Area-Wide Programs for Aflatoxin Mitigation: Treatments to Cotton Can be Cost Effective

Biological control of aflatoxin contamination with atoxigenic strains of A. flavus is currently used commercially on several crops.  However, this technology was first developed and registered for use in preventing contamination of cottonseed.  Applications have influences beyond treated fields and across multiple years.  In areas where atoxigenic biocontrol agents are used, even crops in untreated fields may receive considerable benefit.  Benefits to untreated fields were demonstrated in commercial agriculture in North Central Texas. Influences of fungi moving between fields can be positive (i.e. atoxigenic strains moving from treated areas) or negative (i.e. aflatoxin producers moving from untreated susceptible crops).   In commercial field trials in Arizona, a single strip application of the biocontrol product Aspergillus flavus AF36 Prevail along a single boarder of commercial cotton fields resulted in significant displacement of aflatoxin producing fungi and lower aflatoxin levels.  However, in areas where aflatoxin contamination of cottonseed is severe, whole field treatments are recommended.  In areas in which applications are made primarily for preventing contamination of maize grain or silage, inexpensive boarder applications to neighboring or nearby cotton, may result in both better area-wide and long-term reductions in the aflatoxin-producing potential of fungal communities and improved reductions in incidences of contamination of both cottonseed and other susceptible crops such as maize, pistachio, and peanuts.