New Traits and Technology for Corn Insect Management Agent Update Dr. Ric Bessin Extension...
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Transcript of New Traits and Technology for Corn Insect Management Agent Update Dr. Ric Bessin Extension...
New Traits and Technology
for Corn Insect Management
Agent UpdateDr. Ric Bessin
Extension Entomologist
Southwestern Corn Borer
European Corn Borer
Overwinter SWCB Survival
Year SWCB Survival
SWCB/stalk
1999 10.1 3.64
2000 26.9 5.57
2001 9.7 3.92
2002 5.3 0.63
2003 4.3 1.13
2004 2.5 0.39
2005 5.3 0.30
Caldwell, Henderson, Davies, Hardin CountiesFour fields/county
Planting-Date Study
• UK REC Princeton Kentucky – R. Bessin, D. Johnson, J. Herbek
• Five planting dates, Early April thru early June (every 2 weeks)
A Bt corn hybrid and non-Bt isoline
Yield Benefit by Planting Date 7-Year Average
Planting Date Non-Bt Tunnelin
g (in)
Yield, non-Bt
(bu)
Yield, Diff.(bu)
Early – Mid April
3.2 189.7 3.2
Late April 4.0 198.8 2.7
Early –Mid May
4.1 182.3 6.2
Late May 5.2 160.2 9.2
Early – Mid June
6.3 112.3 21.1
Biotech Tools for Corn Pests
Bt Corn– YieldGard Corn Borer (Cry1Ab)
– YieldGard Rootworm (Cry3Bb1)
– YieldGard Plus (Cry1Ab+Cry3Bb1)
– Herculex I (Cry1F)
– Herculex RW (Cry34Ab1/Cry35Ab1)
– Herculex Xtra (Cry1F+Cry34Ab1/Cry35Ab1)
– Agrisure CB (Cry1Ab)
– Agrisure RW ? (Cry3A)
– Agrisure CB/RW ?
Insects Controlled by Bt Corn
ECBSWC
BBCW FAW CRW
YieldGard CB ++ ++ - + -
YieldGard RW - - - - ++
YieldGard Plus ++ ++ - + ++
Herculex 1 ++ ++ ++ ++ -
Herculex RW - - - - ++
Herculex Xtra ++ ++ ++ ++ ++
Traditional Corn Seed Treatments‘Hopperbox’
Agrox PremiereGermate Plus
Grain Guard PlusKernel Guard
Kernel Guard SupremeKickStart
Lorsban SL
Hopperbox Treatments
• Permethrin, lindane, chlorpyrifos, imidacloprid
• Cheapest treatments available
• Recommended when no soil insecticides used
• Effective against seedcorn maggot and wireworms (low populations)
• High exposure potential
True Seed Treatments
Seed Treatments (Ordered with seed)– Imidacloprid
Gaucho extra (0.6 mg/kernel)
Prescribe (1.34 mg/kernel)
– ThiamethoxamCruiser Extreme Pak (0.25 mg/ker)
Cruiser Extreme Pak CRW (1.25 mg/kernel)
– ClothianidinPoncho 250 (0.25 mg/kernel)
Poncho 1250 (1.25 mg/kernel)
Immediate Plant Back
30-Day Plant Back
120-Day Plant Back
12 Month Plant Back
Insects Controlled
WW WG FB SCM BCW
CRW
Gaucho ++ ++ + ++ - -Prescribe ++ ++ ++ ++ - +Cruiser Ex Pak ++ ++ ++ ++ + -Cruiser EP CRW
++ ++ ++ ++ + ++
Poncho 250 ++ ++ ++ ++ + -Poncho 1250 ++ ++ ++ ++ ++ ++
Common Wireworm species identified from corn fields in KY 2004-2005.
Aeolus mellillus Conoderus lividus
Melanotus depressus Melanotus communis-dietrichi
Herculex RW
• Received full EPA registration in 2005
• Cry34Ab1 + Cry35Ab1• Controls Western and Northern
corn rootworms• European and Japanese approval
pending• Limited marketing for 2006
BT RW IRM Requirements
Requirement
YieldGard RW Herculex RW
Minimum size of refuge
20 % of corn acreage
20 % of corn acreage
Arrangement
Same or adjacent field
Same or adjacent field
Minimum size of refuge strips
6 rows or more 4 rows or more
Rotational history
Refuge same as BT RW field
Refuge –Continuous
BT RW – Continuous or 1st
year
Larvacide? Yes in refuge Yes in refuge
Herculex Xtra
• Received full EPA registration Oct 31, 2005
• Cry34Ab1/Cry35Ab1 + Cry1F• Controls rootworms, corn
borers, cutworms, fall armyworm
• Japanese approval pending• Limited marketing for 2006
Making the Control Decision
• Rotation information– Corn after corn ? After pasture ?
• Planting Date – Very early - wireworms– Very late – corn borers
• Likelihood of Problems– Past problems ?
• Cost – Is rotation more cost effective?
• Equipment
Soybean Aphid Status
Seed Treatments on Soybeans
Agent UpdateDr. Doug Johnson
Extension Entomologist
Updates on Soybean aphid can be found at the KY-IPM home page. Just
click on the Soybean aphid icon
http://www.uky.edu/Agriculture/IPM/ipm.htm
Soybean Aphid Status
• 2005 Present but virtually unseen in KY
• Significant populations limited to northern portions of the mid-west
• Some populations over shadowed by outbreak of spider mites.
• Presence of the “White dwarf” aphid
Soybean Aphid StatusSampling
• MN speed sampling method tends to over estimate the need to spray.
• Will incorporate 05 data in to procedure
• Not useful for a repeat spray
Soybean Aphid StatusDecision
• 250 aphids per plant,• More than 80% plants infested,• With an INCREASING
population,• V through R5 (beginning seed
set) stages. • Provides 7 day lead time
Yield Loss Factors
• Flowering stages most sensitive
• Loss through seed abscission• Some recuperation through
increase in seed size
“White Dwarf” Soybean aphid
Cast Skins
Insecticide Seed Treatments for Soybean
Trials at UK-REC Princeton
• Three years of trials 2003-05• Included seed treatments, foliar
applications and combinations.• Focus on insecticides but some
treatments also contained fungicides.
• All seed treatments applied by professional seedtreaters.
Seed Treatment Test Results
• In NO trial did any treatment ever yield differently from the untreated check.
• In all cases insect populations were minimal.
• In no year was movement of plant virus important.
Recommendations?
• This does NOT indicate that seed treatments do not work.
• This DOES indicate that seed treatments were not needed.
• Recommendations remain the same.
Recommendations
• Use seed treatments in High risk areas.– Early planting, cool \ damp ground– History of significant soil pests
• Select the seed treatment which fits the situational risk e.g.– Seed corn maggot & seed corn beetle– Wireworm history
Seed Treatments in relation to Soybean Aphid• Will provide some control but
are not holding up economically in NC states.
• Are unlikely to be the main method of control if problem develops in KY because the populations will develop too late in the season.