Frogeye leaf spot
Area of impact: Leaves
Description: Small, round brown or gray lesions on leaves with dark violet or reddish margins.
Pathogen involved: Cercospora sojina (a fungus)
Timing/Conditions: Occurs all season in humid wet warm weather.
Contributing factors: Frogeye leaf spot is a common problem in the South. Young leaves are most likely to be infected. Overwinters in soybean residue and seeds.
Management practices: Plant resistant varieties and pathogen-free seeds, rotate with a non-bean crop, use seed treatments, bury infested residue and use foliar fungicides.