new traits and technology for corn insect management agent update dr. ric bessin extension...
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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.
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