Colletotrichum gigasporum

Colletotrichum gigasporum is a prominent fungal pathogen belonging to the Colletotrichum genus, primarily known for causing anthracnose across a diverse range of plant species. As a hemibiotrophic pathogen, it initially colonizes host tissues without killing them, later switching to a necrotrophic phase that destroys host cells. This pathogen is a significant challenge for global agriculture due to its aggressive growth and ability to survive in various environments.

The host range of Colletotrichum gigasporum is vast, impacting economically significant crops such as strawberries, grapes, coffee, citrus, and various legumes. The pathogen can attack all parts of the plant, including leaves, stems, flowers, and fruits. Infections occurring in the late stages of crop development are particularly devastating as they cause rot on fruits, leading to heavy yield losses during transport and storage.

Symptoms typically manifest as dark, water-soaked, sunken lesions on infected tissues. As the infection progresses, these lesions may develop a characteristic fungal mass (acervuli) which appears as pinkish or orange spores under moist conditions. Infected leaves may wilt, yellow, and drop prematurely, while fruits often develop severe decay, rendering them unsuitable for both fresh market consumption and processing.

Environmental conditions such as high humidity, frequent rainfall, and moderate to warm temperatures are ideal for the rapid development of the fungus. The pathogen spreads primarily through conidia dispersed by water splashes and wind currents. Infected plant debris, contaminated seeds, and tools used for pruning are primary reservoirs that facilitate the cycle of infection from one season to the next.

Managing Colletotrichum gigasporum requires an integrated pest management (IPM) strategy to be successful.

• Strict sanitation practices, including the removal of crop residues.
• Using certified disease-free planting material.
• Crop rotation to reduce the inoculum load in the soil.
• Timely application of protective and systemic fungicides during high-risk periods.
• Improving canopy airflow through proper pruning and planting density management.