MANHATTAN, Kan. -- Soaring summer temperatures, coupled with high humidity and dry conditions, make this a year to be mindful of the potential for aflatoxin in the corn crop, a Kansas State University scientist said.

"Aflatoxin is a toxic metabolite produced by the ear-rotting fungus Aspergillus flavus," said Doug Jardine, state plant pathology leader with K-State Research and Extension. "It is favored by hot, humid and droughty conditions during the grain fill period. Historically, southeast Kansas has been a hot spot, but high aflatoxin levels can come from anywhere in the state."

Symptoms of Aspergillus ear rot are masses of yellow-green spores on or between the corn kernels. Oftentimes, only a few kernels per ear are infected. Any part of the ear may be affected by the fungus, but the tip is the most common site.

Dairy producers and livestock breeders should be the most cautious, Jardine said. The acceptable level in milk is zero, and young livestock will only tolerate very low levels of aflatoxin.

The Food and Drug Administration's acceptable level for human food is 20 parts per billion.

"If a field is suspected of having Aspergillus infections, a test to determine the level should be run," he said. "The black light test used by some elevators is inaccurate and can lead to the rejection of corn that may be safe -- or, even worse, the acceptance of corn that may not be safe."

The Kansas Grain Inspection Service, Inc., with offices in Topeka and Hutchinson, offers aflatoxin tests, Jardine said. The inspection service is at 785-233-7063.

More information about corn production in Kansas is available at county and district K-State Research and Extension offices.

SOURCE: K-State news release.