2024
Soybean fungicide efficacy, profitability, and pest resistance over time
Contributor/Checkoff:
Category:
Sustainable Production
Keywords:
DiseaseField management Pest
Lead Principal Investigator:
Andrew Kness, University of Maryland
Co-Principal Investigators:
Project Code:
80141
Contributing Organization (Checkoff):
Leveraged Funding (Non-Checkoff):
In-Kind support from FMC and Corteva
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Institution Funded:
Brief Project Summary:
The goal of the project is to provide fungicide efficacy data to farmers and chemical companies. This data is used to inform best practices for fungicide applications in soybeans.
Key Beneficiaries:
#farmers
Unique Keywords:
#fungicide, #pestresistance, #profitability
Information And Results
Project Summary

Fungicides are becoming increasingly popular in full season soybean production. Land grant institutions across the US and in surrounding states have robust applied research programs where industry ag chemical companies submit new products and formulations for testing for the management of soybean diseases; such a project has been absent in Maryland for several years, creating a dearth in knowledge of fungicide efficacy for our soybean producers in Maryland. This project will provide data that soybean producers would benefit from, such as: fungicide efficacy for managing common fungal diseases of soybean, monitor fungicide resistant pest populations, and track the economic impact of foliar fungicide applications over multiple years and environments unique to Maryland.

Project Objectives

1. Evaluate the efficacy of approximately 10 foliar fungicides on full season soybeans grown on three research farms in Maryland by measuring foliar disease incidence and severity.
2. Determine any greening or green stem effects of the fungicides.
3. Monitor fungicide active ingredient efficacy over time and identify any fungicide insensitive foliar fungal pathogens.
4. Determine the yield impact of foliar fungicides and their economic impact.

Project Deliverables

A full-season commercial soybean variety with good yield potential representative of what’s typically grown in Maryland and will be purchased for use in all trials across all site locations. A soybean variety with a medium rating for frogeye leaf spot and other foliar diseases will be chosen in order to maximize chances of observing response to fungicide applications.

Seed will be direct seeded into soybean residue on three site locations (Western MD Research & Education Center in Keedysville, MD, Wye Research & Education Center in Queenstown, MD, and Central Maryland Research & Education Center in Ellicott City, MD). Plots will be drilled on 7.5 inch rows, 10 feet wide by 30 feet long, arranged in a randomized complete block design.

Fertility and crop management (weeds and insects) will be managed in accordance with extension guidelines.

Stand counts will be conducted approximately two weeks after planting to assess emergence.

Fungicides for the trial will be submitted by chemical companies. Some products may also be purchased and used as checks in the test. All fungicides will be applied per the maximum label rate per label instructions.
o Fungicides will be applied with a CO2 backpack sprayer.

Foliar disease ratings will be assessed prior to treatment application and ratings will continue biweekly until soybeans reach maturity. NDVI ratings (plant greenness) will also be collected to determine any “greening” effect of the treatments. Green stem ratings will be collected at R8. Disease, NDVI, and green stem ratings will be compared statistically.
o Disease ratings will be used over time to compare and track any changes in pathogen resistance to specific active ingredients.

Plots will be harvested with a small plot research combine at maturity. Yields for each plot will be calculated and a statistical analysis will be done to compare treatment yields to determine if there’s any treatment effect. Yield and treatment cost will be used to calculate and compare possible economic benefits of fungicides on full season soybeans.

Data from this study will be published in extension publications and/or peer-reviewed crop production journals. Data will also be presented to growers at regional and statewide meetings and newsletters on an annual basis so that growers can view the most recent fungicide data for soybeans.

Progress Of Work

Updated July 30, 2024:
Plots were established at the Western Maryland Research and Education Center (WMREC), Central Maryland Research and Education Center (CMREC) and Wye Research and Education Center (WYE) on 6/11/24, 5/17/24, and 6/6/24 respectively. WMREC was initially planted on 5/20/24, however, the stand was very thin due to heavy slug damage and the plot was replanted in a different field on 6/11/24. Soybean variety Seed Consultants SC7364E was used for all sites. As of this progress report, all plots are established and growing well and are approximately 7 days from R3. At R3, the first fungicide treatments will be applied with a CO2 backpack sprayer.

Disease data will be collected following fungicide application. Harvest data will be collected with a small plot combine.

Final Project Results

Benefit To Soybean Farmers

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.