Infected canes may blossom normally, but they usually wilt and die before they can set fruit or while they are heavy with fruit.
Black raspberries are more susceptible than red or purple raspberries.
Cankers on apples and roses are also caused by the L. conithyrium fungus. Symptoms and Diagnosis Brown-purple areas develop around cuts or wounds in infected canes. The discoloration will slowly spread down the cane, encircling the stem. Small, smutty patches of olive-green fungal conidia develop on the bark. The spread of the disease through the canes blocks water movement through the plant, causing wilting and, eventually, death.