Pseudomonas syringae pv. syringae
Figure 1 – Small (approximately 1 mm or 1⁄16 inch diameter), circular, brown, necrotic, water-soaked lesions on upper and lower leaf surfaces; lesionsmay develop on petioles and stems.
Figure 2 – Lesion coalescence and shot-hole effects on ragged leaves and canopy; watersoaking may be absent at this stage.
Figure 3 – Large (greater than 3 mm or 1⁄8 inch diameter), circular, water-soaked and necrotic lesions on bean pods.
- Infected seed, infested debris and volunteers from previous seasons
- Susceptible weeds such as hairy vetch
- Rainstorms and sprinkler irrigation
- Moderate temperatures with daily highs less than 30°C [86°F]
Courtesy of R.M. Harveson & H.F. Schwartz [06/09]