Bacterial Blight
Symptoms:
- Can occur on all aerial plant parts, but lesions on leaves and pods are easiest to see.
- Infections begin as small, water-soaked spots that turn yellow and then brown as the tissue dies.
- Spots may merge to form dead patches, and the dead tissue may fall out.
- Seedlings may be stunted or killed if apical tissue is infected, and brown lesions may cover much of infected pods.
Pathogen Involved:
- Pseudomonas syringae pv. glycinea (a bacterium), also infects snap bean and lima bean.
- The pathogen overwinters in crop residue and can be seed transmitted.
Time of Occurrence:
- All season.
Conditions Favoring Disease:
- Cool, wet weather and rain storms.
- Disease progress stops in dry, hot conditions.
- Spread by wind and rain in fields as well as by cultivation when foliage is wet.
Disease Management:
- Plant resistant varieties.
- Rotate with non-host crops.
- Use pathogen-free seed
- Avoid field cultivation when foliage is wet.