ST. Paul, Minn. (September 11, 2000)—There's a fungus among us as the saying goes, and it's one researchers are working hard to eradicate. Recently, plant health scientists, gathered in New Orleans for their Annual Meeting, presented and discussed the latest advancements in controlling the fungi that produce aflatoxins (toxic chemicals that are known to cause cancer in animals).
One of the most promising developments reported at the meeting was the identification of genetic resistance to the production of aflatoxins in more than five major crops. According to Donald White, plant pathologist, University of Illinois-Urbana and a presenter at the meeting, "Commercially usable resistant varieties are being developed and will be available to producers sometime in the future." But he is careful to add, "Genetic resistance greatly reduces the amount of aflatoxin. However, it does not completely eliminate it. Therefore, resistance will be most useful when combined with other techniques that lower fungal infection and aflatoxin production."
The other techniques he's referring to involve crop management practices that help discourage the growth of the fungus that causes aflatoxins to be produced in the first place. States Themis Michailides, a plant pathologist at the University of California-Davis, "We've made progress on several fronts in our efforts to reduce contamination of crops with aflatoxins. Not only with biotechnology and genetic resistance, but also in our understanding of how simple crop management practices like irrigation to avoid drought stress, early harvesting and careful handling can significantly reduce aflatoxin content in crops."
When the fungus Aspergillus flavus (which is responsible for the majority of aflatoxin contamination) attacks crops, it often produces aflatoxins as a by-product. Because of their toxicity, aflatoxins are recognized as serious food safety hazards by most countries of the world and more than 50 countries have established or proposed regulations for controlling them in food and feed. In the U.S. corn, cottonseed, peanuts, and other crops are routinely tested and those containing more than 20 parts per billion of aflatoxins cannot be used in human food or fed to dairy cows. It is estimated that crop loss due to aflatoxin contamination costs U.S. producers more than $100 million per year on average.
"The cost to producers is substantial," states Peter Cotty, plant pathologist, USDA-ARS. "And this cost is passed on to the consumers. By reducing aflatoxin contamination, we reduce the incidence of a potent carcinogen in food and in the environment."
Research advancements on aflatoxins were shared during the Annual Meeting of The American Phytopathological Society. The American Phytopathological Society (APS) is a nonprofit, professional scientific organization dedicated to the study and control of plant disease with 5,000 members worldwide. Visit APSnet for more information.