Citrus Canker
Xanthomonas citri subsp. citri
Overview
A serious bacterial disease of citrus causing raised, corky lesions on leaves, stems, and fruit. Spread by wind-driven rain and contaminated equipment. Subject to quarantine regulations in many regions.
Symptoms
Raised, corky, crater-like lesions with water-soaked margins and yellow halos on leaves, stems, and fruit. Lesions may coalesce. Premature fruit and leaf drop. Twig dieback. Fruit cosmetically damaged.
Environmental Conditions
Humid
Prevention
Use certified disease-free nursery stock. Windbreaks to reduce rain splash. Copper sprays during growth flushes. Control citrus leaf miner (creates entry wounds). Quarantine measures.
Management
Copper-based bactericides during growth flushes and before rain events. Prune infected branches. Windbreaks. Control leaf miner. In quarantine areas, infected trees may require removal.