Diseases

Cotton Bacterial Blight

Gossypium hirsutum L.

Bacterial blight is the most damaging bacterial disease of cotton, caused by the pathogen Xanthomonas citri subsp. malvacearum, which affects all above-ground plant organs throughout the growing season.

In the reference 11 varieties crop Upland cotton, where this is mentioned in the description.

The causal agent of bacterial blight is the bacterium Xanthomonas citri subsp. malvacearum. The disease manifests on cotyledons as oily spots with the exudation of a sticky fluid that dries into grayish films. On leaves, the disease appears in two forms: angular leaf spot, restricted by veins, and elongated streaks along the veins, leading to deformation of the leaf blade.

Infection of stems and branches is characterized by the appearance of oily spots capable of causing thinning, curvature, and breakage of shoots, similar to black leg. Infection of bolls leads to their rotting and deterioration of the fiber. There is also a sticky boll rot, which is a secondary process developing when the infection penetrates through damage caused by insects.

Breeding cotton for resistance to bacterial blight is an important area, often involving distant hybridization methods with wild species. Although classical studies used letter nomenclature for resistance genes, the resistance trait in modern commercial varieties is more often polygenic in nature.

General information about the subject — on the page Bacterial diseases.

Sources8

Varieties of Upland cotton 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.