Mango Cytosphaera dieback

The disease known as mango dieback or cytospheorosis is caused by the fungal pathogen Cytosphaera mangiferae. This fungus acts as a parasite that infects the vascular system and cambium, severely disrupting the transportation of nutrients and water, which ultimately leads to the death of affected branches.

The primary host for this pathogen is the mango tree (Mangifera indica). It poses a significant threat to commercial mango orchards, especially in humid tropical regions. Both young trees in nurseries and mature trees in production fields are susceptible to this infection throughout the growing season.

Symptoms usually begin with the appearance of dark, sunken lesions on the bark of twigs and branches. As the infection progresses, the bark cracks, and gum exudation may occur. Beneath the bark, the necrotic tissue is clearly visible, and small, black, flask-shaped pycnidia of the fungus eventually emerge on the surface.

Environmental conditions play a crucial role in the disease cycle. High humidity and high rainfall facilitate the production and dissemination of fungal spores. The pathogen typically enters the host through mechanical wounds, pruning cuts, or insect-damaged areas, making orchard hygiene a critical factor in disease control.

Effective management strategies include:

• pruning and burning of all infected branches to reduce inoculum load;
• sterilizing pruning tools with alcohol or bleach between trees;
• applying protective fungicides or wound dressings to pruning sites;
• minimizing tree stress through proper irrigation and nutrient management to improve natural defenses.