Frogeye Leaf Spot
Symptoms:
- Symptoms are most visible on leaves.
- Lesions (1/16 to 1/8" diameter) are mostly-round spots, brown to gray in color, surrounded by a thin dark violet/reddish ring.
Pathogen Involved:
- Cercospora sojina (a fungus).
- More than five races are known in the U.S.
- Overwinters in soybean residue and seeds.
Time of Occurrence:
- All season.
- Young leaves are most susceptible.
Conditions Favoring Disease:
- Humid, wet, warm weather.
- Infested soybean residue on soil surface.
- Use of susceptible soybean varieties.
- Common problem in the southern US
Disease Management:
- Use resistant soybean varieties.
- Seed treatments can reduce seed transmission.
- Rotate with a non-bean crop.
- Bury infested residue where feasible and where disease is severe.
- Use seeds free of the pathogen.
- Foliar fungicides can provide some control.