Update on the soybean aphid efficacy program Erin

Update on the soybean aphid efficacy program Erin Hodgson and Greg Van. Nostrand 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 2010 1 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 20001 • ~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 Soybean aphid Bean leaf beetle Stink bugs Japanese beetle Potato leafhopper Thrips Spider mites Caterpillars Other % Primary Pest 93. 8 5. 0 0. 0 % Encountered 97. 6 63. 0 7. 2 0. 6 0. 2 0. 0 0. 3 0. 0 0. 2 17. 9 7. 0 0. 9 28. 9 2. 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, Rag 1 – 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* Rag 1 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 90. 5 89. 0 Friends, Family 79. 9 59. 4 ICM News 63. 2 74. 7 Field Days 63. 1 55. 7 ISU Personnel 58. 6 72. 5 Websites 57. 8 63. 8 Crop Advantage Series 41. 5 70. 3 Outside Iowa 27. 6 33. 6 ICM Conference 27. 2 58. 1 Other 5. 5 91. 3 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: 05 RM 310021; Rag 1: 07 JR 801843 • 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 injury level Economic threshold Soybean aphid efficacy program update 2011 ICM Conference, Ames Iowa

Methods • Target application at threshold or R 5 • Backpack sprayer – 20 gal H 20, 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 • Variable pressure • Late peak >R 6 • Comparison of Rag 1 and susceptible Northeast Farm Northwest Farm Soybean aphid efficacy program update 2011 ICM Conference, Ames Iowa

Johnson CAD and Yield Results Peak aphids = 110/plant; no yield differences Rag 1 suppressed aphids Soybean aphid efficacy program update 2011 ICM Conference, Ames Iowa

Northeast CAD and Yield Results Peak aphids = 425/plant * * Rag 1 suppressed aphids; yield was also lower… Soybean aphid efficacy program update 2011 ICM Conference, Ames Iowa

What is Transform? • • • Dow Agro. Sciences 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 Rag 1 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 R 5 (mid-August) Soybean aphid efficacy program update 2011 ICM Conference, Ames Iowa

Research Summary • Rag 1 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 • Rag 1 plots have fewer aphids • Can prevent ET and insecticides • Rag 1 doesn’t cause yield drag – May not be in highest-yielding seed? • Strongly encourage using Rag 1 or Rag 1+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 Mc. Carville • Mari Kemis, Brandi Geisinger Soybean aphid efficacy program update 2011 ICM Conference, Ames Iowa

Where to get more information • ICM News www. extension. iastate. edu/Crop. News Free pubs and podcasts! • Soybean Aphid www. ent. iastate. edu/soybeanaphid/ • To see more talks www. ent. iastate. edu/dept/faculty/hodgson Soybean aphid efficacy program update 2011 ICM Conference, Ames Iowa

Please take a copy! *Speaker evaluations would be appreciated! See me for details. Soybean aphid efficacy program update 2011 ICM Conference, Ames Iowa

THANK YOU! Or visit my ISU Faculty webpage to see publications and presentations! @erinwhodgson Soybean aphid efficacy program update 2011 ICM Conference, Ames Iowa