e unpruned vine shows two
arms, the spurs of the previous year, from one of which have grown
three vigorous canes and from the other two somewhat less vigorous.
The pruned vine shows a complete unit, that is, a fruit cane with its
accompanying renewal spur on the vigorous side and a spur for the
production of fruit wood for the following year on the other side. If
the vine had been more vigorous two complete units would have been
left and one or two extra spurs.

As the form of the vine is determined by the renewal spurs, special
attention should be paid to their position. In this case, the middle
cane on one arm and the lower cane on the other have been used for
renewal spurs. This brings them both to the same height above the
ground and determines the place of the permanent arms. The next year
each of these spurs will furnish a fruit cane and one or two renewal
spurs. The arms will thus in two or three years be increased to four,
or, with very large vines, to six. These spurs should be chosen as
nearly as possible in the plane of the trellis, that is, they should
not project out sideways. Figure 25 shows vines of this kind of full
size and in full bearing.

The fruit canes also should be as nearly as possible in the direction
of the trellis, though this is not so important, as they can be bent
over to the wire when tied up, and in any case they are removed the
next year.

_Double-headed vines._

Some growers attempt to arrange the arms of their vines in two stages,
one above the other, forming double-headed or two-crowned vines. The
method is applied to both vase-formed and trellised vines. It is open
to the same criticisms as the vertical cordon, the chief of which is
that it cannot be maintained permanently. The lower head or ring of
arms finally becomes weak and fails to produce wood.

It is easier to maintain in trellised vineyards and has some
advantages, the chief of which is that it makes it easier to keep the
vine in the single plane and to prevent arms getting into the
inter-rows. The double trunk is not necessary and is, in fact, a
disadvantage, as one trunk has a tendency to grow at the expense of
the other.

_Vertical and bowed canes._

Figure 24 A shows a long-pruned vine in which the fruit canes have
been tied vertically to a tall stake. This is a method used commonly
in many vineyards. The unit of pruning is the same as in the method
just described, consisting of a fruit cane and a renewal spu