WOOSTER, Ohio — Farmers from Missouri to Ohio are seeing wheat harvested this year rejected by buyers based on mycotoxin levels. That wheat may also pose challenges for feeding to some livestock, but experts say some of the infected wheat could possibly be cleaned and treated to be used in seeding fall cover crops.

The region’s rain-delayed wheat harvest saw more sprouting and disease pressure from wheat head scab. The fungus which causes wheat head scab (fusarium head blight) may also produce mycotoxins. Vomitoxin, named because it can cause vomiting in pigs fed infected wheat, is one of the mycotoxins of economic concern.

The level of vomitoxin in animal feed is regulated by the U.S. Food and Drug Administration. Vomitoxin also affects wheat milling quality, which is why buyers either dock prices or decline from purchasing "vomitoxin wheat" altogether.

That can mean wheat sent back to on-farm storage, creating a puzzle for producers – especially this year, when vomitoxin seems widespread.

When evaluating vomitoxin wheat for cover crop seeding, the mycotoxin is a symptom of a bigger concern. "Vomitoxin that is usually present in scabby seed is not your problem. Damage to the (seed’s) embryo is your problem," said Pierce Paul, plant pathologist with The Ohio State University.

He received so many requests for information about planting vomitoxin wheat that he issued two articles on the topic in an Ohio crop newsletter last month.

According to plant pathologists, embryo damage is best determined by rating fusarium-damaged kernels, or FDK. Fusarium damage can be determined by a visual evaluation of wheat samples, especially kernels that have whitish or pinkish coloration.

Sampling and evaluation guidelines for rating FDK are available online from the Ohio Agricultural Research and Development Center, at http://oardc.osu.edu

Paul recommends not planting wheat with more than 30-40 percent FDK. "However, if you absolutely have to plant scabby wheat, cleaning, germination test and fungicide seed treatment are absolutely necessary," he said.

The seeding rate should be increased when germination is determined to be less than 80 percent, he added.

Mid-August is the right time to start planting fall cover crops, according to Rob Myers, University of Missouri agronomist. Farmers in Missouri are expected to plant more cover crops this year because of a high number of soybean acres that went unplanted.

Cool-season cover crops that have some grazing value, such as wheat and annual rye, could be popular choices here. Other possibilities are oilseed radishes, turnips, crimson clover, hairy vetch, cereal vetch, oats and triticale, according to Myers.

A USDA survey conducted last year showed a 3.1 percent yield increase for corn planted in a field following a cover crop. Soybean yields increased 4.3 percent following cover crops, according to that survey.