ro, Dattier de Beirut, Cornichon, Emperor, Black
Ferrara, Malaga, Olivette de Cadenet, Pis-de-Chevre blanc,
Schiradzouli, Zabalkanski.

These lists must not be taken as indicating absolutely for all cases
how these varieties are to be pruned. They simply indicate their
natural tendencies. Certain methods and conditions tend to make vines
more fruitful. Where these occur, shorter pruning than is indicated
may be advisable. On the other hand, other methods and conditions tend
to make the vines vigorous at the expense of fruitfulness. Where these
occur, longer pruning may be advisable.

The more usual factors which tend towards _fruitfulness_ are:

Grafting on resistant vines, especially on certain varieties such as
those of Riparia and Berlandieri;

Old age of the vines;

Mechanical or other injuries to any part of the vine;

Large development of the trunk, as in the cordon systems.

The more usual factors which tend towards _vigor_ at the expense of
fruitfulness are:

Rich soil, especially large amounts of humus and nitrogen;

Youth of the vines;

Excessive irrigation or rainfall (within limits).

In deciding what system of pruning to adopt, all these factors,
together with the nature of the vine and the uses to which the fruit
is to be put, must be considered. It is best when the vineyard is
started to err on the side of short pruning. While this may diminish
slightly the first one or two crops, the vines will gain in vigor and
the loss will be made up in subsequent crops. If the style of pruning
adopted results in excessive vigor of the vines, it should be
gradually changed in the direction of longer pruning with the object
of utilizing this vigor in the production of crop.

This change should be gradual, or the risk is run of injuring the
vitality of the vines by one or two excessively heavy crops.
Finally, each year the condition of the individual vine should
determine the kind of pruning to be adopted. If the vine appears weak,
from whatever cause, it should be pruned shorter or given less spurs
or fruit canes than the year before. On the contrary, if it appears
unnecessarily vigorous, more or longer spurs or fruit canes should be
left. Every vine should be judged by itself. It is not possible to
give more than general directions for the pruning of the whole
vineyard. It cannot be well pruned unless the men who do the actual
pruning are capable of using sufficient judgment to properly modify
their me