Avocado Bacterial Canker: Cultural Management for Disease Suppression

Understanding Bacterial Canker

Sunken black trunk spots with white powder on avocado are bacterial canker (Pseudomonas or Xanthomonas). Bacteria need water to spread—wet conditions trigger outbreaks.

Cultural Control (Primary)

• Increase air circulation—prune canopy, space plants.
• Stop misting/wetting trunk—keep foliage and bark dry.
• Reduce humidity—avoid overhead irrigation.
• Maximize sunlight—full sun suppresses bacteria.
• Remove infected wood in dry weather; disinfect tools.

No Chemical Cure

Copper sprays may slow spread but don't eradicate established cankers. Cultural management is the only reliable approach.

Prevention

Plant on mounds for drainage. Use certified disease-free stock. Avoid wounding.