Esca of grapevine

Esca is a serious complex wood-decay disease of grapevines, primarily caused by fungal pathogens such as Fomitiporia punctata, often acting in concert with other species like Phaeomoniella chlamydospora. It is considered one of the most destructive trunk diseases in viticulture worldwide.

The primary host for this pathogen is the cultivated grapevine. The fungus enters the plant through physical wounds, which are frequently caused during routine pruning, frost damage, or mechanical injuries. Once established, the pathogen colonizes the perennial wood of the trunk and cordons.

Symptoms are diverse, ranging from chronic foliar discoloration—often described as a tiger-stripe pattern of chlorosis and necrosis—to the sudden apoplectic death of the entire vine. Inside the trunk, the fungus causes a characteristic white rot, turning the wood into a soft, spongy, and necrotic tissue.

The development of Esca is favored by warm weather conditions and the presence of exposed woody tissue. The disease spreads through airborne spores released from fruiting bodies located on dead wood, making the cleanup of debris and pruning practices critical in limiting the spread of the inoculum.

As there are no curative chemical treatments currently available for infected vines, management focuses on preventive strategies. Key control measures include:

• Sanitizing pruning tools frequently to avoid cross-contamination.
• Applying protective sealants or fungicides to all major pruning wounds.
• Avoiding heavy pruning during wet weather conditions.
• Strictly removing and burning dead or diseased wood to reduce the local spore concentration.
• Prioritizing the health and vigor of vines through balanced irrigation and fertilization.