Soybean Diseases in Ohio

Phomopsis seed rot

• Symptoms
  • dead petioles, stems and pods with small black specks
  • severely infected seeds are cracked, shriveled and covered with white mold
  • seedlings from moldy seed have brown to reddish lesions on cotyledons
• Environment
  • prolonged wet periods after flowering and pod set
  • warm, wet conditions at maturity and delayed harvest
  • lodging and increased feeding by bean leaf beetles may increase seed infection
• Survival
  • fungi overwinter on soybean straw or may be seed borne
• Management
  • crop rotation with wheat and corn
  • seed treatment for seed lots with low levels of infection (70 to 90% germination)
  • plow down crop residues for fields with heavy disease pressure
• Scouting