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New Traits and Technology for Corn Insect Management Agent Update Dr. Ric Bessin Extension Entomologist. Southwestern Corn Borer. European Corn Borer. Overwinter SWCB Survival. Caldwell, Henderson, Davies, Hardin Counties Four fields/county. Planting-Date Study. UK REC Princeton Kentucky
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New Traits and Technologyfor Corn Insect ManagementAgent UpdateDr. Ric BessinExtension Entomologist
Overwinter SWCB Survival Caldwell, Henderson, Davies, Hardin Counties Four 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
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 ?
Traditional Corn Seed Treatments ‘Hopperbox’ Agrox Premiere Germate Plus Grain Guard Plus Kernel Guard Kernel Guard Supreme KickStart 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) • Thiamethoxam Cruiser Extreme Pak (0.25 mg/ker) Cruiser Extreme Pak CRW (1.25 mg/kernel) • Clothianidin Poncho 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
Aeolus mellillus Conoderus lividus Common Wireworm species identified from corn fields in KY 2004-2005. 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
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 StatusSeed Treatments on SoybeansAgent UpdateDr. Doug JohnsonExtension 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
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.