Tar spot of corn, a foliar disease caused by the fungus Phyllachora maydis, recently was found in the United States for the first time. The disease was confirmed in Indiana and Illinois. Pictures of the disease and more information about the locations where its presence was confirmed are available online in the Pest & Crop Newsletter (Purdue Cooperative Extension Service) and the Bulletin (University of Illinois Extension).
It is important to document if this disease is present in Kentucky. If symptoms similar to those shown in the articles referenced above are found in Kentucky, samples should be submitted to one of the University of Kentucky Plant Disease Diagnostic Laboratories (located in Princeton and Lexington) via a county Extension agent.
By Carl A. Bradley, Extension Plant Pathologist