Missouri growers urged to scout for emerging corn diseases
Missouri growers are urged to scout their fields for two emerging corn diseases found for the first time in the state last year: tar spot and bacterial leaf streak.
Kaitlyn Bissonnette, MU Extension state plant pathologist, tells Brownfield tar spot can cause up to a 40% yield loss, “That’s the concern that I have as we start to see it move into the state. Now, we are not anywhere near that level right now.” She says research is being done on fungicides in states where tar spot is established and was found in three northeastern Missouri counties (Scotland, Lewis and Clark) in the fall of 2019.
Bissonnette says bacterial leaf streak (BLS) was confirmed last year in west-central (Ray County) and in north-central (Chariton County).
“It can infect corn leaves after strong winds, after the leaves have rubbed together and there’s a lot of rain. It basically infects the tissue and reduces the photosynthetic area” which can cause yield loss.
Bissonnette says growers should look for water soaking and long, necrotic lesions on leaves with irregular margins. She says BLS often looks like gray leaf spot.
Growers are asked to alert their county MU Extension center or MU if they suspect either disease. Email: email@example.com
Bissonnette says Tar Spot is the most concerning of the two emerging corn diseases. The University of Missouri is part of the Greater Tar Spot working group.