How are walnuts grown?

1. Cultivation techniques: \x0d\ 1. Planting time: Walnut is suitable for growing on warm sandy loam and black loam with deep soil layer and good drainage, and is suitable for planting on sunny slopes and leeward places. To develop walnuts in barren hills, we must first build terraces, dig large fish scale pits and do a good job in soil and water conservation. Planting time: early planting in spring after soil thawing, early planting in autumn after defoliation and early planting after soil freezing, and early planting in autumn before soil freezing after defoliation. In arid areas in spring, autumn sowing has a higher survival rate than spring sowing. The second spring sprouted early and grew strong. Seedlings planted in autumn should be ridged to prevent drainage. Methods: The trunk of seedlings was bent into an arch to fix the soil, and the trunk was not exposed. The next spring, I broke through the ground and straightened the trunk. \x0d\ 2。 Planting method: the taproot of walnut seedling is very long, and the pit depth and width are 0.8- 1 m respectively. First, fill the topsoil and base fertilizer at the bottom of the pit, about 20 cm away from the pit surface. When planting, use scissors to cut off the seedlings with soaked roots and fully absorbed water, put them in the into the pit vertically, spread the roots around, then fill them until they are flush with the ground, then fill them with water and seal them. \x0d\ II。 Pruning: \x0d\ Pruning is a very important cultivation technique for early fruiting, high and stable yield of walnut. The pruning period of walnut is different from that of ordinary fruit trees. This is done after the fruit is picked and before the leaves turn yellow. In North China, it is best to prune between "White Dew" and "Cold Dew". Pruning at this time, although the temperature is low, the wound heals slowly, but the nutrient loss is less. Young trees can be pruned early because they have no fruit, and they can start from the "Summer Festival". Spring pruning is generally carried out around the "long summer". It's too late, because the branches and leaves are too big and consume too many nutrients, which is not conducive to the growth of trees. \x0d\ 1。 Pruning of young trees: it is mainly to cultivate the tree skeleton, lay a good foundation, expand the crown quickly, and promote early fruiting and high yield. The tree shape of walnut is generally sparse and scattered, natural and happy. \x0d\ (1) Sparse layer dispersion: the central dominant tree is obvious, with 5-7 main branches in 2-3 layers, so the tree has many branches, large crown and high yield. The key point of plastic surgery is to set the stem height at 1.5-2.5 meters, the soil condition is poor, the stem should be kept low, and the position and direction of main branches should be properly configured. The main branch spacing1-1.5m should not be too close. The first of the three main branches of the base is about 1.5m away from the main branch. If it is too close, it will form a door side, and the branch spacing around the crown should be reduced. Attention should be paid to maintaining the growth advantages of major central branches. Under normal circumstances, you can't change your head easily, which is an important feature different from other fruit tree pruning. \x0d\ (2) Natural joy: the central main stem is not obvious, and it has 2-3 main branches, showing a 2-fork or 3-fork structure. In order to accelerate the crown expansion of young walnut trees, increase the number of branches and achieve early fruiting and high yield, summer pruning and autumn pruning can be adopted to promote more lateral buds to sprout new branches. In summer, when the growth of broken branches comes to an end, cut off the top 2-3 buds from the developing branches over 50 cm to promote the germination of lateral buds, enrich branches and increase the number of branches in the coming year. In autumn, the unfinished part at the top of the elongated developing branches or one-third to one-quarter of the branch length is cut off and cut on the plump outer buds in the middle and upper parts, so that the crown of the tree is expanded year by year and more developing branches are extracted. 1 year-old thin and weak branches that are too dense can be cut off appropriately. \x0d\ 2。 Pruning of fruiting branches: The top buds of fruiting mother branches of walnuts are mixed flower buds, so pruning is generally not allowed every time. Prune only dense twigs, dead branches, diseased branches and overlapping branches to make ventilation transparent and promote the growth of fully robust fruiting and developing branches. \x0d\ (1) Pruning of fruiting mother branches: robust branches that grow around the crown 1 year are usually fruiting mother branches in the second year, and are generally not short-cut. However, if there are too many mother branches, the crown will be closed, which will affect ventilation and light transmission. Proper removal of some fine fruiting mother branches can stabilize the yield and promote the normal development of trees. \x0d\ (2) Pruning of extended branches: For 15-30-year-old trees in full fruit, the 1 year-old extended branches extracted from the top of each group of main branches outside the crown can be shortened at 2-3 buds below the terminal buds. If the top branch is not full, it can be cut off at the full bud to expand the crown and increase the fruiting position. \x0d\ (3) Pruning of tendrils: Most tendrils are sprouted from hidden buds on trunk branches with cavities, which are more common in mature trees and aging trees. In the past, it was mostly cut from the base, which was called "chamber cleaning". In recent years, we have begun to use the fruits of long branches. According to the experience of Hebei, Shandong and other provinces, according to the growth position and growth intensity, the long branches in the open part of the inner chamber can be shortened by one-half to one-third, and fruiting branches can be formed after 2-3 years, which can supplement the gap, expand the fruiting range and achieve the purpose of three-dimensional fruiting. \x0d\ (4) Pruning of drooping branches: retract at the bifurcation, and at the same time cut off the trunk branches of pests and diseases, and cut off the drooping branches that are too dense year by year. \x0d\ Walnut is a deep-rooted fruit tree, which needs deep and fertile soil and likes warm and humid climate. It is a semi-positive plant, and its pH value is 5.5 ~ 7.0, and 6 ~ 7 is the best. It is planted in low mountains with an altitude of 300 ~ 700 meters, with high and stable yield. The propagation of Carya cathayensis mainly depends on sowing and seedling raising. Can also be cut, roots or branches 1 ~ 2 years old. Transplanting and planting can be carried out after defoliation in autumn and before germination in the following spring, but planting in spring should be done sooner rather than later.