Anthracnose

A fungal common foliage and cane disease of blackberries

Anthracnose (causative agent - the fungus Elsinoe Veneta) is a fungal common foliage and cane disease of blackberries. This disease is first visible in the spring as small purplish spots on new canes ads as purple-bordered spots on leafs. As spots on canes enlarge, the become oval in shape and gradually turn gray. Badly infected canes dry out, crack, and cane tips die back. Leaf spots become white with age, and affected tissue frequently drops out leaving a shot-hole effect. The causal fungus also attack fruit, resulting in small, dry, scabby berries. Certain berry cultivars are very susceptible to anthracnose, some cultivars - moderately susceptible. Most erect-growing blackberries are least affected by anthracnose. Some new trailing blackberry cultivars has good resistance to anthracnose.
Anthracnose control on susceptible varieties is accomplished by a combination of cultural practices and chemical control. Before planting, remove any old plants in the nearest area. In wet areas where anthracnose is likely to cause greatest damage, tolerant or resistant cultivars should be used. Remove all pruned stems. Plants on fields or in tunnels must have good air circulation and enough space between. Weed, grass and other plants growth in the blackberry row should be kept down. Good results shows mulching soil between rows and around plants.
Chemical control of anthracnose on susceptible blackberry varieties involves few fungicide spray applications, beginning in early spring when leaf buds have swelled or are just beginning to open. Timing of the first application is very important in preventing later buildup of the causal fungus. Use special or multi-purpose fungicides as Captan, Pristine, Fung-onil, DiseaseEx and others. Typically before bloom and repeat at 7- to 14-day intervals through harvest. Carefully read the user manual and make mixture. Also use copper sulfate or lime sulfur as preventive treatment. When applicate spray, making sure all plant parts are covered thoroughly with fungicide mixture.