Xanthomonas campestris

Bacterial Disease

Xanthomonas campestris

Bacterial Disease

Xanthomonas campestris

Bacterial Disease

Xanthomonas campestris

Bacterial Disease

Xanthomonas campestris

Bacterial Disease

Black rot is a severe bacterial disease affecting cauliflower and other brassica crops, caused by Xanthomonas campestris pv. campestris. It spreads rapidly in warm, humid conditions and can cause substantial yield losses if not managed effectively. The disease is primarily seed-borne but can also spread through rain splash, contaminated tools, and insect activity.

Symptoms of Black Rot

Seedlings: Susceptible to initial infections that may seem to disappear when seed leaves fall off

Mature Plants:

Yellow, V-shaped lesions along leaf margins

Lesions turn brown and necrotic

Dark brown or black veins in infected leaves

Leaf wilting and eventual defoliation

Causes and Spread

Infected Seeds: Primary source of disease introduction

Soil Survival: Bacteria survive in undecomposed plant residues

Entry Points: Wounds caused by hail, insect feeding, or mechanical damage

Water Splash: Spread through rain or sprinkler irrigation

Alternative Hosts: Brassica weeds, wild radish, and wild turnip

Favorable Conditions

Warm temperatures between 25-30°C.

High humidity and wet conditions, including heavy rain or overhead irrigation

Prevention and Management

Certified Seeds: Use disease-free certified seeds.

Crop Rotation: Avoid planting brassicas in the same field for consecutive seasons.

Sanitation: Remove and destroy infected plant residues.

Water Management: Avoid overhead irrigation to reduce water splash.

Weed Control: Eliminate brassica weeds that can harbor bacteria.

Field Monitoring: Regularly inspect plants for early symptoms.

Black rot is a serious threat to cauliflower cultivation. Effective disease management requires a combination of preventive measures, hygiene practices, and vigilant monitoring to minimize crop losses and maintain healthy yields.