Key Takeaways
- The first confirmed tar spot case in Illinois for 2026 was identified in Clark County on June 26.
- Ninety-one of Illinois’ 102 counties have a history of tar spot since it was first detected in 2015.
- Farmers are encouraged to scout fields and apply fungicides at tassel or before the milk stage to manage tar spot.
The season’s first case of tar spot in Illinois has been confirmed in Clark County, according to the latest maps published by the Crop Protection Network. The foliar disease was confirmed June 26.
Ninety-one of the state’s 102 counties have a history of tar spot since it was first detected in Illinois in 2015.
Cases have also been reported in Kansas, Nebraska, Missouri, Iowa, and Indiana this year.
2026 Case and Recommendations
At press time, few specifics about the Clark County case were available…