Diseases

Powdery mildew of cucumber

Cucumis sativus L.

A fungal disease of cucumber caused by the obligate parasites Podosphaera xanthii and Golovinomyces cichoracearum, characterized by the appearance of a white powdery coating on leaves and a reduction in the market quality of fruits.

In the reference 1 031 varieties crop Cucumber, where this is mentioned in the description.

The pathogens of the disease are the ascomycetes Podosphaera xanthii and Golovinomyces cichoracearum. The infection begins with the appearance of an inconspicuous white coating on the underside of the leaves, which later forms white spots on the upper side of the leaf blade, increasing in size and merging into a continuous coating.

As the disease progresses, the leaves become deformed, wavy, and dry out, and in cases of severe infection, the vines die. Although the pathogen rarely affects the fruits directly, the general dehydration of the plant leads to fruit dwarfing, loss of marketability, and the development of bitterness.

Genetic resistance of the crop is controlled by a group of recessive pm genes, including pm-1, pm-2, pm-3, and pm-h. In the international classification of varieties, resistance to the pathogens Px (Podosphaera xanthii) and Gc (Golovinomyces cichoracearum) is indicated by codes HR for high resistance and IR for intermediate resistance.

General information about the subject — on the page Powdery mildew.

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.