AGRICULTURAL PRACTICES, ECOLOGICAL AND VARIETAL EFFECTS ON AFLATOXINS AND OTHER MYCOTOXINS IN CORN
Location: Biological Control of Pests Research Unit
Title: Mycotoxins in food and their control by the use of non-toxigenic biocontrol agents
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: August 15, 2011
Publication Date: September 10, 2011
Citation: Abbas, H.K., Weaver, M.A., Jin, X., Shier, W.T. 2011. Mycotoxins in food and their control by the use of non-toxigenic biocontrol agents. The 1st Internatnional Symposium on Mycotoxins in Nuts and Dried Fruits, Damghan-Iran 10-12, Sep, 2011, page 24.
Mycotoxins problems have been recognized at least since medieval times, when contaminated rye caused neurological problems and death. However, about 50 years ago, mycotoxin contamination of feed caused an epidemic of "Turkey X disease", resulting in the death of thousands of turkeys. The toxin was identified as aflatoxin, resulting from infection of peanut meal with Aspergilllus flavus. Since then extensive research has been done on the role of mycotoxins in food and feed safety with emphasis on aflatoxins. Fields of investigation include toxicology, fungal ecology, analytical methods for determination of mycotoxins, variety testing, and breeding for resistance using conventional and molecular approaches. The number and type of mycotoxins discovered have increased with time and advances in technology. Currently there are more than 300 known mycotoxins. Aflatoxins, trichothecenes, fumonisins, zearalenone, patulin and cyclopiazonic acid (CPA) are the mycotoxins of greatest concern for human and animal health.
The Food and Agriculture Organization (FAO) of the United Nations has estimated that the costs of mycotoxins reaches $923 billion annually. Breeding efforts and agronomic practices have not provided sufficient control. Until recently there was no means for controlling aflatoxin contamination in the field. The USDA has identified strains of A. flavus that do not produce aflatoxin and can be used to competitively displace the toxigenic strains. Strain K49, NRRL 30797, is in evaluation in our laboratory for use on corn. One strain, NRRL 21882, sold as Afla-Guard® brand biological control agent, was developed for use in peanut and is now commercially available for use on peanut and corn in the US. Another strain, AF36, NRRL 18543, is widely used in cotton in the western U.S. and is in limited use in corn and pistachios. Strain AF36, however, produces another mycotoxin, cyclopiazonic acid. With the large number of available strains that do not produce this toxin, continued use of AF36, may seem contrary to the "First Do No Harm" principle.
Efforts are being made in our laboratory to develop efficient, cost-effective methods for delivering biocontrol strains of A. flavus to crops, including Water-Dispersible Granules (WDG) that allow spraying from aerial sprayers onto a broad spectrum of plants, including pistachios and other tree nuts. The technology is promising for the control of aflatoxin and other mycotoxins.