Colletotrichum doitungense

The primary symptom of infection is the development of sunken, necrotic lesions that typically appear dark brown or black on leaves, stems, and fruits.

In humid conditions, the centers of these lesions often display salmon-colored or cream-tinted spore masses, identifying the presence of Colletotrichum fruiting bodies known as acervuli.

Affected fruits show signs of soft rot, shriveling, and premature drop, which significantly impacts the harvest yield and market quality of the produce.

Foliar symptoms include chlorotic spotting and necrosis, often followed by significant leaf drop, which stunts the plant’s growth and reduces its photosynthetic capacity.

In cases of systemic infection, stems may show severe girdling lesions, which interrupt water and nutrient transport, leading to localized wilting and eventual death of the affected plant parts.

Colletotrichum doitungense is a fungal phytopathogen belonging to the Colletotrichum genus, primarily known as a causative agent of anthracnose in various botanical species.

As a member of the Colletotrichum gloeosporioides complex, it exhibits high genetic diversity, which poses challenges for specific diagnostic classification and effective long-term disease management.

The fungus colonizes plant tissues through specialized appressoria, which allow it to penetrate host barriers, eventually leading to the degradation of cellular structures.

It survives in dormant states on infected plant debris, seeds, and soil particles, allowing the pathogen to persist across growing seasons and initiate new infections under favorable weather.

During the active phase, the fungus releases massive quantities of conidia that are disseminated through rain splashes, irrigation water, and wind, infecting healthy nearby tissue rapidly.

High humidity, typically above 80–85%, is the most critical requirement for the germination and penetration of Colletotrichum doitungense spores.

The pathogen thrives in warm temperatures, with the optimal growth range falling between +22°C and +28°C, which facilitates rapid colonization of plant tissues.

Poor air circulation within dense canopies or overcrowded planting patterns creates a microclimate that remains moist for long periods, greatly increasing infection risk.

Physical injuries to the plant, whether caused by insect feeding, hail, or mechanical harvesting, serve as primary entry points for the pathogen into the host.

Frequent rainfall or overhead irrigation, especially when foliage is left wet during the night, creates perfect conditions for the pathogen's life cycle to proceed.

This fungus is responsible for significant economic losses in agriculture, often causing major outbreaks that can devastate crop yields if left unmanaged.

Beyond quantity, the quality of harvest is severely compromised, as infected produce is prone to secondary bacterial rots and lacks shelf-life during shipping.

Plants weakened by the infection show reduced vigor and decreased resilience to environmental stressors like drought or salinity, making farm management more difficult.

Continuous infection cycles lead to the degradation of plantation health over time, necessitating costly interventions and, in some cases, total removal of affected crops.

The persistence of the pathogen in the soil and on crop remains necessitates expensive sanitation and long-term crop rotation practices to suppress its levels.

Integrated management begins with the use of pathogen-free seeds and planting material to prevent the introduction of the fungus into new growing areas.

Sanitation is paramount; removing and destroying infected plant parts prevents the buildup of primary inoculum and reduces the chance of yearly re-infection.

Fungicide applications, particularly those targeting the early stages of spore germination, are an essential component of professional disease management programs.

Strategic pruning and canopy management to improve air circulation and sunlight exposure help keep plant surfaces dry, inhibiting fungal spore germination.

• Utilizing resistant cultivars when available.
• Implementing effective crop rotation strategies.
• Optimizing irrigation to avoid prolonged leaf wetness.