CHAPTER IX

GRAPE-PRUNING ON THE PACIFIC SLOPE

The methods of pruning and training native grapes, discussed in the
last two chapters, do not apply to the Vinifera grapes grown in the
favored valleys of the Rocky Mountains and on the Pacific slope. As we
have already seen, the Vinifera or Old World grape differs markedly in
habits of growth from the American species so that it would not be
expected that pruning which applies to the one would apply to the
other types. The fundamentals, to be sure, are much the same and the
different species of grapes are about equally subservient to the
shears of the pruner, but while pruning to regulate fruit-bearing
finds many similarities in Old and New World grapes, the training of
the vines is radically different.

European practices in pruning and training Vinifera grapes are so many
and so diverse that the first growers of this fruit in America were at
a loss to know how to prune their vines. But, out of a half century of
experience, American growers of Old World grapes have adapted from
European practices and have devised to meet new conditions, methods
which serve very well in the new home for this old grape. Since the
culture of the Old World grape is centered in California, almost
confined to that state, California practice may be taken as a pattern
in pruning and training the vines of this species.

VINE PRUNING IN CALIFORNIA[16]

The systems of pruning in use in California may be divided into two
classes according to the arrangement of the arms on the trunk of the
vine. In the commonest systems, there is a definite head to the trunk,
from which all the arms arise symmetrically at nearly the same level.
The vines of these systems may be called "headed vines." In the other
systems, the trunk is elongated four to eight feet and the arms are
distributed regularly along the whole or the greater portion of its
length. The vines of these systems, owing to the rope-like form of the
trunks, are called "cordons."

The headed vines are divided according to the length of the vertical
trunk into high, 2-3 feet, medium, 1-1-1/2 feet, and low, 0-6 inches.
The cordons may be vertical or horizontal, according to the direction
of the trunk, which is from four to eight feet long. The horizontal
cordons may be single (unilateral) or composed of two branches
extending in opposite directions (bilateral). Double and even multiple
vertical cordons occur, but they are very inadvisab