Efficacy of Foliar Fungicides on Corn Foliar Disease Severity and Yield in Central Pennsylvania, 2024

Tar spot, caused by Phyllachora maydis, and gray leaf spot, caused by Cercospora zeae- maydis, are foliar diseases that cause yield loss in corn ( Zea mays L.) in Pennsylvania each year. Tar spot is characterized by black stromata on corn leaves late in the season, while gray leaf spot foliar symptoms are tan or gray rectangular lesions. These diseases may cause leaf or entire plant death when symptoms are severe. This trial tests the effectiveness of foliar fungicide treatments applied before, at, and after tasseling on disease severity and yield. This trial was conducted at the Russell E. Larson Agricultural Research Center in Pennsylvania Furnace, PA. Results from the trial help inform corn growers on the best management timing and products to prevent foliar disease in corn.