Infection generally occurs in the late spring when the environment is wet and optimal for fungus to proliferate. Symptoms do not become visible until mid to late summer. Visible symptoms include purple and brown expansive lesions appearing below buds, leaves and the lower portion of the stem. leaflets that are infected have wedge-shaped brown patches. Infected leaflets may fall, leaving only the petiole and canes behind. During the next season, branch growth from diseased canes will often be weak and wilted.Heidenreich, Cathy. http://www.fruit.cornell.edu/berry/ipm/ipmpdfs/Raspberry%20cane%20disease%20mgmt.pdf "Managing Raspberry Cane Diseases", March 13, 2006.
