Integration of Sclerotinia sclerotiorum-Targeted Biofungicides Coniothyrium minitans and Bacillus amyloliquefaciens into Season-Long Soybean Pest Management Practices in Indiana

Abstract

Two biofungicides, Coniothyrium minitans and Bacillus amyloliquefaciens, are commercially available and have been shown to limit or suppress Sclerotinia sclerotiorum in soybean. S. sclerotiorum is a soilborne pathogen of soybean that can cause significant yield losses under cool and wet environmental conditions. Integrated soybean pest management practices can include the application of herbicides, fungicides, and insecticides at various times during the growing season to minimize yield losses. However, limited information is available regarding how these biofungicides can be successfully incorporated into a soybean-integrated pest management program. To assess the sensitivity of C. minitans and B. amyloliquefaciens biological activity on S. sclerotiorum to pesticides commonly used in soybean-production systems, a poison plate assay and soil plate and growth chamber experiments were conducted. In the poison plate assay, C. minitans was most sensitive to the preemergence herbicide flumioxazin and the synthetic fungicides boscalid and fluazinam, whereas B. amyloliquefaciens was sensitive only to the synthetic fungicide fluazinam. In the soil plate assay, the mycoparasitic activity of C. minitans on S. sclerotiorum was sensitive to flumioxazin, metribuzin, glyphosate, picoxystrobin, and boscalid. In the controlled environment experiments, none of the pesticides tested decreased the efficacy of B. amyloliquefaciens. [Figure: see text] Copyright © 2023 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

Keywords

• biological control
• chemical control
• disease control and pest management
• fungal pathogens
• soybean
• white mold