Bacterial Pustule
Symptoms:
- Symptoms begin as small light green spots (not water-soaked) with raised, centers on the upper and lower surfaces of leaves.
- Tiny tan elevated pustules often develop in the center of lesions, especially on the leaf underside.
- Small spots may also develop on pods.
- It can cause defoliation and reduced yields.
- The lesions can grow together into large irregular brown areas, and infected areas may rip away from the leaf.
Pathogen Involved:
- Xanthomonas axonopodis pv. glycines (a bacterium).
- This pathogen overwinters in unburied crop residue, and on wheat roots, and can be transmitted by seed.
- It also can infect snap bean.
Time of Occurrence:
- All season.
Conditions Favoring Disease:
- Disease is favored by warm, wet weather conditions.
Disease Management:
- Plant resistant varieties.
- Use seed free of the pathogen.
- Rotate with non-host crops.
- Avoid field cultivation when foliage is wet.
- Deep plowing in fields where disease is common may be helpful.