This disease is most commonly seen on cauliflower and Chinese cabbage. V-shaped lesions with yellow borders form along leaf margins of lower leaves. Vascular tissue develops a dark brown discoloration, which can extend from the roots into the stem. Symptoms may be easily confused with those of black rot.
Conditions for Disease Development
This fungus survives in soil, and continuous cropping can lead to the buildup of inoculum levels. Cool weather and moist soil generally favor disease development.
Implement long rotations to non-susceptible crops or fumigate soil.