Training
Training of kiwi vine is very important,
requiring constant attention. The main aim of training is to establish and
maintain a well-formed framework of main branches and fruiting arms. Training
also facilitates soil management, spraying and harvesting properly.
The supporting branches should be erected even
before planting the vines or thereafter as early as possible. Three types of
supporting structures (fences) are constructed.
A single wire fence is commonly adopted though
another wire is sometimes provided by some growers and then structure takes the
form of kniffin system. One 2.5mm thick tensile wire is strung on the top of
pillars which are 1.8–2.0m high above the ground. The pillars are made of wood,
concrete or iron and are erected at a distance of 6m from each other in a row.
The wire tension at installation should not be over-strained otherwise
wire can break at knot due to crop load.
A cross arm (1.5m) on the pole also carries two
outrigger wires. This training is known as T-bar or overhead trellis/telephone system. The
laterals arising from the main branch are trained on canopy of 3 wires.
A flat topped network or crisscross wires is
prepared to train vines on pergola
or bower system. The system is costly and difficult to manage but gives
higher yield.
T-bar
A strongly growing shoot is selected as a main
trunk to carry the vine up to the wire. The trunk is staked to provide support
and tied at frequent intervals, so that it does not twist around and grows
straight. When the vine attains a height of 2m and reaches near the wire, one
permanent leader can be allowed to grow out in each direction along with centre
wire. To achieve this, the leader can be trained one way along the wire and
suitably placed shoot can be trained in opposite direction as the second
leader. Alternately, the initial shoot can be cut just below the wire to force
the production of 2 leader growths which can be trained as leaders along the
wire.
From the permanent leaders, a system of temporary
fruiting arms 25–40cm apart is developed, at right angle along both sides of
each leader. These arms are tied down to the outrigger wires to hold them in
position taking care not to break them out at their bases.
The leader should not be allowed to twist tightly
around the wire or a restriction of sap flow in future years could result
and weaken the vine beyond constriction.
Using substantial shoots for training as leader
hasten full development of fruiting arms and the time of full production.
Growth may be relatively slow during first season but within 3–4 years the
fence should be furnished with strong leaders and fruiting arms in each
direction.
Pergola
Training of vines over a pergola is similar to
that of T-bar fence. The vines are grown as straight, single trunk until they
reach a height of 2m near the top of the structure. A single, strong, permanent
leader is then allowed to grow in each direction along the main wire.
To form the canopy of the pergola, a system of
fruiting arm is developed from the leaders at right angle to the wire. Fruiting
arms can be retained longer on pergolas and may be more permanent than on
T-bar. On more permanent fruiting arms, temporary fruiting laterals are allowed
to develop. It usually takes up to 7 years for a pergola to become fully
furnished with vine growth.
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