Stubs left after harvest become infected. The fungus then moves down to girdle the cane. Botrytis cinerea Space plants to insure good air circulation. Remove fading flowers and yellowing leaves. Apply azoxystrobin, chlorothalonil, fenhexamid, fludioxonil, iprodione, or vinclozolin to protect healthy tissue.
Cankers girdle and kill the cane.
Coniothyrium fuckelii , Cryptosporella umbrina , Coniothyrium wernsdorffiae , Cylindrocladium scoparium Do not plant stock with cankers. Remove infected canes making the cut immediately above a bud. Sterilize the shears with bromine disinfestant between cuts. Maintain even soil moisture and fertilization. Crown Gall Small white to cream-colored galls that form on stems may enlarge to 6 inches in diameter.