ruit shoots and obtain the light and air they need for their proper
development. This method is used successfully for certain wine grapes
such as Riesling, Cabernet, and Semillon. It is unsuited to large
vigorous varieties or for vines on rich soil planted wide apart. In
these cases two fruit canes are usually insufficient and, if more are
used, the grapes and leaves are so massed together that they are
subject to mildew and do not ripen evenly or well. The bowing and
tying of the canes requires considerable skill and care on the part of
the workmen.

The body, arms, and annual pruning of the system shown in Fig. 25 are
similar to those of Fig. 24, with the exception that the arms are
given a fan-shaped arrangement in one plane. It differs in the
disposal of the fruit canes, which are supported by a trellis
stretching along the row from vine to vine.

This method is largely used for the Sultanina (Thompson's Seedless),
and is the best system for vigorous vines which require long pruning,
wherever it is possible to dispense with cross cultivation. It is also
suitable for any long-pruned varieties when growing in very fertile
soil.

Figure 26 is a photograph of a four-year-old Emperor vine,
illustrating the vertical cordon system. It consists of an upright
trunk 4-1/2 feet high with short arms and fruit spurs scattered evenly
and symmetrically from the top to within fifteen inches of the bottom.
This system is used in many Emperor vineyards in the San Joaquin
Valley.

[Illustration: FIG. 26. Single vertical cordon with fruit spurs.]

Its advantages are that it allows the large development of the vine
and the large number of spurs which the vigor of the Emperor demands,
without, on the one hand, crowding the fruit by the proximity of the
spurs or, on the other hand, spreading the vine so much that
cultivation is interfered with. It also permits cross cultivation.

One of its defects is that the fruit is subjected to various degrees
of temperature and shading in different parts of the vine and the
ripening and coloring are often uneven. A more vital defect is that it
cannot be maintained permanently. The arms and spurs at the top of
the trunk tend to absorb the energies of the vine and the lower arms
and spurs become weaker each year until finally no growth at all is
obtained below. After several years, most of the vines therefore lose
their character of cordons and become simply headed-vines with
abnormally long