plant morphology
There are different opinions about the origin of onions, but most people think that onions are more likely to be produced in the Central Asian Plateau in Southwest Asia, Iran and Afghanistan in Asia Minor, because wild onions can still be found in these areas. Onion originated in continental climate zone, where the climate changes dramatically, the air is dry and the soil moisture changes obviously seasonally. Therefore, in the process of systematic development, due to long-term adaptation to this special environment, onion has not only undergone corresponding changes in morphology-shortened stem disc, water-loving roots, drought-resistant leaves and bulbs with storage function, but also has certain physiological adaptability. In the vegetative growth period, it is required that the temperature is cool, the light intensity is moderate, the soil is loose and fertile, the water retention is strong, the air humidity is low, and the soil humidity is high, showing the characteristics of cold resistance, moisture resistance and fertilizer resistance, but not high temperature resistance, strong light resistance, drought resistance and barren resistance. When the temperature is high and the sunshine is long, it will enter the dormant period. The edible part of onion is the underground hypertrophy bulb (onion head). According to its skin color, it can be divided into three types: white skin with small bulbs, white or slightly green appearance, tender meat, light spicy juice and good quality, suitable for raw food. People in China are often afraid of its unique spicy aroma, but it is known as the "queen of vegetables" abroad, and its nutritional value is not low. Quality requirements of onion: the onion is fat, the skin is shiny, it does not rot, there is no mechanical damage and soil, and the fresh onion has no leaves; After storage, it is not soft and bolting, with dense scales, less water content and strong spicy and sweet taste.
nutritional ingredient
Calories (39.00 calories) protein (1. 10g) Fat (0.20g) Carbohydrate (9.00g) Dietary fiber (0.90g) Vitamin A (3.00) Carotene (20.00g) Thiamine (0.03mg) Riboflavin. Vitamin C (8.00 mg), vitamin E (0. 14 mg), calcium (24.00 mg), phosphorus (39.00 mg), sodium (4.40 mg), magnesium (15.00 mg), iron (0.60 mg) and zinc.
Common recipes
How to eat onions: 1. Onion soup: add water, onion and salt to the pot and cook the soup. 2. Stir-fry the onion: Slice the onion, dip it in the batter and fry it in the oil pan until golden brown. 3. Stir-fry onions: stir-fry with meat, shrimp and cuttlefish. 4. Onion salad: onion, potato, carrot diced and boiled with salt, and an egg sliced. Add mayonnaise and stir well. 5. Onion curry: Dice onions, potatoes and carrots, add soup, water and diced beef, boil, add onions, potatoes and carrots, pour in the fried curry, and add onion segments when boiling.
food therapy
Onion is sweet, slightly pungent, warm in nature, and enters the liver, spleen, stomach and lung meridians; It has the effects of moistening intestine, regulating qi and regulating stomach, invigorating spleen and promoting digestion, dispelling cold and warming yang, promoting digestion and resolving food stagnation, refreshing brain, removing blood stasis and detoxicating, and is mainly used for treating exogenous cold, anhidrosis, stuffy nose, dyspepsia, dyspepsia, hypertension, hyperlipidemia and dysentery.
Food efficacy
1. Onions have the function of dispelling wind and cold, because the bulbs and leaves of onions contain an oily volatile called propylene sulfide, which has a spicy taste. This substance can resist cold and influenza viruses and has a strong bactericidal effect; 2. Onions are nutritious and spicy. It can stimulate the secretion of stomach, intestine and digestive gland, stimulate appetite and promote digestion. Onion contains no fat, and its essential oil contains a mixture of sulfur-containing compounds, which can reduce cholesterol and can be used to treat dyspepsia, anorexia and dyspepsia. 3. Onion is the only food known to contain prostaglandin A. Prostaglandin A can dilate blood vessels and reduce blood viscosity, so it can lower blood pressure, reduce peripheral blood vessels, increase coronary blood flow and prevent thrombosis. It can resist the action of pressor substances such as catecholamine in human body, promote the excretion of sodium salt, and thus lower blood pressure. Regular consumption has a health care effect on patients with hypertension, hyperlipidemia and cardiovascular and cerebrovascular diseases; 4. Onion has a certain refreshing effect, which can help cells make better use of glucose, lower blood sugar and provide heat energy for brain cells. It is a good diet for diabetics and listless people. Onion contains a substance called phlogiston quercitrin 9, which is one of the most effective natural anticancer substances known at present. It can prevent the variation of biochemical mechanism in vivo and control the growth of cancer cells, thus having anti-cancer and anticancer effects; 6. Selenium, a trace element contained in onion, is a strong antioxidant, which can scavenge free radicals in the body, enhance the vitality and metabolic ability of cells, and has the functions of preventing cancer and resisting aging; 7. Onions also contain a certain amount of calcium. In recent years, Swiss scientists have found that eating onions regularly can improve bone density and help prevent osteoporosis. 8. Onions contain phytoncide, such as allicin, which has strong bactericidal ability. Chewing raw onions can prevent colds. Modern medical research also shows that onion contains trace element selenium. Selenium is an antioxidant. Its special function is to produce a large amount of glutathione. The physiological function of glutathione is to transport oxygen for cell respiration. With the increase of human selenium content, the incidence of cancer will be greatly reduced. Therefore, onion is a healthy food. Onion also has hypoglycemic effect, because it contains organic substances similar to metsulfuron, which can produce dermatan with strong diuretic effect in human body. Eating 25 ~ 50g onion per meal for diabetic patients can play a better role in lowering blood sugar and diuresis. Phytoncide in onion can not only stimulate appetite and help digestion, but also stimulate secretion of tube wall when it is excreted through respiratory tract, urinary tract and sweat gland, so it also has the functions of eliminating phlegm, diuresis, sweating, preventing colds, inhibiting bacteria and preserving corrosion. Onion contains sugar, protein, various inorganic salts, vitamins and other nutrients, which has a certain effect on human metabolism, can better regulate nerves and increase memory. Its volatile components also have strong effects of stimulating appetite, helping digestion and promoting absorption. Diallyl disulfide and alliin can also reduce the content of cholesterol and triglyceride in blood, thus preventing arteriosclerosis. Onions are warm and sweet. Has expectorant, diuretic, stomach invigorating, intestine moistening, detoxicating and insecticidal effects. Can be used for treating anorexia, constipation, dysentery, enteritis, insect abdominal pain, traumatic ulcer, leucorrhea with red and white discharge, etc. Prostaglandin A contained in onion has obvious hypotensive effect, and similar substances contained in methylsulfonylurea have certain hypoglycemic effect. It can inhibit the increase of blood lipid caused by high-fat diet, and can prevent and treat arteriosclerosis. Onion extract also has bactericidal effect, which can improve gastrointestinal tension and increase digestive tract secretion. There is a peptide in onion, which can reduce the incidence of cancer.
Therapeutic effect of drugs
Onions can prevent osteoporosis. Housewives don't like to cook with onions, which will make people cry. Many people are also afraid of the smell of onions. Unless it's an excellent onion dish, it's really hard to find onion lovers. But people who want to make their bones strong, grow tall and prevent osteoporosis, it is best to hold their noses and eat onions. Because the latest research report of the authoritative magazine Nature points out that onion is the most effective vegetable to prevent bone loss. The effect of onion on preventing bone loss is even better than calcitonin, a drug for treating osteoporosis. The researchers asked male mice to eat one gram of dried onions every day. After four weeks, the average bone mass of male rats increased by 13.5- 18%. Another group of experiments found that letting mice eat mixed vegetables containing onions can also reduce the problem of bone loss. In experiment 3, the ovariectomized female rats ate1.5g onion every day, and the bone loss rate decreased by 25%. What's more noteworthy is that the health care function of onion can be seen in just 12 hours. Researchers believe that the function of onion may come from "preventing bone loss", so people who want to use onion for health care may eat 200-300 grams (10 ounce) of onion every day to prevent osteoporosis. Medicine and food are homologous. In our daily food, there are many fruits and vegetables with similar drug effects. Onion, an indispensable side dish in western food, has more health benefits than expected. Scrambled eggs with onion, or beef with onion, are delicious and healthy dishes; Onions can also be eaten raw or juiced. According to medical experiments, it can play a variety of magical effects. Onions can prevent high cholesterol. According to Dr. Dick Dogel, a professor of cardiology at Harvard Medical School, eating half an onion raw or drinking the same amount of onion juice every day can increase the high-density lipoprotein (HDL) content of patients with heart disease by about 30% on average (HDL is high-density lipoprotein cholesterol, which is considered to help prevent atherosclerosis and is also a kind of beneficial cholesterol. Eating half an onion raw every day, or drinking the same amount of onion juice to protect the heart, was originally a folk prescription. Dr. Kedo conducted experiments on patients in his own clinic, which proved that onions do have the effect of raising cholesterol, but the more onions are cooked, the less effective they are. Onions can break down fat. Dr. Kedo asked heart patients in the clinic to eat onions every day and found that the compounds contained in onions can also block onions.
Prevent platelet coagulation and accelerate blood clot dissolution. Therefore, when you enjoy high-fat food, it is best to match some onions, which will help offset the thrombosis caused by high-fat food; So it makes sense that steak is usually eaten with onions. Onions can prevent stomach cancer. Onions, garlic, scallions and leeks are all vegetables belonging to the genus Allium. Because they contain anti-cancer chemicals, according to a survey conducted by researchers in a high incidence area of gastric cancer in Shandong Province, China, the more onions you eat, the lower the risk of developing gastric cancer. Onion can resist asthma Onion contains at least three natural anti-inflammatory chemicals, which can treat asthma. Because onion can inhibit the activity of histamine, which is a chemical substance that can cause allergic symptoms of asthma; According to German research, onions can reduce the incidence of asthma by about half. Onions can cure diabetes. Onions have been used to treat diabetes for a long time. In modern times, medicine has also proved that onions can really lower blood sugar. And both raw and cooked food are equally effective. It turns out that there is an antidiabetic compound in onion, which is similar to methanesulfonic acid, a commonly used oral hypoglycemic drug, and has the effect of stimulating insulin synthesis and release.
Culture and propagation
Sowing date: The choice of sowing date depends on the local temperature, light and maturity of the selected varieties. Onions are sensitive to temperature and light. Therefore, autumn sowing is very important for the selection of sowing date. It is necessary to cultivate a certain degree of strong seedlings to prevent scaling.
The growth and development were too large before winter, and after vernalization, early bolting appeared in the next spring. Sowing is usually carried out in September 10-20 in Hengshui area, and the seedling age is 50-60 days. Seedbed preparation: Seedbed should be a field with high terrain, convenient irrigation and drainage, fertile soil and no onion and garlic crops in recent years, and neutral loam is suitable. Too much base fertilizer should not be applied to the seedbed to avoid the seedlings growing too fast. General 100 m2 seedbed is applied with 300 kg of organic fertilizer and 5- 100 kg of calcium superphosphate. Plough and harrow for 2-3 times, and fully and evenly mix the base fertilizer and soil, with the depth of cultivated land about 15cm. Then harrow to make a bed with a width of 1.5- 1.6 m and a length of 7- 1m, and then sow and raise seedlings. Sowing methods: Generally, there are two sowing methods: drilling and sowing. 1. Drill: First, open a 9- 10 cm ditch on the border with a depth of 1.5-2 cm. After sowing, sweep the soil with a broom, then step on the soil in the sowing ditch with your feet and water it. 2. Sowing: First water the bottom of the seedbed, spread a thin layer of fine soil after infiltration, then sow, and then cover with soil 1.5cm ... In order to speed up the emergence of seedlings, seeds can be soaked to accelerate germination. Soaking seeds is to soak the seeds in cold water for 12 hours, take them out and dry them until the seeds are not bonded. Accelerating germination means soaking the seeds, then accelerating germination at the temperature of 18-25℃, cleaning the seeds once a day and sowing until the buds are exposed. Sowing amount: Sowing amount is also related to the robustness of seedlings and bolting first. The density is too high, the seedlings are thin, the density is too thin, and the seedlings grow too thick, which is easy to bolting. Generally, 600-700g seeds are sown per1200m2 seedbed area. The ratio of seedbed area to planting area is generally 1: 15-20. Seedling management: after sowing, the seedbed must be kept moist to prevent soil hardening from affecting seed germination and emergence. It is necessary to properly control watering after the seedlings grow the first real leaf. When the young stem grows to about 4-6 cm, it forms an arch, which is called "pulling the bow"; From the appearance of cotyledons to the straightening of embryonic stems, it is called "stretching". Generally, water is poured on the soles of feet before sowing, not after sowing, and then onions are added when pulling the bow.
Water in time to ensure the whole seedling. If the bottom water is insufficient or there is no watering before sowing, it is usually watered 2-3 times after sowing. Combined with watering and topdressing at seedling stage to promote seedling growth. The fertilization amount is 65,438+00-65,438+05 kg of nitrogen fertilizer per mu, or 65,438+0,000-65,438+0,300 kg of decomposed human excrement and urine. When the seedlings grow 1-2 true leaves, weeding and thinning should be done in time, and the seedling spacing should be kept 3-4 cm when sowing and about 3 cm when drilling. Base fertilizer preparation is not suitable for continuous cropping and continuous cropping with other onions and garlic vegetables. Onion has shallow root system and weak absorption capacity, so the cultivated land should not be deep, but thin. Autumn ploughing, after the previous crop is harvested, the ploughing depth is about 15 cm. After plowing the land, rake it as a boundary. The size of the boundary depends on the climate and the irrigation and drainage conditions of the land. Generally, a wide border with a width of 2 meters and a length of 10 meter can be built to improve the land utilization rate and increase the number of plants planted per unit area. If intercropping and interplanting are needed, the width of the border should be determined according to the requirements of intercropping and interplanting crops. Before planting, base fertilizer should be applied in combination with cultivated land, and the application amount of base fertilizer should be determined according to soil fertility and different types of base fertilizer. Generally, 1330-3340 kg of high-quality decomposed manure can be applied per mu, and 16-20 kg of calcium superphosphate and appropriate amount of potassium fertilizer can be added. Use base fertilizer, spread it wider, and then fully stir and rake it evenly when plowing, so that the soil and fertilizer are mixed evenly. Seedling selection by planting classification: when planting, seedlings with developed roots, strong growth and uniform size should be selected; Eliminate overgrown seedlings, dwarf seedlings, diseased seedlings and branched seedlings, as well as seedlings that grow too big and too small. According to seedling height and seedling thickness, it is generally divided into three levels: the first level seedling height is about 15 cm and the thickness is 0.8cm；; The height of the secondary seedlings is 12 cm, and the thickness is about 0.7 cm. The height of the third-grade seedlings is about 10 cm and the thickness is about 0.6 cm. After grading, you can put the same onion.
Large and small seedlings are planted together, classified and managed, and the field growth is consistent. Planting density: Onion plants stand upright, and reasonable close planting has obvious effect on increasing yield, which is one of the key measures for high yield of onion. Generally, the row spacing is15-18cm, and the plant spacing is10-13cm. About 30,000 plants can be planted per mu. The planting density depends on the variety, soil, fertility and seedling size. Generally, early-maturing varieties should be densely planted, red-skinned varieties should be sparsely planted, those with poor soil fertility should be densely planted, and large seedlings should be sparsely planted. Onions should be planted to the maximum density on the premise of keeping a certain head. Planting time: autumn planting time is suitable for the roots to grow again after planting, but it is not suitable for the plants to grow over the winter. If the plant is planted too early, the plant will start to grow and the overwintering seedlings will be too large, which will easily lead to early bolting in the next year. If it is planted too late, the root system has not resumed growth and is vulnerable to freezing injury. Generally, it is advisable to plant it 30-40 days before the arrival of severe cold. The general planting time in Luohe area is from the end of 10 to the beginning of10. Onion field management: (1) watering. Onion enters the slow seedling stage about 20 days after planting. Because the temperature is low when planting, you can't water a lot. Too much watering will reduce the ground temperature and slow down the emergence of young trees. At the same time, the new roots of the newly planted seedlings have not germinated, so they cannot be short of water. Therefore, onions should be watered more at this stage. The amount of water should be less each time. The general principle is not to wilt the seedlings and not to dry the ground, so as to promote the seedlings to take root and survive quickly. Onion seedlings planted in autumn will enter the wintering period after survival. In order to ensure the safe overwintering of the planted onion seedlings, it is necessary to water them in time. After overwintering, it turns green and enters the growth period of stems and leaves. The requirement of water at this stage should be to water to promote growth, and to control watering to prevent excessive growth. The method of controlling watering is called "squatting seedlings", and squatting seedlings should be mastered according to the weather, soil properties and growth after planting. Under normal circumstances, squatting seedlings should last about 15 days. When the outer leaves of onion seedlings are dark green, wax increases, mesophyll thickens, and the color of heart leaves darkens, the seedlings are squatted and watered. In the future, water is usually poured every 8-9 days to make the soil dry and wet alternately, promote plant growth and prevent white growth. Stop watering onions 7-8 days before harvest.
. (2) fertilization. The fertilizer requirements of onion per mu are nitrogen 13- 15 kg, phosphorus 8- 10 kg and potassium10-/2 kg. Generally, onions are not topdressing from planting to seedling emergence. After overwintering, combined with watering overwintering water, apply human excrement and urine 1000- 1300 kg per mu. When it turns green in spring, it is combined with watering green water and then applying green manure. (3) intertillage and loosen the soil. Loosening soil is beneficial to the root system development and bulb expansion of onion, which is usually carried out 3-4 times at seedling stage, combined with watering each time; The growth period of stems and leaves should be 2-3 times, and intertillage should be stopped after harvesting. The depth of intertillage should be about 3 cm, and the planting place should be shallow and deep from the plant. (4) remove flies. For early bolting onions, cut off from the lower part of the flower bud before the flower bulb forms, or separate from the top of the flower bud and tear two pieces from top to bottom to prevent flowering from consuming nutrients, promote the growth of lateral buds and form fuller bulbs. Practice has proved that for plants bolting in advance, a certain yield can still be obtained after bolting measures are taken. Picking onions is usually from the end of May to the beginning of June. When the onion leaves gradually change to Huang Shi from bottom to top, the false stems become soft and begin to lodging; Bulbs stop expanding, the outer leather is leathery, and enter the dormant period, indicating that bulbs are mature and should be harvested in time. After harvesting, onions should be dried in the ground for 2-3 days. Direct marketing can be cut from the roots, from the false stems on the upper part of the bulbs, and then sold in baskets. If you need to store onions, do not remove the stems and leaves. When the leaves are 70% to 80% dry, you can weave the stems and leaves and hang them in a cool and dry place. This is called hanging onions, or storing them in bags and baskets.
The right crowd
Generally everyone can eat it. 1, especially suitable for patients with cardiovascular diseases such as hypertension, hyperlipidemia, arteriosclerosis, diabetes, cancer, acute and chronic enteritis, dysentery and dyspepsia. 2, onions should not be eaten too much at a time, which is easy to cause paste and fever. At the same time, people with itchy skin, eye diseases, stomach diseases and lung and stomach inflammation should eat less. At the same time, onions are pungent and warm, and patients with fever should eat them carefully; 3. The pungent taste of onion irritates eyes. When suffering from eye diseases and bloodshot eyes, it is not advisable to cut onions.