Glomerella acutata

Glomerella acutata (anamorph: Colletotrichum acutatum) is a significant fungal plant pathogen belonging to the kingdom Fungi and the genus Glomerella. It is recognized globally as the primary agent responsible for anthracnose, a devastating disease that affects a vast array of ornamental, fruit, and vegetable crops, leading to severe yield losses in agricultural sectors.

The host range of this pathogen is broad, with strawberry, blueberry, and various fruit trees being the most susceptible. The fungus infects all above-ground tissues, including leaves, stems, flowers, and fruits. On fruits, the disease is identified by depressed, dark lesions that often develop a salmon-pink or orange sticky spore mass under high-humidity conditions.

The life cycle of the fungus is characterized by both sexual and asexual stages, though the asexual conidia are the primary means of dispersal. These spores are spread through rain splashes, wind, contaminated nursery stock, and farming equipment. Glomerella acutata survives the winter as dormant mycelium in plant debris, infected fruit, or perennial host crowns, ready to reinfect new growth during the spring.

Development and spread of the pathogen are highly dependent on warm and wet weather. Prolonged periods of leaf wetness and temperatures between +20°C and +28°C create ideal conditions for infection. If not managed properly, the pathogen can cause rapid fruit decay, turning fields into massive reservoirs of inoculum and rendering the crop commercially unsalable.

Effective management requires an integrated pest management (IPM) approach. Key strategies include the exclusive use of pathogen-free planting material and rigorous field sanitation by removing diseased residues. Fungicide applications are essential during the flowering and fruit development stages, focusing on rotating chemicals to prevent resistance development. Improving air circulation in plantations is also vital to keep foliage and fruits as dry as possible.