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ARS Home » Southeast Area » Dawson, Georgia » National Peanut Research Laboratory » Research » Publications at this Location » Publication #429566
Research Project: Developing Genetic and Genomic Tools for Peanut Breeding

Location: National Peanut Research Laboratory

Title: Novel approaches using water potential and antagonistic bacteria, to reduce Aspergillus flavus population in soil

Author
item LUCIANO ROSARIO, DIANIRIS - Oak Ridge Institute For Science And Education (ORISE)
item Orner, Valerie
item Sobolev, Victor
item Higbee, Pirada
item Jurick Ii, Wayne
item Arias De Ares, Renee

Submitted to: PhytoFrontiers
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/14/2026
Publication Date: 5/19/2026
Citation: Luciano Rosario, D., Orner, V.A., Sobolev, V., Higbee, P.S., Jurick Ii, W.M., Arias De Ares, R.S. 2026. Novel approaches using water potential and antagonistic bacteria, to reduce Aspergillus flavus population in soil. PhytoFrontiers. https://doi.org/10.1094/PHYTOFR-09-25-0110-R.
DOI: https://doi.org/10.1094/PHYTOFR-09-25-0110-R

Interpretive Summary: Peanut production in the United States is expected to reach $81 billion in 2025 and plant diseases are a major threat to this industry. Specifically, aflatoxin contamination due to pre and postharvest infection of peanuts with Aspergillus flavus results in up to 30% rejection of shelled runner peanuts. A. flavus is present in the USA peanut growing regions, however, focus on cultural methods and soil amendment strategies to control A. flavus colonization in peanuts is limited. In this study, we used a controlled environment system to assess if soil moisture or a soil amendment with antagonistic Bacillus subtilis can be used as a method for A. flavus control. We found that saturated soil conditions led to decreased A. flavus titters when compared to the assessed treatments which had less water content. I addition, soil amendments with the assessed B. subtilis isolate did not result in reduced A. flavus counts. This is the first controlled environment study that quantifies A. flavus abundance in the soil in response to soil moisture content and a soil amendment with antagonistic bacteria. This method provides opportunities for assessing additional soil centric methods for pathogen control.

Technical Abstract: The peanut market in the United States is expected to reach $81 billion in 2025, and the state of Georgia is the main producer. Frequent contamination of peanuts with aflatoxins due to pre- and postharvest fungal infection, mainly with Aspergillus flavus, results in up to 30% rejection of shelled runner peanuts. Most studies to mitigate aflatoxins have been focused on peanut varieties and plant responses to environmental stress such as drought and temperature. Despite A. flavus being present in all U.S. peanut-growing soils, information on management of A. flavus populations in soil is scarce. In this study, we designed and implemented a controlled environment system to assess soil water potential (SWP) and soil amendment with antagonistic Bacillus subtilis for monitoring A. flavus populations in soil over time. We found that saturated soil (0 kPa) conditions led to decreased A. flavus titers compared with dryer conditions (30 to 1,000 kPa), whereas soil amendment with B. subtilis did not significantly affect A. flavus counts. This method will facilitate further research into strategies to reduce aflatoxigenic Aspergilli in soil and to potentially minimize preharvest aflatoxin accumulation.