Black Rot
Xanthomonas campestris pv. campestris
Overview
A serious bacterial disease of brassica crops causing V-shaped yellow to brown lesions from leaf margins and blackening of leaf veins. Can also cause head rot in cabbage and cauliflower.
Symptoms
V-shaped yellow to brown lesions starting from leaf margins. Leaf veins turn black. Leaves may wilt and drop. Head rot in cabbage and cauliflower. Vascular tissue turns dark brown to black. Foul odor in advanced stages.
Environmental Conditions
Humid
Prevention
Use certified disease-free seed. Hot water seed treatment (122°F for 25 minutes). Rotate brassicas on a 3-year cycle. Remove crop debris. Avoid overhead irrigation.
Management
Remove infected plants immediately. Apply copper-based bactericides. Improve air circulation. Avoid working with wet plants. Destroy crop residues after harvest.