Dwarf close planting cultivation is to use manual and chemical control methods to dwarf trees, increase the number of fruit trees planted per unit area, and greatly improve the yield per unit area. The management points of apple dwarf close planting cultivation are as follows:
1. Increase the planting density
The crown volume of apple tree grafted with dwarf rootstock is smaller than that of apple tree grafted with arbor rootstock, and the yield per plant of dwarf rootstock apple tree is lower than that of arbor rootstock apple tree. Therefore, the planting density of dwarf apple trees must be appropriately increased according to different dwarf rootstocks and different types of short-branch varieties, and reasonable close planting should be carried out. For example, M26 intermediate stock apple trees can generally plant 80- 100 plants per mu, and M7 intermediate stock apple trees can plant 50-60 plants per mu.
2. It is not advisable to use big trees with many main branches.
The high planting density of dwarf and dense apple trees leads to the limited growth space of trees, too many branches and leaves and too fast growth, which becomes the main contradiction. Therefore, it is not appropriate to use sparse trunk tree shape when pruning and shaping, but spindle shape, slender spindle shape or improved spindle shape tree shape should be adopted. No matter what kind of spindle-shaped tree, its structural feature is that it has main branches and no side branches. When pruning trees, we should pay attention to controlling the crown size and increasing the number of main branches as much as possible. Because the main branches increase and there are no side branches, it is necessary to prevent the growth potential of the main branches from being stronger than that of the central trunk, and not to make the main branches of trees grow too fast and too thick, so as not to affect the growth potential of the central trunk. The branches of each upper branch should be reduced, and the pruning method is mainly light cutting and short cutting. When pruning in winter, the extended branches of young trees can be left uncut.
3. Pay attention to timely update rejuvenation.
Dwarf close-planted apple trees have high planting density, many fruits per plant and high yield per unit area. However, the illumination conditions in orchards are not as good as those in plantations with sparse trees and rootstocks. Therefore, if the supply of fertilizer and water is slightly insufficient, trees will easily weaken. If the variety is short and the management can't keep up, the tree is more prone to premature aging. Due to the above reasons, some trees bloom to the top only after entering the full fruit period, so special attention must be paid to timely updating and pruning, and nutrition and water supply should be ensured in fertilizer and water management. When pruning, attention should be paid to adjusting the tree potential to balance it, maintaining the growth advantage of the central stem, delaying aging and prolonging the economic life of the tree.
4. Improve the lighting conditions and increase the photosynthetic efficiency of leaves.
Dwarf and densely planted apple trees have many trees, branches and leaves. Therefore, various measures should be taken to improve the light conditions and increase the photosynthetic efficiency of leaves. Therefore, we should pay attention to thinning in winter and thinning in summer when necessary. Adjust the tree structure properly in time to improve the effective leaf area coefficient, and also reduce the shading from around the orchard. To build orchards in mountainous areas, we must build orchards in sunny open areas. It is best to row north and south in a rectangular shape, and the row spacing should be larger than the plant spacing, which can prolong the illumination time and enhance the photosynthetic efficiency. After proper thinning of branches and leaves, the leaves should be prevented from premature aging or falling off to ensure that the photosynthetic efficiency is still good in the later growth stage.