Diseases

Bean leaf spots

Phaseolus vulgaris L.

A group of bean diseases caused by specific bacterial and fungal pathogens. They are characterized by the formation of necrotic spots of various morphologies, controlled by genetically resistant loci.

In the reference 139 varieties crop Common bean, where this is mentioned in the description.

Common bacterial blight is caused by Xanthomonas campestris pv. phaseoli and manifests as large red-brown spots with a yellow halo, often accompanied by systemic vein necrosis. Halo blight, caused by Pseudomonas savastanoi pv. phaseolicola, is distinguished by angular spots with a characteristic wide pale green or yellow halo around the necrotic zone. At least two races of halo blight have been identified, differing in their reaction to differential bean genotypes.

Fungal infections include angular leaf spot caused by Pseudocercospora griseola, alternaria leaf spot with concentric zones, and cercospora leaf spot. Genetic resistance to fungal angular leaf spot is controlled by the Phg-1 — Phg-6 gene complex. The Phg-1 gene is localized on chromosome Pv01 and is linked to the anthracnose resistance gene Co-14, with the resistance control mechanism being either dominant or recessive.

General information about the subject — on the page Leaf spot diseases.

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.