It affects black raspberry, red raspberry , blackberry, and black-red raspberry hybrids. Spots appear on new canes in mid-to late summer. Spots on leaves of first-year canes begin at the edges and grow inwards, following the veins. The spot is V-shaped, and brown with yellow edges. The entire leaf is usually pale.
Leaves usually fall off.
The fungus grows through the leaf, and into the cane. Chestnut brown-to purple spots are formed on the canes, usually around a leaf joint. The spots may grow together, although they usually stop before the next leaf joint is reached. On the second-year canes, the spots fade to gray, and tiny black dots appear in them. Infected canes are weakened.