Grapevine trichovirus

Grapevine trichovirus, scientifically identified as Trichovirus pinovitis, is a viral pathogen that poses a threat to viticulture worldwide. Belonging to the family Betaflexiviridae, this virus is known to cause systemic infection in grapevine varieties. It is often found in complex infections with other viruses, which complicates diagnostic efforts and makes the clinical picture on the vine more severe.

The primary host for this virus is the grapevine (genus Vitis). The virus typically invades the vascular system, disrupting the transport of nutrients and photosynthates throughout the plant. It is primarily transmitted through vegetative propagation using infected rootstocks or scion wood, which makes the choice of high-quality, certified nursery stock critical for vineyard longevity.

Symptoms of Trichovirus pinovitis infection can be variable but commonly include leaf chlorosis, curling of leaf margins, and stunted vine growth. Infected plants often show poor shoot maturation, reduced winter hardiness, and lower berry quality, including poor sugar accumulation and uneven ripening. These symptoms are often exacerbated by environmental stress or poor vineyard management practices.

The spread of the virus within the vineyard occurs mainly through human-mediated activities and biological vectors. Mechanical transmission via contaminated pruning tools is a common pathway if strict disinfection protocols are ignored. Additionally, certain hemipteran insects can act as vectors, moving the virus from infected vines to healthy ones during feeding, particularly in older, unmanaged vineyard blocks.

Effective management and prevention of this virus rely on a comprehensive phytosanitary approach. Because there are no curative chemical treatments for viral infections in grapevines, control measures focus on:

• Sourcing certified virus-free planting material from reputable nurseries.
• Implementing rigorous cleaning and disinfection of pruning equipment between vines.
• Monitoring and controlling insect populations known to transmit plant viruses.
• Rogueing or removing symptomatic vines to reduce inoculum levels.