Only grasslike plants seem to be immune to crown gall. Cane gall occurs only on brambles. Black and purple raspberries are more frequently infected than red raspberries and blackberries. The impact of the disease on plant growth and production can range from no apparent effect to death of the plant. Symptoms Crown and cane gall are characterized by the spongy, rough, tumorlike swellings which become brown, woody knots with age, and range in size from that of a pinhead to a golf ball.
Crown galls develop in the spring on the underground parts, the roots and crown, of the plants.
Cane galls develop as whitish eruptions on the fruiting canes in mid-June. These eruptions later turn brown and then black, and begin to disintegrate. The diseases cause the production of dry, seedy berries and the stunting and prevention of new cane formation. Weakened canes are easily broken by the wind and are more susceptible to winter injury. The plants may show water stress and nutrient deficiency symptoms since the movement of water and nutrients throughout the plant is disrupted.