To study the training in fruit plants
Training refers to the judicious removal of plant part/parts to develop the proper shape of a plant capable of bearing a heavy crop load.
- Pruning Saw
- Bordax paste or Fungicide
Objectives of training
- To facilitate orchard cultural operations.
- To provide an attractive appearance.
- To admit more light and air to the centre of the tree and to expose maximum leaf surface to the sun
- for increasing production
- for complete colour development
- To protect the tree trunk from sunburn injury.
- To secure a balanced distribution of fruit-bearing parts on the main limbs of the plant.
Systems of training
Central Leader system:
- In this system, the main stem of the tree is allowed to grow uninterrupted.
- the first branch is allowed to grow at 45 to 50 cm height from ground level and other branches are allowed to grow on main stem at a distance of 15 to 20 cm.
- If the central leader is allowed to grow indefinitely; it will grow more rapidly and vigorously than side branches resulting in a robust close centre and tall tree. In such a tree the bearing is confined in top portion of the trees.
This system is also called as close centre, since the centre of the plant is closed and also as pyramidal system since the plant trained looks like a pyramid. This system of training is practiced in the case of certain apple varieties and pears.
Merits and demerits:
1) The main advantage of this system is the development of strong crotches.
2) Its main disadvantage is the shading of the interior of the trees. This weakens the central leader and thus shortens the life of the tree
3) Since trees are very tall, harvesting and spraying become difficult and costly.
4) The lower branches, which remain more or less shaded, become ultimately less vigorous and less fruitful.
5) Owing to the shading of the inferior, the bearing surface moves to the periphery (outer shoots) of the tree. Thus fruiting surface is reduced and eventually, yields are reduced.
6) The very high shape of the plants makes them prone to wind damage.
7) This method of training is not suitable for high altitude and hot arid places where wind velocity is high.
Open Centre system:
- In this system, when the plant attains a height of 40 to 50 cm. it is deheaded.
- From the subsequent vegetative growth, 4-5 branches well scattered, arranged, and distributed all around the main stem are selected.
- The tree, thus, trained attains less height
- In this system, the plants take a bowl
- This system of training is practiced in plums and peaches.
Merits and demerits:
1) It allows more light to reach all parts of the tree which is helpful (a) for better colour development of the fruit (b) fruiting area is spread all over the area of the trees.
2) Trees become low-headed. So, pruning, spraying, harvesting, etc., are facilitated.
3) The branches form weak and narrow crotches, which may frequently break under severe stress and strain such as bearing heavy crop and strong winds.
4) Sun scalding of central leader is also possible.
5) The branches form very close to each other all most from the same spot.
6) In this system the plants take a “bowl or vase” shape, which provides a good base for the setting of frost. So this system is not suitable for high altitude areas where frost observance is common.
Modified Leader system:
- This is intermediate between the above two systems and has the advantages of both.
- This system is developed by first training the tree to the leader type allowing the leader to grow unhampered for the first four or five years.
- After that, it is cut at a height of 120 to 150 cm. from ground level.
- On the main stem, the first shoot is selected at a height of 40 cm from the ground, and 4 to 5 branches located at a distance of 15 to 20 cm and placed all around the main stem are selected.
Merits and demerits:
1) This results in a low-headed tree with well-spaced limbs, well-distributed fruiting wood, and low height to carry out orchard operations conveniently.
This system of training is practiced in fruit plants like citrus, pear, apple