Coffee tracheomycosis

Coffee tracheomycosis is a severe vascular disease caused by the fungal pathogen Gibberella xylarioides (anamorph Fusarium xylarioides). The pathogen colonizes the vascular tissues of the plant, causing physical blockage and toxigenic effects that prevent water and nutrient transport, leading to the rapid decline and death of the host.

The disease primarily impacts major commercial species, including Arabica coffee (Coffea arabica) and Robusta coffee (Coffea canephora). This fungus is a major limiting factor in coffee production, particularly in African regions, where it has historically devastated extensive cultivation areas and decimated local yields.

Key symptoms include systemic chlorosis of the foliage followed by necrosis, which starts on one side of the canopy and eventually spreads throughout the entire tree. A diagnostic feature observed in symptomatic plants is the dark, brownish-black streaking inside the wood of the stem and branches, which corresponds to the infected xylem vessels.

The development and spread of Gibberella xylarioides are facilitated by high humidity, ambient temperatures, and mechanical injury to the bark. Pathogen transmission often occurs through contaminated pruning equipment, movement of infected planting materials, and infested soil remnants attached to machinery or tools.

To mitigate the impact of tracheomycosis, a multi-faceted management strategy is essential:

• Planting genetically resistant coffee varieties.
• Rigorous sanitation, including the removal and destruction of infected trees.
• Sterilization of pruning tools using alcohol or bleach solutions between trees.
• Strict quarantine regulations to prevent the introduction of the fungus into disease-free areas.