Yam

Dioscorea zingiberensis

Dioscorea oppositifolia L. is a plant of Dioscorea in dioscoreaceae, which is twined with grass vines. Tubers are long cylindrical and grow vertically. Stems usually purplish red, dextral, glabrous. Leaves simple, alternate below stem, opposite above middle. Male inflorescences are spikes, 2-8 cm long, nearly erect, with 2-8 inflorescences in leaf axils. Capsule not reflexed; seeds borne in middle of each locule. The flowering period is from June to September, and the fruiting period is from July to November.

They are distributed in Korea, Japan and China; in China, they are distributed in Henan, Anhui, Jiangsu, Zhejiang, Jiangxi, Fujian, Taiwan, Hubei, Hunan, Guangdong, Guizhou, Northern Yunnan, Sichuan, Eastern Gansu and southern Shaanxi. It grows in hillside, valley, forest, stream, roadside shrubs or weeds.

Tuber is a commonly used Chinese medicine "Huai yam", which is rich in starch and can be used as vegetable food; it can be used as medicine to fill the loss of spleen and stomach, treat Qi deficiency and weakness, dyspepsia, spermatorrhea, enuresis and unknown swelling poison.

(general drawing reference source:)

morphological character

Twining grass Liana. Tuber long cylindrical, vertical growth, up to more than 1 meter long, section dry white. Stems usually purplish red, dextral, glabrous. Single leaf, alternate in the lower part of stem, opposite above the middle, rarely 3-lobed; leaf variable, ovate triangular to broadly ovate or halberd, 3-9 (- 16) cm long, 2-7 (- 14) cm wide, apex acuminate, base deeply cordate, broadly cordate or nearly truncate, margin often 3-lobed to 3-lobed, middle lobe ovate elliptic to lanceolate, lateral lobes auricular, round, nearly square to long The leaves of seedlings are generally broad ovate or ovate, and the base is deep cordate. There are often bulbils in leaf axils. Dioecious.

The male inflorescence is spike, 2-8 cm long, nearly erect, 2-8 inflorescences in leaf axils, occasionally arranged in panicle; the inflorescence axis is obviously zigzag; the bracts and perianth have purple brown spots; the outer perianth of male flower is wide ovate, the inner one is ovate, smaller; stamens are 6. The female inflorescence is spike, with 1-3 inflorescences in leaf axils. Capsule not reflexed, trigonometric oblate or trigonometric round, 1.2-2 cm long, 1.5-3 cm wide, with white powder on the outside; seeds borne in the middle of each locular axis, surrounded by membranous wings. The flowering period is from June to September, and the fruiting period is from July to November.

Growth environment

It grows in the hillside, valley forest, stream side, roadside shrubs or weeds with an altitude of 150-1500 meters. Dioscorea zingiberensis is a short day, warm crops. The optimum temperature for seedling growth is 15-20 ℃. The optimum temperature at the peak growth stage was 25-28 ℃, and the growth was slow below 20 ℃. It is suitable to grow in loose, fertile and deep soil, but flat and massive species can also grow in shallow and sticky soil. Dioscorea zingiberensis is more tolerant to drought, but not to waterlogging, so it is not suitable to be planted in the soil with too shallow groundwater level or too wet. The water content of sandy soil and loam soil should be about 18%.

Distribution range

They are distributed in Korea, Japan and China; in China, they are distributed in Henan, south of Anhui Huaihe River, Jiangsu, Zhejiang, Jiangxi, Fujian, Taiwan, Hubei, Hunan, Guangdong (Zhongshan Niutoushan), Guizhou, Northern Yunnan (Gongshan, Deqin and Lijiang), Sichuan, Eastern Gansu and southern Shaanxi (350-1500 m).

Methods of reproduction

The propagation of Dioscorea zingiberensis is generally carried out by the methods of reed head propagation and zero surplus seed breeding.

The propagation method of Lutou is as follows

More than one node with buds at the top of root tuber is used as seed, which is called Lutou. In the winter of the first year, the tuberous roots with short neck, thick, no branches and no diseases and insect pests were selected, which could survive the winter underground. The root tuber is weak in water absorption and will wither soon after cutting. It likes a slightly humid environment. Yam requires sandy soil and loam with sunny and leeward terrain. The soil reaction is slightly acidic to slightly alkaline, and the soil layer is deep and fertile. It is not suitable to plant in heavy, sandy or alkaline soil.

The method of zero residue breeding and reproduction was as follows

Before and after frost, when the aboveground stems and leaves of Dioscorea zingiberensis will wither, pick up or pick up the remaining seeds from the leaf axils, air them for 2-3 days, and put them in bamboo baskets, cover them or put them into wooden boxes for storage. Attention should be paid to rat damage and ventilation during storage. One year's cultivation is necessary for the reproduction of Polygonum cuspidatum.

cultivation techniques

soil preparation

Dioscorea zingiberensis should be rotated for 2-3 years. In addition to ploughing after fertilization, the main purpose of soil preparation is to excavate loose ditches for tubers to extend downward. Generally, the ditch depth is more than 1m, the width is 20-25cm, and the spacing is 80-100cm. Manual trenching is time-consuming and is usually carried out before winter. Pay attention not to disturb the sequence of soil layers when backfilling after trenching. The special ditcher has high efficiency and can be used one month before sowing.

plant

It is generally required that the soil temperature of 5cm should be stable, and it can be planted after passing 9-10 ℃. It can be planted in South Sichuan and Guangdong in March, Sichuan in late March to April, North China in mid and late April, and Northeast China in early May. The planting method is to use a hoe to open a ditch for 8-10 cm, put the seed potatoes vertically in the ditch, and spread them evenly according to the bud mouth. The planting density is generally 375-45000 plants / ha, the plant spacing is 25-30 cm, and the row spacing is the ditch spacing. Before sowing, dig a sowing ditch with a depth of about 10 cm right above the furrow. Place the seed blocks in the ditch along the ridge according to the plant spacing. The upper ends of the seed blocks face the same direction. After planting, cover the soil and pat flat.

Administration

Pruning and erecting:

Dioscorea zingiberensis is a climbing plant. Before the seedling is 30 cm high, it must be erected, 1.5-1.7 meters high and 20-30 cm deep. It is often used as a frame or quadrangle frame. When the seed block germinates, generally one main stem can be extended, but sometimes more than two can be extended, resulting in 2-3 tubers, competing for nutrients, making each tuber thin and small, affecting high-quality production. After emergence, the redundant stems should be removed immediately, leaving only one strong main stem. In some varieties, there are too many lateral branches, so the lower lateral branches and the top of main stem and lateral branches should be removed properly in the middle and late stage. In general, it can be controlled at 1500-2250 kg / ha.

apply fertilizer:

Dioscorea zingiberensis needs a large amount of fertilizer. For every 1000 kg tuber, it needs to absorb 4.32 kg of pure nitrogen, 1.07 kg of phosphorus pentoxide and 5.38 kg of potassium oxide. Dioscorea should avoid chlorine, potassium chloride should not be used. In general, 45-75 cubic meters of decomposed organic fertilizer, 350-400 kg of diammonium phosphate, 250-300 kg of urea and 150 kg of potassium sulfate should be applied to the base fertilizer of high-yield field per hectare. Before soil preparation, the fertilizer should be spread in the field and ploughed in the soil layer of about 25 cm. In the vigorous growth period of stem, leaf and tuber, the fertilizer should be applied again. About 400 kg of N, P and K compound fertilizer was applied and watered per hectare.

Irrigation:

In the early stage, as long as the topsoil is less than 5cm wet, there is no need to water. Generally, the first watering should be done at about 1 meter of the seedling, and the second watering should be done at about 20 days' interval when the branches and leaves are in the peak growth stage. The first two watering should be done shallowly, and the flood irrigation should be avoided by all means. About one month after rehydration, the tuber will expand rapidly. If the soil is dry, it needs to be watered thoroughly. In autumn, pay attention to drainage and waterlogging prevention.

recovery

From late October to November, when all the stems and leaves withered, the tubers were harvested. The suitable temperature is 2-4 ℃ and relative humidity is 80-85%. It can be piled, buried or hoarded. In the warm south of China and the Yangtze River Valley, it can be listed as soon as it receives. Zero surplus seeds must be ripe and harvested.

Main value

Yam is the first food to nourish the spleen and stomach. It is a good product for entering the lung, strengthening the spleen and tonifying the kidney. The slimy juice of yam is mainly mucin, which can maintain the elasticity of blood vessels, and has the function of moistening the lung and relieving cough. Yam can be used with jujube for porridge, soup, or fried with various ingredients.

medical:

Dioscorea tuber is a commonly used Chinese medicine "Huai yam", the root can be used as medicine, sweet, warm, flat, non-toxic. It is mainly used in treating injury, tonifying deficiency and winning, eliminating cold and heat evil Qi, tonifying middle, tonifying Qi, growing muscle and strengthening Yin. Long service, smart eyes and ears, light body, not hunger, prolong life. The book of songs. Main head and face wind, head wind, dizzy eyes, lower Qi, stop low back pain, treat asthenia and labor, win thin, fill the five internal organs, remove vexation and heat. Don't record it. To make up for five labors and seven injuries, to cool the wind, to calm the mind, to soothe the soul, to make up for the lack of heart qi, to open up the mind, and to remember more. Zhen Quan. Strong muscles and bones, main discharge essence, forgetful. Daming. Tonifying kidney qi, strengthening spleen and stomach, stopping diarrhea, resolving phlegm and saliva, moistening skin and hair. Shizhen. The raw tamping paste can disperse the swelling and hard poison. Zhenheng.

Food:

Tubers are rich in starch and can be used as vegetables.