Grapevine stem pitting

The causal agent of this disease is the Grapevine rupestris stem pitting-associated virus (GRSPaV), which belongs to the Foveavirus genus. This systemic viral infection disrupts the plant's vascular system, hindering the essential nutrient and water transport between the rootstock and the scion.

The primary host for this pathogen is the grapevine (Vitis vinifera). Susceptibility varies among cultivars, but certain rootstocks, especially those derived from Vitis rupestris, serve as critical indicators and hosts for this specific viral strain.

The hallmark symptom is the formation of deep pits, grooves, and necrotic lesions in the woody cylinder, visible only upon stripping the bark. Externally, affected vines often show stunted growth, chlorosis, reduced vigor, and a gradual decline in foliage health, eventually leading to reduced fruit set.

Transmission occurs primarily through the use of infected vegetative propagation material (cuttings and scions). The virus can also be spread through infected grafting tools or by soil-borne nematodes, which act as vectors, facilitating the movement of the virus between healthy and infected vines.

The economic impact of stem pitting is significant due to the reduction in yield, loss of vine longevity, and the degradation of fruit quality. As viral diseases are irreversible once established, affected vineyards often suffer from long-term loss of productivity, making prevention the only viable management strategy.

• Strict use of certified virus-indexed propagation materials.
• Sterilization of pruning tools between vines to prevent mechanical spread.
• Regular soil testing and management of nematode populations.
• Rigorous inspection of nursery stock to prevent initial introduction.