Symptoms and Signs
Fusarium foot rot causes varying degrees of interveinal chlorosis and necrotic spotting on young foliage. Foliar symptoms may be similar to certain viruses (tomato spotted wilt or alfalfa mosaic). Flowers are often necrotic. Aboveground symptoms may be restricted to single branches. In severe cases, plants die. A dark brown lesion, about 0.5 to 1 inch (1–2.5 cm) long, is visible on the tap root or a main lateral root. Often the lesion completely girdles the root. The lesion usually occurs on the roots within the top 12 inches of soil. Internally, a brown discoloration of the vascular system extends 1 to 4 inches from the lesion.
Comments on the Disease
The fungus probably survives for long periods in the soil as spores. In California, it occurs most commonly north of Merced County. Other host crops are peppers and potatoes.
Limit spread of infested soil by cleaning equipment between fields.