Plant Pathology: Extension: Plant Disease Library

Black Rot - Xanthomonas campestris

Cabbage - Brassica

Disease Symptoms:
V-shaped necrotic lesions around the tip of leaves. Dark viens extending downward into the mid-rib. Cut into the vein just below the discoloration and a black coarse hair-like streaks will be observed. In later stages, the base of the leaf can be taken from the plant and will reveal numerous black coarse hair-like symptoms where the leaf joins the plant. Cut into the mid-rib and observe black vascular symptoms.

Cut through a black vein and under high magnifaction, see tiny rod-shaped bacteria ooze out.

Disease Management:
Disease free seed, disease free transplants, 3-year rotation with any other Brassica crop, control weeds like pepper-grass and wild mustard and turnips.

Compiled by: Dr. Danny Gay, UGA Vegetable Pathologist , Tifton, GA