Armed with data from eight states, a CALS research team has created free mobile software that helps farmers fight a devastating corn disease.
Tar spot, a disease of corn plants caused by the fungus Phyllachora maydis, has been causing problems in Mexico since the 1910s, but it stayed out of northern climes for more than a century. So it was surprising when tar spot was discovered in cornfields in Illinois and Indiana in 2015. The following year, it showed up in Wisconsin and a few other Midwestern states.
“Everybody thought it was a subtropical pathogen at the time,” recalls Damon Smith, professor and extension specialist in the Department of Plant Pathology. “People just sort of said, ‘Well, it’s cosmetic, it’s not going to be a problem.’ ”
Then the epidemic of 2018 happened. During that growing season, U.S. farmers lost approximately 5 million metric tons of corn to tar spot, an economic setback of around $680 million.
“We were just running all over the place, helping farmers try to make decisions plus gathering some data for research,” Smith says. “There was very little out there in terms of what we could do to manage it. We got caught without any solutions.”
In subsequent years, the disease continued to expand its territory. Smith assembled a multi-state team to study the new pathogen, and they secured funding in 2020 via the National Predictive Modeling Tool Initiative, a program of the USDA Agricultural Research Service, which supports the development of research-based tools to forecast U.S. crop diseases.
Read the full story: https://grow.cals.wisc.edu/priority-themes/food-systems-priority-theme/this-app-hits-the-tar-spot