Diseases

Powdery Mildew of Black Currant

Ribes nigrum L.

A fungal disease caused by the obligate parasite Podosphaera mors-uvae. It primarily affects young leaves and shoots, leading to their deformation and necrosis.

In the reference 143 varieties crop Blackcurrant, where this is mentioned in the description.

The pathogen is the fungus Podosphaera mors-uvae, which overwinters as cleistothecia on plant debris and shoots. In the spring, when buds break, primary infection occurs via ascospores. The disease appears shortly after flowering as a white, web-like mycelium, which eventually thickens, darkens, and becomes covered with black dots, the fruiting bodies of the fungus.

The pathogen actively infects young leaves and the tips of growing shoots; black currant fruits are rarely affected. Affected leaves curl and dry out, while the deformation and stunted growth of shoots lead to weakening of the plant and reduced productivity.

In resistance breeding, interspecific hybrids and genetic factors, such as the Sph3 and R genes, are employed. Breeders aim to combine several resistance genes into a single genotype; however, in commercial practice, varieties are evaluated based on their field resistance to local pathogen populations.

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

Sources8

Varieties of Blackcurrant 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.