Bean IPM

Legume ipmPIPE Diagnostic Series


Colletotrichum lindemuthianum (on beans and lentil), C. gloeosporioides (on pea)


On common bean:

  • Anthracnose symptoms appear as linear or angular, dark, brick-red to black lesions or slightly sunken cankers on leaf veins. Petioles, branches and main stems can also exhibit linear lesions. Symptoms develop on the upper leaf surface, as well and, severe infection can lead to a burning of the leaf tip and edge or death of the leaf (Figures 1 and 2).
  • Pod infection produces reddish-brown to black circular spots that develop into light-colored cankers. Cankers are often surrounded by a dark brown to black border, within which beige to pink masses of fungal spores develop during moist periods (Figure 3).
  • Infection produces dark brown to black cankers and spots on seeds, and severe infections shrivel and abort pods (Figure 4).
Factors favoring
  • Infected seed, infested debris and volunteers from previous seasons
  • Rainstorms and sprinkler irrigation
  • Moderate temperatures with daily highs less than 27°C [80°F]
anthracanose leaf veins lesions
Figure 1 - Anthracanose leaf veins lesions
Anthracanose burning of leaf tip and sunken leaf cankers
Figure 2 - Anthracanose burning of leaf tip and sunken leaf cankers
Anthracnose pod cankers
Figure 3 - Anthracnose pod cankers
Anthracnose shriveled and aborted pods
Figure 4 - Anthracnose shriveled and aborted pods
Additional Resources

H.F. Schwartz, Colorado State University, G.D. Franc, University of Wyoming, and R.M. Harveson, University of Nebraska

Photo credits

Howard F. Schwartz, Colorado State University,