Efficacy of Foliar Fungicides on Septoria Brown Spot Severity and Yield in Soybeans in Southeast Pennsylvania, 2024

Septoria brown spot (SBS), caused by Septoria glycines, is a foliar disease that impacts soybean ( Glycine max L. Merr.) production annually. SBS primarily occurs in the lower canopy and consists of small, irregular brown lesions or blotches. SBS may cause leaf necrosis, premature leaf drop, or plant death when symptoms are advanced, though significant yield loss is rarely observed in Pennsylvania. This trial tests the effectiveness of foliar fungicide treatments applied at the R3 growth stage on disease severity and yield. This trial was conducted at the Southeast Agricultural Research and Extension Center in Manheim, PA. Results from the trial help inform soybean growers on the best management to prevent foliar disease in soybeans.