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

Table 7 Prevalence of major grape viruses in V. vinifera grapes based on period of vineyard establishment

Year of Planting	No. of samples tested	GRSPaV	GLRaV-3	GPGV	GRBV	GVA	GVB	GLRaV-2	GLRaV-1
1974–1990	45	91.1	71.1	13.3	2.2	53.3	22.2	6.7	8.9
1991–2005	357	92.7	55.7	21.8	17.9	3.6	2.8	2.0	2.0
2006–2016	74	95.9	37.8	25.7	6.8	1.4	0.0	0.0	0.0
Total	476	443	259	103	70	44	20	10	11

The full names of viruses that are included in this survey are provided in the list of abbreviations
Shown are the percentages of samples tested positive for each virus over the total number of samples collected from grapevines planted in a specific period of years

ISSN: 1743-422X