2025
Optimizing fungicide spray volume for improved white mold management in soybeans
Home
Contributor/Checkoff:
North Dakota Soybean Council
Category:
Sustainable Production
Keywords:
Disease
Parent Project:
This is the first year of this project.
Lead Principal Investigator:
Michael Wunsch, North Dakota State University
Co-Principal Investigators:
Project Code:
NDSC_2025_Agronomy 22
Contributing Organization (Checkoff):
North Dakota Soybean Council
$40,210
Institution Funded:
North Dakota State University, Carrington Research Extension Center
$40,210
Brief Project Summary:
This project seeks to address commonly received questions received soybean producers and crop advisors on the response to fungicide spray volume and the impact of applying fungicides when spray conditions are marginal. The project will quantify the impact of applying fungicides targeting white mold in spray volumes of 5, 7.5, 10, 12.5 and 15 gal/ac under optimal spray conditions (delta T between 4 and 6) and under marginal conditions, targeting early morning applications when plants are covered with dew and relative humidity is close to 100% (delta T between 0 and 2).
Information And Results
Project Summary

This project seeks to quantify the impact of fungicide spray volume on white mold management in soybeans with the goal of minimizing application costs and maximizing the profitability of fungicides for management of white mold in soybeans. The use of fungicide spray volumes greater than 10 gal/ac is widely recommended for improving fungicide performance against white mold in soybeans. Research supporting that recommendation had been lacking, and recent findings suggest fungicide spray volumes of 10 gal/ac may be sufficient. In research conducted in Brazil, increasing fungicide spray volume from 10.7 to 21.4 gal/ac had no impact on white mold management with either of two fungicides evaluated. In research conducted in North Dakota, increasing fungicide spray volume from 10 to 25 gal/ac (dry beans) or 5 to 15 gal/ac (soybeans) had no impact on white mold management in field trials conducted in 2020-2022 (dry beans) and soybeans (2022); data from 2023 will presented in the NDSC mid-year report due Dec. 1. Funding is sought for a third and final year of testing. Field studies will be established under irrigation in Carrington, ND to evaluate the impact of spray volume (5, 7.5, 10, 12.5 and 15 gal/ac) on the efficacy of one vs. two applications of the fungicide Endura (5.5 oz/ac) made under optimal versus marginal spray conditions. The suitability of spray conditions will be quantified by calculating Delta T, a measure of the evaporation potential. Testing will be conducted on soybean varieties differing in architecture (upright, bushy).

Project Objectives

(1) Identify the minimum fungicide spray volume needed to maximize white mold management and soybean yield and quality. (2) Evaluate whether the impact of fungicide spray volume on white mold management differs for one vs. two applications or by environmental conditions. (3) Quantify the impact of soybean architecture (bushy versus upright) on the optimum fungicide spray volume for white mold management.

Project Deliverables

(1) Development of rigorous recommendations on the fungicide spray volume that optimizes white mold management, soybean yield, and soybean profitability under white mold pressure. (2) Dissemination of results to North Dakota soybean growers, crop advisors, and extension personnel

Progress Of Work

Final Project Results

Benefit To Soybean Farmers

This project will improve the profitability of soybean production in fields where Sclerotinia is a problem by identifying profit-maximizing strategies to improve soybean agronomic performance and profitability under white mold disease pressure.

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.