Fungicide Evaluation for White Mold Suppression in Ohio Soybeans
Agronomy & Pest Management
Lee Beers
Assistant Professor, Extension Educator
Ohio State University
Cortland
Abstract
White mold (Sclerotinia sclerotiorium) has long been present in northeast Ohio and is the primary yield limiting pathogen of soybean in this region. Disease has been detected each year since 2016 at varying severity levels, with widespread outbreaks observed in 2020 and 2023. Cultural practices such as 30-inch row spacing, lower plant populations, and resistant varieties have been adopted by most growers. On-farm research trials were conducted in 2022 and 2023 to evaluate the effectiveness of fungicides on the suppression of white mold. Strip trials were conducted using a random block design with a minimum of three replicates for each treatment. Treatment plots were approximately two acres. Fungicides Aproach (picoxystrobin), Endura (boscalid), Revytek (mefentrifluconazole/pyraclostrobin; 2022 only), and Viatude (picoxystrobin/prothioconazole; 2023 only) were compared to non-treated control strips. Fungicides were applied at the R1 growth stage at labeled rates for white mold suppression in 100’ spray passes. Incidence and severity ratings were collected approximately five weeks post application. Treatment plots were harvested two full combine header passes (80’) in the center of the plot and yield was measured using a certified weigh wagon at harvest. White mold pressure was moderate in 2022, and high in 2023. No significant difference was observed in any of the fungicide treatments compared to the non-treated strips for incidence or severity in 2022 and 2023. Yield was significant (P<0.05) for Aproach and Revytek in 2022, and not significant in 2023. Application costs in 2022 were not recovered despite yield increase for either Aproach or Revytek. Although plant health benefits likely contributed to increased yield in 2022, neither Aproach or Revytek reduced the incidence or severity of white mold relative to non-treated controls.
Authors: Lee Beers, Horacio Lopez-Nicora, Noelle Barnes
-
Lee Beers Assistant Professor, Extension Educator, Ohio State University Extension, Ohio, 44410-1455
-
Horacio Lopez-Nicora Assistant Professor, Soybean Pathology and Nematology, Ohio State University, Department of Plant Pathology, Ohio, 43210
-
Noelle Barnes Extension Educator, Ohio State University Extension, Ohio, 44410