soil, the
result being that the cions struck root and became independent,
whereupon the stock dies or becomes so moribund that the beneficial
effects are lost. There are grape-growers who argue that it is
beneficial to the vine to have roots from both stock and cion, but
experience and experiments very generally teach the contrary, it being
found that in most grafts the cion roots grow more vigorously than
stock roots and eventually starve out the latter. The disastrous
effects of cion-rooting are often to be found, also, when grafting has
been done on old vines in the vineyard; and, again, when the graft is
too close to the root system.

Another cause of failure is that different stocks require that the
vineyard soil be treated differently, especially at planting time.
Vulpina stocks require that the soil be much more deeply plowed than
for Viniferas on their own roots, since Vulpinas are deep-rooted and
are exacting in the depth of root-run required. Those who have had
most experience with resistant stocks maintain that all American
grapes require rather deeper plowing than European grapes on their own
roots.

INFLUENCE OF THE STOCKS ON THE CION

Up to the present, the growing of grafted grapes has been carried on
with little thought of the mutual influence of stock and cion; grapes
have been grafted only to secure vines resistant to phylloxera. Yet
there can be no doubt that stock and cion react on one another, and
that any variety of grapes is influenced for better or worse in
characters of vine and fruit by the stock upon which it is grafted. A
plant is a delicate mechanism, easily thrown out of gear, and all
plants, the grape not the least, are more or less changed in the
adjustments of stock and cion. One could fill a large volume on the
supposed reciprocal influence of stock and cion in fruits. Space
suffices, here, however, to mention only those proved and those having
to do with the influence of the stock on the cion when the grape is
grafted.

_Influence of stocks on European grapes summarized._

Common experience in Europe and California indicates that varieties of
Vinifera grapes grafted on resistant stocks which are perfectly
adapted to soil and climate produce not only larger crops but sweeter
or sourer grapes; that the crop ripens earlier or later; that the vine
is often more vigorous; and that there are some minor differences
depending on the stock used. Wine-makers assert that the character of