Diseases

Septoria Leaf Spot of Black Currant

Ribes nigrum L.

A fungal disease caused by Septoria ribis Desm., characterized by the appearance of white spots with dark margins and pycnidia on leaves, shoots, and berries, leading to premature defoliation and yield losses of up to 50%.

In the reference 15 varieties crop Blackcurrant, where this is mentioned in the description.

The causal agent of black currant Septoria leaf spot is the fungus Septoria ribis Desm., whose perfect stage is known as Mycosphaerella ribis Lind. Two races of the pathogen are identified in the pathogenesis of the disease. The disease manifests as the development of small, circular spots 2–3 mm in size, which are initially brown but eventually turn white, retaining a reddish-brown margin. A characteristic diagnostic feature of tissue damage is the formation of black dots, known as pycnidia, in the center of the spots.

The infection affects not only leaf blades, causing them to yellow, curl, and drop, but also petioles and shoots, where elongated spots form. Infection of berries occurs less frequently. Economic damage is reflected in reduced total growth, smaller berry size, and decreased cold hardiness of the crop. Resistance to the disease in breeding is achieved through the use of interspecific hybrids based on Ribes glutinosum, R. cereum, and R. dikuscha species, although specific resistance genes have not yet been identified.

General information about the subject — on the page Septoria leaf blotch.

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.