Branch canker

Branch canker is a serious plant disease caused by the ascomycete fungus Botryosphaeria disrupta. This pathogen invades the vascular and woody tissues of the host plant, resulting in necrotic lesions and significant structural damage to the stems and branches of trees.

The disease is prevalent in tropical and subtropical climates where environmental conditions support fungal proliferation. Among the most common hosts are economically important fruit trees, such as mango (Mangifera indica) and avocado (Persea americana), which are highly susceptible to the colonization of this fungus.

Symptomatic indicators of the infection include the development of darkened, sunken bark patches that gradually enlarge into deep cankers. These lesions often exude sap or gum as the tree attempts to defend itself. As the mycelium colonizes the vascular system, foliage may exhibit chlorosis, sudden wilting, and eventually, the branch dies back completely.

The spread of Botryosphaeria disrupta is highly dependent on humidity and temperature. Spores are disseminated by rain splash, wind, and movement of infected pruning tools. Entry into the host typically occurs through wounds caused by weather events, insect feeding, or improper agricultural practices, such as rough cuts during harvesting or pruning.

The impact of branch canker on agriculture is substantial, leading to reduced fruit yields, degraded fruit quality, and the loss of the canopy architecture. If left unmanaged, the fungus can progress from smaller branches to the main trunk, eventually killing the entire tree and resulting in major financial losses for orchardists.

Effective management strategies include:

• Strict sanitation protocols, including the removal and destruction of infected branches.
• Sterilizing all pruning equipment with alcohol or bleach between trees.
• Sealing large pruning wounds with protective fungicides or pruning sealants.
• Applying preventive copper-based fungicide sprays during periods of high humidity.
• Reducing tree stress through proper irrigation and soil nutrient management.