Machismo or Phytoplasma organisms transmitted by leafhoppers such as Scaphytopius fuliginosus. Symptoms of this disease group may include witches’ broom, virescence (flower petals turn light to dark green), phyllody (unopened, distorted floral structures), elongation of stems, and distorted pods with few seeds which may germinate in healthy appearing pods.
- Presence of previously infested crop debris
- Lack of crop rotation
- Poor sanitation of previous legume and weed debris
- Contaminated seed
- Susceptible varieties
- Moderate to high moisture conditions favor slugs
- Infection at V2 – R2 results in plant death, and/or reduced pod set, poor seed fill, and yield loss
- http://www.apsnet.org/ - Compendium of Bean Diseases 2nd Ed.
Courtesy of G. E. Galvez (CIAT – APS Bean Compendium), S. K. Mohan and H. F. Schwartz