Rupestris stem pitting associated virus-1 is a common and widespread virus of grapevines. It is not regulated in Canada or the U.S. A recent survey found this disease in 4.6% of the samples in the state of Washington.
Rupestris stem pitting causes a slow decline in growth, resulting in vines that are smaller than normal with reduced yields. No leaf discoloration is observed.
The disease affects only grafted vines. Ungrafted vines may be infected but do not usually show symptoms. Small pits may develop in the wood on rootstocks, in particular V. rupestris and American rootstocks.
The severity of the disease is more pronounced in vines that are infected with other viruses of the Rugose wood complex, including grapevine virus A (GVA) and grapevine virus B (GVB).
GVA is associated with kober stem grooving disease. Affected vines may show swelling at the graft union and fail to thrive. GVB is associated with corky bark disease, which may cause an incompatibility to develop at the graft union. Leaf symptoms resemble those of leafroll virus but are more severe.
Spread is mainly through propagation. There is no known insect vector for rupestris stem pitting virus. GVB can be transmitted by some species of mealybugs.
Disease management depends upon use of certified healthy, virus-free stock. Remove vines showing suspicious symptoms.
