4-D

Milkweed, common Between crops glyphosate glyphosatePost Beacon + 2,4-D Cobra/Phoenix

dicamba + 2,4-D glyphosatea

glyphosatea Ultra BlazerPermit/YukonStatus2,4-D

Perennial sowthistle Between crops glyphosate glyphosatePost dicamba glyphosatea

dicamba + 2,4-Dglyphosatea

StatusStinger

Quackgrass Preplow/preplant glyphosate glyphosatePost Accent Assure II

Beacon FusionAccent + Beacon glyphosatea

glyphosatea Poast PlusOption Select

Wirestem muhly Preplow/preplant glyphosate glyphosatePost Accent Assure II

Accent + Beacon Fusionglyphosatea glyphosatea

Igniteb Poast PlusOption SelectSteadfast

Yellow nutsedge PPI acetochlor alachloralachlor DualDual OutlookOutlook

Post Basagran BasagranPermit/Yukon Classic

aThese applications can only be made to Roundup Ready varieties/hybrids with brands of glyphosate clearlyapproved for use in these varieties/hybrids.bApply only in Liberty Link hybrids. A split application will give the best results.


216

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNPRINCIPLES

OF

PESTM

NGMT.


STORED GRAIN INSECT PEST MANAGEMENT

7

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNPRINCIPLES

OF

PESTM

NGMT.


STORED GRAIN INSECT PEST MANAGEMENT

218

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNPRINCIPLES

OF

PESTM

NGMT.

On-farm infestations of small grains aredue primarily to insect-infested equipmentand storage facilities, and grain molds thatattract fungus-feeding beetles. The bestapproach to this problem is to start withclean, dry grain and clean equipment andbins.

Grain containing cracked kernels, weedseeds, or other foreign material tends tobecome infested more readily than sound,clean grain.

BIN PREPARATIONClean out the bin. Never put new grain

on top of old grain. Remove all grain anddebris from inside and outside bins well inadvance of the harvest. This includes feedsacks, cardboard sheets and boxes, boards,and accumulations of grain, crusted grain,and dust. These products harbor the eggs,larvae, pupae, and adults of “bran bugs”and “grain moths.” Use brooms, vacuumcleaners, hoes, or other scrapers to do athorough job. Make sure you wear anapproved dust and mold filtering maskwhile cleaning bins.

Avoid storing grain near animal feeders,feedrooms, or in livestock dwellings. Theseareas may harbor stored grain pests. Eitherfeed the first few bushels from the combineto livestock or discard them. The old grainleft in the combine could be infested.

Patch all holes in the bin to bar entry bybirds and rodents. Make sure the roof doesnot leak.

RESIDUAL BIN SPRAYS ANDEMPTY-BIN FUMIGATION

After bins are emptied and cleaned, spraythe inside surfaces to the point of runoffwith an insecticide approximately 2 weeksprior to harvest. Apply one of the followinginsecticides to the walls, ceilings, roof, andfloors of all bins that will be used to storesmall grains for more than a few weeks:

■ Bin applications of Storcide (chlorpyrifos-methyl plus cyfluthrin) should beapplied only from outside the bin (seeproduct label). Dilute 1.69 fl oz Storcidewith water to make a 1 gal solution.Apply finished spray at the rate of1 gal/1000 sq ft before storing or han-dling grain.

■ 8 ml Tempo SC Ultra (cyfluthrin) per1000 sq ft in sufficient water (about1.5 pt/1000 sq ft) to adequately coverthe area without causing dripping orrunoff (see product label). Note: Neverapply Tempo directly to any grain.

■ 1 lb Insecto dust (diatomaceous earth)per 1000 sq ft (see product label).

■ Chloropicrin fumigant for subfloorplenum. Use restricted to certified grainfumigators.

Spray all cracks and crevices, and arounddoors. The plenum beneath non-removableperforated floors can harbor many insectsand is difficult to treat. While directingextra spray through the perforations willkill some of the insects in this grain debris,it will not kill enough for satisfactory con-trol. Thus, you will either have to fumigateor remove the subfloor to clean out graindebris. Spray the outside bin walls to aheight of 6 ft, and spray the ground out to adistance of 6 ft from the bin foundation.

Do not let the insecticide spray mix standovernight; it may break down and result inpoor control.

Spraying or fumigating empty bins isonly a part of the program for preparingbins for harvest. Before bins are sprayed,they must be thoroughly cleaned. In addi-tion, money spent spraying empty bins iswasted if the grain placed in the bin is notmanaged properly and is allowed to go outof condition.


219

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNPRINCIPLES

OF

PESTM

NGMT.

GRAIN PROTECTION WITHINSECTICIDES

In Wisconsin clean, dry grain suffers lit-tle, if any, damage on the farm during thefirst season’s storage if (1) the precedingsuggestions on bin sanitation and residualsprays are followed, (2) the grain is notstored close to livestock feed or other grainsthat are contaminated with insects, and (3)aeration is used to cool the grain and pre-vent insect feeding and reproduction.

A grain protectant should be used if thegrain will be held beyond June 1 of the fol-lowing year. However, a grain protectantwill not protect grain from insects that feedon molds, such as the foreign grain beetle.A grain moisture of 14 to 18% is favorablefor most stored grain insects. Insects thatfeed on mold prefer the high moistureranges. Thus, proper grain drying and binaeration are integral parts of managingstored grain insects. To help bin aeration,do not overfill bins; it hinders uniform airflow during aeration and makes it harder toinspect and treat the grain. Level the grainand allow at least 8 inches between thegrain surface and the tip of the bin wall.

Drying grain to 12 to 13% moisture isunfavorable for most grain insects andallows prolonged persistence of protectantinsecticides added while the grain is beingbinned.

Storcide (chlorpyrifos-methyl + cyfluthrin)for barley, oat, and wheat

Dilute Storcide with water or FDA-approved food grade mineral oil or soy-bean oil and apply to the moving grainstream as a coarse spray to give a deposit of3 ppm of chlorpyrifos-methyl and 2 ppm ofcyfluthrin on the grain (see product label).Final spray volume with water solutions is5 gal. liquid/1000 bu. of grain. Final sprayvolume with oil solutions should be appliedat rates given by the oil manufacturer.

Actellic 5E (pirimiphos-methyl)for corn and popcorn

Actellic will control malathion-resistantIndian meal moths. It should provide 9 to18 months residual activity depending upongrain moisture and temperatures. Apply 8.6to 11.5 fl oz Actellic in 5 gal of water per1,000 bu corn. Do not apply before high-temperature drying. Do not apply Actellic tobarley, oats, rye, wheat, or soybean.

Liquid protectants can be applied assprays or with a “drip-on” applicator whilegrain is being placed in storage.

Diacon II (methoprene)for barley, corn, oat, and wheat

Diacon is labeled as a stored grain treat-ment. Unlike traditional insecticides, Dia-con II does not kill adult insects. This insectgrowth regulator interferes with the devel-opment of young insects, preventing breed-ing by adult beetles and moths. Dilute Dia-con II with water or FDA-approved foodgrade oils or soybean oil. For maximumresidual and efficacy, apply at 5 ppm. Seeproduct label for application methods andfinished spray concentrations by grain type.

GRAIN SURFACE SPRAYOnce grain is in the bin, surface treat-

ments only are effective against insectsfeeding at the grain surface. Malathion isregistered for such use, but the major grainsurface feeder is the Indian meal moth, aspecies with widespread resistance tomalathion. Because of this, malathion is ofquestionable value for such applications.The following products are suggested foruse as surface treatments.

DiPel (Bacillus thuringiensis)for corn, soybean, and small grains

DiPel is a biological insecticide that con-tains a naturally occurring bacterial organ-ism that kills moth larvae. It is labeled forsurface treatment for control of Indian mealmoth. This insecticide will not control bee-tles, weevils, or bran bugs.

Diacon II (methoprene)for barley, corn, oat, and wheat

Diacon is labeled as a surface treatmentand as a total grain treatment. This insectgrowth regulator prevents breeding by bee-tles and moths; it does not kill adult insects.Dilute with water or food-grade oils or soy-bean oil.

Actellic 5E (pirimiphos-methyl)for corn

Actellic 5E may be used as a surface treat-ment in stored corn and will control Indianmeal moths, beetles, and weevils. Do notapply Actellic to barley, oats, rye, wheat, or soy-bean. Actellic can be used on corn only onceduring the entire storage period, regardless ofthe method of use.


Storcide (chlorpyrifos-methyl + cyfluthrin)for barley, oat, and wheat

Storcide may be used as a surface treat-ment on wheat, oat, or barley if the entiregrain mass is not treated. Mix 3.13 oz ofStorcide for wheat, 1.7 oz for oat, or 2.5 ozfor barley with 2 gal water for each 1000 sqft of grain surface. Make a split application,spraying half of the mixture to the grainsurface and raking it in to a depth of 4inches. Apply the remaining half of themixture to the raked, treated surface. Note:Storcide can be used on grain only once duringthe entire storage period, regardless of themethod of use.

INDIAN MEAL MOTHThis insect is a problem in portions of

Wisconsin. The adult (moth) does no dam-age, but the larvae feed in the upper fewinches of the grain mass and will web thegrain together. If populations are great, thesurface will be crusted, protecting the lar-vae from surface-applied insecticides orfumigants. This pest has developed resis-tance to malathion in many areas. There area few alternatives to malathion that are spe-cific to stored grain: dichlorvos; Storcide(small grains); Actellic 5E (corn); and Bacil-lus thuringiensis and diatomaceous earth(corn, soybean, and small grains). ■ A preventive treatment is to suspend

one dichlorvos (DDVP, Vapona) resinstrip per 1000 cubic feet of space overthe stored grain. This technique is effec-tive against adults only. The strip mustbe hung before moths begin to emergein early spring. The strips usually mustbe replaced every 6 weeks. During thefirst season of storage, the strips shouldbe hung immediately after small grainsare binned.

■ DiPel is a biological insecticide that con-tains a naturally occurring bacterialorganism (Bacillus thuringiensis) thatattacks moth larvae. It can be used tocontrol Indian meal moth larvae. It willnot control adult moths, nor will it con-trol weevils or beetles. Consult theproduct label for rates and specialapplication instructions.

■ Insecto diatomaceous earth is labeled asa surface treatment for Indian mealmoth and may be used on feed grains,

wheat, barley, corn, oats, and soybean.Insects that come in contact with theproduct are scraped by the microscopicparticles. They lose their body fluids,become dehydrated, and die. This is aphysical control, so insects have diffi-culty building up resistance.

Before applying a grain surface treatmentfor Indian meal moth, remove webbing orcrusted or spoiled grain. Follow applicationinstructions for insecticides listed in theGrain Surface Spray section.

It may take several weeks for grain sur-face treatments to control an Indian mealmoth infestation. You may want to hire afumigator for faster results. If you’ll bekeeping the grain in storage, treat the grainsurface with an appropriate insecticidelisted under the Grain Surface Spray sec-tion to prevent reinfestation once it is safeto enter the bin after fumigation.

GRAIN INSPECTIONStored grain must be inspected every 2 to

4 weeks from May through October and atleast monthly from November to April. Ifinfestations are detected early, they can becontrolled before extensive damage occurs.

Check various areas of the grain masswith a grain probe. Sift the grain samplesthrough a screen (10 to 12 mesh to the inch)to separate the insects from the grain. Ifinsects are found, fumigation may be neces-sary.

Probe traps and pitfall traps can be usedfor monitoring the grain mass, and stickypheromone traps can be used to monitorflying moths. It also is important to probethe grain in several locations to monitorgrain temperature and moisture.

SAFETY PRECAUTIONSStored grain, especially flowing grain,

presents many hazards. Following is a listof important safety precautions (adaptedfrom the University of Illinois PesticideTraining Manual for Grain Facility Pest Con-trol Applicators).■ Do not enter a bin of flowing grain.■ Do not enter a bin to break a crust or

remove a blockage when unloadingequipment is running, whether or notgrain is flowing. Restarted flow is ahazard.

220

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNPRINCIPLES

OF

PESTM

NGMT.


■ Before entering a bin, lock out the cir-cuit controlling the unloading equip-ment and post a warning so no one elsestarts the equipment.

■ Do not enter a bin without knowledgeof previous grain removal practices,especially if crusting is evident.

■ Do not trust a surface crust to remainintact.

■ Do not depend on a second person tostart or stop equipment according toshouted instructions. Equipment noisecan prevent communication. The sec-ond person may be unable to completethe task soon enough.

■ When entering a bin that contains poorquality grain or when unloading historyis unknown, have two workers outsidethe bin. The person in the bin shouldwear a safety rope. The companionsoutside the bin should be able to lifthim or her out without entering the bin.One outside companion cannot do this.Having two companions present allowsone to administer first aid while theother goes for help.

■ Always wear a particle respirator capa-ble of filtering fine dust and moldspores when working inside a bin; graindust and molds are a health hazard.

■ Keep children away from equipment,vehicles, and flowing grain.

■ Avoid working in overfilled, peakedbins; crawling about in these bins cancause grain flows that block exits.

■ Maintain proper and effective shieldsand guards on hazardous equipment.

CONTROLLING ESTABLISHEDINFESTATIONS

To date, most insect problems in grainstored on Wisconsin farms are the result ofimproper storage. The development ofgrain molds makes stored grain attractiveto foreign and flat grain beetles. Therefore,your first step should be to correct storageconditions that allowed the grain to deteri-orate.

When insects are found in stored grains,you must determine whether or not theinfestation warrants control. The impor-tance of an insect infestation is determined

not only be the number of insects present,but also by type of grain, insect species,time of year, grain temperature and mois-ture, the planned length of storage, marketpotential, and local elevator quality anddockage guidelines. Table 7-1 lists the Fed-eral Grain Inspection Service (FGIS) stan-dards for grain infestation that will be ineffect until further notice, but local eleva-tors usually enforce more stringent stan-dards. Insect-damaged kernels also mayresult in price discounts. Consider too thatinsect populations and their damage canincrease rapidly.

If you find insects in stored grain, con-sider several possible management options.Sometimes the most profitable option maybe to clean and sell the grain immediatelywithout any chemical treatment. Immediatesale is especially appropriate where earlystages of insect infestations are detectedbefore insect numbers reach elevator dock-age or discount levels.

Sometimes insect problems are limitedprimarily to the surface or central core ofstored grain. If Indian meal moth is theonly problem, you can control light infesta-tions by using Actellic (corn), Storcide (smallgrains), or DiPel (corn, soybean, smallgrains) in conjunction with dichlorvosstrips as outlined in the section on theIndian meal moth. Where abundant web-bing indicates a severe infestation, rakewebbing from the surface before treatment;fumigation may be necessary in this situa-tion. Where bran bugs are the problem andare confined primarily to a central core offine material, remove one or two loads ofgrain to extract that core, allowing safestorage of the remaining grain.

221

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNPRINCIPLES

OF

PESTM

NGMT.

Table 7-1. The number of live insects (perkilogram of grain) required for Federal GrainInspection Service designation as infested

Insect density for designation Crop as infested

Wheat, rye —Two or more live insects that are injuriousto stored grain.

Barley, corn oats —More than one live weevil, or —one live weevil plus five or more other livepest insects, or —no live weevils but 10 or more other livepest insects.


Where infested grain can be moved to aclean bin, transfer and treatment with aprotectant insecticide is recommended. Ifpossible, use a grain cleaner during thetransfer process. Protectant insecticides willnot immediately kill immature insectswithin grain kernels, but residues eventu-ally provide control and protect againstreinfestation for a period dependent upongrain moisture and temperature.

This information was adapted from theIllinois Agricultural Pest Management Hand-book, produced by the University of Illinois.

FUMIGATIONInfested grain that cannot be treated suc-

cessfully in any other way should be fumi-gated. Fumigation of farm-stored grain isdifficult, hazardous, and requires specialtraining and equipment.

You must receive supplemental certifica-tion to apply fumigants. If you are a certi-fied private applicator, you must receiveadditional certification in the AgriculturalFumigation subcategory. Commercialapplicators must be certified in the Spaceand Commodity Fumigation category.

All fumigants are extremely toxic anddangerous if improperly used. Use them instrict accordance with label directions andfollow all safety precautions. Failure to fol-low all label instructions is unsafe andillegal.

Always work in pairs; an observershould be present outside the bin. Labelingrequires the use or availability of a self-con-tained breathing apparatus for respiratoryprotection during one or more stages of thefumigation process. Fumigators also mustmeasure fumigant gas concentrations todetermine that the fumigant has dissipatedsufficiently before unprotected persons canenter the fumigated space. Follow specificlabel directions concerning respiratory pro-tection equipment and gas detectiondevices. If you are uncertain about the safeuse of a fumigant, contact the manufacturerfor detailed instructions.

The following steps are suggested forfumigation:1. Level the grain; the grain surface must

be 8 inches or more below the bin lip toallow good aeration plus sufficient

space for inspection and treatment.Remove or break up any caked orcrusted area.

2. Use tape and plastic sheeting to thor-oughly seal all cracks and holes in thebin, including eaves, hatches, sidedoors, unloading auger shaft, and fanopenings. Leave only the necessaryaccess openings to seal after fumigantapplication.

3 . Fumigate on a still day when the graintemperature is above 60°F. Wind causesrapid leakage of the gas and will reducethe effectiveness of the fumigation.

4. The method of application will varywith the type of fumigant, commodity,and storage facility. Apply the productat labeled rates and follow all safetyprecautions.Chloropicrin—The primary use of thisheavier-than-air fumigant will be tocontrol insects in the subfloor area ofempty bins.Phosphine—This is available in solidformulations of aluminum or magne-sium phosphate and is used for fumiga-tion of insect-infested grain. Whenexposed to heat and moisture, the for-mulations release phosphine, a highlytoxic gas. Even moisture from handscan activate the pellets, so neoprene orcotton gloves must be used.

5. Never fumigate alone. Always work inpairs and wear an approved respirator.

6. Seal all access doors to the bin. Placewarning signs as directed by the fumi-gant label.

7. Keep the bin closed for at least 72 hoursbefore airing out bins following alu-minum phosphide or chloropicrin fumi-gation. Do not enter the bin during orafter fumigation until gases have beenthoroughly removed by aeration.

Fumigated grain must be aerated thor-oughly before processing or feeding. Onceit is aired out, fumigated grain may becomereinfested. Surface application of protectantinsecticide and/or placement of dichlorvosresin strips should follow fumigation ifstorage is to continue. If the infestation wasa result of poor grain storage practices,these conditions must be corrected.

222

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNPRINCIPLES

OF

PESTM

NGMT.


APPENDIX

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNPRINCIPLES

OF

PESTM

NGMT.


STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNPRINCIPLES

OF

PESTM

NGMT.

Appendix Table 1a. HERBICIDE products and related information

Restricted- Restricted-Commercial Manu- use Signal entry intervalname Formulationa,b Common name Site of inhibitionc facturer pesticide word (REI)d

Accent 75DF nicosulfuron ALS DuPont caution 4 hrAffinity 25 thifensulfuron ALS DuPont caution 12 hr

BroadSpec + 25SG + tribenuron ALSAim EW 1.9L carfentrazone PPO FMC caution 12 hrAlly 60DF metsulfuron ALS DuPont caution 4 hrAssure II 0.88EC quizalofop ACCase DuPont danger 12 hrAtrazine, others 90DF, 4L atrazine photosystem II several RUP caution 12 hrd1

Authority 3.33 sulfentrazone PPO FMC caution 12 hrAssist + 0.67S + imazethapyr ALS

Authority First 62.1 sulfentrazone PPO FMC caution 12 hr+ 7.9DF + cloransulam ALS

Authority MTZ 0.18 sulfentrazone PPO FMC RUP danger 12 hr+ 0.27DF + metribuzin photosystem II

Autumn 10DF iodosulfuron ALS Bayer caution 12 hrBanvel 4S dicamba auxin Arysta warning 24 hrBasagran 4S bentazon photosystem II Arysta caution 48 hrBasis 50 rimsulfuron ALS DuPont caution 4 hr

+ 25DF + thifensulfuron ALSBeacon 75DF primisulfuron ALS Syngenta caution 12 hrBicep II 2.4 s-metolachlor seedling shoot Syngenta RUP caution 24 hrd1

Magnum + 3.1L + atrazine photosystem II+ safener —

Bicep Lite II 3.33 s-metolachlor seedling shoot Syngenta RUP caution 24 hrd1

Magnum + 2.67L + atrazine photosystem II+ safener —

Boundary 6.5 5.25 s-metolachlor seedling shoot Syngenta caution 12 hrd1

+ 1.25L + metribuzin photosystem IIBuctril 4EC, 2EC bromoxynil photosystem II Bayer warning 24 hrBullet 2.5 alachlor seedling shoot Monsanto RUP caution 12 hrd1

+ 1.5ME + atrazine photosystem IIButyrac 200 2S 2,4-DB amine auxin Albaugh danger 48 hrCadet 0.91EC fluthiacet PPO FMC warning 12 hrCallisto 4L mesotrione pigment Syngenta caution 12 hrd1

Camix 3.34 s-metolachlor seedling shoot Syngenta warning 24 hrd1

+ 0.33L + mesotrione pigmentCanopy 64.3 metribuzin photosystem II DuPont caution 12 hr

+10.7DF + chlorimuron ALSCanopy EX 22.7 chlorimuron ALS DuPont caution 12 hr

+ 6.8DF + tribenuron ALSCelebrity Plus 10.6 nicosulfuron ALS BASF caution 12 hr

+ 42.4 + dicamba auxin+ 17DF + diflufenzopyr auxin synergist

Cimarron Max Part A: 60DF metsulfuron ALS DuPont danger 48 hrPart B: 1 + 2.87S dicamba + 2,4-D auxin

Cimarron Plus 48 metsulfuron ALS DuPont caution 4 hr+ 15DF + chlorsulfuron ALS

Cimarron X-tra 30 metsulfuron ALS DuPont caution 4 hr+ 37.5DF + chlorsulfuron ALS

224

Footnotes on page 231. (continued)


STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNPRINCIPLES

OF

PESTM

NGMT.Cinch 7.64EC s-metolachlor seedling shoot DuPont caution 24 hrd1

+ safener —Cinch ATZ 2.4 s-metolachlor seedling shoot DuPont RUP caution 24 hrd1

+ 3.1L + atrazine photosystem II+ safener —

Cinch ATZ 3.33 s-metolachlor seedling shoot DuPont RUP caution 24 hrd1

Lite + 2.67L + atrazine photosystem II+ safener —

Clarity 4S dicamba auxin BASF caution 24 hrClassic 25DF chlorimuron ALS DuPont caution 12 hrCobra 2EC lactofen PPO Valent danger 12 hrCrossbowe 1 triclopyr auxin Dow caution —-

+ 2EC + 2,4-D ester auxinCurtail 0.38S clopyralid auxin Dow danger 48 hr

+ 2.0S +2,4-D amine auxinDefine SC 4L flufenacet seedling shoot Bayer warning 12 hrd1

Degree 3.8ME acetochlor seedling shoot Monsanto caution 12 hrd1

+ safener —Degree Xtra 2.7 acetochlor seedling shoot Monsanto RUP caution 12 hrd1

+ 1.34 ME + atrazine photosystem II+ safener —

Distinct 50 dicamba auxin BASF caution 12 hr+ 20DS + diflufenzopyr auxin synergist

Dual II 7.64EC s-metolachlor seedling shoot Syngenta caution 24 hrd1

Magnum + safener —Enlite 2.85 chlorimuron ALS DuPont caution 12 hr

+ 36.21 + flumioxazin PPO+ 8.8DF + thifensulfuron ALS

Envive 9.2 chlorimuron ALS DuPont caution 12 hr+ 29.2 + flumioxazin PPO+ 2.9DF + thifensulfuron ALS

Eptam 7EC, 20G EPTC seedling shoot Syngenta caution 12 hrd1

Escort 60DF metsulfuron ALS DuPont caution 4 hrExpert 1.74 s-metolachlor seedling shoot Syngenta RUP caution 12 hrd1

+ 2.14 + atrazine photosystem II+ 0.74L + glyphosate EPSPS

Express 50DS tribenuron ALS DuPont caution 12 hrExtreme 0.17 imazethapyr ALS BASF warning 48 hr

+ 1.5S + glyphosate EPSPSField Master 2 acetochlor seedling shoot Monsanto RUP caution 12 hrd1

+ 1.5 + atrazine photosystem II+ 0.56L + glyphosate EPSPS

+ safener —FirstRate 84DF cloransulam ALS Dow caution 12 hrd1

Flexstar 1.88S fomesafen PPO Syngenta warning 24 hrForefront 0.33 aminopyralid auxin Dow danger 48 hr

+ 2.67S + 2,4-D amine auxinFulTime 2.4 acetochlor seedling shoot Dow RUP caution 12 hrd1

+ 1.6ME + atrazine photosystem II+ safener —

225

Appendix Table 1a. HERBICIDE products and related information (continued)




STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNPRINCIPLES

OF

PESTM

NGMT. Fusilade DX 2EC fluazifop ACCase Syngenta caution 12 hr

Fusion 2 fluazifop ACCase Syngenta caution 24 hr+ 0.66EC + fenoxaprop ACCase

Gangster FR 84DF cloransulam ALS Valent caution 12 hrGangster V 51DF flumioxazin PPO Valent caution 12 hrG-Max Lite 2.25 dimethenamid-P seedling shoot BASF RUP caution 12 hrd1

+ 2.75L + atrazine photosystem IIGramoxone Inteon 2S paraquat photosystem I Syngenta RUP danger 12 hrd2

Guardsman Max 1.7 dimethenamid-P seedling shoot BASF RUP caution 12 hrd1

+ 3.3L + atrazine photosystem IIHalex GT 2.09 s-metolachlor seedling shoot Syngenta caution 24 hrd1

+ 2.09 + glyphosate EPSPS+ 0.209L + mesotrione pigment

Harmony Extra 16.7 tribenuron ALS DuPont caution 12 hr+ 33.3SG + thifensulfuron ALS

Harmony SG 50SG thifensulfuron ALS DuPont caution 4 hrHarness 7EC acetochlor seedling shoot Monsanto warning 12 hrd1

+ safener —Harness Xtra 4.3 acetochlor seedling shoot Monsanto RUP caution 12 hrd1


Harness Xtra 3.1 acetochlor seedling shoot Monsanto RUP caution 12 hrd1

5.6L + 2.5L + atrazine photosystem II+ safener —

Hornet WDG 18.5 flumetsulam ALS Dow warning 48 hrd1

+ 50WG + clopyralid auxinHuskie 0.3 pyrasulfotole pigment Bayer warning 12 hr

+ 1.75EC + bromoxynil photosystem II+ safener

Ignite 2.34 S glufosinate GS Bayer warning 12 hrImpact 2.8L topramazone pigment Amvac caution 12 hrIntrro 4EC alachlor seedling shoot Monsanto RUP danger 12 hrd1

Journey 0.75 imazapic ALS BASF caution 12 hr+ 1.5S + glyphosate EPSPS

Keystone 3 acetochlor seedling shoot Dow RUP danger 12 hrd1


Keystone LA 4 acetochlor seedling shoot Dow RUP danger 12 hrd1


Laddok S-12 2.5 bentazon photosystem II Sipcam RUP danger 12 hr+ 2.5L + atrazine photosystem II

Lariat 2.5 alachlor seedling shoot Monsanto RUP warning 12 hrd1

+ 1.5L + atrazine photosystem IILaudis 3.5L tembotrione pigment Bayer caution 12 hr

+ safenerLexar 1.74 s-metolachlor seedling shoot Syngenta RUP caution 24 hrd1

+ 1.74 + atrazine photosystem II+ 0.224L + mesotrione pigment

226





STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNPRINCIPLES

OF

PESTM

NGMT.Lightning 52.5 imazethapyr ALS BASF warning 12 hr

+ 17.5DF + imazapyr ALSLorox 50DF linuron photosystem II Griffin caution 24 hrLumax 2.68 s-metolachlor seedling shoot Syngenta RUP caution 24 hrd1

+ 1 + atrazine photosystem II+ 0.268L + mesotrione pigment

Marksman 1.1 dicamba auxin BASF RUP caution 24 hrd1

+ 2.1L + atrazine photosystem IIMCPA Amine Various MCPA auxin several danger 48 hrMCPA Ester Various MCPA auxin several caution 12 hrMilestone 2.0S aminopyralid auxin Dow caution 12 hrNorthStar 7.5 primisulfuron ALS Syngenta caution 12 hrd1

+ 39.9DF + dicamba auxinOption 35DF foramsulfuron ALS Bayer caution 12 hr

+ safener —Orion 0.033 florasulam ALS Syngenta caution 12 hr

+ 2.34S + MCPA auxinOutlook 6EC dimethenamid-P seedling shoot BASF warning 12 hrd1

Overdrive 50 dicamba auxin BASF caution 12 hr+ 20DS + diflufenzopyr auxin synergist

Peak 57DF prosulfuron ALS Syngenta caution 12 hrPendimax 3.3EC pendimethalin seedling root Dow caution 24 hrd1

Permit 75DF halosulfuron ALS Gowan caution 12 hrPhoenix 2EC lactofen PPO Valent danger 12 hrPlateau 70DF imazapic ALS BASF caution 12 hrPoast 1.5EC sethoxydim ACCase BASF warning 12 hrPoast Plus 1EC sethoxydim ACCase BASF caution 12 hrPrefix 4.34 s-metolachlor seedling shoot Syngenta warning 24 hr

+0.95EC + fomesafen PPOPrincep 90DF, 4L simazine photosystem II Syngenta caution 12 hrd1

Priority 12.5 carfentrazone PPO Tenkoz caution 12 hr+ 50DF + halosulfuron ALS

Prowl H2O 3.8ME pendimethalin seedling root BASF caution 24 hrd1

Pursuit 2S, 70DF imazethapyr ALS BASF warning 12 hrd1

Pursuit Plus 0.2 imazethapyr ALS BASF caution 24 hrd1

+ 2.7EC + pendimethalin seedling rootPython 80DF flumetsulam ALS Dow caution 12 hrd1

Rage D-Tech 0.13 carfentrazone PPO FMC caution 12 hr+ 3.93EC + 2,4-D ester auxin

Raptor 1EC imazamox ALS BASF caution 4 hrd1

Require Q 6.25 rimsulfuron ALS DuPont warning 24 hr+ 48.12DF + dicamba auxin

+ safenerResolve 25DF rimsulfuron ALS DuPont caution 4 hrResolve Q 18.4 rimsulfuron ALS DuPont caution 4 hr

+ 4DF + thifensulfuron ALS+ safener

227





STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNPRINCIPLES

OF

PESTM

NGMT. Resource 0.86EC flumiclorac PPO Valent warning 12 hr

Roundup 4.5S glyphosate EPSPS Monsanto caution 4 hrWeatherMax

Select Max 0.97EC clethodim ACCase Valent warning 24 hrSencor 75DF metribuzin photosystem II Bayer caution 12 hrd1

Sequence 2.25 glyphosate EPSPS Syngenta caution 24 hr+3EC + s-metolachlor seedling shoot

Shotgun 2.25 atrazine photosystem II Platte RUP danger 12 hr+ 1L + 2,4-D ester auxin

Sonic 62.1 sulfentrazone PPO Dow caution 12 hr+ 7.9DF + cloransulam ALS

Spartan 4F sulfentrazone PPO FMC caution 12 hrd1

Spikee 20G tebuthiuron photosystem II Dow caution —-Starane 1.5EC fluroxypyr auxin Dow warning 12 hrStatus 40 dicamba auxin BASF caution 24 hr

+ 16DF + diflufenzopyr auxin synergist+ safener

Steadfast 50 nicosulfuron ALS DuPont caution 4 hr+ 25DF + rimsulfuron ALS

Stinger 3S clopyralid auxin Dow caution 12 hrStout 67.5 nicosulfuron ALS DuPont caution 4 hr

+ 5DF + thifensulfuron ALSSureStart 3.75 acetochlor seedling shoot Dow caution 12 hrd1

+ 0.29 + clopyralid auxin+ 0.12L + flumetsulam ALS

Surpass 6.4EC acetochlor seedling shoot Dow warning 12 hrd1

+ safener —Synchrony XP 21.5 chlorimuron ALS DuPont caution 12 hr

+ 6.9DF + thifensulfuron ALSThistrol 2S MCPB auxin Bayer caution 12 hrTopNotch 3.2ME acetochlor seedling shoot Dow caution 12 hrd1

+ safener —Touchdown 3, 4.17, 5S glyphosate EPSPS Syngenta caution 12 hrTreflan 4EC, 10G trifluralin seedling root Dow caution 12 hrd1

Ultra Blazer 2S acifluorfen PPO United danger 48 hrPhosphorus

Unity 75DF thifensulfuron ALS Gowan caution 4 hrValor SX 51DF flumioxazin PPO Valent caution 12 hrValor XLT 30 flumioxazin PPO Valent caution 12 hr

+10.3DF + chlorimuron ALSVelpar 75DF hexazinone photosystem II DuPont danger 24 hrWeedmaster 2.87 2,4-D amine auxin BASF danger 48 hr

+ 1S + dicamba auxinYukon 12.5 halosulfuron ALS Gowan caution 12 hr

+ 50DF + dicamba auxin2,4-D Amine various 2,4-D auxin several danger 48 hr2,4-D Ester various 2,4-D auxin several caution 12 hr

228





STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNPRINCIPLES

OF

PESTM

NGMT.

229

Appendix Table 1b. INSECTICIDE products and related information

Restricted- Restricted-Commercial use Signal entry intervalname Formulationa,b Common name Manufacturer pesticide word (REI)d

Actellice 5EC pirimiphos-methyl Agriliance warning —Alias 4F imidacloprid Makhteshim Agan caution 12 hrAmbush 2E permethrin Amvac, Syngenta RUP warning 12 hrAsana XL 0.66EC esfenvalerate DuPont RUP warning 12 hrAztec 4.67G, 2.1G tebupirimphos + cyfluthrin Amvac, Bayer RUP warning 48 hrd1

Baythroid 1XL cyfluthrin Bayer RUP warning 12 hrBrigade 2EC bifenthrin FMC RUP warning 12 hrCapture 1.5LFR bifenthrin FMC RUP warning 12 hrCobalt 2.5 chlorpyrifos Dow RUP danger 24 hr

+ 0.045EC + gamma cyhalothrinCounterf 15G terbufos Amvac RUP danger 48 hrd1

Cruiser seed treatment thiamethoxam Syngenta caution 12 hrd1

Delta Gold 1.5EC deltamethrin Agriliance RUP danger 12 hrDiacon IIe 2.5EC methoprene Wellmark Int’l caution —Dimethoate 4EC, 400 dimethoate several warning 48 hrDipel DF, ES Bacillus thuringiensis Valent caution 4 hrEndigo 1.18 thiamethoxam Syngenta RUP warning 24 hr

+ 0.88ZC + lambda-cyhalothrinForce 3G tefluthrin Amvac, Syngenta RUP caution noneForce CS tefluthrin Syngenta RUP warning 12 hrFortressf 5G chlorethoxyfos Amvac RUP danger 48 hrFuradanf 4F carbofuran FMC RUP danger 48 hrd4

Gaucho seed treatment imidacloprid Bayer caution 12 hrd1

Hero 1.24EC zeta cypermethrin FMC RUP caution 12 hr+ bifenthrin

Imidan 70WP phosmet Gowan warning 24 hrInsectoe 90D diatomaceous earth Natural caution —Intrepid 2F methoxyfenozide Dow caution 4 hrLannatef 2.4LV, 90SP methomyl DuPont RUP danger 48 hr Lorsbanf 15G chlorpyrifos Amvac, Dow caution 24 hrd1

Lorsbanf 4E, Advanced chlorpyrifos Dow RUP warning 24 hrd1

Kernel Guard seed treatment permethrin Bayer caution 12 hrd1

SupremeMalathion 57EC malathion several caution 12 hrMustang Max 0.8EC zeta-cypermethrin FMC RUP warning 12 hrOrthene 90S acephate Valent caution 24 hrPenncap-M 2ME methyl parathion Cerexagri RUP warning 4 daysPhorate 20G phosphorodithioate several RUP danger 48 hrPoncho seed treatment clothianidin Bayer caution 12 hrd1

Pounce 3.2EC permethrin FMC RUP caution 12 hrProaxis 0.5CS gamma-cyhalothrin UAP, Tenkoz RUP caution 24 hrRegent 4SC fipronil BASF RUP warning noneSevin XLR Plus 4F carbaryl Bayer caution 12 hrSilencer 1EC lambda-cyhalothrin Makhteshim Agan RUP warning 24 hr



STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNPRINCIPLES

OF

PESTM

NGMT.

230

Storcide IIe 1.92 chlorpyrifos-methyl Bayer danger —+ 1.28L + cyfluthrin

Tempo SC Ultrae 1S cyfluthrin Bayer RUP caution —Tracer 4L spinosad Dow caution 4 hrVaponae industrial strip dichlorvos several caution —Warrior II 2CS lambda-cyhalothrin Syngenta RUP warning 24 hr

Appendix Table 1c. FUNGICIDE products and related information


Alto 100 SL cyproconazole Syngenta caution 12 hrApron XL LS 3.3S mefenoxam Syngenta warning 48 hrd1

Bayleton 50DF triadimefon Amvac caution 12 hrBravo 6F chlorothalonil Syngenta caution 12 hrWeather Stik

Bumper 41.8EC propiconazole Makhteshim-Agan warning 24 hrCaptan 5D, 7.5D, 80WP captan several danger 4 days d3,5

Caramba 90 SL metconazole BASF warning 12 hrCuprofix MZ 30 mancozeb Cerexagri caution 24 hr

Disperss + 22DF + copper sulfateCuprofix Ultra 40DF copper sulfate Cerexagri caution 12 hrDithane 75DF, F45, M45 mancozeb Dow caution 24 hrDividend 0.15S, 0.31S difenoconazole Syngenta caution 12 hrd1

Domark 230ME 1.9EW tetraconazole Isagro caution 24 hrEcho 90DF chlorothalonil Sipcam Agro USA danger 12 hrEcho Zn 4.17F chlorothalonil Sipcam Agro USA warning 12 hrEcho 720 6F chlorothalonil Sipcam Agro USA warning 12 hrEnhance 20 + 20D carboxin + captan Trace Chemicals danger 48 hrd1

Folicur 3.6F tebuconazole Bayer caution 12 hrHeadline 2.09EC pyraclostrobin BASF warning 12 hrLaredo 2EC myclobutanil Dow danger 24 hrManzate 4F mancozeb DuPont caution 24 hrManzate Pro-Stick 75DF mancozeb DuPont caution 24 hrMaximh 4S fludioxonil Syngenta caution —Mertect 340 4.1F thiabendazole Syngenta danger 12 hrPenncozeb 75DF mancozeb Cerexagri caution 24 hrProline 480 4SC prothioconazole Bayer caution 48 hrPropiMax 3.6EC propiconazole Dow warning 24 hrd1

Prosaro 421 SC prothioconazole Bayer caution 48 hr+ tebuconazole

Quadris 2F azoxystrobin Syngenta caution 4 hrQuadris 2F azoxystrobin Syngenta caution 48 hrd1

Ridomil Goldg + 4EC + mefenoxamQuadris Xtra 280 SC azoxystrobin Syngenta caution 12 hr

+ cyproconazoleFootnotes on page 231. (continued)

Appendix Table 1b. INSECTICIDE products and related information (continued)



STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNPRINCIPLES

OF

PESTM

NGMT.

Appendix Table 1c. FUNGICIDE products and related information (continued)


Quilt 1.04 + 0.62EC azoxystrobin + propiconazole Syngenta caution 24 hrRaxil MD 0.039 + 0.051L tebuconazole + metalaxyl Bayer caution 24 hrd1

Raxil XT 15 + 20WP tebuconazole + metalaxyl Bayer caution 24 hrd1

Raxil-Thiram 0.055 + 1.84F tebuconazole + thiram Bayer caution 24 hrd1

Ridomil Gold 5G, 50WP, 4EC mefenoxam Syngenta caution 48 hrd1

Ridomil Gold 5 mefenoxam Syngenta danger 48 hrCopper + 60WP + copper hydroxideStratego 1.04 propiconazole Bayer warning 24 hr

+ 1.04S + trifloxystrobinTerraclor 4F, 75WP PCNB Uniroyal caution 12 hrd1

Thiram 65WP thiram Taminco caution 24 hrTilt 3.6EC propiconazole Syngenta warning 24 hrd1

Topsin M 4.5F, 70WP thiophanate- methyl Cerexagri caution 12 hrTrilex AL trifloxystrobin + metalaxyl Bayer caution 24 hrTrilex FL trifloxystrobin + metalaxyl Bayer caution 12 hrVitavax-200 1.67 + 1.67F carboxin + thiram Crompton caution 24 hrd1

FOOTNOTES for Appendix Tables 1a–c

a CS = capsule suspension; D = dust; DF = dry flowable; DS= dry soluble; EC = emulsifiable concentrate; ES = emulsi-fiable suspension; EW = emulsifiable in water; F = flow-able; G = granular, L = liquid flowable; ME = micro-encapsulated; S = soluble; WG = wettable granules; WP =wettable powder; WSP = water-soluble packet.

b Numbers before the dry formulations represent percentactive ingredient; numbers before liquids representpounds of active ingredient or acid equivalent per gallonof product.

c Site of inhibition: ACCase = acetyl CoA carboxylase (lipidsynthesis inhibitor); ALS = acetolactate synthase (aminoacid synthesis inhibitor); auxin = growth regulator;EPSPS = 5-enolpyruvylshikimate-3-phosphate synthase(amino acid synthesis inhibitor); GS = glutamine syn-thetase (nitrogen metabolism inhibitor); photosystem I =cell membrane disrupter; photosystem II = photosynthe-sis inhibitor; pigment inhibitor = isoprenoid pathway;PPO = protoporphyrinogen oxidase (cell membrane dis-rupter); seedling shoot = seedling shoot growth inhibitor;seedling root = seedling root growth inhibitor.

d REI as required by the Worker Protection Standard toprotect agricultural workers and handlers of agriculturalpesticides. Labeled nonagricultural uses may have differ-ent REIs or worker notification requirements.

d1REI EXCEPTION: If the product is soil-injected or soil-incor-porated or used for seed treatment, the Worker ProtectionStandard, under certain circumstances, allows workers toenter the treated area if there will be no contact with any-thing that has been treated.

d2REI EXCEPTION: The REI is 24 hours for harvest aid anddesiccation applications.

d3REI EXCEPTION: After the first 48 hours of the REI, workersmay enter the treated area to perform hand labor or othertasks involving contact with anything that has beentreated, such as plants, soil, or water, without time limit,if they wear the early-entry personal protective equip-ment (PPE) listed on the label.

d4REI EXCEPTION: The REI is 14 days for foliar applications tocorn, sunflowers, and sorghum. For the last 12 days ofthe REI, workers may enter the treated area to performhand labor or other tasks involving contact with anythingthat has been treated, such as plants, soil, or water, with-out time limit, if they wear the early-entry personal pro-tective equipment (PPE) listed on the label.

d5REI EXCEPTION: The REI for strawberries is 24 hours. Afterexpiration of the 24-hour period, no PPE is required.

e Under the Worker Protection Standard, this is a nonagri-cultural use product, thus there is no REI requirement.

f Under the Worker Protection Standard, this productrequires dual notification to workers: verbal AND posted.Wisconsin has additional posting requirements when thisproduct is applied to areas within 300 feet of a residence,migrant labor camp, school, day care facility, health carefacility, commercial or industrial facility, public recreationarea, or other nonagricultural area where people arelikely to be present during the REI.

g Sold in two containers (co-packs).h For use only by commercial seed treaters.

231


STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNPRINCIPLES

OF

PESTM

NGMT.

232

a The hybrids Merit, Carnival, and Sweet Success require 15M. b If the soil pH is 6.5 or greater, do not plant for 18M. c Use the shorter interval for winter wheat and the longer interval for

spring wheat.d Use shorter interval after 8 oz/a or longer interval after 16 oz/a.e A 12M interval exists following the 2.67 pt/a of Command 3ME.f Imidazolinone tolerant corn hybrids have no restrictions.g If the soil has less than 2% organic matter and less than 15 inches

of rain has fallen, do not plant for 18M.h Following application to fallow or crop stubble.i Interval depends on rate and formulation.j A 10M interval exists for transplant tobacco after 0.3 oz/a

FirstRate or less.

k A 10.5M interval exists for hybrids listed on the supplementallabel.

l Rotational intervals are for 0.33 oz/a rate.mOnly corn or sorghum can be planted FY if applied after June 1.n Wait 9M if using 0.5 oz/a rate.o Interval of 18M if <18 inches of rainfall or if soil pH is <6.2.p For rates over 0.375 oz/a, the interval is 18M.q Interval of 18 months if soil pH is >7 and organic matter is <1.5%.r Rotational intervals are for 0.25 oz/a rate.s Rotational intervals are for 0.5 oz/a rate.t Rotational intervals are for 12 oz/a rate.

Appendix Table 2. Planting interval for rotational crops. See the label for information on crops not listed below.

Snap Field Sweet Soy-Herbicide Alfalfa Barley beans corn corn Oats Peas Potato bean Tobacco Wheat

Accent 10M 8M 10M 0 10Ma 8M 10M 10Mb 15D 10Mb 4–8Mc

Affinity BroadSpec 45D 0 45D 14D 45D 45D 45D 45D 7D 45D 0Assure II 120D 120D 0 120D 120D 120D 0 120D 0 120D 120Datrazine 2Y 2Y 2Y 0 0 2Y 2Y 2Y FY 2Y 2YAuthority Assist 12M 9.5M 10M 10M 18M 18M 10M 26M 0 9.5M 4MAuthority First/Sonic 12M 12M 30M 10–18Mq 18M 12M 30M 18M 0 30M 4MAuthority MTZ 12M 4M 18M 10M 18M 18M 18M 12M 0 12M 4MAutumn 18M 8M 18M 30D 90D 9M 18M 18M 90D 18M+BA 4–8Mc

Banveld AH AH AH 0 AH AH AH AH AH AH AHBasagran — — — — — — — — — — —Basisl 10M 8M 8M 0 10M 8M 8M 0 15D 18M 4–8Mc

Beacon 8M 8M 18M 14D 8M 8M 8M 18M 8M 8M 3–8Mc

Bicep Lite II 2Y 2Y 2Y 0 0 2Y 2Y 2Y FY 2Y 2YBoundary 6.5 4.5M 8M 12M 8M 8M 12M 8M 0 0 12M 4.5–8Mc

Buctril 30D 30D 30D 0 30D 30D 30D 30D 30D 30D 30DBullet/Lariat 2Y 2Y 2Y 0 0 2Y 2Y 2Y FY 2Y 2YButyrac 200 — — — — — — — — — — —Cadet — — — 0 0 — — — 0 — —Callisto 10M 120D 18M 0 0 0 18M 10M 10M 10M 120DCamixm 18M FY 18M 0 0 FY 18M FY FY 18M 4.5M–FYc

Canopy 10M 4M 12M 10M 18M 30M 12M 30M 0 10M 4MCanopy EX 12M 3M 9M 9M 18M 3M 9M 30M 0 9M 3MCelebrity Plus 10M 8M 10M 7D 10Ma 8M 10M 10Mb 4M 10Mb 4–8Mc

Cimarron Max/Plusr BA BA BA BA BA 10M BA BA BA BA 1MCimarron X-tras BA 24M BA BA BA 16M BA BA BA BA 4MClarity 120D 15–30D 120D 0 120D 15–30D 120D 120D 14–28D 120D 15–30DClassic 9M 3M 9M 9M 9M 3M 9M 30M 0 15M 3MCobra/Phoenix — — — — — — — — — — —Define SC 12M 12M 12M 0 12M 12M 12M 1M 0 12M 12MDegree 9M FY 2Y 0 0 FY 2Y FY FY FY 4MDegree Xtra 2Y 2Y 2Y 0 0 2Y 2Y 2Y FY 2Y 2YAbbreviations: 0 = no restriction; M = month; AH = after harvest; Fall = fall after application; D = day; Y = year; (continued)BA = bioassay required; FY = following year; — = no restrictions for rotational crops listed on label.


STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNPRINCIPLES

OF

PESTM

NGMT.

233

Dual II Magnum 4M 4.5M 0 0 0 4.5M 0 0 0 FY 4.5MEnlite 12M 4M 9M 9M 9M 12M 9M 30M 0 9M 4MEnvive 12M 4M 12M 10M 18M 30M 12M 30M 0 10M 4MEptam AH AH AH AH AH AH AH AH AH AH AHExpress 45D 0 45D 45D 45D 45D 45D 45D 45D 45D 0Extreme 4M 9.5M 4M 8.5Mf 18M 18M 4M 26M 0 9.5M 3MField Master 2Y 2Y 2Y 0 FY 2Y 2Y 2Y FY 2Y 2YFirstRate 9M 30M+BA 9M 9M 18M 9M 9M 18M 0 10–30Mj 3MFlexstar 18M 4M 0 10M 10M 4M 10M 18M 0 18M 4MForeFront 12M+BA 12M 12M+BA 12M 12M 12M 12M+BA 12M+BA 12M+BA 12M+BA 12MFulTime 15M 15M 2Y 0 0 15M 2Y 15M FY 15M 15MFusilade DX 0 60D 0 60D 60D 60D 0 0 0 0 60DFusion 0 60D 0 60D 60D 60D 0 0 0 0 60DGangster 30M+BA 30M+BA 9M 9M 18M 9M 9M 18M 0 30M 3MGlyphosate 0 0 0 0 0 0 0 0 0 30D 0G-Max Lite 2Y 2Y 2Y 0 0 2Y 2Y 2Y FY 2Y 2YGramoxone Inteon 0 0 0 0 0 0 0 0 0 0 0Halex GT 10M 120D 18M 0 0 18M 18M 10M 10M 10M 120DHarmony Extra 45D 0 45D 45D 45D 0 45D 45D 45D 45D 0Harmony SG 45D 0 45D 0 45D 0 45D 45D 0 45D 0Harness 9M FY 2Y 0 0 FY 2Y FY FY FY 4MHarness Xtra 2Y 2Y 2Y 0 0 2Y 2Y 2Y FY 2Y 2YHornet WDG 10.5M 4M 10.5M 0 10.5–18Mk 4M 10.5M 18M 10.5M 18M 4MHuskie 9M 7D BA 9M 9M 7D BA 9M 4M BA 7DIgnite 180D 70D 180D 0 180D 70D 180D 180D 0 180D 70DImpact 9M 3M 9–18Mn 0 0 3M 9M 9M 9–18Mn 18M 3MIntrro FY FY 2Y FY FY FY 2Y 2Y 0 2Y FYJourneyt 36M+BA 24M 18M 36M+BA 36M+BA 24M 36M+BA 48M+BA 18M 36M+BA 12MKeystone LA 15M 15M 2Y 0 0 15M 2Y 15M FY 15M 15MLaddok S-12 FY FY FY 0 FY FY FY FY FY FY FYLaudis 10M 4M 10M 0 0 4M 10M 10M 8M 18M 4MLorox 4M 4M 4M 4M 4M 4M 4M 4M 0 4M 4MLumaxm 18M FY 18M 0 0 FY 18M 18M FY 18M 4.5MMarksman 2Y 10M 2Y 0 FY 10M 2Y FY FY 2Y 10MMilestone 12M+BA 12M 12M+BA 12M 12M 12M 12M+BA 12M+BA 12M+BA 12M+BA 12MNorthStar 8M 8M 8M 14D 8M 8M 8M 8M 8M 8M 3–8Mc

Option 60D 60D 60D 7D 7D 60D 60D 60D 14D 60D 60DOrion 9M 14D 12M 3M 3M 14D 12M 9M 9M 12M 14DOutlook FY 4M FY 0 0 4M FY FY 0 FY 4MPermit 9M 2M 9M 1M 3M 2M 9M 9M 9M 2Y 2MPoast Plus 0 30D 30D 30D 30D 30D 30D 30D 0 30D 30DPrefix 18M 4.5M 0 10M 10M 4.5M 10M 18M 0 18M 4.5MPrincep 2Y 2Y 2Y 0 0 2Y 2Y 2Y FY 2Y 2Y

Appendix Table 2. Planting interval for rotational crops (continued)


(continued)


STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNPRINCIPLES

OF

PESTM

NGMT.

a The hybrids Merit, Carnival, and Sweet Success require 15M. b If the soil pH is 6.5 or greater, do not plant for 18M. c Use the shorter interval for winter wheat and the longer interval for

spring wheat.d Use shorter interval after 8 oz/a or longer interval after 16 oz/a.e A 12M interval exists following the 2.67 pt/a of Command 3ME.f Imidazolinone tolerant corn hybrids have no restrictions.g If the soil has less than 2% organic matter and less than 15 inches

of rain has fallen, do not plant for 18M.h Following application to fallow or crop stubble.i Interval depends on rate and formulation.j A 10M interval exists for transplant tobacco after 0.3 oz/a

FirstRate or less.

k A 10.5M interval exists for hybrids listed on the supplementallabel.

l Rotational intervals are for 0.33 oz/a rate.mOnly corn or sorghum can be planted FY if applied after June 1.n Wait 9M if using 0.5 oz/a rate.o Interval of 18M if <18 inches of rainfall or if soil pH is <6.2.p For rates over 0.375 oz/a, the interval is 18M.q Interval of 18 months if soil pH is >7 and organic matter is <1.5%.r Rotational intervals are for 0.25 oz/a rate.s Rotational intervals are for 0.5 oz/a rate.t Rotational intervals are for 12 oz/a rate.

234

Priority 12M 2M 12M 1M 3M 2M 12M 12M 9M 18M 2MProwl FY FY 0 FY FY FY 0 0 0 0 120D–FYc

Pursuit 4M 9.5M 4M 8.5Mf 18M 18M 4M 26M 0 9.5M 3MPursuit Plus 9.5M 9.5M 4M 8.5M 18M 18M 4M 26M 0 9.5M 4MPython 4M 4M 4M 0 10.5–18Mk 4M 4M 12M 0 9M 4MRage D-Tech 30D 30D 12M 3D 30D 30D 12M 30D 7D 12M 30DRaptor 3M 4M 0 8.5M 8.5M 9M 0 9Mo 0 9M 3MRequire Q 10M 9M 10M 0 10M 9M 10M 4M 10M 18M 3–9Mc

Resolve Q 10M 9M 10M 0 10M 9M 10M 1.5M 10M 18M 3–9Mc

Resource 30D 30D 30D 0 30D 30D 30D 0 0 30D 30DSelect Max 0 30D 30D 30D 30D 30D 30D 30D 0 30D 30DSencor 4M 4M 12M 4M 4M 12M 8M 12M 0 12M 4MSequence 4M 4.5M 0 0 0 4.5M 0 FY 0 FY 4.5MStarane 120D 0 120D 0 0 0 120D 120D 120D 120D 0Status 30D 30D 120D 7D 120D 30D 120D 120D 30D 120D 30DSteadfast 10M 8M 10M 0 10Ma 8M 10M 10Mb 15D 10Mb 4–8Mc

Stinger 10.5M 0 18M 0 10.5M 0 18M 18M 10.5Mg 18M 0Stout 10M 8M 10M 0 10M 8M 10M 10M 10M 18M 4–8Mc

SureStart FY FY 2Y 0 10.5–18M FY 2Y 18M FY 18M 4MSurpass/TopNotch FY FY 2Y 0 0 FY 2Y FY FY FY 4MSynchrony XP 9M 3M 9M 9M 9–18Mp 3M 9M 30M 0 9M 3MTreflan 5M 12M 0 12M 12M 12M 0 0 0 5M 12MUltra Blazer 100D 40D 100D 100D 100D 40D 100D 100D 0 100D 40DUnity 45D 0 45D 0 45D 0 45D 45D 0 45D 0Valor SX 10M 4M 4M 1M 4M 10M 4M 12M+BA 0 2M 2MValor XLT 12M 4M 12M 10M 18M 30M 12M 30M 0 10M 4MVelpar 2Y 2Y 2Y 12M 2Y 2Y 2Y 2Y 2Y 2Y 2YYukon 9M 2M 9M 1M 3M 2M 9M 9M 9M 2Y 2M2,4-Dh 3M 3M 3M 7–14D 3M 3M 3M 3M 7–30Di 3M 3MAbbreviations: 0 = no restriction; M = month; AH = after harvest; Fall = fall after application; D = day; Y = year; BA = bioassay required;FY = following year; — = no restrictions for rotational crops listed on label.

Appendix Table 2. Planting interval for rotational crops (continued)



STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNPRINCIPLES

OF

PESTM

NGMT.

Appendix table 3 lists many of the common herbi-cides used in Wisconsin field crops and their approxi-mate costs in 2008. Prices are listed on both a unitbasis and for many of the frequently used rates. Theunit prices represent the average from severalsources. These prices provide a general guide whenconsidering the cost of herbicide programs. Actualprices will vary depending on container size, date ofpurchase, and changes in manufacturer pricing. Thecosts of adjuvants or application are not included.

The comments specify whether the rate is for a cer-tain soil type or how the rate compares to the range ofrates recommended on the label. These rates are only aguide for comparing herbicide costs. Refer to the labelfor the exact rate that is required for your situation.

Under the crop heading, the following abbrevia-tions indicate that only specific herbicide-resistantvarieties or hybrids can be treated (CF = Clearfield,LL = Liberty Link, and RR = Roundup Ready).

Appendix Table 3. Herbicide price list, 2008

Price Price at the following rates: Herbicide Crop Timing $/unit $/acre rate/acre Comments

Accent WDG corn Post 41.00 oz 27.47 0.67 oz standard rateAlly grass pasture Post 13.69 oz 4.11 0.3 oz full rate, grass pasture onlyAssure II soybean Post 156.73 gal 4.90 4 fl oz 12-inch volunteer corn rateatrazine 90DF corn Pre/Post 3.05 lb 2.29 0.75 lb coarse soil, maximum rate

4.57 1.5 lb medium soil, maximum rateAuthority First soybean Pre 64.45 lb 12.89 3.2 oz low rate

32.23 8 oz high rateAuthority MTZ soybean Pre 17.01 lb 10.63 10 oz RR soybean program

17.01 16 oz standard rateAutumn corn, soybean Pre 20.79 oz 6.24 0.3 oz full rateBanvel corn, small grains, Post 70.38 gal 4.40 0.5 pt low rate

pasture 8.80 1 pt standard rate2.82 4 fl oz full rate, small grain

Basagran corn, soybean Post 90.25 gal 22.56 2 pt high rateBasis corn Pre, Post 16.83 oz 16.83 1 oz pre, high rateBeacon corn Post 32.18 oz 24.45 0.76 oz full rateBicep Lite II corn PPI/Pre 56.88 gal 15.64 1.1 qt coarse soilMagnum 21.33 1.5 qt medium soil

Boundary soybean PPI/Pre 77.30 gal 12.08 1.25 pt coarse soil16.91 1.75 pt medium soil

Buctril corn, alfalfa, Post 73.36 gal 9.17 1 pt low ratesmall grains 13.76 1.5 pt standard rate

Butyrac 200 alfalfa Post 38.68 gal 19.34 2 qt medium rateCallisto corn Post 636.42 gal 14.92 3 fl oz standard rateCamix corn Pre/Post 63.12 gal 31.56 2 qt soil OM less than 3%

37.87 2.4 qt soil OM 3% or greaterCinch corn/soybeans PPI/Pre 115.63 gal 19.22 1.33 pt medium soilCinch ATZ Lite corn PPI/Pre 56.99 gal 21.37 1.5 qt medium soilClarity corn, small grains, Post 103.71 gal 6.48 0.5 pt low rate

pasture 12.96 1 pt standard rate3.24 4 fl oz full rate, small grain

Classic soybean Post 15.59 oz 3.90 0.25 oz reduced rate for tank mix7.80 0.5 oz low rate

Cobra soybean Post 167.63 gal 7.86 6 fl oz reduced rate for tank mix16.37 12.5 fl oz high rate

Crossbow pasture Post 68.94 gal 103.41 1.5 % cost per 100 gal

235

(continued)


STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNPRINCIPLES

OF

PESTM

NGMT.

236

Curtail pasture Post 42.53 gal 21.26 2 qt light - Canada thistle infest.31.89 3 qt heavy - Canada thistle infest.

Degree corn PPI/Pre/Post 49.33 gal 18.50 3 pt coarse soil 24.67 4 pt medium soil

Degree Xtra corn PPI/Pre/Post 38.84 gal 28.16 2.9 qt coarse soil 35.93 3.7 qt medium soil

Dual II Magnum corn, soybean PPI/Pre 121.14 gal 15.14 1 pt coarse soil20.14 1.33 pt medium soil

Durango DMA many Post 41.48 gal 7.78 24 fl oz standard rateEptam alfalfa, birdsfoot PPI 38.81 gal 10.92 2.25 pt annual grasses

trefoil, clovers 21.83 4.5 pt full rateExpress TotalSol wheat, barley Post 16.33 oz 4.08 0.25 oz standard rateExtreme soybean Pre/Post 39.50 gal 14.81 3 pt full rateField Master corn 32.50 gal 36.56 4.5 qt medium soilFirstRate soybean PPI/Pre/Post 31.08 oz 9.32 0.3 oz postemergence rate

23.31 0.75 oz high rate, soil appliedFlexstar soybean Post 122.05 gal 15.26 1 pt standard rateForeFront pasture, CRP Post 58.12 gal 14.53 2 pt/a standard rateFusilade DX soybean Post 189.00 gal 5.91 4 fl oz 12-inch volunteer corn rateFusion soybean Post 179.03 gal 5.59 4 fl oz 12-inch volunteer corn rateGangster soybean EPP/Pre 6.69 oz 12.04 1.8 oz RR soybean program

20.74 3.1 oz conventional soybean programG-Max Lite corn PPI/Pre 67.09 gal 20.97 2.5 pt coarse soil

25.16 3 pt medium oilGramoxone Inteon many Post 33.01 gal 8.25 2 pt low burndown rateHalex 47.34 gal 21.30 3.6 pt standard rateHarmony GT XP small grain, Post 19.01 oz 1.52 0.08 oz high soybean rate

soybean 9.50 0.5 oz fallow, wheat, and barley rateHarmony Extra XP small grain Post 16.33 oz 4.90 0.3 oz standard rateHarness corn PPI/Pre 97.81 gal 15.28 1.25 pt coarse soil

22.01 1.8 pt medium soilHarness Xtra corn PPI/Pre 60.18 gal 27.08 1.8 qt medium soilHarness Xtra 5.6L corn PPI/Pre 46.41 gal 26.68 2.3 qt medium soilHornet WDG corn PPI/Pre/Post 61.90 lb 11.61 3 oz post, medium rate

15.47 4 oz pre, medium soilImpact corn Post 19.88 oz 9.94 0.5 oz soybean rotation rate

14.91 0.75 oz high rateIntrro soybean PPI/ Pre 24.57 gal 12.28 2 qt coarse soil

15.36 2.5 qt medium soilKeystone LA corn PPI/Pre 51.98 gal 25.99 2 qt standard rateLaddok S-12 corn Post 50.59 gal 14.74 2.33 pt high rateLariat corn PPI/Pre 24.42 gal 15.26 2.5 qt coarse soil

22.90 3.75 qt medium soilLaudis corn Post 4.95 oz 14.86 3 oz standard rateLiberty LL corn Post 75.60 gal 16.54 28 fl oz high rateLorox DF soybean Pre 19.06 lb 19.06 1 lb coarse soil

Appendix Table 3. Herbicide price list (continued)


(continued)


STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNPRINCIPLES

OF

PESTM

NGMT.

Lumax corn Pre 59.57 gal 37.23 2.5 qt soil OM less than 3%44.68 3 qt soil OM 3% or greater

Marksman corn Post 34.26 gal 8.56 2 pt low rate14.99 3.5 pt high rate

Milestone pasture Post 356.73 gal 19.34 7 fl oz Canada thistle rateNorthstar corn Post 2.37 oz 11.87 5 oz full rateOption corn Post 10.58 oz 15.86 1.5 oz standard rateOutlook corn/soybeans PPI/Pre 170.69 gal 18.67 14 fl oz coarse soil

21.34 16 fl oz medium soilPermit corn Post 18.77 oz 12.58 0.67 oz standard ratePhoenix soybean Post 167.63 gal 10.48 8 fl oz standard ratePoast Plus soybean, alfalfa Post 58.88 gal 11.04 1.5 pt annual grass ratePrefix soybean Pre 46.71 gal 11.68 2 pt standard ratePrincep Caliber 90 corn PPI/Pre 4.69 lb 12.20 2.6 lb medium soilProwl H20 corn, soybean Pre:corn 34.26 gal 8.56 2 pt coarse soil for corn

PPI:soybean 12.85 3 pt medium soil for cornPursuit soybean, CF corn PPI/Pre/Post 595.35 gal 18.60 4 fl oz full rate

seedling alfalfa Post 13.95 3 fl oz standard rate for alfalfaPursuit Plus soybean, CF corn PPI:soybean 55.23 gal 17.26 2.5 pt full ratePython corn, soybean PPI/Pre 10.73 oz 10.73 1 oz medium soil, standard rateRage D-Tech corn, small grains Pre/Post 53.75 gal 3.36 8 oz standard rate

soybean Preplant 5.04 12 oz standard soybean rateRaptor soybean, alfalfa Post 601.26 gal 18.79 4 fl oz standard rateResolve corn PPI/Pre 7.63 oz 7.63 1 oz standard rateResource corn, soybean Post 193.14 gal 6.04 4 fl oz low tank mix rateRoundup many Post 62.09 gal 10.67 22 fl oz standard ratePowerMaxRoundup many Post 71.54 gal 12.30 22 fl oz standard rateWeatherMaxSelectMax soybean Post 128.25 gal 6.01 6 fl oz 12-inch volunteer corn rateSencor DF soybean Pre 16.31 lb 5.38 0.33 lb coarse soil for soybean

8.16 0.5 lb medium soil for soybeanalfalfa Spring dormant 16.31 1 lb alfalfa rate

Sequence corn, soybean Pre, Post 52.56 gal 16.42 2.5 pt standard rateStatus corn Post 2.59 oz 12.94 5 oz standard rateSteadfast corn Post 26.88 lb 20.16 0.75 oz standard rateStinger corn, cereals, Post 489.20 gal 15.29 0.25 pt low rate

pasture 30.58 0.5 pt pasture - Canada thistle rateSureStart corn EPP/Pre/Post 72.47 gal 15.85 1.75 pt medium soil, 3% OM or

greaterSurpass corn PPI/Pre 85.99 gal 16.12 1.5 pt coarse soil

21.50 2 pt medium soilSynchrony XP soybean Post 7.56 oz 2.83 0.375 oz postemergence rate



Abbreviations: CF=Clearfield, LL=Liberty Link, and RR=Roundup Ready. (continued)Full rate = the rate when a single rate is recommended on the label. Low rate = the lowest rate listed on the label. Standard rate = the typical rate used when the label lists multiple rates. High rate = the highest rate listed on the label.

237


STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNPRINCIPLES

OF

PESTM

NGMT.

238

TopNotch corn PPI/Pre 39.80 gal 19.90 2 qt coarse soil22.39 2.25 qt medium soil

Touchdown Total RR corn, Burndown 59.20 gal 11.10 1.5 pt standard rateRR soybean

Treflan soybean PPI 18.69 gal 2.34 1 pt coarse soil3.50 1.5 pt medium soil

Ultra Blazer soybean Post 71.94 gal 13.49 1.5 pt high rateValor SX soybean Pre 79.13 lb 9.89 2 oz standard rateVelpar L alfalfa Pre-greenup 70.59 gal 22.06 2.5 pt coarse soil

35.30 4 pt medium soilWeedMaster pastures Post 30.13 gal 3.77 1 pt annual weed rate

7.53 2 pt perennial weed rateWideMatch small grains, Post 67.73 gal 11.26 1.33 pt standard rate

corn, CRPYukon corn Post 2.65 oz 10.59 4 oz standard rate2,4-D Amine (4) corn, small grains, Post 14.43 gal 1.80 1 pt standard rate

pastures2,4- Ester (LV 4) corn, small grains, Post 16.37 gal 2.05 1 pt standard rate

pasturesAbbreviations: CF=Clearfield, LL=Liberty Link, and RR=Roundup Ready.Full rate = the rate when a single rate is recommended on the label. Low rate = the lowest rate listed on the label. Standard rate = the typical rate used when the label lists multiple rates. High rate = the highest rate listed on the label.




STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNPRINCIPLES

OF

PESTM

NGMT.

239

this page intentionally left blank


STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNPRINCIPLES

OF

PESTM

NGMT.

240

Banvel dicamba G F/G P/F G/E — — F/G — F/G F P/F F/G F/G — — F/GButyrac 2,4-DB — F/G — N — — F N N — — — — — — — — — — — — N — — — — — — — — —Cimarron Max metsulfuron + 2,4-D G/E G/E G G/E G G/E G/E — F/G — — F — G/E

+ dicambaCimarron Plus metsulfuron — G — G — G — — — — — — — — — — — F/G —

+ chlorsulfuronCrossbow 2,4-D + triclopyr G/E F/G G G/E F/G — G/E — F/G — — G/E — GCurtail 2,4-D + clopyralid G F — — F — F — — — — G F/G — — —Escort/Ally metsulfuron G/E G/E F/G G/E G/E G G/E — P/F G/E — P — GForefront 2,4-D + aminopyralid G/E F/G P G/E F/G G/E G/E — — — — E E —Fusilade fluazifop N N N N N N N N N N N N N N N N N N F/G N NGarlon triclopyr G/E F/G G/E E — G/E F/G G F G G G/E — —GramoxoneNS paraquatNS P/F P P P/F P P P P P P/F P P/F P P P/F P P P P P/F P/F P P P P/F P P/F P/F P/F P PGrazon P+D* 2,4-D + picloram E G P/F E F — E — G — — E G —HabitatNS imazapyrNS G — P P/F E P G/E — G/E G/E — F — —JourneyNS imazapic+glyphosateNS — P P P/F P P F/G — F/G G/E — F/G — —MCPA MCPA — N — N — — F/G — P/F — P/F — F/G — — — — — N F/G — N — — — — — — — — —Milestone aminopyralid G/E P/F P/F G/E P G/E G — — — — G E —OustNS sulfometuronNS — G — G/E — G/E F/G — — G/E — — — — — — F/G — — — —Outrider sulfosulfuron — — — — — — — — — G — — — —Overdrive dicamba G F/G P/F F P — G/E — G/E F — F/G — — — F

+ diflufenzopyrPastureguard fluroxypyr + triclopyr — G/E G/E — — — G/E — — — — G — — — — —Plateau imazapic — N N N P N F/G G F/G G/E G F — — — P F N PPoast sethoxydim N N N N N N N N N N N N N N N N N N P/N N NPursuit imazethapyr — — — N — N F/G — N/P — — F/G — — — — — — — — — F — — — P — — — — —Redeem clopyralid + triclopyr G/E G P E F/G — G — G/E — — E G —RoundupNS glyphosateNS G G G P/F F/G F/G G/E G F/G G/E G/E F/G — G/E GStarane fluroxypyr — — G/E — — — G — F/G — — — — — — — — — — — — — P — — — — — — — —Stinger clopyralid G/E P P G/E F G/E G — P — F/G G/E F/G — — —Telar chlorsulfuron G G — P/F G/E — F/G — — — — — — — — — — F/G —Tordon* picloram G/E G/E F E E — G/E — F/G — — E F/G — —Weedmaster 2,4-D + dicamba G G P/F E G/E G/E G/E — F/G F — E — F/G — —2,4-D 2,4-D G/E F/G P/F F/G G F/G F/G — F F P/F G F/G G2,4-D + glyphosateNS 2,4-D + glyphosateNS — — — — — — — — F/G — — F/G — — — — — — — — — — F/G —Control ratings: E = excellent (90–100%), G = good (80–90%), F = fair (60–80%), P = poor (<60%), N = none (0%), — = no information.* Restricted-use product in Wisconsin.NS Nonselective herbicide, will injure both grasses and broadleaf plants.

Burd

ock

Cana

dago

lden

rod

Chin

ese

lesp

edez

a

Clov

er,w

hite

&ye

llow

Com

mon

tans

y

Crow

nve

tch

Curl

ydo

ck

Dam

esro

cket

Fiel

dbi

ndw

eed

Gar

licm

usta

rd

Gia

ntho

gwee

d

Gia

ntra

gwee

d

Haw

kwee

ds

Hill

mus

tard

Appendix Table 4. Herbicide effectiveness onlisted invasive weeds in CRP fields

Commercial Common namename (active ingredient)


STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNPRINCIPLES

OF

PESTM

NGMT.

241

— F/G G F/G N P/F G N P/F G/E G/E F — G/E G/E G/E F— — — — — — — N — — — — — — — — —— — F/G G/E N G/E E N F/G G/E G/E F/G — E E G/E —

— — — F/G — E G/E N — F/G G/E G — G/E — — —

— — G G N F/G G N F G G/E F — G/E G/E — G— — G — N P G N P G/E G/E G — G G/E — G— — F G/E N G/E G/E E N — F/G G F/G G G/E G/E — E— — E F/G N P G/E G N P G/E G/E G/E — E G/E — GN N N N F/G N N G/E N N N N N N N N NG F/G P/F F/G N G/E F/G G N P/F — F F — F/G F — F

P/F P P P P P/F P/F P P P P/F P P/F P/F P/F P P— — F/G G N F/G G N G/E E E G — E E — G— G/E F G/E G/E G/E E G/E G/E G G/E G F — F/G — G/E —— F F P F G/E — G/E G/E G/E G G/E P — F/G — — F— — — — N F/G — N — — — — — — — — —— — E F N P G/E F N P E E E — E E — F— — F/G — — — — G/E P/F F — G — G — — —— — — — — — — — — N/P — — — — — — —— F G/E — — P G/E — — G/E G/E G — G/E G/E — G/E

— — — G/E — — — — — — — — — — — — —— P F N P G/E — G/E G/E G/E G F P — F — — PN N N N P/N N N G/E N N N N N N N N N— — — — — — — F — — — P — — — — —— — G/E P N F/G G/E N P E G/E F/G — G/E G/E — FG F/G G/E G G/E G G/E G/E G/E F/G G/E G/E G/E F/G G/E G/E G/E G/E— — — — — — — — P — — — — — — — —— — G/E P N P P N P G/E G/E G/E G G/E G/E G/E F— — — F/G — G/E G/E N — G/E — F/G — G/E — G/E G/E— G G/E G N G G N G/E G/E G/E G — G/E G/E — —— — G/E F N G G/E N P/F G/E G/E F/G — G/E G/E — G/E— F/G F P/F N F P/F G/E N P/F G G/E F — G/E G/E P/F G/E— — — — — — — — F/G — G/E G — — — — —

Japa

nese

hedg

epa

rsle

y

Japa

nese

knot

wee

d

Kna

pwee

dsp

p.

Mul

tiflor

aro

se

Phra

gmites

Pois

onhe

mlo

ck

Purp

lelo

oses

trife

Que

enAnn

e’s

lace

(wild

carr

ot)

Reed

cana

rygr

ass

Spur

ge,le

afy

&cy

pres

s

Teas

el,cu

tlea

f&

com

mon

This

tle,

bull

This

tle,

Cana

da

This

tle,

mar

sh

This

tle,

mus

k

This

tle,

plum

eles

s

Wild

cher

vil

Wild

pars

nip

BanvelButyracCimarron Max

Cimarron Plus

CrossbowCurtailEscort/AllyForefrontFusiladeGarlonGramoxoneNS

Grazon P+D*HabitatNS

JourneyNS

MCPAMilestoneOustNS

OutriderOverdrive

PastureguardPlateauPoastPursuitRedeemRoundupNS

StaraneStingerTelarTordon*Weedmaster2,4-D2,4-D+glyphosateNS

Appendix Table 4. Herbicide effectiveness onlisted invasive weeds in CRP fields (continued)

Commercialname

Control ratings: E = excellent (90–100%), G = good (80–90%), F = fair (60–80%), P = poor (<60%), N = none (0%), — = no information.* Restricted-use product in Wisconsin.NS Nonselective herbicide, will injure both grasses and broadleaf plants.


STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNPRINCIPLES

OF

PESTM

NGMT.

Corn

Corn Earworm (A3655)Corn Fertilization (A3340)Corn Replant/Late-Plant Decisions in

Wisconsin (A3353)Corn Rootworms (A3328)Corn Silage Production, Management, and

Feeding (NCR574)European Corn Borer (A1220)Herbicide Persistance and Carryover

(A3819)Herbicide Resistance Management in

Vegetable Rotations—poster (A3822)Insect Resistance Management and Refuge

Requirements for Bt Corn (A3857)Seed Corn Maggot (A3820)Uneven Emergence in Corn (NCR344)Western Bean Cutworm: A Pest of Field

and Sweet Corn (A3856)

Forages and small grains

Alfalfa Germination and Growth (A3681)Alfalfa Management Guide (NCR547)Alfalfa Stand Assessment: Is This Stand

Good Enough to Keep? (A3620)Buying Horse Hay (A3772)Determining Pasture Condition (A3667)Forage Variety Update for Wisconsin

(A1525)Identifying Pasture Grasses (A3637)Identifying Pasture Legumes (A3787)Pastures for Horses: A Guide to Rotational

Grazing—CD (A3764)Pastures for Profit: A Guide to Rotational

Grazing (A3529)Small Grain Varieties for Grain and Forage

in Wisconsin (A3397)

Weed management

Common Weed Seedlings of the NorthCentral States (NCR607)

Herbicide-Resistant Weeds (NCR468)Weed Identification and Management—

DVD (A3829)

ADDITIONAL RESOURCESThe following publications may be purchased from your county Extension office or fromExtension Publications. You can order online at learningstore.uwex.edu or call toll free877-WIS-PUBS (947-7827).

242


Related UW-Extension web sites

Extension Publications: learningstore.uwex.eduAgronomy: agronomy.wisc.eduForages: www.uwex.edu/ces/crops/teamforageGrains: www.uwex.edu/ces/grainsInsects: www.entomology.wisc.eduPesticide Applicator Training: ipcm.wisc.edu/patPlant diseases: www.plantpath.wisc.edu/pddcSoybeans: www.plantpath.wisc.edu/soyhealth

and soybean.uwex.eduWeeds: ipcm.wisc.edu/uw_weedsWeed identification: weedid.wisc.eduWeed profiles: ipcm.wisc.edu/uw_weeds/

extension/weedprofiles.htmWisconsin Crop Manager: ipcm.wisc.edu/wcm

STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNPRINCIPLES

OF

PESTM

NGMT.

243


STORED

GRAININSECTS

PERENNIALW

EEDSSM

ALLGRAINS

APPENDIXFO

RAGES&

PASTURESSO

YBEANCO

RNPRINCIPLES

OF

PESTM

NGMT.


Copyright © 2008 University of Wisconsin-System Board of Regents doing business as the division of Cooperative Extensionof the University of Wiscosnin-Extension. Send inquiries about copyright permission to: Manager, Cooperative ExtensionPublications, 432 N. Lake St., Room 103, Madison, WI 53706.

Authors: Chris Boerboom is professor of agronomy, Eileen Cullen is assistant professor of entomology, Paul Esker is assistantprofessor of plant pathology, Roger Flashinski is pesticide applicator education specialist in agronomy, Bryan Jensen is inte-grated pest management coordinator, and Mark Renz is assistant professor of agronomy. All hold joint appointments with theCollege of Agricultural and Life Sciences, University of Wisconsin-Madison and Cooperative Extension, University ofWisconsin-Extension. Produced by Cooperative Extension Publications, University of Wisconsin-Extension.

University of Wisconsin-Extension, Cooperative Extension, in cooperation with the U.S. Department of Agriculture andWisconsin counties, publishes this information to further the purpose of the May 8 and June 30, 1914 Acts of Congress; andprovides equal opportunities and affirmative action in employment and programming. If you need this material in an alterna-tive format, contact the Office of Equal Opportunity and Diversity Programs or call Cooperative Extension Publications at(608) 262-2655.

This publication is available from your Wisconsin county Extension office or from Cooperative Extension Publications.To order, call toll free 877-WIS-PUBS (877-947-7827) or visit learningstore.uwex.edu.

Pest Management in Wisconsin Field Crops—2009 (A3646) R-10-08-2.7M

A3646-09, Cover:A3646/04, Cover (alt2) 10/16/08 2:59 PM Page 2

Pest management in WisconsinFieldCrops - Corn...

Documents

Transcript of Pest management in WisconsinFieldCrops - Corn...