Tar spot has been causing problems in Mexico since the 1910s, but has recently shown up in Midwestern states.

Insignum AgTech has begun a collaboration with researchers in Purdue University’s College of Agriculture and College of Engineering to create tools for farmers to identify early stages of tar spot disease outbreaks in their corn plants.

At least 11 states in the U.S. have confirmed reports of tar spot in corn, according to the Crop Protection Network.

Bayer Crop Science researchers have been able to artificially inoculate tar spot in field test plots, a key step in helping to gain a deeper understanding of how to manage the disease. This development shows promise for advancing both genetic and crop protection research on the pathogen that can severely impact yield.

Rotating to soybean in the following year may help reduce the tar spot inoculum in that field. Another consideration is to plant a tar spot tolerant hybrid in that field and surrounding fields.

Tar spot, as the name suggests, is characterized by the presence of raised, black, tar-like spots called stromata predominantly on leaf blades.