Scientists Unveil New Techniques for Managing Corn Tar Spot

Tar spots typically appear as small, black spots on leaves, eventually destroying plant tissue.
Tar spots typically appear as small, black spots on leaves, eventually destroying plant tissue.

As agricultural producers know, crops are vulnerable to various diseases, which can affect yield if not treated quickly. Corn producers across Michigan first recognized one of these diseases — tar spot — in their state back in 2016. Although people discovered this fungal disease in Central and South America, it has since been seen in 19 states in the U.S. Now, scientists from Michigan State University (MSU) are working with other researchers to find new techniques to prevent, identify, and treat the disease.

Tar spots typically appear as small, black spots on leaves, eventually destroying plant tissue. Wet conditions allow the disease to thrive and spread. Once it has begun to impact a field, it can be difficult to control the situation.

“Weather is the key driver to tar spot development,” said MSU associate professor Martin Chilvers. “We know that much for certain, so most of our recommendations are based on the work we’ve done around that idea, and some are common sense or concepts borrowed from the management of other diseases. We are still trying to put data sets together to better inform or demonstrate management implications.”

Everything from a smartphone app to a disease prediction algorithm has been created thus far to help farmers affected by tar spots. The app utilizes GPS coordinates to determine if local weather conditions may contribute to the development of the disease.

“We’ve learned a lot of valuable information on the environmental conditions that lead to disease onset and the effectiveness and profitability of various management strategies – especially as it relates to fungicide products and timing of applications – as a direct result of Dr. Chilvers’ research,” said Kristin Poley, research manager for the Corn Marketing Program of Michigan. “Most importantly, we’ve been able to compare each of these insights year over year to further refine our management recommendations.”

More information on the agricultural solutions that may help can be found by contacting your local John Deere dealer.