There are a few things farmers can do to help overcome the risk of aflatoxin in late-planted corn.

Selection of regionally adapted hybrids with drought tolerance, combined with high grain quality is a good first step. Though relatively few corn acres in the upper Southeast are irrigated, timely application of water is another way to reduce risk.

At harvest time growers can minimize aflatoxin risk by combining corn when it is first ready. Setting combines to minimize broken and lightweight kernels will help, as will rapid drying and separate storage of grain from irrigated fields versus dryland fields.

In corn, aflatoxins are measured and regulated in parts per billion. One part per billion is equivalent to one second in 32 years or one kernel of corn in a 10,000 bushel bin.

A good target for farmers to shoot for is 20 parts per billion of aflatoxin. Though some uses, such as feed for mature cattle, can be 200-300 parts per billion, sticking to the 20 part per billion limit will pay off for farmers.

In most states, corn with aflatoxin levels of 20 parts per billion or higher cannot be sold for transport across state lines. Limitations for use of aflatoxin infested corn extends even to ethanol production, because of the risk of contaminating distillers grain, a by-product of the ethanol production process.

A five-year comprehensive study on the cost of aflatoxins to the U.S. food industry is in its final stages and scheduled for release in September.

A separate USDA case study in corn estimates that the total measurable annual loss to the U.S. corn industry is $192 million. Of this amount, market losses make up $163 million, livestock health losses $4 million, and sampling and testing costs $25 million.

In addition, “intangible” economic losses, including the costs of grower disposal of contaminated corn, sampling errors, losses on a geographical basis, and losses associated with aflatoxin concentration in the production of ethanol, increase the average annual loss due to aflatoxin in corn to over $200 million.