Colletotrichum gloeosporioides

Taxonomic classification and pathogen nature. The pathogen belongs to the kingdom Fungi, genus Colletotrichum, and species Colletotrichum gloeosporioides (teleomorph: Glomerella cingulata). It is a highly versatile hemibiotrophic fungus known for being a major causal agent of anthracnose across a vast array of botanical hosts.

Host range and symptoms. This fungus affects hundreds of plant species, including tropical fruits (mango, papaya, avocado), pome fruits, vegetables, and ornamentals. It causes typical anthracnose symptoms such as dark, sunken lesions on leaves, stems, flowers, and fruits, often accompanied by characteristic salmon-colored conidial masses.

Biology and life cycle. The pathogen survives as mycelium or dormant structures (acervuli, sclerotia) in infected crop residues, dead wood, or soil. During the growing season, conidia are produced and dispersed by rainfall splash and wind. Upon contact with a host, the spores germinate, develop appressoria, and penetrate the plant cuticle to initiate infection.

Development conditions. C. gloeosporioides thrives in warm, humid environments. Temperatures between 20°C and 28°C combined with high moisture levels are critical for rapid conidial germination and host colonization. These conditions often lead to severe epidemics, especially in regions with frequent rainfall or heavy dew.

Impact and control measures. Anthracnose causes significant economic loss through yield reduction and post-harvest fruit decay.

• Sanitation through removal and destruction of infected debris.
• Use of disease-free propagation material.
• Application of systemic and contact fungicides (e.g., strobilurins, triazoles).
• Improved canopy management to increase aeration and reduce humidity.