Grapevine leafroll-associated virus 13

The causal agent of this disease is Ampelovirus tredecimvitis, a member of the Closteroviridae family. This viral pathogen primarily affects the vascular system of the host plant, leading to systemic infection that disrupts essential physiological functions.

The primary host for this virus is the grapevine (Vitis vinifera). The virus typically colonizes the phloem tissue, which significantly impairs the translocation of sugars and other nutrients from leaves to the fruit and roots, eventually weakening the entire vine.

Symptoms usually manifest as the downward rolling of leaf margins, which becomes highly visible during late summer and autumn. Leaves show specific discoloration patterns; in red-berried varieties, they turn reddish or purple, while in white-berried varieties, they become yellow, often with green veins remaining prominent.

The spread of the virus occurs mainly through the use of infected propagation material, such as cuttings or rootstocks. Additionally, insect vectors, specifically mealybugs and soft scales, play a critical role in transmitting the virus from infested to healthy vines within the vineyard.

The economic impact of the virus is significant, as it leads to delayed fruit ripening, reduced sugar accumulation, and poor vine vigor. Over time, infected vines exhibit decreased cold tolerance and lower crop yields, eventually leading to reduced economic lifespan of the vineyard.

• Use only certified virus-tested propagation material.
• Implement strict management practices for insect vectors like mealybugs.
• Sanitize pruning tools regularly to prevent mechanical transmission.
• Rogue and destroy symptomatic vines to contain the spread of the pathogen.