Grapevine angular mosaic

Grapevine angular mosaic is a viral disease caused by the Grapevine angular mosaic virus (GAMV). It primarily affects Vitis vinifera, causing systemic infection that disrupts the plant's metabolic functions and overall vitality. As a viral pathogen, it remains within the plant tissue for its entire life cycle, making it a permanent condition once a vine is infected.

The disease is most commonly found in vineyards where phytosanitary standards for propagation material are not strictly followed. Because the virus propagates through vegetative parts, it can quickly spread throughout a vineyard block if infected mother vines are used for grafting or rooting cuttings, leading to long-term crop management challenges.

Symptoms are primarily observed on the foliage. The name of the disease reflects the typical appearance of angular, yellow or light-green spots on the leaves, which are delineated by the fine leaf veins. As the infection progresses, these spots may coalesce into larger patterns, leading to leaf malformation, crinkling, and localized necrosis, which impairs the photosynthetic capacity of the vine.

Transmission occurs through the movement of infected plant material and mechanical spread via contaminated pruning tools. Unlike fungal pathogens, viral diseases like angular mosaic do not respond to fungicides. Environmental factors, such as spring temperatures and moisture levels, may influence the visibility of the symptoms, but they do not serve as a direct cause for the infection onset.

The impact of this disease includes significant yield reduction, lower sugar content in berries, and decreased winter hardiness of the vines. Over time, infected vines exhibit stunted growth and reduced fruit quality. Since curative treatments are unavailable, professional vineyard management focuses on prevention, rapid identification of infected plants, and strictly avoiding the use of symptomatic vines for propagation.

• Utilize only certified virus-free rootstock and scion material.
• Implement strict sterilization protocols for pruning tools between vines.
• Rogue out and destroy infected vines to prevent secondary spread.
• Conduct regular inspections of the vineyard during the early spring flush.
• Avoid propagating material from vineyards with known viral presence.