1. Cultivation techniques: 1. Planting time: Walnuts are suitable for growing on warm, deep, well-drained sandy soil and black loam soil, and should be planted on sunny slopes and leeward locations. To develop walnuts in barren hilly areas, terraces should be built first, large fish scale pits should be dug, and soil and water conservation should be done well. Regarding planting time, plant early after the soil thaws in spring, plant early after the leaves fall and the soil freezes, and plant early after the leaves fall and before the soil freezes. In spring drought areas, autumn planting has a higher survival rate than spring planting. The next spring germinates early and grows vigorously. When planting seedlings in autumn, the soil should be cultivated to prevent the seedlings from drying out. Method: Bend the seedling trunk into a bow shape, fix it, and cultivate the soil, mainly without exposing the trunk. In the spring of the second year, break the ground and straighten the trunk. 2. Planting method: The main root of walnut seedlings is very long. Dig a pit that is 0.8-1 meter deep and 1 meter wide. First fill the bottom of the pit with topsoil and base fertilizer, about 20 centimeters from the surface of the pit entrance. When planting, use scissors to trim the roots of the soaked seedlings whose roots have fully absorbed water, then place them vertically in the pit, with the roots extending to all sides, then fill the soil firmly until it is flush with the ground, then fill it with water and seal the soil. 2. Shaping and pruning: In order to achieve early fruiting, high yield, stable yield and reasonable pruning of walnuts, it is a very important cultivation technique. The pruning period of walnuts is different from that of ordinary fruit trees. It is done after the fruits are harvested and before the leaves turn yellow. In North China, pruning is best between "white dew" and "cold dew". When pruning at this time, although the temperature is low and the wound heals slowly, the loss of nutrients is small. Since saplings have not produced fruit, they can be pruned early, during the "summer heat" season. Spring pruning is generally carried out around the "beginning of summer". If it is too late, the branches and leaves will be too large and consume too much nutrients, which is not good for the growth of the trees. 1. Plastic pruning of saplings: The main purpose is to cultivate the tree skeleton, lay a good foundation, quickly expand the crown, promote early fruiting, and early high yield. The tree shapes of walnuts are generally sparsely dispersed and natural open-shaped. (1) Sparse-layered scattered shape: The central leader tree is relatively obvious, with 5-7 main branches divided into 2-3 layers. In this way, the tree shape has many branches, a large crown, and high yield. The focus of shaping is to set the trunk height to 1.5-2.5 meters. If the soil conditions are poor, the stem should be kept low, and the position and direction of the main branches should be properly configured. The distance between the main branches is 1-1.5 meters, and cannot be too close. The first side branch of the three main branches at the base is about 1.5 meters away from the main trunk. If it is too close, it will form a gate. The distance between the side branches should be narrowed toward the periphery of the crown. Pay attention to maintaining the growth advantage of the central leading branch. Under normal circumstances, the head cannot be changed easily, which is an important feature different from other fruit tree pruning. (2) Natural open-shaped shape: The central leading trunk is not obvious, with 2-3 main branches, with a 2- or 3-fork structure. In order to accelerate the expansion of the crown of walnut saplings, increase the number of branches, achieve results and early high yields, summer planting can be used The methods of pruning and autumn pruning promote more lateral buds to sprout new branches. During summer pruning, when the growth of broken branches is about to end, cut off the top 2-3 buds of developing branches over 50 cm in order to promote the germination of side buds and the enrichment of branches, and increase the number of branches in the coming year. Autumn pruning is carried out before the leaves fall. Cut off the unfulfilled top part of the outer-extended developing branches or one-third to one-quarter of the branch length, and make the cut on the full and plump outer buds in the middle and upper parts, so as to expand the crown year by year and produce more developing branches. . Thin and thin branches that are too dense in one year can be appropriately pruned. 2. Pruning of fruit-bearing branches: The top buds of walnut fruit-bearing mother branches are mixed flower buds. Generally, they should not be cut off. Only densely grown thin branches, dead branches, diseased and insect-infested branches, and overlapping branches should be cut off to allow ventilation and light transmission, and promote full growth and fruiting. Strong fruiting mother branches and developing branches. (1) Pruning of fruiting mother branches: The strong branches that have grown in the outer part of the crown for one year are often the fruiting mother branches of the next year. Generally, they are not pruned short. However, when there are too many fruiting mother branches, it will cause the crown to be closed, affecting ventilation and light transmission. Appropriate pruning is required. Thin out some weak fruit-bearing mother branches to stabilize yield and promote normal tree development. (2) Pruning of extension branches: For 15-30-year-old trees in full fruiting period, the 1-year extension branches that emerge from the top of each group of main branches on the periphery of the crown can be shortened 2-3 buds below the terminal bud, such as the top If the branches are not full, they can be cut at the full buds to expand the crown and increase the fruiting area. (3) Pruning of leggy branches: Leggy branches are mostly formed by the germination of hidden buds on the inner trunk branches. They occur more frequently on vigorously growing adult trees and senescent trees. In the past, they were usually cut off from the base, which is called "clearing the trunk". . In recent years, leggy branches have been used to produce fruit. According to the experience of Hebei, Shandong and other provinces, the leggy branches with hollow parts can be cut short at one-half to one-third of the branches with full buds, depending on the location and growth strength. The branches can be cut 2-3 years after It can form fruiting branches, fill the gaps, expand the fruiting range, and achieve the purpose of three-dimensional fruiting. (4) Pruning of drooping branches: Retract at the bifurcation, and cut off dry and diseased branches at the same time. Overly dense drooping branches should be cut off year by year. Treatment measures after frost damage to walnut trees

After frost damage to walnut trees, antifreeze measures must be taken as soon as possible to avoid affecting the yield and disease occurrence in the coming year.

1. Trunk protection

(1) For walnut trees with level 4-5 frost damage, in order to prevent the aggravation of frost damage and the occurrence of rot diseases, tree protector paint or general paint should be applied immediately. Carry out tree trunk whitening work.

(2) After the snow, the snow around the trunk should be cleared in time. After the ground temperature rises and the ground surface thaws, a plastic film of about 1 square meter should be laid with the trunk as the center for trees under 4 years old.

2. Fertilize and water

(1) Fertilize and water once immediately after the soil thaws and before germination (early to mid-March).

Use the ring or radial fertilizing ditch method. Apply 50kg of organic fertilizer and 1-2kg of urea to large trees; apply 0.2-0.5kg of urea to young trees. Water immediately after fertilization. After the leaves unfold, the tree body is sprayed with a mixture of 0.1-0.3% urea and potassium dihydrogen phosphate for top dressing outside the roots.

(2) After the soil thaws, the tree trays should be loosened as soon as possible, and where conditions permit, the forest land should be plowed and loosened comprehensively.

3. Timely pruning

(1) For trees with frost damage above Level 2, before the buds sprout and the leaves unfold (from mid-to-late March to mid-April), distinguish the frost-damaged parts of the branches. , perform timely and moderate pruning. Cut off the dead parts of the branches, and smear and disinfect the cut with 3-5 degrees lime sulfur mixture or 50% thiophanate methyl wettable powder. The cut branches are transported out of the forest and burned together.

(2) In early and mid-May, select and retain the budding branches and new branches on the pruned branches. Select and cultivate new backbone branches and fruiting branch groups, and prune back branches, upright branches, overly dense branches, cross branches, etc. to restore tree vigor and shape as soon as possible.

(3) In mid-to-late May, the whole upper part of the ground is frozen to death of the saplings and the grafted parts of the trees, and the sprouting new branches on the branches are selected and retained, and the new ones are selected and cultivated. The trunks of saplings and new branches need to be grafted. Cut off other sprouting branches and new branches for summer bud grafting.

4. Prevention and control of rot disease

(1) Walnut trees are prone to secondary disease - rot disease after freezing damage. In early spring (early to mid-April), prevent and treat rot in time as soon as it is discovered:

Scraping out the rot: Use a sharp blade to scrape off the rot, making the scraping shape into a "long shuttle" shape, with smooth and complete edges. Scrape off a 0.5cm wide intact cortex starting from the lesion. Do not leave any lesion tissue behind.

Apply: Use Tree Protector or 50% thiophanate methyl wettable powder 50 times liquid or 50% antibacterial wettable powder 50 times liquid, or 5-10 baume lime sulfur Mix the mixture, apply it to the scraped wound to disinfect it, and then apply Bordeaux liquid to protect the wound.

5. Scratch protection

After applying the medicine to the scrape, wrap the scrape with a strip of cloth or dark plastic strip to facilitate wound healing. Collect the scraped disease tissue together and transport it out of the forest to be burned. Do not leave the scraped disease tissue in the forest. The prevention and treatment of rot diseases should be "scratching early, scraping small and scraping".