As you source for clean materials for the upcoming seasons, whether they are from your own vineyards, a neighbor's, a friend's or a nursery, we would like to share some good practices from growers who are in the know in order to best protect your investment:
1. All plant materials, including top grafting vines or new scion buds, should have their virus status independently tested and verified.
2. Depending on the number of buds (i.e. vines) needed, back-calculate the number of mother vines needed with certain overage ratio based on the number of buds per mother vine.
3. Sample and test every mother vine for a suitable panel of economically important viruses prior to grafting.
4. Use composite sampling to reduce testing cost. We can process up to ten cuttings per sample.
5. If testing the mother vines are impractical, use statistically sound methods to sample and test starting, finishing, or finished product
6. If testing budget is limited, test, at the least, grapevine leafroll 3 virus and red blotch virus - two of the most devastating viruses affecting grape production.
7. Inspect potted and bare root vines suitably in advance before delivery for physical conditions to permit sourcing of alternate materials should plants be in poor physical condition or test positive for virus.
8. Consider hiring an outside experienced expert if your internal resources are limited.
Please contact Agri-Analysis at (800)506-952 and info@agri-analysis.com; or James at 707-217-2539 and james@