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ARS Home » Southeast Area » Tifton, Georgia » Crop Protection and Management Research » Research » Publications at this Location » Publication #164034
Title: PREVENTION OF PREHARVEST AFLATOXIN CONTAMINATION: INTEGRATION OF CROP MANAGEMENT AND GENETICS IN CORN

Author
item Guo, Baozhu
item Widstrom, Neil
item LEE, R - UNIVERSITY OF GEORGIA
item WILSON, D - UNIVERSITY OF GEORGIA
item COY, A - UNIVERSITY OF GEORGIA

Submitted to: Journal of Toxicology Toxins Reviews
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/6/2004
Publication Date: 6/23/2005
Citation: Guo, B., Widstrom, N. W., Lee, R. D., Wilson, D. M., Coy, A. E. 2005. Prevention of preharvest aflatoxin contamination: Integration of crop management and genetics in corn. In: Abbas, H. (ed.). Aflatoxin and Food Safety. Boca Raton, Florida: CRC Press. Pp. 437-457.

Interpretive Summary: Aflatoxins are considered to be the most potent naturally-occurring carcinogen, and are produced primarily by fungus, called Aspergillus flavus. The production of aflatoxin in corn can be dramatically influenced by several environmental factors that affect growing corn. Some of these factors are beyond control of producers; rainfall, ambient temperatures, humidity, and farm soil type. Although considered uncontrollable, even these may be modified in the field by appropriate management practices, i.e. irrigation or careful selection of the location on the farm for growing corn in the rotation. In the Southern U.S., aflatoxin contamination of corn in the field is a chronic problem. First of all, insect populations are extremely large every year. Second, drought stress is conducive to A. flavus infection and aflatoxin production. Third, loose-husked hybrids are used in the South. When grown in the south, they accentuated insect damage and aflatoxin contamination. The development and breeding of "Southern-Type" hybrids with tight husk coverage and flint-like corn are essential to control preharvest aflatoxin contamination. Integration of crop management tactics and genetic strategies, conventional or molecular, will constrain the problem and help Southern corn growers produce a quality, profitable crop.

Technical Abstract: Preharvest aflatoxin contamination in corn is a chronic problem in the southeastern U.S. and influenced by factors that increase plant stress. In the Southern U.S., insect populations are usually large every year. Drought stress caused by warmer and drier than normal weather is conducive to Aspergillus flavus infection and aflatoxin contamination of corn. When typical "corn-belt" loose-husked hybrids are planted in the Southern U.S., insect damage of ears and aflatoxin contamination are accentuated. Crop management and the development of "Southern-Type" hybrids with tight husk coverage and flint-like corn are essential for control of preharvest aflatoxin contamination. The breeding of Southern-Type hybrids should include drought/heat tolerance, corn earworm resistance, and good husk coverage of the ear and hard kernel (flint-type). Molecular biotechnology may make an impact on tackling the complexity of preharvest aflatoxin contamination of corn. Integration of crop management tactics and host resistance strategies, conventional or molecular, may constrain the problem and help Southern corn growers produce a quality, profitable crop.