Pruning is done in terms of either light or heavy or in between depending on the type and size of fruit trees. It has many advantage and disadvantage in fruit trees. The pruning practices are done at different times by the different methods in fruit trees. This influences plant’s vegetative growth to the production and quality of fruit.
Table of Contents
Pruning Effects in Fruit Trees
The effects are –
i) Effect on the vegetative growth
Normally length of the main stem of the plant, it’s spread and the number of leaves greater in unpruned plants. Such vegetative growth is reduced to an optimum level due to pruning operation. Research report indicated that development of root is dependent on the supply & production of carbohydrate and phytohormones in leaf and bud. After pruning such supply is increased due to the development of new larger size leaf and bud. As a result, there is an increased growth and development of root. Plants are given good size and shape through this process. This helps plant keeping low headed. After this practices reduced the number of shoots and buds get more nutrient and moisture and, as a result, they become vigorous. Reduced vegetative growth favors reduced transpiration causing less water loss from the plant helps the early establishment of young seedlings.
ii) Effect on flower bud development
Flower bud initiation is delayed if pruning is done on young plants and this delay also depends on the degree of it. But pruning of older tree produces many short stronger shoots which hastens to flower in such trees and as such production is increased. Flowering is enhanced in pruned weak plants. It has been found that flowering is advanced in pruned plants due to the balance of C: N ratio. Gibberellin is produced in young leaf and bud which restricts the development of flower and inflorescence. Removal of such leaves reduces the endogenous level of gibberellin and creates a balance between gibberellins and cytokinin. This results in flowering.
iii) Effect on fruit bearing
The number of flower and inflorescence is increased due to pruning is responsible for increased fruit production. If some of the fruit-bearing places are removed through pruning rest of the places get sufficient amount of nitrogen and water causing increased flowering and fruit production. Sometimes excessive vegetative growth results in a dense canopy which restricts entry of light and air in the fruit bearing region and causes the reduction in fruit production. But through this process, fruit production is increased by ensuring entry of light and air. In some cases, total fruit production is increased due to this practices e.g., Jujube.
iv) Effect on fruit quality
It is an established fact that the quality of fruit in terms of color, flavor, taste and size is improved by pruning. Due to pruning along with increased vegetative growth supply of nutrient and water is increased which causes the increase in a size of the fruit. Fruits lose their normal color without getting direct sunlight. Shading caused by leaves and branches destroys color and this can be avoided by this practices such branches and leaves. Fruit size is increased in papaya by fruit thinning and the color is increased in apple by removing leaves and branches.
Pruning practices in Different fruit trees
The plants are allowed to grow without pruning up to 4 years of planting. After that, it is pruned following heading back method. This gives a low headed and bushy plant. Fruit bearing habit in mango is terminal. As such heading back of the stem is done after harvesting. Dried out, insect and disease infested, dead and weak branches should always be removed. It gives better results in fruit trees aged between 30 and 50. This process is done in such plants 4-4.5 months before flower initiation. Light pruning should be done in mango just after harvesting during the period from June to August.
Generally, trunk and other branches bear fruits. Therefore, these parts should not be disturbed. Just for the maintenance of strong framework side shoots should be removed. For regular bearing in Jackfruit, some root and shoot are pruned according to necessity. Dead, insect and disease infested and weak branches are removed. After harvesting of the crop, the fruit stalk is cut from its base which gives new shoot and these shoots bear fruit again. Like mango jackfruit is given light pruning just after fruit harvesting.
Training is done in young litchi plants after planting to give a strong framework. Generally, litchi bear on a new flash of growth and, for this reason, very often older stems are removed to grow new fruit-bearing shoots. Litchi plants are pruned naturally during harvesting of the crop. Trusses of fruits are harvested along with a portion of the shoot. To check excessive vegetative growth root pruning and for breaking too much bushiness some stems are removed. A severe pruning is necessary for old trees as they produce small size leaf and low-quality fruits. Generally, This practices is done in litchi during the month of May – June after harvesting.
Guava plants are naturally bushy and for that development of a strong framework is needed. For this small branches around the stem and the suckers are removed. After 2-3 years of planting when growth advances only 3-4 strong branches are allowed to grow and rest of the branches are removed. In the 3rd or 4th year, all branches growing vertically are removed to allow easy entry of air and light to the center of the plant. Horizontally placed branches should not be pruned. When a strong framework is formed after 4-5 years heading back should be done on the main stem. The water suckers must be removed. Dead, dried, insect and disease infested stems must be removed. Generally light pruning is given in guava plants during February- March except older plants.
Pruning is very much essential in jujube because of its fast growing nature. This encourages good bearing and production next year. As because jujube can tolerate excessive removal of plant parts heavy pruning is recommended for this crop. Keeping a couple of topless strong branches all other branches are cut from the base. This practices in jujube is done every year after harvesting of the crop. February – March is the best time for practicing this process in jujube. During seedling stage, it should be trained to keep a 2m trunk to bear the canopy and for that, all side shoots or branches coming out from the base or main stem should be removed.
Generally pruning in lemon is done before flowering to give the plant a strong and beautiful framework. All the side shoots and branches are removed from the main stem up to 1m above the ground. For easy entry of light and air, some sporadic branches are to be removed up to 3 years of planting. Flowering at the juvenile stage should be discouraged. Water suckers should be removed at slight because this hinders flower initiation. Generally, This practice is done in lemon during the months of September and October after harvesting of the crop. However light pruning is recommended for lime and lemon.