Seed treatment and rotation with crops other than cole crops or greens will also reduce disease. Spray every seven to 10 days after transplants are set. Apply all chemicals according to directions on the label. In general, yellow, V-shaped lesions appear along the tips of the leaves with the point of the V directed toward a vein. When lesions enlarge, wilted tissue expands toward the base of the leaves.
Veins turn black or brown.
Infection may spread into the stems. Cutting into the stems often reveals a black-brown discoloration with a yellowish slime present. Symptoms on cauliflower may appear as numerous black or brown specks, black veins and discolored curds. The bacteria survive the winter on plant debris and on weeds, such as wild mustard and Shepherd s purse. It also can survive in and on seeds from infected plants.