Technical Abstract: Mycotoxins that contaminate peanuts are essentially restricted to the aflatoxins, produced by Aspergillus flavus and A. parasiticus, and cyclopiazonic acid (CPA), produced by A. flavus. Most methods currently in use to control mycotoxins in peanuts seek to remove individually contaminated kernels from lots that became contaminated either in the field or during storage. These include screening, kernel sizing, density separations, and electronic color sorting. Recently however, a method for biological control of aflatoxin and CPA contamination has been developed that prevents much of the contamination that might otherwise occur. It is based on competitive exclusion that is achieved by inoculating fields with a competitive, nontoxigenic strain of A. flavus. Large-scale field studies have demonstrated aflatoxin reductions in farmers= stock peanuts averaging 86% and reductions in edible-grade, shelled peanuts as high as 98%. The biocontrol technology has been commercialized and is marketed as the biopesticide, afla-guard7.