Coffee Anthracnose

Pathogen and disease type. The fungus Colletotrichum paranaense is the causative agent of this specific form of anthracnose in coffee plants. As a pathogenic fungus, it colonizes plant tissues and triggers localized cell death, leading to necrotic symptoms. It is a significant concern for coffee plantations due to its potential to rapidly colonize various aerial parts of the tree.

Host plants. The primary host for Colletotrichum paranaense is the coffee tree, primarily Coffea arabica. The disease is frequently identified in coffee-growing regions where environmental conditions favor the proliferation of fungal pathogens. It impacts both young seedlings and mature, fruit-bearing trees, posing a risk to general plantation health.

Symptoms and signs. Typical symptoms include the appearance of dark, sunken lesions on leaves, stems, and berries. These spots often develop concentric rings, and under humid conditions, salmon-colored or gray fungal sporulation structures may appear on the surface of the lesions. Over time, the affected tissues wither, leading to leaf drop and fruit rot.

Conditions for development and spread. High relative humidity, frequent rainfall, and warm temperatures are the primary drivers for the development of Colletotrichum paranaense. The fungus spreads through the dispersal of conidia via splashing rain, strong winds, and contaminated tools. Stagnant moisture within the canopy creates an ideal microclimate for the fungus to establish infection.

Harmfulness and protection measures. The disease causes significant economic loss by reducing both the quantity and quality of coffee yields. Effective protection strategies include:

• Sanitary pruning to remove infected branches and fruit.
• Improving canopy aeration to reduce humidity levels.
• Timely application of copper-based or systemic fungicides.
• Sterilization of pruning equipment to prevent cross-contamination.

Integrated management is essential, involving the regular monitoring of plantations and the use of resistant varieties, which are key to mitigating the impact of this pathogen on coffee production.