Hot, dry growing seasons and warm summer nights aren't just
devastating for the development of corn; they can also lead to
the development of Aspergillus ear rot, and the potential for
aflatoxin contamination. Aflatoxin, a mycotoxin produced by the
fungus Aspergillus flavus, shows itself as a yellow-green or
gray-green mold on corn kernels. Prolonged hot and dry
conditions post-pollination increase the possibility of
aflatoxin production. Alison Robertson, plant pathologist at
Iowa State University, says aflatoxin requires nights with
temperatures greater than 70 degrees and days with temperatures
greater than 86 degrees to effectively develop. Often confused
for aflatoxin, vomitoxin is produced during cool, wet growing
seasons. It likely poses no threat for this growing season.
Aflatxoin, however, is a known carcinogen, and the Food and Drug
Administration lists the highest possible aflatoxin content as
20 ppb for the human food supply. For finishing cattle, that
content may go no higher than 300 ppb. Univer