“Mycotoxins? That’s a problem with hogs, right? Or maybe with dairy cattle? I don’t have livestock. I will just flip past this story. Why should I care?”

Stop! Just because you don’t raise livestock doesn’t mean you should scoot past articles about ear molds and mycotoxins. They affect you if you sell corn, notes Dan Quinn, Purdue Extension corn specialist.

All corn that is marketed is subject to testing for vomitoxin and other mycotoxins. They’ve been detected with increasing frequency over the past couple of seasons in central and northern Indiana and western Ohio, and they’re a perennial problem in Michigan.

You’re not off the hook if you sell to ethanol plants either, Quinn says. They’re concerned because mycotoxins wind up in dried distillers grains, a key byproduct from ethanol plants sold and used as livestock feed.

Manni Singh, an Extension specialist with Michigan State University, has studied mycotoxins and how to minimize them for years through research trials.

“Cool and wet weather, with high relative humidity around silking, tends to be favorable for ear and stalk rot fungi to develop,” he explains. “That can lead to mycotoxin accumulation. Bird and insect feeding, especially by insects like western bean cutworm and European corn borer, provides easy entry for the fungus and intensify infections.”

Management tips

Careful management may not eliminate mycotoxin concerns, but it can minimize them, Singh says. Here are management tips for ear molds and mycotoxins:

Select best hybrids. Take a close look at disease resistance ratings in hybrids, but also evaluate insect protection traits, Singh says. If traits protect against ear-feeding insects, that tends to reduce severity of ear rots and could decrease concentrations of mycotoxins.

Adjust planting date. Silking stage is most susceptible. Adjust planting date, often by planting early, so silking does not fall when conditions are typically most favorable for fungal diseases and mycotoxin production. Planting in late April to early May could result in fewer issues with ear-feeding insects.

Evaluate plant populations. Excessive plant densities can stress plants. They also create denser crop canopies, which hold moisture and create an environment more favorable for fungi, Singh says.

Consider fungicide applications. Triazole-based fungicides can help prevent ear rot infections, Singh says. Research shows that how well fungicides work depends on timing. Efficacy declines as the time interval between silking and application increases.

However, assess the situation before applying fungicides. If insect injury drove infection with fungi, fungicides may not be as successful or profitable, he adds.

Harvest first. Harvest infected fields first, whether for silage or grain. If more than 10% of kernels are infected with mold in 10 or more plants, or if 10 or more plants are lodged, schedule harvest as soon as possible. This requires scouting to make the assessment.

Handle and store grain properly. Dry corn harvested from an infected field to 15% moisture as soon as possible, Singh suggests.

Manage feed with mycotoxins. Denaturing mycotoxins in feed is almost impossible, Singh says. The best option may be mixing clean feed with contaminated feed to dilute it. Mycotoxin binders can help minimize impacts on animals. Binders include silica-based inorganic compounds, activated carbon, humic acid, micronized dietary fibers and polymers like resin cholestyramine.