The season’s first cases of tar spot in Ohio have been confirmed in Darke, Wyandot, Morrow, Clark, Fayette, Pickaway, and Ross counties, according to the latest map published by the Crop Protection Network. The foliar disease was first confirmed in Ohio on July 10 in Clark County.
Forty-nine of the state’s 88 counties have a history of tar spot since it was first detected in Ohio in 2018.
Timing
Here’s a timeline of how the disease has been detected in the state:
- July 10 – Clark County
- July 13 – Darke County
- July 16 – Ross County
- July 17 – Fayette County
- July 21 – Wyandot County
- July 21 – Morrow County
- July 22 – Pickaway County
Cases have also been reported this year in Illinois, Indiana, Iowa, Kansas, Kentucky, Michigan, Minnesota, Missouri, Nebraska, New York, Virginia, and Wisconsin.
Agronomist Report
“Ohio’s corn crop continues to make excellent progress week by week as we get closer to harvest season,” said Jacob Foote, a field agronomist for Stine Seed Co., covering Indiana, Michigan, and Ohio. “Pollination continued in many fields, with later-planted corn entering peak silking, while earlier planted corn is beginning to advance into the dough stage.”
Foote says the cooler weather resulted in reduced heat stress, and a positive impact on pollen viability…