Project Details:

Title:
Improving soybean insect management

Parent Project: Improving soybean insect management
Checkoff Organization:Iowa Soybean Association
Categories:Insects and pests, Crop management systems
Organization Project Code:
Project Year:2015
Lead Principal Investigator:Erin Hodgson (Iowa State University)
Co-Principal Investigators:
Keywords: Insecticide Evaluations, Outreach and Extension, Soybean Educational Activities, Soybean Insect Studies

Contributing Organizations

Funding Institutions

Information and Results

Click a section heading to display its contents.

Project Summary

This practical entomology project has resulted in generating information that has been the basis of several Extension publications, workshop presentations, videos, and technical publication on the management of soybean aphids and spider mites.

The goal of this continuing research project is to protect soybean yields by optimizing productivity and improving pest management strategies. This project will evaluate existing and emerging insect suppression tactics, like insecticides and host plant resistance, to protect yield and develop a suitable management plan. Insecticides will be evaluated and research findings will be communicated to Iowa soybean growers as part of the Extension educational program.

Project Objectives

1. Evaluate insecticide efficacy for soybean insects.
2. Communicate research fillings for improved pest management.

Project Deliverables

This project will evaluate existing and emerging insect suppression tactics, like insecticides and host plant resistance, to protect yield and develop a suitable management plan.

An annual report of our data was written and made available to the public in December.

Progress of Work

Update:
Small plots were harvested at the Northwest Research Farm with the help of Joshua Sievers (Farm Superintendent) on 15 October 2014. Small plots were also harvested at the Northeast Research Farm with the help of Ken Pecinovsky (Farm Superintendent) on 11 October 2014. Harvested seed weight and moisture were recorded for each plot, calculated in bushels per acre at 13% moisture, and averaged by treatment at both locations. Data collected during the 2014 growing season regarding aphid populations, plant stands, and yield was summarized after harvest and reported to project contributors.

In 2014, there was light soybean aphid pressure at both locations until August. There were strong differences between aphid populations on host plant resistant and susceptible seed. However, there was not enough season accumulation of soybean aphids at either location to exceed the economic injury level and cause yield loss. A full summary is reported in our annual Yellow Book publication (see link below).

Land for 2015 small plot evaluations is confirmed at the Northwest Research Farm with the help of Joshua Sievers (Farm Superintendent) and at the Northeast Research Farm with the help of Ken Pecinovsky (Farm Superintendent). Treatment lists have been generated (25 at NW Farm and 35 at NE Farm), including seed- and foliar-applied insecticides, host plant resistance to soybean aphid, and fungicides. We are collaborating with five industry companies in 2015. Seed and seed treatments have been ordered and delivered. Planting will start late April, based on appropriate planting conditions. Five undergraduate students haven been hired and will have staggered start times in May and June. We are also hosting an undergraduate student from Brazil to learn more about efficacy evaluations in soybean.

Final Project Results

During 2013-2015, two field locations were established each year. Plots were set up in a randomized complete block design with four replications, including different foliar insecticides, insecticidal seed treatments and host plant resistance. Soybean aphids were sampled weekly and an estimate of seasonal exposure was estimated for each treatment. Yield was also evaluated for each treatment.

Results of the 3-year study:
• Foliar insecticides labeled for soybean aphid were efficacious; meaning they all had good knockdown or killing power.
• Insecticidal seed treatments could reduce cumulative aphid days, but did not offer sufficient yield protection compared to foliar insecticides.
• Host plant resistance did reduce cumulative aphid days and were comparable to foliar insecticides in yield protection; however, yield potential of host plant resistant varieties was lower compared to susceptible soybean varieties.

Conclusions of the 3-year study:
• Farmers have a wide range of foliar insecticides to choose from if they need to protect yield from a soybean aphid outbreak.
• Scouting and timely treatment with foliar insecticides is recommended over the use of prophylactic seed treatments.
• Using host plant resistance dramatically decreases the likelihood a foliar insecticide will be needed to protect yield.

Benefit to Soybean Farmers

This project will evaluate existing and emerging insect suppression tactics, like insecticides and host plant resistance, to protect yield and develop a suitable management plan.

Performance Metrics

Project Years