Cane blight occasionally impacts homegrown and commercial raspberries and blackberries in Kentucky. The disease causes lesions to develop on both primocanes (current-year canes) and floricanes (second-year or fruiting canes) and can result in reduced yield and cane death. Fungicides are available; however, sanitation is a critical step in prevention and management.
Cane Blight Facts
• Symptoms include brown to purple cankers (Figure 1) that expand to girdle canes throughout the season. Wilting and dieback are observed in areas above the canker. During periods of high moisture, black fruiting bodies (pycnidia) may be visible.
• Hosts include red raspberry, black raspberry, and blackberry.
• Primary infection occurs in spring when spores, moved by wind or water, enter through pruning cuts, insect damage, broken fruit stems, bark cracks, or wounds.
• Caused by the fungus Leptosphaeria coniothyrium.
• Overwinters in dead or diseased canes.
• Prune to improve air circulation and rapid drying.
• Remove weed hosts.
• Maintain plant health with proper nutrition and irrigation practices.
• Remove wild brambles from the area.
• Prune and burn or bury all old canes and diseased or dead plant tissue.
• Protect plants from winter damage.
• Manage insect pests.
• Homeowners may apply fungicides containing lime sulfur during dormancy and products containing copper or captan beginning at vegetative growth and continuing through bloom.
• Commercial growers should refer to Midwest Fruit Pest Management Guide (ID-232) for up-to-date fungicide recommendations.
Go to laurel.ca.uky.edu to find the additional information listed below:
• Backyard Berry Disease Management Using Cultural Practices (with Low Spray, No Spray & Organic Options) (PPFS-FR-S-25)
• Commercial Midwest Fruit Pest Management Guide (ID-232)
• Fruit, Orchard, and Vineyard Sanitation (PPFS-GEN-05)
• Cane Blight of Raspberries (The Ohio State University Extension, PLPATH-FRU-10)