Alias: yam, Chinese yam, Huai yam, earth yam, yam, yam, yam, yuyan.

Odor: (root) sweet, warm, flat, non-toxic.

English name: nagaimo, yamaimo, Chinese yam, Japanese mountain yam, Korean yam;

Family Genus

Domain: Eukarya

Family: Plantae

Division: Plantae

Department: Angiosperms Magnoliophyta

Phylum: Monocotyledon Liliopsida

Order: Dioscoreales

Family: Dioscoreaceae

Genus: Dioscorea

Species: Yams (D. polystachya

) Polystachya

Origin and distribution

Monocotyledonous plants, 10 genera and 650 species, widely distributed in temperate and tropical regions of the world, there is one genus of Dioscorea in our country, about 80 species.

Distributed in China's North China, Northwest and Yangtze River Basin provinces and regions.

The planted ones are called home yam, and the wild ones are called wild yam; the Chinese herbal medicine is called huai yam, huai yam, huai yam and so on.

Because of its nutritious, since ancient times has been regarded as a good and inexpensive tonic, can be used as a staple food, can be used as a vegetable, but also can be made into a candy cane and other snacks.

China's main production in Henan Province, Boai, Qinyang, Wuzhi, Wenxian and other places, Hebei, Shanxi, Shandong and south-central, southwestern regions are also cultivated. Digging in winter after the withering of stems and leaves, cut off the root head, wash and dry.

China's cultivated yam mainly has two categories: common yam and field yam. Ordinary yam tubers are smaller, especially in the ancient Huaiqingfu (now Henan Qinyang) yam produced by the famous, known as "Huai Shen", for the country's top.

Morphological features

The rootstock is thick, straight, up to 1 meter long. Leaves alternate, to the central part of the opposite, rare or 3 whorls, leaf axils often bead buds (zero Yu Zi), leaf shape varies, triangular-ovate to triangular broadly ovate, often 3-lobed to y cleft. Flowers dioecious, very small, greenish white, both in spikes, male inflorescences erect, female inflorescences decurrent. Capsule 3-winged. Perennial twining herbs; with tuberous or rhizomatous underground stems; leaves alternate, sparsely opposite, simple or palmately compound, divided or divided; flowers dioecious; rarely sympodial, forming spikes, racemes, or panicles; tepals 6, in 2 whorls, united at base; stamens 6, sometimes 3 developed, 3 degenerate; female and male flowers similar, but stamens degenerate or absent; ovary inferior, 8-loculed, styles 3, separate; capsule or berries; seeds winged. Yam

Growth habit

Cold-resistant, light-loving. It is suitable to grow in well-drained, loose and fertile loamy soil. Avoid waterlogging. Underground stems are cylindrical, fleshy and plump. Stem cylindrical, leaf axils bearing ovate bead buds. Leaf blade triangular-ovate to triangular-broadly ovate, base hastate-cordate. Male inflorescences spikelike, not pendulous, long axis mostly zigzag, male flowers subsessile, bracts triangular-ovate, shorter than perianth, tepals 6, ovate, stamens 6, developed; female inflorescences similar to male, ovary stigma-3-lobed. Capsule 3-winged, fruiting wings several times as long as wide, shortly stipitate, with 2 seeds per locule, inserted in center; seeds ovoid, surrounded by thin chestnut-shell-colored wings, wings ca. 6 mm wide, unequally wide all around. Flowering June-August, fruiting August-October.

Garden Use

Dioscorea can be used as vertical greening material for climbing fences in gardens. The tubers are often eaten as vegetables. The tubers (yam) and bead buds (zeroyuzi) are used medicinally to strengthen the spleen.

Saponin extracted from Dioscorea peltata is the starting material of steroidal hormones (Fujian), with which it can synthesize and produce adrenocorticotropic hormone with anti-inflammatory, analgesic, anesthesia, contraception and other functions, sex hormones, anabolic hormones, three major categories of 6 levels of steroidal hormones more than 60 kinds of drugs, which are widely used in the treatment of heart disease, anti-tumor, rheumatoid, serious infections and other diseases, and the treatment is complete and not easy to relapse, no It is widely used in the treatment of heart disease, anti-tumor, rheumatoid, severe infection and many other diseases. Dioscorea bulbifera is a wild plant, with the wide application of saponin in medicine, and the wild resources are decreasing year by year, far from meeting the market demand. Kai County from 2001 the introduction of Dioscorea bulbifera seed for artificial cultivation has been successful, has developed to more than 2,000 acres in 2004 can be developed to 10,000 acres, sufficient Dioscorea bulbifera resources, the need to invest in the introduction of advanced processing technology and equipment, in situ processing of hydrolyzed material and then extract saponin. In order to take the shield leaf Dioscorea as an industry to develop, need to invest in the establishment of a processing leading enterprises, in order to drive the development of shield leaf Dioscorea.

Cultivation techniques

Variety selection

At present, the main cultivation of yam varieties are fine hair long yam, two hair yam and Japanese "Yamato taro" yam and other varieties. Fine hair long yam and two hairy yam belong to the common yam long column varieties. Japanese yam is a strong adaptability, good quality, disease resistance, high yield, promising varieties. Peng Juntian is the choice of Japanese "Yamato" yam varieties.

Selection of ditching and bed

Yam planting should try to avoid heavy cropping, generally every three years crop rotation, and avoid planting peanuts, taro stubble. To choose a deep, loose and fertile soil plots as well, the requirements of the upper and lower soil quality is consistent, such as the lower layer of clay and heavy soil layer and white sand Gang soil layer, ditching should be thoroughly broken, at least 1 ~ 1.2 meters of soil layer can not be clay, soil sand particles, such as interlayers. Otherwise, it will affect the appearance of the tubers and have an impact on the quality. The soil is preferable to neutral, and at present, the opening of furrows is generally used to mechanically open the furrow. Yam cultivation in the north-south direction is appropriate, can take two rows of planting or single row planting (according to individual plots need to be east-west planting when you can take the row spacing widening), two rows of planting, large row spacing of 1.7 ~ 1.8 meters, small row spacing (ditch spacing of two trips of the yam) 40 centimeters, the plant spacing in the 20 ~ 25 centimeters, the depth of the ditch 85 ~ 100 centimeters, the ditch width of 70 centimeters. When leveling the ground and beds, it should be leveled to prevent uneven watering when watering. It is also necessary to do a good job of drainage design to ensure that there is no stagnant water in the field beds. Single row planting row spacing 80 to 100 cm, ditch width 30 cm, ditch depth 90 to 100 cm, plant spacing 20 to 25 cm.

Sowing at the right time

The greenhouse yam is usually planted around New Year's Day, generally requiring a stable ground temperature of 5 cm above the surface of the ground of more than 9 to 10 ℃. Before sowing the yam seedlings to dry a little, so that you can activate the seed potato, but also can play a role in sterilization, high germination rate. If you use yam stems cut off to make seed potato, you can use lime powder to dip well in time at the incision, which can play the role of sterilization. In the seed to do a piece of buds under, the size of the general large piece under, so that the buds will come out of the flush, in addition, but also with 500 times of carbendazim, 1000 times of powder rust Ning, 72% of Chlorothalonil 1000 times soaked seeds for 3 to 5 minutes, drying can be sown.

Yam to organic fertilizer (such as rotting cake fertilizer, chicken manure, duck manure or human and animal manure, etc.) as the main, supplemented by inorganic fertilizer, the dosage of general per mu can be applied to 2,000 to 4,000 kilograms, plus high-potassium composite fertilizer 40 to 60 kilograms, or with yam special bio-organic fertilizers 200 to 300 kilograms, and the soil is fully mixed well in order to prevent the burning of seedlings.

Field management

1, shallow fertilizer. If the base fertilizer is applied more, less fertilizer or no fertilizer, in order to ensure that the yam is high-yielding, generally 2 to 3 times, in the ground when the plant grows to about 1 m, a high-nitrogen compound fertilizer, and then every week or so after the chase, 3 times can be. Yam expansion period to phosphorus and potassium content of high multi-element compound fertilizer (yam on nitrogen, phosphorus, potassium demand ratio is 1.5: 2: 5), about 30 kilograms per mu, the best to take the method of flushing. Late growth can be foliar sprayed with 0.2% potassium dihydrogen phosphate and 1% urea to prevent premature failure. In particular, it should be noted that the absorption of the yam root system is shallow, occurring early, stretching horizontally, fertilizer should be applied to the shallow soil layer for the absorption of the yam root system.

2, the frame should be firm. Shelf and weeding yam after sowing covered with 6 to 10 cm of floating soil, watering with "yam special herbicide" 150 to 200 grams of water 100 kilograms of uniform spray, and then cover the film, seedlings in time to set up the shelf, the shelf height of about 2 meters, the front of the "people" Zigzag, side to side diagonal cross, every 7 to 8 meters with a thick bamboo pole or stick reinforcement, in short, must be firmly built to prevent crooked.

3, skillful watering. Yam afraid of flooding should not be too drought, if too drought will seriously affect the expansion of the yam, especially in the tuber expansion period, the time is about in mid-April to late May, during this period of time, generally about 10 days to water a thorough watering, watering in late May after the watering should be appropriate watering according to soil moisture.

4, pest control to follow. Pests and diseases in the heavy crop plots are heavier, the first year of planting plots are lighter, in the yam vine on the shelf, start spraying to prevent and control.

The main disease of yam is anthracnose, which is a fungal disease, the old people say leaf drop disease, the performance of the initial leaf yellowing, small spots on the leaves, and finally the stem withered and leaf drop, this disease to prevent the main, do a good job of rotating crops and changing stubble, choose disease-free seed potatoes, before sowing, use 25% polymyxin powder 500 times to dip the seed for 25-30 minutes for the disinfection of seed potatoes, cultivation and strengthen the field management, enhance the resistance of plants to disease.

Generally in the early stages of the disease with 70% Dyson Manganese Zinc 500 to 600 times liquid, 50% Metribuzin 700 to 800 times liquid spray alternately, the onset of the disease can be used in Japan, "Yamato taro" yam special formulation of pesticides, the onset of the disease every 7 to 10 days for spraying, generally spraying 2 to 3 times can be used continuously.

Harvest

Normal open-ground yam harvest is very long, from August 20 to the next year in April, May, yam in the ground does not rot, does not deteriorate, generally before and after the frost for the centralized harvesting period for the Spring Festival market. But greenhouse yam is different, due to the harvest time in June 20 or so, the yam itself has less starch content, high moisture content, so intolerant of long storage, greenhouse yam should be harvested in a timely manner after the sale. In addition, due to the scale of planting and other factors, greenhouse yam is now more manual digging, because the yam skin is very thin, in digging yam to prevent mechanical damage, yam with mud wrapped skin stacked for sale.

or

The first: it is suitable for growth in the cave tube. In addition to cave tube cultivation, reasonable fertilization or complete application of well-rotted organic fertilizers can enhance the yield and quality of yam. Organic fertilizers can improve soil composition, provide sufficient nutrients, extend the time for nutrient release and utilization, enhance root respiration, and provide sufficient water. Yam plants that are just starting to sprout new shoots get their nutrients from the mother potato. Yams that are in the early stages of development need more nitrogen fertilizer to promote its growth, and potash is especially important when the potato clods start to form. Yams seem to readily absorb phosphorus fertilizer from the soil, and in addition, the addition of magnesium fertilizer would also help with yields.

The second: the cultivation of yam, must choose fertile soil, deep soil, water and fertilizer retention, good aeration, drainage and irrigation convenient sandy soil deep turning 35-45 cm, deep turning of the land, to first turn the top layer of topsoil above the 20-30 cm to one side, and then continue to deep turning to 35 -45 centimeters, do not turn over the soil layer. After the deep turning of the land, a cultivation ditch is formed, and the base fertilizer can be applied to the cultivation ditch. Base fertilizer is generally applied 20 kg of calcium superphosphate, 3000 kg of rotted organic fertilizer, 200-300 kg of grass ash. Fertilizer can be applied to the bottom of the planting ditch filled with the original turn up the topsoil, the thickness of 15 cm, and then applied to the base fertilizer on top of the soil layer, and then finally covered with soil 15 cm.

The yam fertilizer mainly in the growth of the middle and late, the early need for fertilizer is less. Yam seedlings neatly after the application of 1 time 20% of human urine fertilizer, and then every 20-30 days to apply 1 time. Fertilizer can be dug 30 cm away from the plant in a 6-10 cm deep fertilizer ditch, mu 700-1000 kg of human urine. When the underground tubers enter the vigorous growth period, they should be reapplied 1 time of fertilizer. Mu with 20-30 kg of compound fertilizer, cake fertilizer 40-60 kg hole or ditch, covering the soil after fertilization to ensure that the tuber elongation and expansion of sufficient nutrients. Later on, depending on the growth of the plant to determine whether the fertilizer.

Medicinal use

(Note: It is the rhizome of yam in the genus Dioscorea, family Dioscoreaceae).

1, heart and abdominal distension, hands and feet syncope, do not think of food. Use Dioscorea half raw and half fried for the end. Each serving two money, rice soup off Ding. The second time a day.

2, forbidden mouth dysentery. The treatment is the same as above.

3, urination. Use Dioscorea (alum boiled in water), Poria, equal parts of the end. Each serving of two coins, water to send down.

4, phlegm wind asthma. Use raw Dioscorea (pounded) half a bowl, add sugar cane juice half a bowl, and well, a drink.

5, weak spleen and stomach, do not think of food. With Dioscorea, Atractylodes macrocephala each one or two, ginseng seven and a half, *** research for the end, add water and paste made into pills, such as small beans. Each serving forty to fifty pills, rice soup sent down.

6, dampness and heat deficiency. Use Dioscorea, Cangzhu and other points, add rice to make pills sent in rice soup.

7. Swelling and poisoning at the beginning. With the mud of dioscorea, castor beans, glutinous rice and other points, soaked in water, research and apply a fine coating that is dispersed.

8, hands and feet frostbite. There is a cut of Dioscorea, grinding mud on the compress.

Rootstocks into medicine, nourishing and strong, treating deficiency of the spleen and stomach, etc., can also be used as a side food and winemaking raw materials.

Dioscorea bulbifera is a plant of Dioscoreaceae family, the rhizome of which is transverse and resembles ginger, also known as yellow ginger. The root is used as medicine.

The rhizome of Dioscorea peltata is mainly used to extract diosgenin, which is a good raw material for synthesizing adrenocorticotropic hormone drugs. Now the international and domestic use of Diosgenin as raw material for the production of 60 to 70 kinds of steroid hormone drugs, widely used in the treatment of cancer, cardiovascular and cerebrovascular diseases, respiratory diseases, contraceptives and other aspects.

Nutritional Analysis

1. Strengthening the spleen and stomach, digestion:

Yam contains amylase, polyphenol oxidase and other substances, which is conducive to the spleen and stomach digestion and absorption function, it is a flat complement to the spleen and stomach of the dual-use of medicine and food products. Whether the spleen yang deficiency or stomach yin deficiency, can be eaten. Clinically, it is often used to treat weak spleen and stomach, eating less body tiredness, diarrhea and other diseases;

2. Nourish the kidney and benefit the essence:

The yam contains a variety of nutrients, there is a strong body, nourish the kidney and benefit the role of the essence. Any kidney loss sperm, women's leukorrhea, urination, etc., can be served;

3. beneficial lung cough:

Yam contains saponins, mucus, lubrication, moisturizing effect, so it can be beneficial to the lungs, nourish the lungs, lung yin, lung deficiency phlegm cough cough of the disease;

4. lowering blood glucose:

yam contains mucus proteins, has a lowering of blood glucose can be used for the treatment of diabetes, is diabetic diet. Treatment of diabetes, diabetic dietary therapy good;

5. prolong life:

Yam contains a large number of mucus protein, vitamins and trace elements, can effectively prevent the precipitation of blood lipids in the blood vessel wall, to prevent heart and blood diseases, to obtain the benefits of tranquility, prolonging the efficacy of life;

6. anti-hepatoblastic coma

In recent years, studies have found that yam has a sedative effect, can come to the anti-hepatoblastic coma. The most important thing to remember is that it can be used as an antidote to hepatic coma.

Consumption of people

The general public can eat.

1. Suitable for diabetics, bloating, post-disease weakness, chronic nephritis patients, long-term diarrhea;

2. Yam has the effect of astringency, so the dryness of the stool should not be eaten; in addition, there are solid evils of the people who avoid eating yam.

Food Compatibility

Do not consume yam and Gan Sui together; also should not be taken with alkaline drugs.

Preparation guide

1. Yam needs to be soaked in salt water immediately after slicing to prevent oxidization and blackening.

2. Fresh yam will have mucus when cut, it is very easy to slip the knife and hurt your hand, you can wash it with water and a little vinegar first, which can reduce the mucus.

3. Yam texture is delicate, sweet flavor, however, the skin of the yam can easily lead to skin allergies, so it is best to use the peeling method, and peeled yam hands do not touch, wash your hands a few times right away, otherwise you will scratch wherever itchy.

4. Good yam skin without injury, with mucus, fault snow white, mucus more, less water. The skin can be freshly fried, or dried and fried soup, porridge. Peeled to eat, so as not to produce hemp, prickly and other abnormal taste.

5. Fresh yam is mostly used for deficiency cough and thirst disease, fried and eaten to treat the spleen and stomach, kidney qi deficiency.

The eating method of yam

Introduction of several common eating methods:

(1) chicken stewed yam (simmering soup)

Main ingredients: 2000 grams of fresh yam, fresh chicken 1000 grams. Accessories: 2 green onions (cut into pieces), 3 slices of ginger, sesame oil, salt, pepper a little. Practice: 1, the yam cut into segments. 2, with a pressure cooker will be fast chicken slightly pressure three mature and pour into the yam segment and add accessories and then burn 20 minutes with a slight fire can be.

(2) stir-fried sliced yam

Main ingredients: fresh yam a number of. Accessories: 2 green onions (cut into pieces), garlic 1 (chopped), ginger, vinegar, sesame oil, salt, pepper a little. The practice and vinegar fried lotus root slices like.

(3) yam fried meat

Main ingredients: 200 grams of fresh yam, 300 grams of tenderloin. Accessories: 50 grams of carrots, 50 grams of cucumber, 2 green onions (cut into sections), 3 slices of ginger, salt, wine, pepper each a little. Herbs: astragalus 5 money, windproof 3 money, atractylodes 2 money, 10 jujube. Practice: 1, the carrot, cucumber with a serrated knife cut into sections. 2, herbs plus ginger slices with 4 bowls of water to boil 1 bowl of medicinal juice standby. 3, tenderloin cut thin slices and add all the seasoning mix marinade. 4, a little oil fried scallions, into the meat slices stir-fried until brown. 5, pour yam, carrots and cucumber, pour down the medicine juice, add salt seasoning stir fry for about 1 minute.

(4) will be fresh yam peeled and washed, cut into soybean particle size, into the soybean milk machine grinding and cooking, that is, known as yam pulp (can add the right amount of sugar)

therapeutic effect

yam taste sweet, sex flat, into the lungs, spleen, kidney meridian; not dry and not greasy;

with the spleen and lungs, stomach, kidney, kidney, kidney and sperm, bright ears and eyes, to help the five viscera, strong muscles and bones, It has the effect of strengthening the spleen and tonifying the lungs, benefiting the stomach and tonifying the kidney, helping the five organs, strengthening the bones and muscles, strengthening the muscles and bones, increasing the will and tranquillizing the mind, prolonging life;

It is mainly used in treating the weakness of the spleen and stomach, tiredness and weakness, loss of appetite, prolonged ejaculation and dysentery, weak lung qi, phlegm, asthma and coughing, deficiency of the kidney qi, soreness of the waist and knees, weakness of the lower limbs, thirst and frequent urination, premature ejaculation, leukorrhea, redness of the skin and obesity.

Other related

"Compendium of Materia Medica" summarizes the five functions "benefit kidney qi, strengthen the spleen and stomach, stop dysentery, phlegm and saliva, moist skin," yam porridge or simmering with rock sugar and take, on the poor body, enteritis, kidney deficiency and other chronic diseases have therapeutic effects.

1. Tonic spleen and stomach: treatment of weak spleen and stomach, diarrhea, body fatigue, low food, sweat.

2. Benefit the lungs and kidneys: this product is not cold and not dry, sweet taste and moist, can treat thirst, spermatorrhea and dyspareunia of the lungs and kidneys deficiency and other conditions.

★ Warning

1. Saponin contained in the skin of the yam or the mucus contains phytochemicals, a small number of people will cause allergic itching yam contact, yam should be avoided in direct contact with the handling of yam.

2. Can not be eaten raw, because the raw yam has certain toxins.