2023
Using Simulated Injury and Natural Populations of Insect Pests to Refine Treatment Thresholds in Soybeans
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Contributor/Checkoff:
South Carolina Soybean Board
Category:
Sustainable Production
Keywords:
Biotic stressCrop protectionField management Pest
Parent Project:
This is the first year of this project.
Lead Principal Investigator:
Jeremy Greene, Clemson University
Co-Principal Investigators:
Project Code:
Contributing Organization (Checkoff):
South Carolina Soybean Board
$20,000
Institution Funded:
Clemson University
$20,000
Brief Project Summary:
Insect pests are a major limiting factor to producing soybeans in South Carolina. Numerous species like stink bugs, podworm, soybean looper, velvetbean caterpillar, green cloverworm, threecornered alfalfa hopper, kudzu bugs, lesser cornstalk borer and many others, infest soybeans in the state annually. Data and recommendations regarding efficacy of insecticides and appropriate timing and termination of chemical control are needed. This work addresses the pod-feeding complex and includes defoliators and stem feeders, as well. This project provide insecticide efficacy data on stink bugs and other arthropod pests in soybeans and investigates appropriate timings for initiating and terminating insecticide applications for stink bugs and other major insect pests.
Key Beneficiaries:
#agronomists, #extension agents, #farmers
Unique Keywords:
#insect management, #insects, #insects and pests
Information And Results
Project Summary

Because insect pests are a major limiting factor to producing profitable soybeans in South Carolina, and our treatment thresholds for controlling those pests are in need of refinement, we propose to simulate defoliation and stem injury to plots and correlate with yield impacts. While conducting these trials with artificial injury, we will also run similar opportunistic trials with natural populations of insects, as available.

Because stem feeders, such as threecornered alfalfa hopper (TCAH), lesser cornstalk borer (LCB), Dectes stem borer, and other species, can reduce stands and yields, we propose to target selected fields with a high probability of developing problems (e.g. planted into cover crop with late burndown) and evaluate treatment thresholds with natural populations. We also propose to simulate stem-feeding injury in soybeans with two methods: 1) hand thinning of stands with scissors or shears and 2) selective elimination of plants with herbicides.

Project Objectives

1. Compare various levels of simulated defoliation injury with impacts on yield.
2. Compare various levels of simulated injury to stems with impacts on yield.
3. Conduct threshold trials with natural populations of defoliating and stem-feeding insects.

Project Deliverables

The results of this project will be communicated to soybean producers in South Carolina and beyond through use of multiple information outlets, such as newsletters, soybean production meetings, phone hotlines, web-based media, field days, scientific papers, etc. Quarterly and final reports will be submitted by each deadline.

New data gathered on the impacts of simulated insect injury, coupled with data from trials using natural populations of insect pests, will be used to help refine management strategies for these yield-limiting and costly pests of the crop. Adoption of any new recommendations will be ascertained via formal and informal surveys of producers during the 2024 season.

Progress Of Work

Final Project Results

Benefit To Soybean Farmers

Because insect pests are a major limiting factor to producing profitable soybeans in South Carolina, and our treatment thresholds for controlling those pests are in need of refinement, we propose to simulate defoliation and stem injury to plots and correlate with yield impacts. While conducting these trials with artificial injury, we will also run similar opportunistic trials with natural populations of insects, as available.

The United Soybean Research Retention policy will display final reports with the project once completed but working files will be purged after three years. And financial information after seven years. All pertinent information is in the final report or if you want more information, please contact the project lead at your state soybean organization or principal investigator listed on the project.