Florida Agricultural Experiment Station


To prune a grape vine properly, one must know what, where
and how much wood should be left. The fruit is borne on the
new growth produced from the previous season's wood and
therefore it is entirely useless to leave on the vines any wood
over a year old, except for framework. If vines are too severely
pruned an excess of wood but a small amount of fruit will be
produced. On the other hand, if insufficient pruning is done
wood production will be light and the fruit will be borne in many
small clusters and the individual berries in these clusters will
tend to be small. Consequently, a balance must be maintained
and some experience is necessary to know how much wood to
leave on individual vines. However, vines of varieties now
grown in Florida appear to carry 40 to 60 buds to good ad-
vantage. The best canes are those which are pencil size or a
little larger, on which the buds are plump and well formed,
and usually four of such canes containing 10 to 15 buds each
are left on a vine (Fig. 5). That the bearing wood may be
kept close to the main trunk, it is well to leave about three
spurs with two buds each near the center of the vine and near
the lower wire from which fruiting canes may be obtained the
following year.
 The best system of training bunch grapes in Florida is on
the familiar Munson three-wire canopy trellis (Fig. 1). The
posts are set in the rows at 16 to 24-foot intervals in such
manner that two or three vines can be planted between them.
All posts should be long enough to stand at least 51/ feet above
ground and the ones on the ends should be well braced and
somewhat larger than the others. No. 10 to No. 12 galvanized
smooth wire is suitable for trellising and 400 to 600 pounds
are required per acre. All trellis wires should be tightly stretched
to avoid sagging between posts. The lower wire, to which the
vines are first trained, should be stapled to the posts 4/2 to 5
feet or even more about the ground. Vines growing on trellises
lower than this have been found to have more disease than
those growing on higher trellises. The first season or two, de-
pending on the amount of growth, the vines are forced to grow
onto this wire by removing all lateral buds until the wire is
reached, when the terminal bud is pinched out and the two
upper laterals are forced to grow on the wire, one in each
direction.
 As soon as any considerable growth is made along the lower
wire (usually during the second season) the two upper wires