Photo courtesy of University of Missouri
From staff reports
Although tar spot is not new to the corn belt, this year it will be more widespread.
Most recently, tar spot has shown up in seven counties in the northwestern part of Missouri, said Peng Tian, director of The Plant Diagnostic Clinic at the University of Missouri–Columbia. This is a new disease for the state and is expanding. In addition, he said it causes as much as an 80% yield loss. Because of its quick spread and resistance, tar spot has not yet been researched for seed genetics.
Tar spot isn’t the only disease pressure Midwestern farmers are expecting to deal with this year. Producers also are experiencing bacteria leaf streaks. In 2016, the leaf streak was found in Nebraska and then spread to Iowa and Illinois and then into Kansas. Goss’ wilt disease also is popping up in the western part of the corn belt.