Three separate fungi cause the canes of raspberry and loganberry to die back. Cane blight kills entire canes by invading at ground level. Spur blight causes individual spurs on the canes to die. Cane spot causes purple spots on canes and leaves, and part of canes can die in a bad attack.
Avoid over-feeding the plants, which makes them soft and more easily attacked. While these diseases are serious for commercial growers, they result in a smaller crop in gardens. If the damage is severe, spray at bud-burst for cane spot and when the new canes are 15 centimetres high for spur blight. For cane blight, avoid injury to the canes, such as hoeing.