Diseases

Cucumber Scab

Cucumis sativus L.

A fungal disease of cucumber caused by Cladosporium cucumerinum, manifesting as olive-colored leaf spots and fruit lesions. The crop's resistance to the pathogen is controlled by a dominant monogenic trait designated as the Ccu gene.

In the reference 568 varieties crop Cucumber, where this is mentioned in the description.

The causal agent of the disease is the fungus Cladosporium cucumerinum Ellis et Arth., belonging to the class Dothideomycetes. The infection affects all above-ground plant organs, including stems, petioles, leaves, and fruits. On young cucumbers, the disease manifests as small watery spots that turn into deep brown lesions, from which gum may exude, causing deformation and growth cessation of the fruits.

On leaf blades, angular spots form with an olive-gray hue and a yellow halo, on the underside of which, under high humidity, a characteristic velvety olive-black coating of conidial sporulation develops. Damage to stems and petioles by dry lesions leads to nutrient disruption and subsequent plant wilting.

In breeding practice, cucumber resistance to olive leaf spot is transmitted as a dominant monogenic trait. This resistance gene is identified by the symbol Ccu, which is used when describing breeding hybrids and cultivars of the crop.

General information about the subject — on the page Leaf mold (brown leaf spot).

Sources8

Varieties of Cucumber 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.