Xanthomonas axonopodis pv. phaseoli
Figure 1 – Large (often greater than 12 mm or ½ inch diameter), irregular, brown, necrotic, watersoaked lesions that may be bordered by a narrow yellow border on upper and lower leaf surfaces; lesions often develop from leaf margins and also may develop on petioles and stems.
Figure 2 – Younger lesions may be circular, flaccid, with small water-soaked areas apparent on lowersurface at the edge and interveinal area of an infected leaf.
Figure 3 – Small to medium (less than 3 mm or 1⁄8 inch diameter), circular to irregular, water-soaked, red-brown lesions on bean pods.
- Infected seed, infested debris and volunteers from previous seasons
- Rainstorms and sprinkler irrigation
- Warm temperatures with daily highs greater than 30°C [86°F]
H.F. Schwartz, Colorado State University