ARS researchers have found that a biological control called Afla-Guard® that they developed to stop the fungi which causes aflatoxin on peanuts can also be used to protect corn. [Photo courtesy of Microsoft Clipart.]

After extensive study and research trials in Texas, Afla-Guard® was registered by the US Environmental Protection Agency (EPA) for use on corn, beginning with the 2009 crop.

Recently retired Agricultural Research Service (ARS) microbiologist Joe Dorner at the National Peanut Research Laboratory in Dawson, Georgia, helped develop Afla-Guard®, a biological control for the aflatoxin-producing fungi Aspergillus flavus and A. parasiticus in peanuts. ARS is USDA's principal intramural scientific research agency.

A. flavus and A. parasiticus, naturally-occurring soil fungi, can invade food and feed crops, contaminating them with aflatoxin. Aflatoxin is a human carcinogen produced by the fungi and is also toxic to pets, livestock, and wildlife.

Afla-Guard® is composed of hulled barley coated with spores of a nontoxic strain of A. flavus. The nontoxic Aspergillus fungi successfully compete against the toxic species for the limited space and nutrients each needs to grow and thrive. In peanuts, Afla-Guard® reduced aflatoxins by an average of 85 per cent in farmers' stock peanuts and up to 97 per cent in shelled, edible-grade peanuts.

In light of this success, Dorner and other ARS scientists conducted a two-year study of Afla-Guard® in corn. They again found that it was effective in reducing aflatoxin levels—showing an overall reduction of 85 percent, when compared to control fields.

Afla-Guard® was applied to the corn crop in different ways: to soil when corn was less than a meter tall, in plant whorls prior to tassel formation, and as multiple sprays during silking.

Read more about this and other corn-related research in the September 2010 issue of Agricultural Research magazine.

The research was published in the Journal of Food Protection.