Survey for major viruses in commercial Vitis vinifera wine grapes in Ontario.

This is the first such comprehensive survey for grapevine viruses in Ontario and one of the most extensive surveys ever conducted in Canada. The recent outbreaks of viral diseases in Ontario vineyards were likely caused by GLRaV-3, GRBV and GPGV. Findings from this survey provides a baseline for the grape and wine industry in developing strategies for managing grapevine viral diseases in Ontario vineyards.