Phaeoacremonium alvesii

Phaeoacremonium alvesii is a fungal pathogen belonging to the Ascomycota division, recognized as a primary agent in the development of grapevine trunk diseases, particularly Petri disease and esca. This pathogen colonizes the xylem of the vine, causing irreversible damage to the water-conducting tissues and severely impacting the structural integrity of the plant.

The primary host for this fungus is the cultivated grapevine (Vitis vinifera). However, research indicates that the fungus has a broad host range, potentially persisting in various woody shrubs and trees surrounding agricultural areas. This versatility makes it difficult to eradicate, as the surrounding ecosystem often acts as a permanent inoculum source for vineyard infections.

Symptoms of the infection range from chronic stunted growth and leaf chlorosis to acute symptoms like "apoplexy" or sudden wilting. When examining the cross-section of an infected vine trunk, one can observe localized brown spots or long-term streaking, which are indicative of tissue necrosis. These vascular symptoms block the normal flow of water and minerals, eventually leading to the death of affected branches or the entire vine.

The development of the fungus is highly dependent on environmental moisture and temperature conditions, which facilitate the production and dispersal of spores via wind or rain splash. Spores primarily enter the plant through pruning wounds, which act as gateways for the infection. Because the incubation period can last for years before visible symptoms appear, the disease often spreads undetected across the vineyard.

Management and prevention focus primarily on strict sanitation and protective measures during cultivation. Pruning should be performed during periods of low spore activity, and all major wounds must be treated immediately with protective sealants or fungicides to prevent colonization. Furthermore, early detection through diagnostic sampling of wood is crucial to remove infected sources before they jeopardize the entire vineyard block.

• Regular disinfection of all pruning tools using approved solutions.
• Avoidance of pruning during wet weather conditions.
• Application of Trichoderma-based biological agents for wound protection.
• Removal and destruction of highly symptomatic vines to reduce inoculum.