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USDA ARS conducting a lot of tar spot research

The USDA’s Agricultural Research Service is working on multiple research projects to better understand tar spot, a growing problem in U.S. corn.

Steve Goodwin, ARS researcher in West Lafayette, Indiana says they’re screening corn varieties and germplasm lines for their susceptibility or resistance to tar spot, “We started to see some lines look almost immune and others look very highly susceptible which is not what I was expecting to see. And that implies a more major gene for resistance.”

Goodwin tells Brownfield they’ve been working two years toward understanding the tar spot fungus which has spread from the Great Lakes Region to Iowa, Missouri, Pennsylvania, Florida, and Ontario, Canada.

“When it first got here, you know, we didn’t think it would be a problem based on where it occurs elsewhere but clearly everything they thought about it was wrong (hahaha) based on Central America. The other pathogen is not here. It’s spreading on its own.”

Outbreaks of tar spot were first detected in 2015 in Illinois and Indiana and can reduce yields by 20 to 60 bushels an acre. While fungicides are “the hardest hitting counter-punch,” Goodwin says resistance to the disease in corn would be far better.

Besides ARS, Purdue, Michigan State, Iowa State, Ohio State, and the University of Missouri are working in partnership with the National Plant Disease Recovery System for solutions to tar spot.