How to grow walnuts in clay fields
I. Cultivation techniques:
1. Planting time: Walnut is suitable for growing on warm sandy soil and black loam with deep soil layer and good drainage, and is suitable for planting on sunny slopes and leeward. 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.
2. Planting method: the taproot of walnut seedlings 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.
Second, plastic trimming:
It is an important cultivation technique to make walnut bear fruit early, high and stable yield and reasonable shaping and pruning. 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.
1, young tree pruning: mainly to cultivate tree skeleton, lay a good foundation, quickly expand crown, and promote early fruiting and high yield. The tree shape of walnut is generally sparse and scattered, natural and happy.
(1) Sparse layer dispersion: the central dominant tree is obvious, and 5-7 main branches are divided into 2-3 layers, so that there are many branches in the tree, the crown is large and the yield is high. The key points of plastic surgery are: setting the height of trunk 1.5-2.5 meters, poor soil conditions, keeping trunk low, and rationally allocating the position and direction of main branches. 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.
(2) Natural joy: the central main stem is not obvious, with 2-3 main branches in a 2-fork or 3-fork structure. In order to accelerate the crown expansion of young walnut trees, increase the number of branches, and realize fruit setting and early high yield, summer pruning and autumn pruning can be used 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.
2. Pruning of fruiting branches: The top bud of the fruiting mother branch of walnut is mixed flower bud, so it is generally not allowed to prune every branch, only the dense twigs, dead branches, disease and insect branches and overlapping branches are pruned, so as to make ventilation transparent and promote the growth of fully robust fruiting mother branches and developing branches.
(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 cut short. However, if there are too many fruiting mother branches, the crown will be closed, which will affect ventilation and light transmission. Therefore, it is necessary to prune some fine fruiting mother branches appropriately to stabilize the yield and promote the normal development of the tree.
(2) Pruning of extended branches: For the 15-30-year-old trees in full fruit, the 1 year-old extended branches extracted from the top of each main branch outside the crown can be cut short 2-3 buds below the terminal bud. If the top branches are not full, they can be cut off at the full buds to enlarge the crown and increase the fruiting parts.
(3) Pruning of long branches: Long branches are mostly germinated from hidden buds on the main branches of the inner room, which are more common in mature trees and aging trees. In the past, many people cut off contacts with the base, which is called "cleaning the room". 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.
(4) Pruning of drooping branches: retract at the bifurcation, and cut off dead branches of diseases and pests at the same time. Too dense drooping branches should be cut off year by year.
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.
Carya is Carya of Juglandaceae. There are about 20 species, 4 of which are native to China. 1984 Zhejiang Forestry College discovered a new species in Jinzhai, Anhui Province. There are 1 1 species native to North America.
I. Distribution area
China's pecans are mainly distributed in Lin 'an, Chun 'an, Ji 'an and Tonglu in Zhejiang and Ningguo, Shexian, Jixi and Jingde in Anhui. In recent years, the planting area in Zhejiang Province is about 250,500 mu, with a total output of 6,300 tons, accounting for 85% of the total national pecan production, mainly produced in Lin 'an County.
Second, the significance of cultivation
Carya cathayensis nuts are delicious and edible, with an egg content of 7.23% and an oil content of 48% ~ 53%, most of which reach 69%. 27 ~ 30 kg of high-grade edible oil and industrial oil can be squeezed out per 100 kg of nuts. Shell can be used to make activated carbon, involucre can extract tannin, and wood can be used to make furniture and military industry.
Carya cathayensis has the characteristics of shade tolerance and strong adaptability to soil pH, and is a good tree species for building economic forests on barren hills and slopes. It also has the characteristics of late flowering, early harvest, no frost and cold damage in the fruit-bearing growth period, small shell and fruit volume, storage and transportation resistance and long service life, and can be harvested for many years once planted.
Third, cultivate characteristics
Carya cathayensis is an anemophilous flower. During male and female flowers and flowering, it is rainy, the temperature is lower than 10℃, or the temperature drops greatly, which is extremely unfavorable for pollination and fruit setting. Carya cathayensis is tall and dry, the terminal buds and nearby buds are easy to germinate, and the germination ability in the middle and lower parts is weak. In order to promote the early fruiting of young trees, the backbone branches can be appropriately shortened. In order to facilitate management, the top of the tree is usually picked at the full fruit stage (10 ~ 15), and the height of the tree is controlled at about 5 meters.
Carya cathayensis 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.
Four, the main varieties and excellent varieties
1. Main types
C. Populus davidiana is about 30 meters high, with smooth epidermis, odd pinnate compound leaves and 5-7 leaflets. Nuts are oval or broadly oval, with large tops and thick shells. 1 kg has about 292 nuts. The nucleolus is very large, usually with four cracks. It tastes delicious after astringency removal, and can be used for frying or processing sweets and cakes, and can also be used for oil extraction.
2. Excellent varieties
Most round pecans belong to this type. The top of the nut is oval, the top of the fruit is sharp, the left and right halves are skewed, the size is asymmetric, and the shell is thick. The inner wall has two large partitions and six small partitions, and the shell is easy to peel and the nut is often complete.
The nut of flat fruit is oblate, with a slightly prominent top, a round base and a thick shell. The interior wall is divided into three big partitions and then into nine small partitions. Because there are many grooves in the shell, it is difficult to peel the shell, and most of the peeled kernels are incomplete.
Thin-shell species are mainly produced in Lin 'an area, with shell thickness of 0.08 ~ 0. 10 cm, kernel yield of 46%, oil yield of 72% and good quality. At present, the number of plants is small, so it should be propagated and popularized vigorously.
3. Scorch, Illinois
Carya cathayensis and Carya cathayensis belong to different species Also known as pecan, pecan. Native to the Mississippi River valley and the southern Gulf of Mexico. According to Professor Wu Gengmin's investigation, around 1900, American female missionaries were introduced to Jiangyin, Jiangsu, China. At present, the introduction is widely distributed in China, and there are many plants in Nanjing, Jiangyin, Huai 'an, Hangzhou, Lin 'an, Wenzhou and Xiamen, but no commodity base has been established so far.
Pecan nuts are delicious, which is the best quality among walnut trees. It can be eaten raw, fried or made into candy, and can also be used to extract oil. Wood is strong, tough and dense, and can be used for national defense or making exquisite furniture. Magnificent trees are suitable for street trees or trees beside rivers and reservoirs, and are easy to reproduce. Besides grafting, it can also take root by cutting, which is suitable for planting in the warm and humid environment in the south.
Many varieties of Carya cathayensis can't blossom at the same time because of the tall trees, inconvenient management and late entry into the high-yield period, so artificial pollination is needed to improve the fruit-setting rate.
Carya cathayensis is not produced as a processed commodity in China. After being graded, washed and shelled by factories in the United States, nuts are mostly used as raw materials for making candy, bread, ice cream or snacks.
Verb (short for verb) Harvest, process and sell.
Usually, the color of the involucre of the fruit changes from green or blue-green to yellow-brown, that is, it is mature. If the empty fruit is caused by poor fertilization and other reasons, it is not easy to separate it, so that good fruit and bad fruit can be distinguished. The pruned nuts should be steamed immediately, otherwise they will go bad easily. Nuts that can't be treated in time should be thinly covered in a ventilated place indoors and dried in the shade.
At present, the main processed products in China are salt and pepper hickory, hickory candy and so on. Due to the limited output, the demand exceeds supply, and the market prospect is good.
Treatment measures of walnut trees after freezing injury
After the walnut tree is frostbitten, anti-freezing measures must be taken as soon as possible to avoid affecting the yield and diseases in the coming year. 1, trunk protection (1) 4-5 frozen walnut trees. In order to prevent the freezing injury from aggravating and rotting, we should immediately apply tree protectant or whitewash the trunk. (2) Clear the snow around the trunk in time after the snow, and the ground temperature will rise. After the surface is thawed, the trees less than 4 years old will be covered with plastic film with the trunk as the center, covering an area of about 1 m2. 2. Fertilize and water (1) After the soil is thawed, apply fertilizer and water once immediately before germination (first half of March). The annular or radial fertilization ditch method was adopted, and 50 kg of organic fertilizer and 0/-2 kg of urea were applied to the big trees. Apply 0.2-0.5 kg of urea to young trees and water them immediately after fertilization. Spraying the mixed solution of urea and potassium dihydrogen phosphate with the concentration of 0. 1-0.3% on the leaves, and topdressing outside the roots. (2) After the soil is thawed, the pine trees and conditional woodlands should be ploughed and loosened as soon as possible. 3. Prune in time (1) For trees with frost damage above Grade 2, identify the frozen parts of branches before germination and leaf opening (from mid-March to mid-April), and prune them appropriately in time. Cut off the dead parts of branches, and apply 50 times solution of 3-5 degree sulfur mixed solution or 50% thiophanate-methyl wettable powder to the cut mouth for disinfection. Transport the cut branches out of the forest land and burn them centrally. (2) In early and mid-May, select and keep the sprouting and tender branches on the pruned branches. Select and cultivate new trunk branches and fruiting branches, pruning branches, upright branches, over-dense branches, cross branches, etc. And restore the shape and shape of the tree as soon as possible. (3) In the middle and late May, select and preserve the whole overground part and grafted part of frozen seedlings and saplings, select the trunk of new saplings to be cultivated and new branches to be grafted, cut off other new branches and bud grafting in summer. 4. Prevention of Rot Disease (1) The walnut tree is prone to secondary disease-rot disease after freezing injury. In early spring (early and middle April), once the rot disease is found, it should be prevented in time: scrape off the diseased spots: scrape off the rotten diseased spots with a sharp knife, and the scraping mouth becomes a "long spindle" with smooth and complete edges. Scrape 0.5㎝ wide intact cortex from the lesion, leaving no diseased tissue. Usage: Use 50 times solution of Shuguan bacteria or 50% thiophanate methyl wettable powder or 50% bacitracin wettable powder or 5- 10 Baume mixture to disinfect the scraped wound, and then brush Bordeaux solution to protect the wound. 5. Protect the scraping mouth after application, and wrap the scraping mouth with cloth or dark plastic strip to facilitate wound healing. Collect the scraped diseased tissues in a centralized way and transport them out of the forest land for burning. Never leave the scraped diseased tissue in the woodland. To prevent rot, we should "scrape early and scrape small"