The role of young tree pruning
Navel orange trees from planting to production 1~3 years are called saplings. The pruning amount of navel orange young trees should be light, and appropriate pruning should be carried out on the basis of plastic surgery to promote the appearance of spring shoots, summer shoots and autumn shoots, so as to form fruiting crowns as soon as possible.
Young tree pruning method
1. Short-cut extension branch method: After the navel orange saplings are planted, in late May, when the spring shoots are mature, the weak parts of the extension branches are short-cut, so as to promote branching and extract more robust summer shoots. Summer pruning is carried out in the middle and late July. Generally, after 5~7 effective buds are reserved, the elongated branches are cut off to promote more and stronger autumn shoots and expand the crown. The direction and growth potential of extended branches are adjusted by the selection direction and degree of cutting buds.
2. Long branch coring method in summer and autumn: For young trees that have not been harvested, long branches in summer and autumn can be used to cultivate backbone branches and expand the crown. For the vigorous summer and autumn shoots, 5~8 leaves can be left for coring when the tender leaves are first displayed. By engaging in the heart, it can promote its growth, mature early and promote the next bud. After coring for many times, adding branches is beneficial to the growth of branches, expanding the crown and accelerating the formation of trees. However, the mother branches of autumn shoots released 1 year before production cannot be topped, so as not to reduce the flower quantity in the following year.
3. Bud-thinning method: When young navel oranges are pruned in spring, summer and autumn, they are pruned according to the principle of "three divided by one and five divided by two". At the same time, attention should be paid to thinning out the long branches and the transverse branches in the short crown that disturb the tree shape.
4. Method of thinning useless branches: The pruning amount of navel orange young trees should be light, and appropriate branches should be kept as auxiliary branches as much as possible. At the same time, a small number of dense weak branches are properly thinned, useless branches such as pests and diseases are cut off, and tree branches are disturbed to save nutrients and help to expand the crown.
5. Bud thinning method: the young navel orange tree has a weak crown and nutrition does not run. If it blooms and bears fruit too early, it will affect the growth of branches and is not conducive to the formation of crown. Therefore, the young navel orange trees should be plucked within 2~3 years after planting. After three or four years, only the young navel orange trees can bear fruit on the auxiliary branches in the lower part of the crown, but the buds on the main branches and auxiliary branches still need to be removed to ensure the further growth of the young navel orange trees, expand the crown until the ideal tree shape is reached and the crown is basically formed.
The pruning purpose of the first navel orange tree:
Navel orange trees begin to bear fruit 3~4 years after planting. At this stage, the young navel orange tree grows and bears fruit. Production should focus on growth, constantly expand the crown, so that the period will enter the full fruit period as soon as possible.
Pruning method of first-fruit navel orange tree;
1. Method of promoting spring shoots: As navel orange young trees enter the fruiting period, the spring shoots in the middle and lower part of the crown gradually transform into fruiting mother branches, and the spring shoots in the upper part are new base branches. Therefore, for the spring shoots in the middle and lower part of the crown, except the tender shoots, the rest should be kept as much as possible to let them bear fruit. For the spring shoots at the upper part of the crown, the peripheral main branches, secondary branches, extended branches of lateral branches and long branches of autumn shoots can be appropriately shortened during the germination period of spring buds, and the dense branches and weak vegetative branches at the same node can be thinned, and the buds at the upper part of the crown can be removed to promote strong spring shoots, so as to prepare for pruning and promoting branches in summer and continuing crown expansion. In winter, the fruiting branches and fruiting branches can be shortened by 1/3~ 1/2, so that the strong branches can be shortened and the weak branches can be shortened. After short cutting, robust spring shoots can be produced in the second year, and then summer shoots and autumn shoots will continue to be produced, becoming good fruiting mother branches.
2. Wipe summer shoots: For trees with more fruits, in order to prevent aggravating physiological fruit drop and alleviate the contradiction between growth and fruiting, summer shoots should be wiped in time from May to July. Usually erase 1 time in 3~5 days until the tip is cut in summer; For trees with few fruits, 5-8 leaves should be reserved at the beginning of the young leaves of long branches in summer and autumn for coring, so as to promote their vigorous growth, early maturity and promote the next branch. After many times of coring treatment, branches can be increased, crown can be expanded and trees can be accelerated. When the vigorous summer and autumn shoots sprout more, the robust summer and autumn shoots with the number of 1/3 can be cut short in winter, and 2~3 buds are left at the spring stage or base to germinate and prepare branches. Leave 1/3 summer and autumn shoots with moderate growth as fruiting mother branches to make them blossom and bear fruit. Prune 1/3 weak summer and autumn branches, reduce the number of fruiting mother branches and flowers, and save tree nutrients.
3. Autumn shoot storm method: Autumn shoot is the main fruiting mother branch of navel orange saplings. From the end of June to the beginning of July, the young navel orange trees with the first fruit should be reapplied with the fertilizer of strengthening fruit and promoting bud. In late July, 3~4 effective buds were left on the oblique and thick spring shoots outside the crown, and then they were cut short. For navel orange young trees with strong tree potential and many fruits, we can choose a single top fruit branch at the periphery of its crown, leave 3~4 effective buds at the base of the fruit branch, cut off the young fruits and change the tips with the fruits. In this way, after the young navel orange trees take measures to storm the autumn shoots, they can promote a sufficient number of strong autumn shoots as excellent fruiting mother branches in the second year.
4. Continue to cut short and stretch branches: When pruning navel orange trees, stretch the main branches and lateral branches at an angle of about 70, and those with strong growth can be pulled horizontally and those with particularly strong growth can be pulled down to weaken the top advantage. At the same time, cut off the weak part of the tip of the extension branch, promote the bud germination of the lateral branch tree or the base, cultivate the bearing mother branch in the inner cavity and the middle and lower part, and increase the bearing capacity.
Pruning navel orange trees in full fruit period:
Spring pruning method
1, denucleation of spring shoots: The new shoots in Wang Changchun were denucleated from March to April, which weakened the growth, eased the conflict between new shoots and fruits for nutrients, and improved the fruit setting rate.
2. Drain the inner branches of the crown: for closed trees, according to the crown size, drain the middle or left and right branches of 1~2, and open the skylight, which can not only control the flourishing growth, but also improve the lighting conditions in the crown and give full play to the fruiting ability of branches in various parts of the crown.
3. Dense and weak branches outside the crown: Dense branches outside the crown 1 branch should be thinned according to the principle of "three to one and five to two". According to the branch spacing of 10~ 15 cm, the weak branches are removed and the dense branches are sparse, so as to improve the lighting conditions of the tree and give full play to the fruiting ability of branches in different parts of the crown.
4. Appropriately understand the strong branches outside the crown: cut the strong branches outside the crown, promote branching, and form fruiting branches. At the same time, by cutting off the strong branches, improving the illumination conditions of the inner cavity of the crown, cultivating the inner cavity branches, and making the crown bear three-dimensional fruits from top to bottom.
5. Take back the long branches: The long branches of the navel orange fruit tree are about 40 cm long, which will disturb the crown and consume nutrients. For long branches, pruning can be carried out according to different positions: if long branches are on big branches, there is no need to use space and reserve, and they should be thinned from the base as soon as possible; If the long branches are suspended in the crown, and the position is suitable and valuable, they should be shortened by 20 cm to promote new shoots. Through retraction and pruning, branches are promoted, lateral branches are formed, gaps are filled, fruiting branches in the crown are formed, and a compact crown is cultivated; Generally speaking, it is not advisable to prune the long branches that grow on the last branch, and they can be picked before stopping growth and cultivated into fruiting branches.
Summer pruning method
1. Wipe summer shoots: from late May to early July, wipe summer shoots in time, 1 time every 3-5 days to prevent summer shoots from sprouting in large numbers and wash off fruits, which is beneficial to fruit preservation.
2. Pruning and closing branches: For navel orange trees with depressed crown, small side branches of 1~2 dense parts can be pruned in the middle and late July, and "small window opening" can be implemented to improve the lighting conditions of the crown, cultivate the fruiting branches of the crown, prevent premature aging of the tree and prolong the fruiting period.
3. Shoot control to promote flowers: September -65438+ 10, twist strong branches. The method is as follows: when the branch tip is 30 cm long and not lignified, twist the branch tip in the opposite direction of growth from 5~ 10 cm above the base of the long and strong branch tip, that is, twist it 180 degrees from the base and stuff it between the lower branches, which can control the vigorous growth of the branch tip and promote the differentiation of flower buds.
4. Promote autumn shoots: from the end of June to the beginning of July, apply strong fruit fertilizer to promote shoots. In the middle and late July, 3~4 effective buds are left for the oblique thick spring shoots and fallen flower branches outside the crown, and they are cut short to promote the development of strong autumn shoots into excellent fruiting branches in the next year.