Grevillea anthracnose

Colletotrichum grevilleae is a pathogenic fungus responsible for anthracnose, a destructive disease affecting various species of the Grevillea genus. As a specialized pathogen, it attacks plant tissues, leading to lesions that impair the growth and health of these ornamental plants.

The primary hosts of this pathogen are Proteaceae family members, specifically Grevillea plants. Infections are frequently observed in nursery settings, greenhouse production, and landscapes where these plants are cultivated, often leading to significant aesthetic and biological damage.

The disease is characterized by the formation of necrotic, sunken spots on leaves, stems, and petioles. These lesions often expand rapidly, causing foliage drop, tip dieback, and general weakening of the plant structure. In moist conditions, the pathogen produces characteristic acervuli containing masses of spores.

Disease progression is highly dependent on environmental factors, particularly humidity, rainfall, and moderate temperatures. The fungus spreads through water splash, wind-blown spores, and the movement of contaminated tools, making hygiene a critical component of disease management in any botanical collection.

Effective control requires an integrated approach to minimize crop loss. Key strategies include:

• Pruning and removing infected plant tissue;
• Improving air circulation to reduce humidity;
• Applying appropriate fungicides, such as copper-based or systemic products;
• Ensuring quarantine of new plant material to prevent the introduction of the fungus.