Raspberry spur blight is a fungal disease that mainly affects raspberries but can also occasionally attack loganberries. It most frequently occurs in wet seasons but can appear in any year regardless of the weather pattern. Attacks are more likely to occur if the canes are overcrowded or fertilizers high in nitrogen have been used. Unwanted new canes should be thinned out in spring.

Dark purple patches appear around the buds on new canes during late summer. These increase in size and spread up and down the cane from the original point of infection. The colour changes in autumn and winter to a greyish-silver and small black fruiting bodies appear. The infected cane rarely dies but in spring many buds fail to grow or produce weak shoots that wither and die, any shoots that do grow crop poorly. Cut out and burn the affected canes