The fruit tree, called Voloshsky or Greek walnut in Russia, belongs to the genus Juglans regia. This is the largest representative in the family, distributed in the subtropics of Asia, Europe and the North American continent.
Botanical Description
Walnut - Tall Spreading Tree. Instances over the age of 50–70 years reach 25–30 m in height, and the diameter of their trunks in the lower part exceeds 1.5 m. The bark is dark gray, thick, covered with cracks. The root system consists of a powerful central rod that penetrates to a depth of 3–3.5 m, and subordinate shoots that develop after the tree reaches the age of 7–10 years. The crown is hipped, thick. The petiole leaves are complex, unpaired, dark green with a bluish tinge. They consist of 7–11 elongated lobes with pointed tips, 8–12 cm long.
Flowers same-sex, bloom simultaneously with leaves in late April. Stamen and pistil inflorescences are located on the same tree. The first - in the form of pale green hanging earrings, the second - rounded sessile, with fused perianth, grow at the tops of shoots or in the axils of the leaves. Pollination occurs crosswise, since flowering on one crown is uneven.
Nuts ripen in September or October.. Their strong woody shell is surrounded by light green fibrous pericarp, which burst independently in the fall. Edible kernels are located under the ribbed shells of the shell in cavities separated by thin septa. The mass of whole fruits is 6–15 g. The yield of kernels, depending on the variety, ranges from 40 to 68%.
The first nuts appear on trees aged 7–9 years. Plants reach full maturity by the age of 20 and continue to bear fruit until 150–200 years. The life span of individual specimens exceeds the 500-year mark.
Walnut is not cold resistant. Full cultivation is possible in regions where the average annual temperature is at least + 10–12 ° C, and during the active growing season + 20–25 ° C. Adult specimens survive short frosts up to –25–28 ° C, during prolonged cold weather the culture freezes. In a temperate climate, trees reach maturity and begin to bear fruit when using competent agricultural technology.
Spread
The homeland of walnut is the regions of Asia Minor, Central and Southeast Asia. Wild species are common in the nature of Transcaucasia, northern India, in China. Natural habitats include floodplains, gentle slopes and mountain ravines.
Cultivated in the south of Europe: in the Balkans, in Greece, Spain, Italy, Ukraine, Moldova. In Western Europe, introduced in Germany, Norway. In North America, it is grown in well-moistened areas up to 56 ° north latitude. In Russia, it is cultivated in the Crimea, Krasnodar Territory, the Stavropol Territory, the Rostov Region, and Kabardino-Balkaria. With varying success is developing in the southern Volga region.
Varieties
Various breeding forms of walnuts differ in terms of ripening, fruit mass, yield, resistance to disease and pests.
Popular varieties:
- Skinino. Trees 10-12 m high with thick, dense crowns, winter-hardy. Fruits are egg-shaped, weighing up to 15 g, with a thick shell and large kernels. Ripen in mid-September.
- Codrene. Moldovan large-fruited cold-resistant variety with spherical heavy nuts weighing 10-15 g. The shell is thin, the yield of the kernel is more than 60%.
- Santa Rosa Soft Shell. Californian nut with a light shell and oily white kernels.
- Dessert. Russian high-yielding variety with early ripening fruits. Heat-loving, drought tolerant.Nuts are spherical, large, weighing 10-12 g, with a strong shell of medium thickness.
- Giant. Variety with high adaptive properties. It can be grown in temperate climates. Productivity is high, regular. Spherical nuts, weighing 8-10 g.
Application
Walnut - a valuable fruit crop. This determines the priority of its application. The number of collected nuts from one adult tree of a high-yielding variety per season can reach 300-350 kg. In mature kernels are concentrated:
- 70–75% fatty oil;
- 20% protein;
- B vitamins, PP, E, D vitamins, carotene, ascorbic acid;
- iron, selenium, zinc, phosphorus, copper and other minerals.
Walnuts are a highly nutritious product. They are used in cooking for the manufacture of a wide range of confectionery, sauces, dishes of national cuisine.
Walnut oil has nutritional value, is used in pharmaceuticals, cosmetics.
The leaves and green pericarp of the plant contain bitterness, alkaloids, essential oils, tannins and other biologically active substances. These are raw materials for the production of cosmetics for skin and hair care.
In folk medicine, preparations based on decoctions and tinctures of nut greens are used in the treatment of infectious, gastric, dermatological diseases, to accelerate the healing of ulcers and wounds.
Ground hard shells are used in the production of building materials, as abrasives. The juice of the pericarp and leaves is part of the dyes for leather industry.
Walnut is considered a valuable ornamental and carpentry material.. The array is distinguished by a variety of shades: from grayish and golden red to deep brown. The structure of the tree is finely fibrous, with the presence of frizzy areas, pronounced texture and a contrasting dark pattern. Density varies from 500 to 720 kg / m³, viscosity and impact resistance are moderate.
On an industrial scale, timber is not harvested, given the fruit value of the crop. For this reason, the raw materials are mainly used for the production of veneers for furniture and decoration panels. Piece parquet, arms lodges, home decoration and souvenir products are made from walnut.
Beneficial features
Walnuts are useful as a natural source of vitamins, organic acids, animal fats, amino acids, macro and micronutrients. In terms of nutrient content, they are comparable to meat and dairy products, and in terms of energy value they exceed them by 1.5–2 times.
Eating walnuts is recommended:
- children
- physically weakened and exhausted people;
- suffering from nervous disorders;
- with insufficient immune defense;
- pregnant
- with violations of the endocrine glands;
- with hypovitaminosis;
- with atherosclerosis;
- with heart disease;
- with helminthiases.
Means based on nuts with honey and other additives are recommended in the treatment of hypogonadism, reducing potency in men.
Fatty oil, extracts of leaves and green walnut shells have a bactericidal, regenerating, firming, choleretic, hemostatic, anti-cancer effect. Preparations based on them are effective in:
- liver diseases;
- bacterial and viral infections;
- intestinal disorders;
- varicose veins;
- tuberculosis
- furunculosis;
- autoimmune pathologies.
Harm and contraindications
The high concentration of biologically active substances in walnuts requires a careful attitude to this product. Doctors do not recommend eating more than 5 kernels at a time. The magnesia contained in the pulp has a sharp vasodilating effect and after consumption in large quantities causes paroxysmal headaches and dizziness.
The incidence of neurodermatitis or psoriasis is a reason to be careful about the fruits of a walnut tree. Often they provoke exacerbations.
Walnuts are contraindicated in case of increased blood coagulation, chronic pancreatitis, and obesity.
Interesting Facts
Walnuts were first named in Kievan Rus, where they were among other goods brought by Athenian merchants. In biblical Babylon, these trees grew in hanging gardens.
In many peoples of the Caucasus, walnuts are considered sacred, and in Moldova there is a custom to plant this plant in the yard when a child is born in the family.
The largest is considered to be a walnut tree, which until the end of the 19th century existed on the territory of modern South Ossetia. The circumference of its trunk exceeded 8 m, and several dozen mounted horsemen could hide in the shadow of the crown. The average yield from the giant was about 1.5 tons of fruits per season.
Landing
It is necessary to place trees on sunny flat or elevated areas with loose neutral soil. For group landings, the distance between the trunks should be at least 8 m.
Recommended planting time is spring. With insufficient nutrition of the soil, preliminary preparation is required.
- Pits for seedlings with a depth and width of about 1 m dig at the end of September.
- Part of the excavated soil - its upper layer - is mixed with equal volumes of peat and humus, 2 kg of superphosphate, 2 kg of wood ash, 800 g of potash fertilizer, 500 g of chalk or dolomite flour are added.
- A pit is filled with a substrate, 20 l of water is poured into it and left until spring.
Further work is carried out in April.. The soil is removed from the pit, a strong support 2.5–3 m high is driven into the bottom. Before being placed into the soil, seedlings are dipped into a liquid mash from 3 parts of clay, 1 part of rotted manure and water. At the bottom of the hole pre-poured 20 cm of drainage from small stones. Above is a mound of substrate. The tree is set in such a way that the root neck is 3-5 cm above the surface of the soil. Then the roots are sprinkled on all sides with soil.
Immediately after planting, the trunk is watered with 20-25 liters of water. When moisture is absorbed, the seedling is tied to a support. The trunk circle should be mulched with sawdust in a 2-3 cm layer.
Care
Walnut demanding moisture. In hot time - from May to July - it is necessary to water it twice a month, spending about 5 liters per 1 m² of soil. To collect and rationally use rainwater, it is recommended to surround the trunks with a 15-cm roller from soil or sand in a radius of 40-50 cm. In August, the frequency of irrigation is reduced to 1 time per month. With heavy rainfall, you can do without additional moisture.
Walnut roots do not like loosening, therefore, all weed grasses that appear must be removed immediately, and the mulch layer should be regularly updated.
In the first 3 years, seedlings have enough fertilizer applied to the soil during planting. In the future, during the growing season, the walnut needs:
- 8-10 kg of superphosphate;
- 2.5 kg of potassium chloride;
- 5 kg of nitrate;
- 7-8 kg of ammonium salt.
Nitrogen compounds are introduced in spring and in the first half of summer. Phosphates and potassium mixtures - from July to autumn.
Pruning of dried and diseased shoots is carried out in March, before the start of the growing season.. They begin to form a crown when the stem reaches a height of 80–100 cm. They do this in October: cut lateral shoots, shorten skeletal branches by 10–20 cm. Secateurs must be sterilized before starting work. Places of damage thicker than 5 mm are lubricated with garden var.
Preparing for the winter
In late autumn, tree trunks are cleaned of fallen leaves, shoots of shoots. Under the root, pour 25 liters of water. Before the onset of frost, the trees are insulated: thicken the layer of mulch up to 10-15 cm, lay on top a layer of compost or manure. For winter, seedlings under 5 years old are wrapped in burlap.
Breeding
The most productive is the seed method of propagation of the tree. Thus obtained seedlings are easier to adapt to the local climate and soil.
Ripe nuts stratify before germination. If the shell is thick, store at 0–5 ° C for three months.Thin-shell - at + 10–12 ° C for about 1.5 months. Then the material is placed in wet sand for 1-2 weeks. When the flaps open and the germ of the shoots appears, the nuts are planted in the soil to a depth of 10–12 cm. They do this when the soil warms up to 10 ° C. When sowing a large number of linear trenches are digging, placing seeds 15 cm apart. So that young shoots do not die from the cold, in the autumn they transfer it to greenhouses. After 2-3 years, the seedlings become suitable for open ground.
In warm regions, walnuts are propagated by grafting, placing a cut shield of the desired variety under the rootstock bark.
Diseases and parasites
Gray, brown, black spots on the foliage, fruits and shoots of a nut are signs of a defeat by bacteriosis or marsoniosis. They can be caused by prolonged dampness, improper watering, and an excess of nitrogen fertilizers. For the prevention of diseases, it is necessary to monitor agricultural technology. In spring, you need to free the trunks from dead bark, freezing branches, treat the trees with a 1% solution of vitriol or Bordeaux fluid. Affected parts of plants - cut and burn. Regular treatment of trees with a 7% aqueous solution of urea helps to prevent the development of mycoses and scare away pests.
Appearing growths on the trunks - symptoms of root cancer. Such neoplasms must be opened, cleaned with caustic soda and washed with plenty of water.
The annual whitewashing of trunks with lime to a height of 1–1.5 m from the earth helps to protect the bark from parasites. To get rid of trees from aphids, you need to spray the crowns with Actellic or Antitlin preparations.
Moth caterpillars and their nests must be collected manually, hang special traps on the branches. The larvae of butterflies-whites destroy 30% solution of Dendrobacillin, spraying the crown outside the flowering period. When plants are affected by a nut mite, acaricides are used - Actaru or Kleschevit.
In a temperate climate, the age of fruiting of a walnut occurs 2-3 years later than in the south, and the yield is an order of magnitude lower. However, with proper care, spherical carved tree crowns will become the main decoration of the garden.