Non-Conventional Methods of Soil-borne Fungal Disease Management in Soybean and Pea

Abstract

As demand increases for organic and sustainable methods of agricultural production, interest also increases in non-conventional methods of disease management. Non-conventional methods for managing fungal disease, such as biological control and biorational pesticides, are becoming more important as chemical inputs are scrutinized and fungicide resistance develops in pathogen populations. In this study, non-conventional methods of managing soybean sudden death syndrome, a fungal disease caused by Fusarium virguliforme, and Aphanomyces root rot of peas caused by A. euteiches, were compared to conventional (chemical) methods of control. A biological control agent Bacillus pumilus and rapeseed meal were compared to two chemical fungicides in greenhouse assays to determine which treatments could reduce disease severity and maintain plant biomass when plants were subjected to conditions suitable for disease development. B. pumilus was also tested for antagonism in vitro against these pathogens, and all fungi showed reduced growth in the presence of B. pumilus. The results of this study showed that conventional methods of fungal disease control were more effective than non-conventional methods in maintaining plant biomass under conditions conducive to disease. However, the non-conventional methods reduced disease severity and may possibly have value in organic production systems. In the United States, Minnesota is the third largest producer of soybeans and the largest producer of organic soybeans and a major producer of peas, so any treatment that reduces the impact of soil-borne pathogens has the potential to make a large economic impact.