Raspberry: Anthracnose
categories: Raspberry Raspberry Diseases Small Fruits
revision date: 2022-12-07 12:00
Photo by: R.S. Byther
Biology
Anthracnose is a fungal disease. It occurs primarily on raspberry canes, but can also affect leaves and fruit. Initial infections typically occur on the lower portions of canes toward the inside of the plant. Canes show small, circular, sunken spots. These are initially reddish to purple, but enlarge and turn tan to gray with raised purple margins as the disease progresses. Severe infections may girdle canes, causing dieback. Leaves and leaf stems may show various degrees of purple spotting, depending on the plant variety. Berries affected by anthracnose may ripen unevenly and have abnormally small drupelets (the small sections of the fruit). The fungus is spread by splashing water and overwinters on infected canes. Black raspberries are susceptible, as are some varieties of red raspberries. Red raspberry symptoms may be limited to gray, unsunken areas on the canes.
Management Options
Use Integrated Pest Management (IPM) for successful plant problem management.
Non-chemical Management
Select non-chemical management options as your first choice!
- Plant resistant red raspberry varieties such as ‘Chilcotin’, ‘Heritage’, ‘Meeker’, ‘Nootka’, and ‘Willamette’.
- Plant only disease-free stock.
- Space plantings, prune, and train to provide good air circulation and reduce humidity.
- Avoid overhead irrigation.
- Do not overfertilize. Excess nitrogen promotes growth of succulent, susceptible tissues.
- Control weeds around plantings to help reduce humidity and improve air flow.
- Remove old fruiting canes and all dead or damaged canes after harvest. Also remove infected canes and destroy (burn or bury) them. Do not compost diseased materials.
Chemical Management
IMPORTANT: Visit Home and Garden Fact Sheets for more information on using pesticides.
- A late dormant or delayed dormant application just before buds open may be adequate.
Approved Pesticides
Listed below are examples of pesticides that are legal in Washington. Always read and follow all label directions.