Aflatoxins are carcinogenic poisons produced by some strains of the common fungus (Aspergillus flavus) that contaminate crops throughout the world. Cotton, corn, peanuts, and several tree crops including almonds, pistachios and figs are just some of the crops susceptible to aflatoxin contamination.
Crops with aflatoxin content exceeding regulatory limits set by the FDA and several key U.S trading partners prevent these crops from entering premium markets and are at a severe trading disadvantage.
In Arizona alone, aflatoxins have cost Arizona’s cotton producers annual losses of over $10 million. Cottonseed containing over 20 parts per billion of aflatoxin cannot be fed to dairy cows, and results in at least $20-$50 per acre loss in revenue per season.
Pioneering research conducted by the University of Arizona, USDA ARS, identified certain native strains of Aspergillus flavus which do not contain aflatoxin. They occur naturally in the southwest at low levels.
One of these atoxigenic (non-toxin producing) strains, Aspergillus flavus AF36, has been shown to competitively displace aflatoxin-producing strains when applied to cotton fields. This displacement is associated with reduced aflatoxin levels in Arizona cottonseed.
Aspergillus flavus AF36 was evaluated in commercial fields in Yuma, Arizona, during the period of 1996-1998. The results suggested a high potential for reducing the vulnerability of all crops grown in a treated region to aflatoxin contamination. This provided the opportunity for an areawide aflatoxin management suppression program.
The Arizona Cotton Research & Protection Council (ACRPC) established a working partnership with USDA ARS to both manufacture AF36 and advance atoxigenic strain technology.
The biological control Aspergillus flavus AF36 Prevail has established itself as an effective tool in managing aflatoxins by using a native strain of the fungus that naturally does not produce aflatoxins.
The beneficial fungus, AF36, is coated onto a carrier grain that is sterilized (will not germinate) and serves as a food source for the fungus. By applying AF36 Prevail to crops at the appropriate time, the fungus grows on the carrier grain in the field, and moves to the desired crop before the aflatoxin-producing strains have an opportunity to infect the crops.
Using AF36 actually changes the composition of the fungi in the environment, shifting the majority of the population from aflatoxin producers to the safe non-toxin producing strain of Aspergillus flavus.