Diseases

Ascochyta blight of bean

Phaseolus vulgaris L.

A fungal disease of common bean caused by Ascochyta boltshauseri or Phoma exigua var. exigua. It affects all above-ground organs, manifesting as spotting with pycnidia and reducing seed quality.

In the reference 7 varieties crop Common bean, where this is mentioned in the description.

The pathogens of the disease are the fungi Ascochyta boltshauseri and Phoma exigua var. exigua. The disease affects all above-ground parts of the plant, including leaves, stems, pods, and seeds. Small dark brown or black dots, which are the pycnidia of the pathogen, form in the center of the spots on the infected tissues.

Symptoms on leaves appear as spots with a dark brown border, often with concentric rings. Merging spots form on the stems, leading to breakage. On pods, the spots are usually small, and seeds from diseased plants become shriveled, covered with spots, and lose germination capacity. Infection development is favored by high humidity of over 90% and temperatures of +20...+25°C.

General information about the subject — on the page Ascochyta blight.

Sources8

Varieties of Common bean mentioned in the description

Selection based on the description text, not on official evaluation: these data are absent from registers. For specific variety details, please refer to its profile.