Glomerella cingulata

Systematic position and pathogen type: Glomerella cingulata is an ascomycete fungus that belongs to the order Phyllachorales. Its asexual stage is recognized globally as Colletotrichum gloeosporioides. It is considered a highly destructive and polyphagous pathogen capable of infecting a vast range of hosts including fruit trees, vegetables, and ornamental plants.

Diseases and host crops: This fungus is the primary cause of bitter rot in pome fruits, as well as anthracnose on various berries, citrus, and avocados. The symptoms usually manifest as sunken, dark lesions on fruits, which eventually produce masses of salmon-colored conidia. The rot can progress rapidly, eventually colonizing the entire fruit and leaving it as a shriveled mummy.

Biology and life cycle: The pathogen survives as mycelium or spores within infected plant tissues, bark cracks, and dead fruit. In spring, primary infection occurs through splash-dispersed conidia or ascospores released during rainfall. The fungi can remain latent in fruits for weeks or months, only becoming active and causing visible symptoms as the fruit begins to ripen.

Development conditions and severity: Warm and humid environments, specifically temperatures between 20°C and 30°C with high relative humidity, favor the development of Glomerella cingulata. It is a major economic threat, often destroying a significant portion of fruit crops during wet growing seasons. Furthermore, the infection can spread rapidly during post-harvest storage, leading to substantial losses in market quality.

Protection and control measures: Effective management of this pathogen requires an integrated strategy to minimize inoculum levels and protect plant tissues:

• Sanitation: removing all mummified fruits and infected pruning debris from the orchard.
• Pruning: maintaining open tree canopies to improve airflow and reduce humidity around fruits.
• Chemical control: applying registered fungicides during the fruit development stage when weather conditions are wet.
• Pest management: controlling insects that cause wounds on fruit surfaces.
• Storage hygiene: cooling harvested produce quickly to inhibit fungal growth during transit and storage.