Some blackberry varieties, as well as black and purple raspberries, are susceptible to the fungal disease anthracnose. This disease causes circular or oval, grayish-white cankers or scabby spots on the canes and sometimes on the leaves. Anthracnose is caused by the fungus Elsinoe veneta, but other cane canker and cane blight fungi can cause similar symptoms. The infections often girdle the canes, killing them and aborting the fruit crop. Brambles injured by exposure to cold winter temperatures are more susceptible to cane canker diseases. To avoid this disease, always plant disease-free nursery stock. If the disease is found in a planting, infected canes should be removed at ground level and destroyed. In very early spring, apply fungicide to brambles when the buds are swelling and the leaves are just showing green or when they are about 1/8 inch long. Red raspberries are less likely to be seriously damaged by anthracnose, but sprays should be applied if there has been anthracnose on the plants. Contact your local Extension office for fungicide recommendations.

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