Bacterial necrosis of grapevine

The causal agent of this disease is the bacterium Xylophilus ampelinus. It is a systemic vascular disease that severely restricts the translocation of water and nutrients within the vine, eventually leading to the decline and death of canes or entire grapevines.

Grapevines are the primary host for this pathogen. The bacteria colonize the xylem vessels, where they multiply and produce toxins, causing structural damage to the plant tissue that is often irreversible once the infection becomes established in the woody parts of the vine.

The characteristic symptoms include the formation of elongated, dark brown lesions on green shoots, which eventually crack to form deep necrotic cankers. In severe cases, the foliage may show chlorotic or necrotic spots, and inflorescences often wither and drop before reaching the fruit set stage.

The development of the disease is favored by high humidity and moderate temperatures, particularly during the spring sap flow period. The pathogen is easily disseminated by splashing rain, contaminated pruning tools, and the movement of infected dormant propagation material across different vineyard sites.

The economic impact of bacterial necrosis is significant, as it leads to reduced yield and long-term decline of vineyard vigor. Infected vines often exhibit poor growth, reduced winter hardiness, and eventual collapse, requiring extensive removal and replacement of the affected plants.

• Use certified virus-free and bacteria-free propagation material.
• Sanitize all pruning equipment with a 10% bleach solution or alcohol.
• Prune out and burn all infected wood to reduce the local inoculum density.
• Apply preventative copper-based sprays during the early growth stages to protect fresh wounds.