The fungal disease has been confirmed in Cottonwood, Fillmore, Jackson, Murray, and Nobles counties in the southwestern corner of the state. Extension specialists say no confirmed cases have been announced this season in North Dakota or South Dakota, but growers across the Northern Plains are encouraged to scout fields as corn moves through the grain fill. Tar Spot thrives under extended periods of leaf wetness and can reduce yields if it becomes established before dent stage. Timely scouting and fungicide applications remain the best management tools.
