Typically Aspergillus flavus will colonize the damaged kernels, resulting in aflatoxin concentrations ranging in the parts per million range. This type of damage is easily identified by the abundant sporulation of the fungus on the damaged kernels. Although the number of affected kernels is small, the enormous amount of toxin in these damaged kernels makes insect damage a significant component in the aflatoxin problem. In addition, the infrequent kernel with extremely high levels of toxin complicate the analysis of corn for aflatoxin. This is the major reason why a 10 pound sample of corn is required for analysis for aflatoxin contamination in corn.
Insect damage is frequently more severe in drought years adding to the overall problem.
The most effective strategy for the control of aflatoxin in corn is to prevent or reduce its development in the field by using good production practices such as subsoiling, weed control and adequate nitrogen fertilization. Efforts should be made to minimize additional development of aflatoxin in the harvesting process and storage of the grain. Harvest corn as soon as it is mature and make certain your combine is properly adjusted to prevent excess damage to the kernels. Do not allow the corn to stand in wagons for extended periods of time without air movement through the grain. Once the corn is contaminated, very few practical options exist to remove it.