First of all, the variety determines the future sales, which is certain. At present, the important new varieties of apple seedlings in China are Liuli, Qincui, Qinmi, Yanfu 10, Jinxingjin, and traditional fine varieties such as Honggala, Wanglin and Gongmei Fuji, all of which have strong adaptability. As long as you adapt to your local climate and have strong sales channels, the benefits of planting dwarf apple seedlings are still considerable.
It is not enough to have good varieties, but also good seedlings. The future may be a market environment dominated by dwarf seedlings. At present, China is still mainly planting arbor seedlings. Due to different production conditions, some areas with fertile soil gradually began to plant dwarf apple seedlings, with the aim of increasing the yield per unit area, reasonably controlling the load of apple trees and improving the commercialization of fruits. That is to say, the purity of dwarf apple seedlings has always been a concern of everyone.
Why say three years? Because the apple seedlings dwarfed by the middle rootstock are standard 3-year-old seedlings, it is not excluded that there are fast-growing seedlings in the market. The difference between fast-growing seedlings and standard seedlings is that they are eager to graft and rush out of the nursery. When the rootstock and scion are not completely synchronized, the second grafting begins. Under normal circumstances, dwarf rootstocks are planted in the spring of 20 18 and grafted in the spring of 20 19.
Key points of cultivation and management of dwarf apple trees
1, the crown area is small, so the planting density should be increased.
Under the same cultivation and management conditions, the crown volume of dwarf apple trees is smaller than that of rootstock apple trees, and the yield per plant is lower than that of rootstock apple trees.
Dwarf apple trees (including short-branch varieties) can not give full play to the high-yield advantages of dwarf trees if they are planted thinly like arbor apple trees, and their yield per unit area will be lower than that of arbor apple trees. Therefore, in order to plant dwarf apple trees, it is necessary to appropriately increase the planting density and carry out reasonable close planting according to different dwarf rootstocks and different types of short-branch varieties. 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. Dwarf apple trees should not use trees with three main branches and a cross at the base. More main branches.
Dwarf apple trees, with high planting density, should not adopt the tall tree shape with sparse trunk and multi-layer main branches, but adopt spindle shape, slender spindle shape or improved spindle shape. Whether spindle-shaped or slender spindle-shaped, the contradiction between limited growth space and the increase and rapid growth of plant branches and leaves is the main contradiction of dwarf and dense planting apple trees.
No matter what kind of spindle-shaped tree, its structural feature is that it has main branches and no side branches. In the process of shaping and pruning, we should pay attention to controlling the size of the crown. The number of main branches should be increased. Because there are many main branches and no side branches, it is necessary to prevent the growth potential of the main branches from being stronger than that of the central trunk. Don't let the main branches of trees grow too fast and too thick, which will weaken the growth potential of the central trunk. The branches of the main branches should be reduced, and the pruning method should pay attention to light cutting. When pruning in winter, the main branches of young trees can be lengthened, but not shortened.
3. Trees are weak easily, so we should pay attention to renewal and rejuvenation.
Dwarf and close-planted apple trees have high planting density, and the illumination conditions in orchards are not as good as those in sparse orchards. There are many fruits per plant and high yield per unit area. Therefore, if the supply of fertilizer and water is slightly insufficient, the tree vigor will be weakened easily, and if the varieties are short-branched, the management can't keep up, and it is more prone to premature aging. For the above reasons, some trees bloom to the top only after entering the full fruit period, so special attention must be paid to renewal and pruning. In fertilizer and water management, to ensure the supply of nutrition and water, Ribelli Bird's Nest water-soluble fertilizer and foliar fertilizer should be applied. 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.
There are many plants, branches and leaves.
Another feature of dwarf and densely planted apple trees is that there are many trees per unit area, and the total number of branches and leaves in the whole garden is much higher than that in sparsely planted apple orchards. The growth conditions of branches in the whole garden are poor, and the growth area of each tree is limited. When the number of leaves in a tree exceeds a certain limit, the leaves will inevitably shade each other, which will seriously affect the light in the canopy, and the organic nutrition synthesized by leaves through photosynthesis will be reduced, which is not conducive to the growth and flowering of the tree. Therefore, various measures should be taken to improve the light conditions and increase the photosynthetic efficiency of leaves.
Therefore, when necessary, we should pay attention to more thinning in winter and less thinning in summer, adjust the tree structure in time and improve the effective leaf area coefficient. Shading around orchards should be reduced, orchards should be built in mountainous areas and orchards should be built in sunny open areas; It is best to plant in rectangular rows in the north-south direction, and the row spacing should be greater than the plant spacing to prolong the illumination time and enhance the photosynthetic efficiency; After properly thinning the branches and leaves, it is necessary to prevent the leaves from aging or falling off prematurely to ensure photosynthesis in the later growth stage.