Status of the Aflatoxin Problem in Corn

Abstract

AbstractAflatoxin, a potent carcinogenic metabolite produced by the fungus Aspergillus flavus, has been clearly demonstrated to be a kernel contaminant in both preharvest and postharvest corn. Research has been conducted on: (i) fungus invasion of the ear; (ii) effects of the environment on aflatoxin levels; and (iii) methods of control.A. flavus infects developing ears in both southern and corn belt regions but growing conditions in the southern U.S. are more conducive to the fungal infection process and subsequent toxin production. Most observations indicated that a break in the pericarp is necessary for fungal establishment. Insects, particularly larvae of the second European corn borer, corn earworm, and fall armyworm, have been implicated in causing breaks as well as serving as vehicles for carrying the inoculum to the potential infection site. Conditions of stress such as those caused by drought have been shown to enhance the aflatoxin contamination problem. Suggested control methods are: (i) plant only adapted hybrids with the highest level of resistance against ear‐damaging insects; (ii) employ management practices that will either reduce stress or shift the ear development stage to miss a likely stress period.Preliminary results suggest that either A. flavus growth or aflatoxin levels are under genetic control, but corn genotypes cannot be recommended at this time that would entirely eliminate the aflatoxin contamination problem in corn.