THERE IS NO GRAPE THAT IS MORE TRUE TO THE VARIETAL THAN THOSE FROM OWN ROOTED VINES
In 1974 our old vine Cabernet Sauvignon was planted on its own roots. It is one of the few vineyards in the world that can brag that their wine is varietal from the roots up. There can be no question that this wine is not modified in any way by the type of rootstock used and rootstock can change the character of a wine.
In 1976 we planted Zinfandel, again on its own roots, in the Reeves vineyard right next door to Sierra Vista Vineyards. The soil is similar and the climate almost identical although the western slope gives the heat necessary for good zinfandel even at our 2800' elevation.
In 1979 we planted cuttings of Syrah on their own roots. These vines are presently being propagated as the Estrella clone because there were a few of us that got cuttings from the Estrella River Vineyards before phyloxera wiped those vineyards out. Even though in the Estrella Vineyard the vines were on rootstock it turned out that that particular rootstock was susceptible to phyloxera.
When vines were originally brought from Europe to the USA it was found that there was a root louse, phyloxera, that the European vinifera vines were not resistant to and thus succumbed to the louse and died. Native American grapes had developed a resistance to phyloxera so the vinifera vines were grafted onto American rootstock and thus were resistant to phyloxera but is the resulting grape the same as those grapes grown on their own roots? I suspect that all rootstock changes the character of the resulting wine to some extent, some more then others.
We at Sierra Vista did a test block of 4 different vinifera vines on 3 different rootstocks. The grapes were Chardonnay, Syrah, Cabernet Sauvignon and Viognier. The rootstock was 110R, 420A and 10114.
After several years a taste test of the grapes showed that the grapes from 110R tasted the most like those from their own roots, the control, while the grapes from the 420A were least like the control and in fact did not taste good. The 10114 was somewhere in the middle. It also is a plus in that the 110R rootstock is drought resistant so we water our vines much less than many others. In 2009 we did not water most vines at all.
One advantage of own rooted vines is that new vines can be propagated by a method called layering. That is taking a long cane from an existing plant and burying part of the cane leaving a tip several buds long in a new plant position. This can be done to replace a dead plant or start a new plant. In one of our recent Syrah plantings we planted the purchased 110R rootstock (based on our test block results) Syrah plants 8' apart. This is insurance against phyloxera. Then when the plants started growing long canes we used those canes to start new plants so that now that block has half the vines on rootstock and half on own roots all 4 ft apart. Thus we get the advantage of own rooted vines and the protection from phyloxera from the vines on rootstock.
Another advantage is that if a vine gets diseased such as with eutypa a sucker from the roots at the bottom of the plant can be trained up to start a new plant and the diseased plant is then cut off below where the diseased portion is.
For a discussion on wine quality from own rooted vines click here or go to: