The fungal disease tar spot is showing up in some corn fields in Minnesota. University of Minnesota Extension Plant Pathologist Dr. Dean Malvick says while it’s not widespread yet in the state, it can cause a great deal of damage. So, growers need to scout for it.
He says last year, tar spot caused significant damage and yield loss in states neighboring Minnesota.
Malvick says tar spot is a fairly new disease but there are many fungicides that will work to combat it if it is detected.
Tar spot is caused by a fungus that infects leaves and sometimes husks and produces small raised structures on the leaf surface. The black structures look fairly smooth on the surface, are firm and do not break open or rub off like rust does.
