I. Soil management
1, soil deep ploughing: In autumn, the soil should be deeply ploughed after the trees have fallen leaves and before the soil is frozen. The general depth is 20 ~ 25 cm.
2. Tree-making tray: take the trunk as the center, repair the tray, and build a ridge to store water. Generally, it is a semi-circular or circular square tree disk with a diameter or side length of 1 ~ 2 meters, depending on the crown size and topography. The purpose is to store water and conserve moisture, improve soil and improve soil fertility.
3. Re-application of base fertilizer: mainly use decomposed organic fertilizer, and apply it as early as possible during the period from fruit harvesting to defoliation (with deep ploughing). Fertilization amount is 25-50kg/plant for young trees, 50-100kg/plant for trees in early fruit period and 200-250kg/plant for trees in full fruit period.
4. Pouring frozen water: Before the soil is frozen, you can pour frozen water according to the soil moisture and planting conditions.
Second, shaping and pruning
Walnut trees can be pruned except in winter dormancy period. However, it is the best pruning time for walnut trees from harvest to defoliation, and pruning at this time will not bleed.
1, pruning period
Pruning walnut trees after defoliation often leads to bleeding and is generally not suitable for pruning; The most suitable pruning period is autumn, which is beneficial to the early healing of wounds in that year. Young trees do not bear fruit, and can start from the end of August in advance. It is suitable for adult trees to start after fruit picking 10 months and before leaves turn yellow. 、
2. Young tree shaping
Walnut trunk is stout, and the advantage of terminal bud is particularly obvious. The development of terminal buds is fuller and fuller than that of lateral buds, and the crown layering is obvious. Combined with this feature, the shape of sparse layer of trunk is more suitable and easy to form. The shaping method is as follows: the height of the stem is 80 ~ 100 cm (if the height of the seedling is not enough in that year, it can be shaped after the seedling grows for one year), the trunk is straightened in the planting year, and the terminal bud is protected (if the terminal bud is damaged, it can be replaced with a strong bud first). After germination in spring, the terminal bud will grow upright and take it as the central stem, accounting for 5 ~ 10% of the lower part of the terminal bud. In the second year, the second layer of main branches is also cultivated, and 2 ~ 3 main branches are left in the second layer (60 ~ 80 cm away from the first layer). In the third year, the main branch of the third layer is selected, and the main branch of 1 ~ 2 is reserved, which is 50 ~ 70 cm away from the second layer. 1 ~ 4 years, the main branches do not need pruning, and they can naturally branch and expand the crown. It usually takes 3 to 4 years to form, and the height of the tree is about 4 to 6 meters when it is formed. When the tree height reaches more than 6 meters, it should be capped at 5.5 ~ 6 meters, and the tree height should be controlled at about 6 meters.
In the case of thin soil layer, high planting density, early maturity of varieties and large slope, natural open-heart shaping and pruning can also be used. Natural pistachios are simple in shape, easy to shape and trim, and have stronger ventilation and light transmission ability than evacuation layered shapes. Generally, there are three main branches and two main branches, including trunk, main branches, lateral branches, secondary lateral branches and fruiting branches. There is no central trunk, and each main branch is equipped with 2 ~ 4 lateral branches.
Step 3 prune fruit trees
Walnut has entered the full fruit stage, the crown is still expanding, and the number of fruiting parts is increasing, which is prone to the contradiction between growth and fruiting. Ensuring high and stable yield of walnuts is the main task of pruning in this period. Therefore, in pruning, we should always pay attention to make good use of auxiliary branches and long branches, cultivate good branches, and deal with back branches and drooping branches in time. From the initial stage of fruiting, it is necessary to cultivate strong fruiting branches in a planned way, constantly increase the fruiting parts and expand the fruiting area. Prevent the cavity of the crown from becoming empty, causing the parts to move outward. After entering the full fruit stage, it is necessary to strengthen the cultivation and rejuvenation of branches. Can the Culture Section use it? Put it first and then shrink it? And then what? Remove the back branches, leaving the oblique branches and back branches? The pruning method of. Generally, no long branches are left at the beginning of the fruit, so as not to disturb the tree. The back branches should be controlled in time during the full fruit period so as not to affect the main branches and fruiting mother branches. The drooping branches are not full, the fruiting ability is poor, and only nutrients are consumed. The specific situation is specific.
Third, pest control.
There are many kinds of pests and diseases on walnut trees, and the wintering period in autumn and winter is also an important period for control. Grasping this season for prevention and control can get twice the result with half the effort. The main pests of walnut trees in Shangluo, Shaanxi Province are: walnut trees, walnut caterpillars, longicorn beetles, walnut caterpillars and so on. The main diseases are walnut rot, walnut canker, walnut branch blight, walnut black spot and walnut anthracnose. In autumn and winter, most diseases and insect pests go into dormancy and overwinter in hidden places such as cracks in bark, litter, fruit drop and soil. And this season can be used for centralized control.