Symptoms of verticillium include older leaves turning yellow, dying, and dropping off infected plants without wilting of the entire plant. Shoot tips wilt during the day and may curl upward. Lower stem tissue, under the epidermis, is darkened by the infection.
This is a soil-borne fungal disease that affects dozens of vegetable crops, especially tomato, potato, eggplant, pepper, strawberry, and bramble plants.
Fruit production is reduced and the entire plant may die. This disease is more prevalent in states north of Maryland. Purchase the seed of resistant cultivars and plant disease-free transplants. Destroy infected plants; use a three-year rotation for susceptible crops.
Photo: Gerald Holmes, Strawberry Center, Cal Poly San Luis Obispo, Bugwood.org