Pellicularia koleroga

The fungus is characterized by the formation of a delicate, web-like mycelium that spreads across the surface of the leaves and branches of the host plant.

Taxonomically, the fungus is often associated with the genus Ceratobasidium, reflecting the complex classification of such corticioid fungi.

The pathogen thrives in high-humidity environments, where its life cycle is optimized for rapid dispersal through airborne spores and water splashing.

It remains dormant in the form of mycelial mats on branches, ensuring its survival during dry spells until conditions improve for new infection.

The fungus is primarily known for causing a severe disease in coffee plantations known as "koleroga" or thread blight, which affects plant vitality.

Aside from coffee, it can infect a broad variety of botanical species, making it a threat to diverse agricultural and ornamental horticultural settings.

The economic impact of the pathogen is centered on extensive defoliation, which severely limits the plant's ability to photosynthesize and produce fruit.

Young twigs are frequently girdled by the mycelium, causing the death of terminal growth and long-term damage to the plant structure.

Without intervention, severe outbreaks can lead to total yield loss, threatening the economic stability of farming operations.

Early symptoms appear as water-soaked lesions that transition into necrotic brown to black spots on the leaves.

A distinctive sign is the thin, grayish mycelial network that connects dead leaves to branches, keeping them hanging even after they are detached from the plant.

Affected tissues become brittle and die, with the fungus progressively covering twigs and stems with its white, thread-like fungal growth.

During prolonged rainy seasons, the infection can escalate rapidly, covering large portions of the canopy within a matter of days.

The physical presence of mycelial threads, often visible to the naked eye under close inspection, is a definitive diagnostic feature of the infection.

Effective management requires a combination of cultural practices, such as pruning to remove infected tissue and improve overall canopy aeration.

Reducing planting density is essential to limit the microclimatic conditions that favor the rapid proliferation of the fungal mycelium.

Chemical control usually involves the application of copper-based fungicides or appropriate systemic fungicides during the early stages of the rainy season.

Monitoring for the first signs of the fungus is critical for implementing timely measures that prevent the widespread dispersal of spores.

• Sanitary pruning of diseased branches
• Improved air circulation in the canopy
• Application of protective fungicides
• Maintenance of plant health to improve resistance