As the tough 2011 cropping year draws to a close, farmers can take solace in knowing that despite unfavorable weather conditions, corn molds don't seem to be of widespread concern, says Charles Woloshuk, a Purdue University plant pathologist.
Summer drought often leads to Aspergillus ear rot infections in corn, which produces aflatoxin – a carcinogen and liver toxin that affects livestock. Luckily, it doesn't look like most farmers will have to worry too much about it.
"People might have yield problems with late planting and drought stress, but it doesn't appear that ear rot will be a widespread problem this year," says Woloshuk.
Aspergillus ear rot is common in plants with drought stress because it thrives in weak plants. Since many other diseases need cool weather to survive, Aspergillus has little competition.
Woloshuk also says many of the other grain diseases don't seem to be a problem this harvest. One common concern is Gibberella rot, which is associated with another toxin, called vomitoxin, or DON. However, Gibberella thrives in cool weather during silking and pollination – something Indiana farmers didn't experience this year.
"Since the corn's growth stages were behind and we had a dry summer, Gibberella isn't a problem," Woloshuk says.
The one corn disease that producers and horse owners may want to keep an eye on is Fusarium ear rot. This particular ear rot has been associated with neural tube defects in humans and illnesses or death in horses. The fungus tends to live in hot weather and is relatively common – especially in southern Indiana and in the sandy, drought-prone soils of northern Indiana.
So far this year, however, Woloshuk says he's received no reports of widespread disease.
Farmers who are concerned about grain quality should be sure to store corn properly and to make sure grain is dry in storage. They also can have grain samples analyzed through Purdue's Animal Disease Diagnostic Laboratory.