New corn disease confirmed in Indiana

Plant pathologists from Purdue Extension have identified tar spot, a corn disease not previously reported in the United States, in plant samples collected In Indiana.

The specific fungal disease found in the state had minimal impact on yield in other areas where it is endemic, including Mexico and Central America, and experts say no action is needed to manage it this late in the growing season.

"We are still determining the impact, if any, that the disease may have in Indiana," said Kiersten Wiseand Gail Ruhl, in an article published in the latest issue of Purdue's Pest and Crop online newsletter. "However, it is important to alert Extension specialists if you observe the disease to accurately document its distribution in the state."

Initial symptoms of tar spot are brownish lesions on the leaves. Black, spore-producing structures called ascomata appear later, protruding from the leaf surface and giving the leaf a rough or bumpy feel.

 Symptoms and signs of tar spot might also appear on leaf sheaths and husks. Tar spot can be caused by two different fungi -- Phyllachora maydis and Monographella maydis.

Purdue University in West Lafayette, Indiana, is the flagship university of the six-campus Purdue University system. It offers more than 200 options for major areas of study and has both undergraduate and graduate programs. Purdue enrolls more than 39,000 students.