Symptoms of Verticillium wilt first appear on leaves, usually in late spring after fruit production has begun. Older leaves may turn brown along the margins and between veins, may develop an off-green color, or may wilt. Leaves dry up as the disease progresses. Eventually the entire plant wilts and dies. Browning of the oldest leaves while young leaves remain green is characteristic. If the crown of an affected plant is sliced open, brown discoloration of the vascular tissue can often be seen.
Life cycle
The pathogen that causes Verticillium wilt is a soilborne fungus that infects roots and invades the water-conducting tissue of the plant. Verticillium dahliae attacks a wide range of broadleaf plants and can survive in the soil for many years without hosts. Verticillium levels are most likely to be high in fields where tomatoes, potatoes, or cauliflower have been grown.
Solutions
Verticillium wilt can appear in new strawberry plantings that are planted in soil where the pathogen has built up on strawberries or another crop host of the disease. Hosts include crucifers, cucurbits, eggplant, tomato, potato, and mint. Rotating to nonhosts can help reduce the pathogen in the soil. Using soil solarization and planting resistant cultivars can help minimize problems. Check with a local advisor or garden supply catalog to see which cultivars may be available in your area.
