About Grape
Rootstocks
Rootstocks are
one of the important ways grape growers can better manage for an array of
vineyard problems and improve quality. Grape rootstocks can also help
mitigate vineyard problems relating to soil conditions such as ph extremes, salt
excess and nutrient excess. They can also improve adaptability to local
climatic conditions such as shortened growing seasons, drought and excessively
cool or hot growing conditions. The most important function of grape
rootstocks has been to provide resistance against soil borne pest such as
phylloxera and nematodes. Resistance to phylloxera and nematodes in
many cases can only be provided through the use of rootstocks.
The performance of
rootstocks will be very site dependent and the compatibility for a given
scion/rootstock combination can vary. It is highly recommended that you consult
with local vineyard manager before making your order. The best wines of
the world are produced on low to moderate vigor rootstocks. It is
important to adapt the rootstock choice to the soil and climate to optimize vine
size. You should not use vigorous rootstocks in fertile soils, however,
high vigor rootstocks can be of great value under very dry conditions, and
non-irrigated vineyards.
Three
North American species are the most common parents of grapevine rootstocks:
Vitis rupestris, Vitis riparia,, and Vitis berlandieri.
Vitis
ruprestris grows in dry, sunny
sites that have periodic rain. Its plunging roots help it tap a deep water
supply, but are ill suited to shallow soils in drought conditions.
Ruprestris has
a very long vegetative cycle with early bud break and late fruit and wood
maturation. Its growth strategy can be described as vigorous during periods of
high water and nutrient availability with reduced activity during drier periods.
Three of the rootstocks suited to Oregon are 3309 Coudrec, 101-14 Mgt. and
Swartzmann. All are resistant to phylloxera with 3309 Coudrec and 101-14 Mgt.
having moderate resistance to nematodes and Swartzmann having high resistance to
nematodes.
Vitis riparia
is adapted to cold climates with short seasons,
the roots grow laterally and its large leaves are well adapted to shade but not
drought. Bud break is early as are fruit set, although a shortened growth
span would decrease the total production by the plant each year. It
ensures completion of growth, fruit and wood ripening before the onset of
winter. Riparia gloire is used in Oregon vineyards with deep soils and drip
irrigation. Riparia gloire is highly resistant to phylloxera.
Vitis
berlandieri is a vigorous climbing vine with strong
fleshy plunging roots. It is the most drought tolerant and can also tolerate
very low winter temperatures. It is not adapted to cool regions because of
its long growing cycle and late maturity. All are resistant to phylloxera and
some are more resistant to nematodes than others.
44-53 Malegue
is a complex cross of V. riparia, V.
cordifolia and V. rupestris . This rootstock has a deep growing
root system and performs well under drought conditions. It has similar
vigor to 3309 Coudrec, with moderate to early ripening. 44-53 Malegue is
resistant to phylloxera and to nematodes.
For more information:
Lon J. Rombough sell grape
cutting www.bunchgrapes.com
Cornell University Grape Pages
www.nysases.cornwell.edu/hort/faculty/pool/grapesPagesIndex/htm
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