Pseudomonas syringae pv. phaseolicola
Symptoms
Figure 1 – Medium, circular, chlorotic to yellow-green (4 – 8 mm or ¼ – ½ inch diameter), necrotic (1 – 2 mm or 1/16 – 1/8 inch diameter), water-soaked lesions on upper and lower leaf surfaces; lesions may develop on petioles and stems
Figure 2 – Lesion coalescence, plant yellowing and translocation of toxin to new upper growth with leaf distortion; chlorosis may be less noticeable at high temperatures or later in the season
Figure 3 – Small to medium (less than 3 mm or 1/8 inch diameter), circular, water-soaked and necrotic lesions on bean pods and seed
Factors favoring
- Infected seed, infested debris and volunteers from previous seasons
- Rainstorms and sprinkler irrigation
- Moderate temperatures with daily highs less than 25oC [77oF]

Figure 1

Figure 2

Figure 3
Additional Resources
Photo credits
Courtesy of H. F. Schwartz [06/09]