Two-year study in San Joaquin County indicates sampling procedures to find nepoviruses in grapevines need improvement

Abstract

Two debilitating grapevine diseases, fanleaf and yellow vein, are caused by nepoviruses. Once these viruses are established in vineyards along with their nematode vectors, they are extremely difficult to eradicate. Since the use of infected propagating wood can spread the diseases further, the development of rapid diagnostic procedures for these viruses is highly desirable. However, a 2-year study on the identity and incidence of nepovirus-infected grapevines in San Joaquin County vineyards indicates that sampling procedures and ELISA protocols will have to be improved before this virus assay can be used reliably in nursery certification programs.