North Carolina Corn Insect Pest 2014 Update

Dominic Reisig NCSU Entomology

Contents of This Presentation• Refuge compliance• Does corn earworm impact corn yield?• Cry1F-resistant fall armyworm

• Seed treatment value for NC corn• Resistance development of corn earworm to Bt• Stink bug management in corn

Research Issues Not in This Presentation

Description Caterpillar Traits Rootworm Traits

Agrisure CB/LL Cry 1AB (Bt11) None

Agrisure 3000GT Cry 1AB (Bt11) Cry 3A (modified)

Herculex I (HX1) Cry 1F (HX1) None

Herculex XTRA (HXX) Cry 1F (HX1) Cry 34/35Ab1

YieldGard VT Triple (VT3) Cry 1AB (YGCB) Cry 3Bb1

Genuity VT Triple Pro (GENVT3P) Cry 1A.105 + Cry2Ab2 Cry 3Bb1

Genuity VT Double Pro (GENVT2P) Cry 1A.105 + Cry2Ab2 None

Genuity VT Double Pro RIB (GENVT2P RIB) Same as above + RIB * None

Genuity or Dow AgroSciences SmartStax (GENSS or SSX) Cry 1A.105 + Cry2Ab2 + Cry 1F (HX1) Cry 3Bb1 + Cry 34/35Ab1

Genuity or Dow AgroSciences SmartStax RIB (GENSS or SSX) Same as above + RIB * Same as above + RIB *

Agrisure Viptera 3110 Cry 1Ab (Bt11) + VIP3A (MIR162) None

Agrisure Viptera 3111 Cry 1Ab (Bt11) + VIP3A (MIR162) Cry 3A (modified)

Agrisure Viptera 3220 Cry 1Ab (Bt11) + VIP3A (MIR162) + Cry1F (HX1) None

Optimum Intrasect Cry1Ab (YGCB) + Cry 1F (HX1) None

Optimum AcreMax Cry1Ab (YGCB) + Cry 1F (HX1) None

Optimum AcreMax Xtra Cry1Ab (YGCB) + Cry 1F (HX1) Cry 34/35Ab1

Traits of Selected, Commercially Available Bt Corn Products

* Non-Bt Refuge in Bag Slide adapted from Scott Stewart, U. Tennessee

* Unless Cry1F-resistant fall armyworm is present Slide adapted from Scott Stewart, U. Tennessee

Traits / Brands Corn borers Cutworm Corn earworm Fall armyworm

Western corn

rootwormAgrisure CB/LL Excellent Poor Fair Good None

Agrisure 3000GT Excellent Poor Fair Good GoodHerculex I (HX1) Excellent Good Poor Very Good * None

Herculex XTRA (HXX) Excellent Good Poor Very Good * Excellent

YieldGard VT Triple (VT3) Excellent Poor Fair Fair Excellent

Genuity VT Triple Pro (GENVT3P) Excellent Poor Good Very Good Excellent

Genuity VT Double Pro (GENVT2P) Excellent Poor Good Very Good None

Genuity VT Double Pro RIB (GENVT2P RIB) Excellent Poor Good Very Good None

Genuity or Dow AgroSciences SmartStax (GENSS or SSX) Excellent Good Very Good Very Good * Excellent

Genuity or Dow AgroSciences SmartStax RIB (GENSS or SSX) Excellent Good Very Good Very Good * Excellent

Agrisure Viptera 3110 Excellent Good Excellent Excellent None

Agrisure Viptera 3111 Excellent Good Excellent Excellent Good

Agrisure Viptera 3220 Excellent Very Good Excellent Excellent None

Optimum Intrasect Excellent Very Good Fair Very Good * None

Optimum AcreMax Excellent Very Good Fair Very Good * None

Optimum AcreMax Xtra Excellent Very Good Fair Very Good * Excellent

Relative Efficacy of Selected, Commercially Available Bt Corn Products

Traits / Brands Refuge Requirement

Agrisure CB/LL 50% In-field, adjacent, block ½ mileAgrisure 3000GT 50% In-field, adjacent, block ½ mileHerculex I (HX1) 50% In-field, adjacent, block ½ mile

Herculex XTRA (HXX) 50% In-field, adjacent

YieldGard VT Triple (VT3) 50% In-field, adjacent

Genuity VT Triple Pro (GENVT3P) 20% In-field, adjacent

Genuity VT Triple Pro RIB (GENVT3P RIB) 20% + RIB * In-field, adjacent

Genuity VT Double Pro (GENVT2P) 20% In-field, adjacent, block ½ mile

Genuity VT Double Pro RIB (GENVT2P RIB) 20% + RIB * In-field, adjacent

Genuity or Dow AgroSciences SmartStax (GENSS or SSX) 20% In-field, adjacent, block ½ mile

Genuity or Dow AgroSciences SmartStax RIB (GENSS or SSX) 20% + RIB * In-field, adjacent, block ½ mile

Agrisure Viptera 3110 20% In-field, adjacent, block ½ mile

Agrisure Viptera 3111 20% In-field, adjacent

Agrisure Viptera 3220 20% In-field, adjacent, block ½ mile

Optimum Intrasect 20% In-field, adjacent, block ½ mile

Optimum AcreMax 20% + RIB * In-field, adjacent, block ½ mileOptimum AcreMax Xtra 20% + RIB * In-field, adjacent, block ½ mile

Refuge Requirements (Southern US) of Selected, Commercially Available Bt Corn Products

* Non-Bt Refuge in Bag Slide adapted from Scott Stewart, U. Tennessee

Why refuge?

Slide adapted from Department of Soil and Crop Sciences at Colorado State University

Example Refuge Configurations

Image adapted from Canadian Corn Pest Coalition

Common Refuge Questions

• Can the refuge be protected from lep. pests?– Yes, using non-Bt insecticides

• How should the refuge hybrid be selected?– Chose a hybrid with a similar maturity and plant it as

close in time as possible to the Bt hybrid

• What happens to those who don’t plant refuge?– Required by law through EPA– Contract occurs at time of purchase of Bt hybrid– Warning letter on first offense, with compliance

assessment the following year– No Bt corn after second offense (in consecutive year)

Common Refuge Questions

• Who checks for compliance– Independent third parties

• Telephone survey, on-farm visits

• Are seed purchases tracked?– Of course, but companies don’t share information

• How can I know the refuge requirement?– Check the bag tag– Online search “refuge calculator”

• Yes, there is an app for that- iPhone and Android…

Common mid- to late-season lep. pest

Occasional mid-

to late-season lep. pests

Cutworm

Armyworms

Southern cornstalk borer

European corn borer

Corn earworm

No control• Agrisure RW• Herculex RW• YieldGard Rootworm• YieldGard VT

Rootworm/RR2

Poor-fair control• Herculex I• Herculex XTRA

Fair-good

Very good• YieldGard VT2 Pro• YieldGard VT Triple Pro • SmartStax

• Agrisure CB/LL• YieldGard Corn Borer• Agrisure CB/LL/RW• Agrisure GT3000• YieldGard Plus• YieldGard VT Triple

Corn earworm control with Bt hybrids

Excellent

• Agrisure Viptera

Slide from F.P.F. Reay-Jones, Clemson U.

To date, I have not documented a single yield loss due to corn earworm feeding in the ear in

North Carolina

Does corn earworm impact yield?

Example of past experiment- 2011

Does Corn Earworm Affect Yield?• Plots of 14 rows x 50 ft planted in Florence, SC, and in Plymouth, NC

(n = 4 replications).• Near-isolines for Bt and non-Bt hybrids (HX1; HX1 + YGCB; VT3;

VT2Pro).• Applications of Prevathon (20 oz/ac) twice a week (15 applications in

Florence, 18 applications in Plymouth) using a backpack sprayer.• Created treated and untreated subplots

• Sampled 20 ears per plot for corn earworm injury and yield

Florence, SC Plymouth, NC

Area of Kernels Injured by Earworm in 2012

= hybrids shared same genetic background

Florence, SC Plymouth, NC

Area of Kernels Injured by Earworm in 2013

= hybrids shared same genetic background

Relationship between feeding and yield

Conclusions• Corn earworm did not affect yield (NC or SC)• Hybrids should be chosen based on other

agronomic considerations than earworm• Bt is probably still necessary for stalk pests

(southern cornstalk borer & European corn borer)• Some of these genes active against corn earworm

also have activity on other pests– May have fit for late-planted corn

– Aflatoxin level may be reduced by eliminating earworm, but effect is highly dependent on hybrid genetics and environment

armyworm

Safe for any use

Fit only for cattle, will not accept above this level

Non-Bt

Cry1F-resistant fall armyworm found in Hyde County, 2013

What adjustments should we make in 2014?

• Hybrids with Genuity SmartStax, Herculex and Optimum Intrasect contain Cry1F– Widestrike countains Cry1F + Cry1Ac

• Closely monitor corn and cotton for resistance– August

• Plant refuge• Plant refuge• Plant refuge