WEST LAFAYETTE, Ind. — Corn growers are on the lookout for signs of ear rot from deoxynivalenol (DON), the same mycotoxin causing widespread wheat quality problems in the southern Corn Belt this year.

Risks for DON contamination in corn can be greater in areas with high levels of DON wheat contamination, according to Charles Woloshuk, Purdue University plant pathologist. That said, he still expects a normal year for ear rot in Indiana. He surveyed cornfields last week in north-central Indiana, where corn mycotoxins were high during 2009.

“Much of the corn was way behind in development, but there was no indication of corn tip infections,” he said. “(Ear rot) problems will likely be only in fields planted with very susceptible hybrids.”

Ear rot from DON is more likely to develop during cooler, wetter weather. Animals fed grain with high levels of DON, also called vomitoxin, can have health and weight issues.

Another mycotoxin produced by the same fungus producing DON, zearalenone, can impact livestock breeding and lactation.

Weather during the rest of August and September will determine the extent of corn mycotoxin risks.

“Cool and extended wet weather would not be ideal,” said Max Hawkins, a nutritionist at Alltech, a Kentucky-based company marketing mycotoxin management tools.

Even in areas where wheat vomitoxin contamination was high, recent weather patterns are not favoring corn mycotoxin development. While a cool front brought rain and some severe storms to parts of the region last week, drier and warmer conditions are expected for the near-term, according to the Aug. 19 outlook from the National Weather Service (NWS).

Most of this region has a 40-60 percent chance of above-normal temperatures through Sept. 2, according to the NWS outlook. It also predicts drier conditions – up to a 50 percent chance for below-normal precipitation through Sept. 2 – in the region.

Drier weather will be welcomed in southern Illinois and Missouri, where DON wheat contamination was widespread.

In Missouri, June rainfall set a record, and July was the fourth-wettest in 121 years, according to University of Missouri climatologists. Data released by USDA on Aug. 17 showed Missouri leading the country in prevented corn and soybean plantings.

Management tools are available if ear rot is of concern.

Wet-weather mycotoxins can require testing similar to that for aflatoxin, the mycotoxin more prevalent in corn during drought years.

Testing corn silage for mycotoxins presents challenges. Samples should be taken both from silage that is apparently moldy, as well as unaffected silage.

Producers submitting silage samples should follow all handling and shipping guidelines from the testing facility.

A website at www.cornmycotoxins.com/home is an outreach effort from several land grant universities. “We are continually updating the information at this site,” said Woloshuk.