Soybean aphid efficacy program update 2011 ICM Conference, Ames Iowa Update on the soybean aphid efficacy program Erin Hodgson and Greg VanNostrand Department of Entomology

Soybean aphid efficacy program update 2011 ICM Conference, Ames Iowa Outline Review of survey to Iowa soybean growers in 2010 Soybean aphid efficacy evaluation Where to get more info, handouts

Soybean aphid efficacy program update 2011 ICM Conference, Ames Iowa Background… In 2010, paper survey mailed to every ISA member (4,908) 18.5% response rate (903); 24% ac grown ?’s about production, pests, information sources

Soybean aphid efficacy program update 2011 ICM Conference, Ames Iowa Survey Goals… Encouraged to conduct needs-assessment to stakeholders Grower awareness of primary soybean pests How often are they scouting? How many acres are being treated with insecticides? Where are they getting management info?

Soybean aphid efficacy program update 2011 ICM Conference, Ames Iowa A decade of changes Few economic soybean pests Soybean aphid confirmed in 2000 – 40% economic loss potential – Quickly became #1 pest – Production costs increased

Soybean aphid efficacy program update 2011 ICM Conference, Ames Iowa A decade of changes 1.1 million fewer soybean acres in Iowa 1 Increased seed prices 2 – Up 108% from 2001 Higher market values 1 – $4.54/bu in 2000, $9.97/bu in USDA-NASS; 2 Neuman New York Times 2010

Soybean aphid efficacy program update 2011 ICM Conference, Ames Iowa Increased insecticide use 130-fold increase in soybean since ~73% soybean with seed treatment in 2009* 1 Ragsdale et al. Ann Rev. Entomol. 2011; *Hodgson et al. Journal of Extension, in press

Soybean aphid efficacy program update 2011 ICM Conference, Ames Iowa Percent increase of soybean acres treated with a foliar insecticide in 2009 compared to 2000 (1,423% average statewide increase).*

Soybean aphid efficacy program update 2011 ICM Conference, Ames Iowa What are their soybean pests?* Pest% Primary Pest% Encountered Soybean aphid Bean leaf beetle Stink bugs Japanese beetle Potato leafhopper Thrips Spider mites Caterpillars Other0.22.3

Soybean aphid efficacy program update 2011 ICM Conference, Ames Iowa Are they scouting? IA growers reported fields are scouted weekly (60%) or every 2 weeks (34%)* Fields are scouted by themselves (55%), agribusiness (44%), and/or consultants (32%)* 17% use Speed Scouting regularly*

Soybean aphid efficacy program update 2011 ICM Conference, Ames Iowa Newest management tool Host plant resistance – Naturally occurring germplasm – Commercially released in 2010 – Single gene expression, Rag1 – Moderate “killing power” Complementary to chemical control Not widely promoted by industry yet

Soybean aphid efficacy program update 2011 ICM Conference, Ames Iowa Awareness of HPR for SBA ~20% IA growers haven’t heard of HPR for SBA* ~43% IA growers said they would consider trying HPR* Rag1 plot (left) and susceptible plot, heavily infested with soybean aphid. Note sooty mold on the susceptible plants.

Soybean aphid efficacy program update 2011 ICM Conference, Ames Iowa Where are they getting info?* Source% Used% Mostly/Very Helpful Agribusiness Friends, Family ICM News Field Days ISU Personnel Websites Crop Advantage Series Outside Iowa ICM Conference Other

Soybean aphid efficacy program update 2011 ICM Conference, Ames Iowa Survey Summary Soybean production has changed – Decision making is more complicated SBA is the primary pest Most are scouting! Getting info from many sources – Agribusiness is highly trusted – Where is agribusiness getting data?

Soybean aphid efficacy program update 2011 ICM Conference, Ames Iowa New Survey Goals Repeat survey in 3 years New pests, market? Improve HPR awareness, IPM

Soybean aphid efficacy program update 2011 ICM Conference, Ames Iowa QUESTIONS ABOUT THE SURVEY?

Soybean aphid efficacy program update 2011 ICM Conference, Ames Iowa 2011 SOYBEAN APHID EFFICACY EVALUATION

Soybean aphid efficacy program update 2011 ICM Conference, Ames Iowa Methods Susceptible: 05RM310021; Rag1: 07JR RCBD, 4 reps/treatment – # trts/location was variable 6 rows wide, 50 feet long

Soybean aphid efficacy program update 2011 ICM Conference, Ames Iowa 2011 ISU Research Farm Locations

Soybean aphid efficacy program update 2011 ICM Conference, Ames Iowa Methods Sampled control plots weekly until July Sampled all plots in Aug/Sept Whole plant counts (20 -> 3)

Soybean aphid efficacy program update 2011 ICM Conference, Ames Iowa Cumulative aphid days = Area under the curve Economic threshold Economic injury level

Soybean aphid efficacy program update 2011 ICM Conference, Ames Iowa Methods Target application at threshold or R5 Backpack sprayer – 20 gal H20, 40 psi

Soybean aphid efficacy program update 2011 ICM Conference, Ames Iowa New for 2011…a 6-row sprayer!

Soybean aphid efficacy program update 2011 ICM Conference, Ames Iowa Johnson Farm Northeast Farm Northwest Farm Variable pressure Late peak >R6 Comparison of Rag1 and susceptible

Soybean aphid efficacy program update 2011 ICM Conference, Ames Iowa Johnson CAD and Yield Results Peak aphids = 110/plant; no yield differences Rag1 suppressed aphids

Soybean aphid efficacy program update 2011 ICM Conference, Ames Iowa Northeast CAD and Yield Results Rag1 suppressed aphids; yield was also lower… Peak aphids = 425/plant * * * *

Soybean aphid efficacy program update 2011 ICM Conference, Ames Iowa What is Transform? Dow AgroSciences Sulfoxaflor; sulfoximine class (novel) Activation of nicotinic acetylcholine receptors Broad spectrum activity Targeting fluid feeders Should be approved for 2012

Soybean aphid efficacy program update 2011 ICM Conference, Ames Iowa Northwest CAD and Yield Results Peak aphids = >800/plant Rag1 suppressed aphids; yield was also higher…

Soybean aphid efficacy program update 2011 ICM Conference, Ames Iowa Research Summary Variable aphid #’s between locations – Johnson, Northeast, Northwest Fields colonized mid-July, early August Applications made R5 (mid-August)

Soybean aphid efficacy program update 2011 ICM Conference, Ames Iowa Research Summary Rag1 suppressed aphid growth at all locations Seed treatment further reduced CAD Foliar application at ET still protected yield Northwest Farm

Soybean aphid efficacy program update 2011 ICM Conference, Ames Iowa Summary HPR to soybean aphid is a new tool – Single gene with moderate resistance – Slowed population growth – Continue to scout – May exceed thresholds – Still need to protect yield

Soybean aphid efficacy program update 2011 ICM Conference, Ames Iowa Summary Rag1 plots have fewer aphids Can prevent ET and insecticides Rag1 doesn’t cause yield drag – May not be in highest-yielding seed? Strongly encourage using Rag1 or Rag1+2

Soybean aphid efficacy program update 2011 ICM Conference, Ames Iowa Acknowledgments ISU Farm Managers: Kent Berns, Ken Pecinovsky, Ryan Rusk Matt O’Neal, Mike McCarville Mari Kemis, Brandi Geisinger

Soybean aphid efficacy program update 2011 ICM Conference, Ames Iowa Where to get more information ICM News Soybean Aphid To see more talks Free pubs and podcasts!

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