Trining & Pruning in Apple

Training

             The plants are trained according to growth habit and vigour of the rootstocks. Training helps to establish a strong framework of scaffold limbs capable of supporting heavy yield with quality fruits, regulate annual succession of crops, expose maximum leaf surface to the sun, direct the growth of the trees so that various cultural operations like spraying and harvesting become economical, protect the trees from sun-burn and promote early production. The training procedures for standard and dwarf plants differ.

The standard trees are trained on modified central leader system. The ideal standard tree can be trained as:

• The plants are pruned to 50–60cm above the ground at the time of planting
• During first year, 2–3 well-spaced scaffold limbs are selected with the lowest at 30cm above the ground and others spaced vertically 10–15cm apart in a spiral fashion. The growth of the unwanted shoots is depressed by pinching 3–5cm of the shoot tips during mid-April–mid-May.
• The selected primary scaffolds during summer are headed back to one-fourth to one-fifth of the growth.
• During second year dormant pruning, the central leader and primary scaffold branches are headed back similar to first dormant pruning. More scaffold branches are retained on the trunk at the vertical distance of 45–75cm. A total of 5–7 secondary branches/tree usually two on each primary scaffold are also selected in the second dormant pruning which are directed partially outward. The primary scaffold should have the crotch angle of 45° with trunk. The proper crotch angle can be developed by tying the branches with ropes or inserting the branch spreaders.
• Third year training consists of thinning out of unwanted branches and heading back others to desirable side limbs. Secondary branches often develop spurs during third growing season.
• By fourth year, training is largely completed. By this time, the proportional growth of central leader and side scaffold branches should be attained which should be 1 : 1.5. This will help in lateral growth rather than upward growth of plants favourable for proper spur development.
• When the tree attains the height of 4–4.5m, the central leader should be headed back near to moderate side growing shoot to check the height of the plant.
  Dwarf plants are trained to spindle bush/slender spindle, i.e. one-year old plant is headed back to 45–60cm at the time of planting.
• During first summer, 2–3 laterals or feathers, 30cm from the base are selected to form main scaffold branches. The scaffolds should have wide angle and be well-spaced around the stem. Vigorous growing laterals are tied down in August when the extension growth has ceased in order to develop wide crotch angle.
• During first winter, 2–3 well-spaced laterals are retained and unwanted branches are removed. The scaffold branches are headed back to one-third to half of the length to a outward growing bud if the growth is weak. Otherwise the main branches can be left unpruned. The leader is also cut back to more or less erect but a weak lateral. Any vigorous, upright shoot, growing near the forming leader and competing with it should also be removed.
• During August of second year, suitable laterals are tied down to form more scaffold branches.
• To check excessive vigour of central leader, it may again be cut back to suitably placed weak growing lateral which is trained to take the place of the central leader. Delaying pruning until late winter also helps in checking vigour.
• During subsequent winters, branches are allowed to grow from central leader at regular intervals, choosing wide angled shoots. Higher placed branches should be kept shorter than lower ones to allow the light penetration into the lower tree canopy to the maximum extent.
• The main branches should be so trained and spaced that there is plenty of room for fruiting laterals and those should not be allowed to fork at terminal.
• In order to keep sufficient wood in the spindle bush while it is being built up, a small surplus of wide angled branches is retained, which may be cut when branches require more space and get crowded. 

Pruning

          

           Pruning in apple is essential to maintain a proper balance between vegetative growth and spur development. The basic steps of pruning standard bearing trees are:

• Start pruning at the top of the trees and work downward.
• Cut upward growing limbs back to strong lateral
• Remove the crowding branches and thin out the remaining leaving the vigorous fruiting wood well spaced along the length of limbs.
• Remove dead, broken and diseased wood.
• Remove parallel growing shoots causing crowding and shading and opposite growing shoots at a point on the stem.
• Remove all water sprouts except the occasional ones which may be needed to fill a vacant space in the canopy.
• While removing a thick branch, first small cut should be made on the underside of limb to avoid bark peeling.
• Divert branches to open areas by pruning to desirable laterals.
• The plants trained on spindle bush system can be pruned as:
• Once the central leader has reached its desirable height of 2.5m, the extension growth should be cut back each year to a weaker side branch.
• Strong growing shoots towards the top of the tree should be removed completely.
• Renewal pruning of the fruiting branches lower down should be carried out each year to maintain vegetative growth and fruit quality in lower part of the tree.
• The branches causing shade to the other lower branches should be removed or headed back.
• In thinning out of branches to main stem, a stub should be left to encourage the regrowth of moderately vigorous fruitful bud.
• Avoid removing too many branches and so reducing potential fruit yield. The main branches which have lost the vigour can be stimulated by pruning. Worn out wood of heavy cropping varieties should be removed periodically.

Precautions in pruning

• When a limb larger than 3cm in diameter is removed, the pruning cut should be made as close as possible to the branch from which the limb arises without leaving a stub.
• Large pruning wounds should be protected with Bordeaux paste or Chaubattia paste to check the entry of rot-causing fungi.
• In 1- or 2-year-old shoots, heading back can be done to promote growth of side shoots and quick wound healing. In 3-year-old and older shoots, pruning should be shifted to thinning out cuts to reduce vegetative growth and promote fruiting.
• The competing branches should be thinned out rather than headed back.