First 2026 Tar Spot Case Confirmed in Missouri. Natalina Sents Bausch is the Digital Director for Successful Farming and Agriculture.com. Natalina joined the Successful Farming team in 2017 to cover new farm machinery and news coverage for Agriculture.com. * The first case of tar spot in Missouri this season was confirmed in Cooper County on June 22. * Tar spot has a history in 66 Missouri counties since 2019 and has also been reported in nearby states this year. The season’s first case of tar spot in Missouri has been confirmed in Cooper County, according to the latest map published by the Crop Protection Network. Sixty-six of the state’s 114 counties have a history of tar spot since it was first detected in Missouri in 2019. “We’ve detected tar spot in June in each of the last three years, and I anticipate the same for 2026,” she said. Monday’s Crop Progress report said 98% of Missouri’s corn crop had emerged the week that ended June 21.