Phaeoacremonium parasiticum

Phaeoacremonium parasiticum is a pathogenic fungus that belongs to the group of fungi associated with grapevine trunk diseases. It is widely recognized as one of the primary agents involved in the development of esca and related Petri disease, causing significant decay in the vascular system of woody plants.

The primary host for this pathogen is the grapevine (Vitis vinifera), but its host range also extends to several other woody species, including various fruit trees. The fungus colonizes the xylem, obstructing water and nutrient transport, which inevitably leads to the decline of the infected plant.

Typical symptoms include the slow decline of the vine, stunted growth, and the characteristic "tiger-stripe" pattern of leaf necrosis in some cases. On longitudinal and transverse sections of the wood, one can clearly see dark brown or black streaks or sector-like necrosis, indicating deep infection of the vascular tissues.

The fungus thrives in environments where wounds are left unprotected. It spreads primarily through conidia dispersed by rain splashes or wind, which enter the plant during pruning or via mechanical injuries. Moist conditions significantly increase the risk of infection and colonization of healthy wood tissues.

Effective management requires a proactive approach centered on sanitation and preventive care to stop the spread:

• Strict sanitation of all pruning tools using disinfectant solutions between vines.
• Immediate application of wound sealants or fungicides to fresh cuts.
• Removing and destroying symptomatic wood to eliminate inoculum sources.
• Monitoring nurseries to ensure planting material is free from wood-inhabiting pathogens.