Soybean Diseases in Ohio

Cercospora leaf spot and Purple stain

Cercospora kikuchii

• Symptoms
  • small reddish purple angular lesions
  • veinal necrosis can also be observed
  • defoliation starting with upper leaves
  • pink to purple discoloration in the seed coat
• Environment
  • warm, humid weather (73-80°F)
• Survival
  • overwinters in soybean residue and on soybean seed
  • fungus grows on cotyledons, stems and leaves
  • spores are blown or splashed onto flowers.
• Management
  • plowdown crop residues
  • crop rotation
  • plant quality seed
  • seed treatment