Bean IPM

Legume ipmPIPE Diagnostic Series

Ascochyta Blight

Aschochyta rabiei, A. phaseolorum, A. pisi, A. lentis, A. pinodes and Phoma medicaginis var. pinodella

Tags
Chickpeas
Common bean
Lentils
Pea
Symptoms

Figure 1 – Ascochyta blight symptoms: elongate lesions on stems (top), and circular lesions on leaves (bottom right) and pods (bottom left).

Figure 2 – Circular arrangement of pycnidia (structures that produce infective spores) on both stem (left) and leaf (right).

Figure 3 – Effect of infection on seed size and quality. Seeds (top) harvested from pods (bottom) collected from a severely infested field—healthy (left) and infected (right).

Factors favoring
  • Infected seed, infested debris and volunteers from previous seasons
  • Rainstorms and sprinkler irrigation
  • Moderate temperatures with daily highs less than 25°C [77°F]
Elongate lesions on stems (top), and circular lesions on leaves (bottom right) and pods (bottom left).
Figure 1
Circular arrangement of pycnidia
Figure 2
Effect of infection on seed size and quality.
Figure 3
Additional Resources
Authors

R.M. Harveson, University of Nebraska, S.G. Markell, North Dakota State University, and M. Burrows, Montana State University

Photo credits

Courtesy of R.M. Harveson and S.G. Markell