Esca of grapevine

Esca is a complex and destructive wood-decaying disease of grapevines primarily associated with the pathogen Phaeomoniella chlamydospora. This fungal infection colonizes the perennial wood of the vine, progressively destroying the vascular tissue and disrupting the plant's ability to transport water and nutrients.

The disease mainly affects Vitis vinifera cultivars worldwide, often appearing in older vineyards. Esca is characterized by its long incubation period, during which the pathogen silently spreads within the trunk before visible symptoms appear on the foliage or the plant experiences sudden collapse.

Common symptoms include the distinctive «tiger-striped» chlorotic and necrotic patterns on leaves, while cross-sections of the trunk reveal soft, yellow-brown, spongiform rot. In acute cases, often referred to as apoplexy, healthy-looking vines may undergo rapid wilting and die within a few days during the peak of summer.

• Infection through pruning wounds
• Contaminated nursery propagation material
• High humidity and rainfall during pruning
• Mechanical damage to the bark
• Vines under environmental stress

The transmission of the fungus is largely facilitated by airborne spores that land on fresh pruning wounds or physical injuries. Once inside the xylem, the pathogen slowly colonizes the wood, gradually causing decline. Environmental conditions, especially rainy weather during the dormant pruning season, significantly increase the risk of infection.

Current management practices focus on prevention, as there is no definitive cure for infected vines. Essential strategies include implementing strict sanitation practices, such as disinfecting pruning tools, applying protective sealant pastes to large cuts, and removing severely infected vines to minimize inoculum levels in the vineyard.