Dr. Eric P. Prostko

Extension Weed Specialist

Dept. Crop & Soil Sciences

University of Georgia December 2003

2004 Weed Control Update(Peanut, Field Corn, Sunflowers)

Topic for DiscussionTopic for Discussion

Peanuts Field Corn Sunflowers? Problems questions

PeanutsPeanuts

Valor FormulationsArrowProwl H20newer metolachlor formulations

PeanutsPeanutsValor FormulationsValor Formulations

2001: 51 WDG 2002-03: 51 WP 2004: Valor SX

51WDG

* smaller particles

* dispersing agents

* easier to get into suspension

Peanut yield response to Valor (3 Peanut yield response to Valor (3 ozs/A) formulation and timing.ozs/A) formulation and timing.

4892 4920 4896 49344548 4534 4653

0

1000

2000

3000

4000

5000

6000

2001 2002-03 2004 Untreated

Formulation

Yiel

d (l

bs/A

)1 DAP 4 DAP

PE-02-03Attapulgus

P = 0.80CV = 12

PeanutsPeanutsArrow 2ECArrow 2EC

clethodim POST grass control in broadleaf crops generic Select Makhteshim-Agan 6 -16 ozs/A price/service

Texas Panicum Control with POST Grass Texas Panicum Control with POST Grass Herbicides (44 DAT)Herbicides (44 DAT)

98 98 98

0

25

50

75

100

Arrow (6 ozs/) Select (6 ozs/A) Poast (16 ozs/)

PE-19-03Ponder Farm

Applied to 2-4” tall grass

PeanutsPeanutsProwl HProwl H2200

2004 3.8 lbs/gal 2.0 pts/A water-based micro-encapsulated less staining better for strip-

tillage? increased price

Peanut Yield Response to PREPeanut Yield Response to PREApplications of DNA HerbicidesApplications of DNA Herbicides

6000 6000 5955 5884 5922 6058 6039

0

1000

2000

3000

4000

5000

6000

7000

Untreated Sonalan Sonalan Prowl EC Prowl EC Prowl H20 Prowl H2O

PE-11-03Ponder Farm P = 0.346

2 pts/A 3 pts/A 1.8 pts/A 2.4 pts/A 1.6 pts/A 2.1 pts/A

PeanutsPeanutsNew Metolachlor FormulationsNew Metolachlor Formulations

Cinch Dupontsame as Dual II Magnum

Stalwart C Sipcam Agro USA Inc. “old” Dual EC formulation (7.8 lbs/gal) not labeled for peanut

Me-Too-LachlorDrexel“old Dual EC formulation (8 lbs/gal) rates are too low

Field CornField Corn

Option vs. Accent Aim (harvest-aid) Basis Gold vs.

Steadfast ATZ RR corn issues

Pioneer RR corn hybrids

glyphosate timings

Field CornField CornOption vs. AccentOption vs. Accent

POST grass control except crabgrass OP/SU interaction roughly same cost/A similar weed control

and yields in UGA tests

Texas Panicum Control in Field Corn- I Texas Panicum Control in Field Corn- I Accent and OptionAccent and Option

8595 95 95

8494 94 94

0

20

40

60

80

100

11 DAT 23 DAT 36 DAT 83 DAT

Rating Date

Cont

rol -

%Accent Option

CN-03-03Ponder Farm

Applied 24 DAPPANTE = 1”; 2-3LF

Texas Panicum Control in Field Corn- IITexas Panicum Control in Field Corn- IIAccent and OptionAccent and Option

66 70

85

6570 7080

68

0

20

40

60

80

100

12 DAT 19 DAT 29 DAT 96 DAT

Rating Date

Cont

rol -

%Accent Option

CN-04-03Attapulgus

Applied 24 DAPPANTE = 2”; 2-5 LF

Corn Yields with Accent and OptionCorn Yields with Accent and Option

209175

212181

166

95

0

50

100

150

200

250

Ponder Attapulgus

Location

Bu/A

Accent Option Untreated

a a

CN-03-03CN-04-03

b ab a

c

Accent vs. OptionAccent vs. OptionAttapulgus - 2003 (19 DAT)Attapulgus - 2003 (19 DAT)

Untreated Accent @ 0.67 ozs/AAgrioil @ 1% v/v

Option @ 1.5 ozs/AMSO @ 1.25% v/v

AMS @ 3 lbs/AApplied 24 DAP/0.25-2” tall PANTE

Field CornField CornAim (Harvest-Aid)Aim (Harvest-Aid)

24C label in GA, MS, LA, NC

up to 1.9 ozs/A COC @ 1% v/v 3 day PHI morningglories pigweeds weak on sicklepod

Field CornField CornBasis Gold vs. Steadfast ATZBasis Gold vs. Steadfast ATZ

3 way mixes of atrazine/Accent/Matrix

Steadfast has more Accent

Both have greater potential to cause crop injury

confirm hybrid tolerance

Corn Hybrid Herbicide Susceptibility ChartsCorn Hybrid Herbicide Susceptibility Charts

Field CornField CornRR Corn IssuesRR Corn Issues RR Corn 2 (NK 603 event)

Up to 30” tall (over-the-top)

30-48” tall (drop nozzles) higher in-crop use rates/A

(64 ozs vs 44 ozs RUWM) Pioneer will have several

varieties Will this change the

game?

U.S. Corn Acres Planted to HerbicideU.S. Corn Acres Planted to HerbicideResistant VarietiesResistant Varieties

78

11

15

0

2

4

6

8

10

12

14

16

2000 2001 2002 2003

Year

% o

f Acr

es

Source: NASS

SunflowersSunflowers

Dual Magnum label IMI-Tolerant

sunflowers (Clearfield)

SunflowersSunflowersDual MagnumDual Magnum

PPI or PRE1-1.33 pts/Acoarse soils with

3% or less OM

SunflowersSunflowersIMI-Tolerant (Clearfield)IMI-Tolerant (Clearfield)

Mycogen seed8N429CL

non-GMO Beyond 1AS imazamox 4 ozs/A 2-8 leaf stage less rotation

restrictions than other imi’s

cotton = 9 months

Weed Control in IMI (Clearfield) SunflowersWeed Control in IMI (Clearfield) SunflowersAttapulgus, GA 2003 (60 DAT)Attapulgus, GA 2003 (60 DAT)

Untreated Beyond 1AS @ 4 ozs/AAMS @ 3 lbs/A

80/20 @ 0.25% v/vProwl 3.3EC @ 2.4 pts/A over entire test.

Problems Worthy of Note in 2003Problems Worthy of Note in 2003

misapplications of glyphosate

rain-free periods FL pusley unusually unusual

weed problems groundcherry eclipta copperleaf

Glyphosate Mishaps in Peanut!Glyphosate Mishaps in Peanut!

Roundup WeatherMax vs. Crop OilRoundup WeatherMax vs. Crop Oil

Groundcherry spp.Groundcherry spp.

SWSS SWSS

EcliptaEclipta

Hophornbeam CopperleafHophornbeam Copperleaf

Does this field have a weed problem?Does this field have a weed problem?

A closer look?A closer look?

University ofGeorgia

Extension Weed Science

(gaweed.com)