Grape Rootstocks
Are used when the roots of the fruiting grape variety are not adapted to the conditions of the soil in the vineyard
Phylloxera-Resistant Rootstock Varieties
St. George (syn. Rupestris du Lot)
vigorous vines
drought-tolerant
roots well, easily budded and grafted
flat petiolar sinus, glabrous
produces male flowers
A X R #1 (syn. Ganzin No.1)
is a hybrid between Vitis vinifera and V. rupestris
produces high yields of high quality fruit
roots, grafts, and buds easily
the most widely used rootstock in California
is resistant to biotype A phylloxera
is highly susceptible to biotype B phylloxera
leaves are glabrous
produces male flowers
illegal in France
3309 (syn. Couderc 3309)
is a hybrid between V. riparia & V. rupestris
is widely used in France
upper leaf surface is glabrous
lower leaf surface is glabrous except at junction of large veins produces male flowers
SO4 (syn. Selection Oppenheim No. 4)
is a hybrid between V. berlandieri & V. riparia of Teleki
is widely used in Europe
is being planted extensively in California
produces male flowers
5C
is a sister selection of SO4.
has been called SO4 in California for many years
is being planted extensively in California
O39-16
is a hybrid between V. vinifera Almeria & M. rotundifolia
produced by the University of California
is patented
is being planted widely is California
is sterile
110-R
is a hybrid between V. berlandieri & V. rupestris
widely used in Europe
gaining popularity in California
easy to root, graft & bud
tolerant to limestone soils
produces mail flowers
Nematode-Resistant Rootstock Varieties
Dogridge
is a selection from the wild of V. champini
is very vigorous (scion)
produces zinc deficiency (scion)
root with difficulty
easy to bud and graft
produces female flowers and small clusters of fruit
leaves are pubescent on upper & lower surfaces
Freedom
is a hybrid between 1613 (some V. vinifera blood) & Dogridge
developed by the USDA on the CSUFresno farm
easy to root, graft, & bud
produces large yields of fruit (scion)
excellent for raisin and table grapes (scion)
produces female flowers and small bunches of grapes
leaves are pubescent on upper & lower surfaces
illegal in France
Harmony
is a sister selection of Freedom (same parents)
scion on Harmony not as vigorous or as high yielding as when on Freedom
easy to root, graft & bud
leaves are pubescent on upper & lower surfaces
illegal in France