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.