While ear mold is always a concern in late-harvested corn, growers who find blackish mold in their fields on corn husks may not have ears that are infested with grain-damaging and toxin-contaminated mold. Rather, the mold could be a variety that may only impact the husks, according to an Ohio State University Extension plant pathologist.
But growers won't know what kind of ear mold the fields may be infested with unless they examine the moldy-looking ears and send samples to a lab for testing, says Pierce Paul, who is also a researcher with the Ohio Agricultural Research and Development Center.
OARDC is the research arm of Ohio State University's College of Food, Agricultural, and Environmental Sciences.
The concern for ear mold is higher than normal for some growers this year thanks to the drought, which created ripe conditions for the development of the fungal disease Aspergillus ear rot in some Ohio fields during the summer, Paul said.
"Harvests that were delayed due to excessively wet conditions in areas that were affected by the drought during the summer and had problems with aflatoxin are of concern since delaying harvest may also increase aflatoxin contamination," he says. "Stalk, root and ear rots may also cause considerable damage in fields waiting to be harvested.
"Root and stalk rots leave plants weak and highly vulnerable to lodging, while ear rots may lead to grain contamination with mycotoxins."
The concern is that drought-stressed corn is more susceptible to infection by Aspergillus flavus, an ear rot fungus that produces a very potent group of carcinogenic (cancer-causing) toxins, called aflatoxins, which can be harmful for animals and for humans if used in corn for grain and human food consumption, Paul said.