brings the vines in productive bearing a year or two years earlier
than they would have borne had the pruning been neglected. This early
pruning, since it is done with an eye to the vigor of each vine,
insures greater uniformity in the growth and productiveness of the
vineyard. Uniformity thus brought about is important not only for the
time being, but for the future development of the vines, since weak
vines, if unpruned, are stunted and may require years to overtake more
vigorous vines in the vineyard.
The quality of the crop may be regulated by pruning. When vines bear
too heavily, the grapes are small, and wine-makers have found that
they seldom develop sugar and flavor as do grapes on vines not
over-bearing. Grapes on vines too heavily laden seldom ripen or color
well. Not only are the grapes on poorly pruned and unpruned vines poor
in quality but the grapes on such vines are usually not well
distributed and therefore ripen and color unevenly. The results just
mentioned follow because the bunches in a poorly distributed crop
receive varying amounts of light and heat depending on the distance
from the ground, the distance from the trunk and on the amount of
shade.
Pruning may be used to regulate the quantity of grapes borne in a
vineyard and so be made somewhat helpful in preventing alternate
bearing. Abnormally large crops are usually followed by partial crop
failure and biennial bearing sometimes sets in, but the large crop may
be reduced by pruning and the evil consequences wholly or partly
avoided. It follows that pruning must depend much on the vigor of the
vine; for a weak vine may be so pruned as to cause it to overbear;
and, on the other hand, a vigorous vine pruned in the same way might
not bear at all.
_Results attained in pruning to regulate the vine._
It is necessary to regulate the shape of the vine by training so that
tilling, spraying, pruning and harvesting can be easily performed and
the crop be kept off the ground. The cost of production is always less
in a well-pruned vineyard because all vineyard operations are more
easily carried out.
The life of a vineyard is lengthened when the vines are well trained,
because when the parts of a vine are properly disposed on trellis or
stake the plants are less often injured in vineyard operations.
Moreover, not infrequently vines die from over-production and
consequent breaking of canes or trunks which might have been prevented
by pruning to sha
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