U.S. Department of Agriculture: Agricultural Research Service, Lincoln, Nebraska


Date of this Version


Document Type



Agricultural Research January 2002


Peanut farmers could soon have a biological pesticide for protecting their crop’s prized seed from fungi that produce aflatoxin—the chief culprits being Aspergillus flavus and A. parasiticus.

Circle One Global, Inc. (COGI), of Cuthbert, Georgia, has applied for an exclusive license on an ARS technique for making the biopesticide from spores of a nontoxigenic, or benign, strain of A. flavus.

In Florida, Georgia, and Alabama—top peanut-producing states— aflatoxin outbreaks from 1993 to 1996 caused losses averaging $26 million annually, ARS economist Marshall C. Lamb estimates. The Peanut Administrative Committee strictly regulates the sale or use of shelled peanuts having above 15 parts per billion of aflatoxin. Those peanuts can’t be used in edible products, and shellers receive a much lower price for them.

Currently, there’s no direct action peanut farmers can take to control fungi that produce aflatoxin. But ARS researchers are hoping to change that by helping COGI commercialize a biopesticide that peanut farmers can apply to their fields.

The approach is known as biocompetitive exclusion, explains Joe W. Dorner, a microbiologist in charge of the project at ARS’ National Peanut Research Laboratory, in Dawson, Georgia. It involves formulating the benign mold’s spores and seeding them into soils around peanut plants. There, by colonizing the peanut pod zone, the mold becomes a living shield against toxigenic fungi.