The older, lower leaves of plants infected with Verticillium wilt turn yellow and wilt. Yellowing generally develops between major veins of leaves. These leaves eventually turn brown and drop off the stem, usually when plants approach maturity. The water-conducting tissues of the stems and roots become black. Overall growth of the plant may be stunted.
Solutions
Verticillium wilt is usually a minor problem on cole crops. In coastal areas it may be more of a problem, especially on cauliflower. Cool soil temperatures favor infection and disease symptom development. Symptoms are more prevalent in late-summer and autumn crops. Known infested areas should be planted only in winter or early spring. Some cauliflower cultivars may be more tolerant to Verticillium wilt than others.
