DES MOINES, IA (DTN)--Farmers should test their corn for aflatoxin fungus before storing it in the bin, one crop insurance agent told DTN.
If undetected, crop insurance coverage could fail as early as January, and the affected corn's marketability would be limited.
This year, corn fields in southwest Illinois, southeast Nebraska, central and northeastern Kansas have been found to be infected by aflatoxin.
Marketing corn that was infected with the aflatoxin fungus is becoming a concern for many farmers in the Corn Belt who have experienced it mainly in poor yielding fields.
"We have a severe aflatoxin outbreak," one southwest Illinois farmer, told DTN. "Many farmers haven't even tested for it before putting it in the bin and don't seem concerned. When they take it out in January, there could be a lot of disappointment."
In the United States, corn with more than 20 parts per billion (ppb) of aflatoxin--which is the equivalent of just one ounce in 3,125 tons--is not considered fit for feeding to animals that produce meat or milk for humans, according to the U.S. Department of Agriculture.
A known carcinogen, aflatoxin is the metabolic byproduct of Aspergillus flavus fungi. USDA said grain with more than five ppb gets thumbs down for making food-grade corn products. And in the South and in areas where occasional drought stresses corn and increases A. flavus levels, farmers may lose opportunities to produce corn valued for export markets.
Once in the bin, inspecting the corn for aflatoxins is very difficult.
"It only takes eight kernels out of every 3,500 bushels, so finding that small amount in a bin could be really hard," said Gene Schott, manager of the Shawnee Terminal elevator in Topeka, KS.
Crop insurance will cover the damage provided a farmer works closely with his insurance company by having his standing corn tested before it goes in the bin.
"It's imperative farmers that are in affected areas check their corn before simply storing it and trying to market the grain in three to six months," said one crop insurance agent.
Normally, farmers in an aflatoxin-affected area will receive information from the area's agriculture extension office suggesting testing for the toxin.
Emerson Nafziger, University of Illinois agronomist, told DTN, the fungus shouldn't be ignored.
"Even if the farmer dries the grain, the toxin doesn't go away," said Nafziger.
The maximum toxin level accepted by elevators is 20 parts per billion.
"It doesn't take long for the toxins to reach this level," said Nafziger. "In Illinois, there have been a lot of loads turned away at the elevator. If the elevator does take the infected corn, they might use it to blend for feed."
Schott said, "About 20% of the loads we tested were contaminated with aflatoxin, but we didn't test every load due to time constraints."
A lot of the corn that is turning up with aflatoxin in Kansas is being sold to brokers who in turn sell it to users such as cattle feedlot owners.
Aflatoxin corn can also be used in corn based-ethanol as an added fuel alternative. However, since part of the left over ingredients of ethanol, known as mash, is fed to animals, there is some concern about aflatoxin corn being used to produce ethanol.
Farmers should file a probable loss claim for the contaminated corn soon after having the grain tested.
For those farmers who feed their corn to their own animals, testing is still recommended.