Cause Two fungi, Verticillium dahliae and a different Verticillium sp., that survive in soil and diseased plants and infect through plant rootlets.
Symptoms Leaves turn yellow and die from the base up. Dying leaves can show a tiger-stripe effect because bands of dark necrotic tissue alternate with yellow. Stems cut near the base of the plant usually show a light brown discoloration of vascular tissue.
- Avoid excessive irrigation during the spring.
- Apply sufficient nitrogen for crop needs, but avoid excessive fertilization of this nutrient.