Leaves have black spots or black or brown necrotic areas.

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Leaf edges are brown, some white fungal mycelium may be present on the leaves.

Powdery Mildew

Severe powdery mildew on black currant 'Topsy' at Corvallis, Oregon

Severe powdery mildew on red currant 'Rolan' at Corvallis, Oregon

• Causal organism: Sphaerotheca mors-uvae (Schwein.) Berk. & Curt., North America, Europe, Asia, Australia, New Zealand
• Crops affected: Black, red, white, ornamental currant, and gooseberries

The disease increases in cool, humid, and rainy periods during the spring and early summer. Tips of young shoots are attacked and may become distorted. Both sides of the leaf can be covered with the white mycelium and spores which turn rusty brown with age. Leaves and berries in all stages of development can be attacked. Edges of leaves can turn brown and black. Severe infection reduces shoot growth and adversely impacts the following year's crop.

See: Powdery mildew leaf symptoms

See: Powdery mildew fruit symptoms

See: Additional photos and control information from Oregon State University