Spores produced throughout the growing season on previously infected floricanes are rain splashed to healthy primocanes, where new infections begin. Primocanes that survive the winter rapidly wilt and die the following season. Visual symptoms are typically expressed the following spring as lesions on the floricanes. These lesions appear black, brown, or gray and contain black pimple-like pycnidia. Lesions often extend through several internodes on one side of the cane.
Infected canes tend to be brittle and often break near the lesion.
Cane blight causes wilting, death of axillary buds and lateral branches, and death of the cane. Gray mold on fruit. Gray, velvety mass of fungal material covers berry. Spur blight is most frequently observed as lesions surrounding the nodes on primocanes. Infection initially begins along the margins of the leaf and progresses inward, through the petiole, to the stem.