Farmers in Minnesota and elsewhere have seen toxins shrivel and kill their wheat crops in recent years.

In November, University of Minnesota researchers helped over 100 scientists at universities nationwide and in China clone a gene resistant to wheat scab — a disease they say is the greatest threat to crops.

“We’re talking about identifying one gene out of 60,000 genes,” said James Anderson, University agronomy and plant genetics professor and researcher on the project. “It’s like looking for a needle in a haystack.”

Fusarium head blight, often called wheat scab, is a fungus that makes wheat dangerous for other plants and for animal consumption. Between 1993 and 2001, it caused billions of dollars in crop yield losses — the disease’s largest epidemic.

Not only does the disease affect yields, but the toxin can cause vomiting in humans and animals.

Anderson and other University professors have worked to breed scab-resistant wheat over the last two decades.

He said they make new gene combinations by crossing multiple genes, picking desirable traits and testing those in trial yields. On average, they release one resistant wheat variety per year.

“The gene found is not only resistant to Fusarium head blight, but to other diseases as well,” said University of Minnesota Plant Pathology Professor Ruth Dill-Macky.

Wheat scab and other small grain diseases, like stem rust, only affect the plants for a short period of time.

Fusarium head blight strikes late in wheat’s growth cycle when the plant flowers, Dill-Macky said, about two weeks before it turns golden brown.

Wheat with scab has a bleached-out tan color on its head, and the toxin eats away the seeds.

“The yield damage is economically important, but it really affects the farmers more than anything else,” Dill-Macky said.

Dill-Macky said farmers combat the disease by using fungicides and rotating their crops.

Carmen Fernholz, owner and operator of A-Frame Farm in Madison, Minnesota, has seen parts of his wheat crops die from similar toxins.

As an organic farmer, Fernholz doesn’t use fungicides on his crops and instead rotates corn, soybean and wheat to fight toxins left in the soil.

He said his farm has not felt significant economic effects from the toxin. Parts of his profits are due to a grain-testing process that sorts bad grains from good ones.

University of Minnesota plant pathology assistant professor Melania Figueroa said breeding programs are the most sustainable way to fight the disease.

“Basically, you’re using the immunity of the plant to combat the fungus, and you don’t just apply fungicides that could be harmful to human health and the environment,” Figueroa said.

A previous version of this article misspelled Melania Figueroa’s name.