Damon Smith, Department of Plant Pathology, University of Wisconsin-Madison presents a short lecture about Tar Spot on Corn Symptoms, Severity, and Hybrid and Fungicide Trial Results in Wisconsin in 2018.
Further reading:
https://badgercropdoc.com/2018/12/19/effect-tar-spot-corn-hybrids-wisconsin-2018/
https://badgercropdoc.com/corn/