A New Technique for Planting Chinese Medicinal Material Yam

I. requirements for environmental conditions

Chinese yam is a perennial vine, sexual warmth, not resistant to frost. The optimum temperature for germination, stem and leaf growth, tuber expansion and tuber expansion were 25 ℃, 25 ℃, 25 ℃-28 ℃, 20 ℃-24 ℃ and 10 ℃ respectively. Chinese yam is shady-tolerant, but the formation of tubers and the accumulation of nutrients still need strong sunlight. Chinese yam avoid continuous cropping, drought-resistant and waterlogging-resistant, and grow well in deep, neutral, loose and fertile sandy loam.

II. Cultivated varieties

Yam tubers are long columnar, flat or cylindrical. There are two kinds of Chinese yam cultivated in China: common yam and field potato, and the cultivated varieties are all local varieties. Famous varieties include Henan Boai, Huaxian Huashan yam, Shandong Jinan Changmao yam, Jiangsu Peixian flower seed yam, Jiangxi Shanggao sweet potato, Jiangxi Nancheng foot yam, Jiangxi Guangfeng big sweet potato, Jiangxi Ruichang yam and so on.

III. Cultivation techniques

1. In the cultivation season, Chinese yam is generally cultivated in the open field, planted in spring and harvested in autumn, and the growing period is more than 180 days. The Yangtze River basin is usually planted in the first and middle of April.

two。 Selecting land for fertilization, Chinese yam is drought-resistant and afraid of stains, so we should choose sandy loam soil with high dry topography, deep soil layer, drainage and irrigation, and rich in organic matter. In winter, deep ditches were dug with a distance of 1 meter, a width of 30 centimeters and a depth of 1 meter. After the Beginning of Spring, 5000 kg of rotten farm manure, 100kg of cake fertilizer, 50kg of calcium magnesium phosphate fertilizer and 150kg of plant ash were applied per mu as base fertilizer, which was fully mixed with the turned-out soil and backfilled in the ditch. Then ridge, ridge width of 70 cm, ridge height of 25 cm, and covered with black plastic film to wait for planting.

3. Reproduction method ① zero seed breeding method. Chinese yam bean, also known as yam bean, is an aerial tuber formed in the axils of yam leaves. When the yam is harvested, the leftover seeds growing on the stem are picked, dried and stored in a low-temperature dry place. Before sowing, bury the leftover seeds in wet sand and maintain the temperature of 20 ℃-30 ℃. After 10-15 days, the seeds can sprout. When 80% of the seeds sprout, plant 2 rows according to a wide border of 1 meter, the plant spacing is 10 cm, and grow into a small yam tuber of 25-30 cm in that year, and the next year it is planted with a whole tuber. ② tuber propagation method. During harvest, the large tubers with strong resistance, high yield, pure variety and correct individual were selected as seed plants and stored in a dry and cool place after drying. Any part of the long tuber likes to produce adventitious buds and can be propagated in segments at will. Lumpy species tend to germinate only at the top and should be cut longitudinally when chopped. Seed block 50-100g, cut with plant ash and planted indoors for 2-3 days. ③ yam planting and breeding method. The upper end of the yam tuber is thinner, the apex has hidden buds and stem scars 30-40 cm long, weighing about 100 grams, often cut this section for seed use, called yam planting. Coat the cut with plant ash, dry it, store it in a cool and dry place, and plant it in the next year.

Among the above three propagation methods, the Chinese yam seed propagation method sprouts quickly and the seedlings grow healthily, but the workload is heavy, so it is difficult to use in large-scale production. The advantage of tuber propagation method is that it is not easy to degenerate for many years, which is beneficial to variety improvement, but it consumes more tubers and takes time and time to cut. The method of zero seed propagation can save a lot of tubers and save labor, which is mainly used in production, but it will lead to germplasm degradation if it is used continuously for many years, and it is usually propagated once every 3-5 years.

4. Plant a row in each ridge, dig the planting hole according to the plant distance of 25 cm, plant the breeding material in the planting hole, 1 plant in each hole, cover the soil and compact after planting, and pour enough water to fix the root.

5. Field management ① scaffolding and pruning. After the emergence of Chinese yam, the vines are slender, crisp and tender, should be set up in time, commonly used herringbone or tripod, 1.5-1.8 meters high. The stem and vine of Chinese yam is strongly branched, the vine leaves are clustered, and the nutrition consumption is large, so it should be pruned properly, and the basal side branch or only one main stem should be deleted to facilitate ventilation and light transmission and increase the yield. When propagating with tuber cuttings, several buds sprout at the same time, generally retaining a robust bud and wiping out the excess buds. ② fertilizer and water management. After the emergence of yam, 5-8 kg urea per mu was applied to water to promote the growth and growth of stems and leaves. When the tuber began to expand, 10-15 kg of N, P and K ternary compound fertilizer was applied per mu. At the same time, starting from the expansion of tubers, potassium dihydrogen solution was used every 10-15 days to prevent plant premature senescence. Chinese yam is generally not watered in the early stage of growth, but in the peak period of tuber growth, the soil must be kept moist and not watered. In the rainy season, attention must be paid to ditching and drainage to prevent waterlogging. Straw was covered between rows in mid and late June to lower the temperature. It is dry in August and can be watered properly. ③ pest control. The main diseases of Chinese yam are anthracnose, brown spot and nematode, and the pests are leaf wasp, mole cricket, grub and other underground pests. Anthrax can be sprayed with 50% anthrax Fumei wettable powder 300 times or 75% chlorothalonil wettable powder 500 times at the initial stage of the disease. Brown spot can be sprayed with 70% mancozeb at the initial stage of the disease, once every 3-7 days, 2-3 times in a row. Underground pests such as nematodes, mole crickets and grubs can be irrigated with 1500 times of 50% phoxim EC or disinfected with Milol. The leaf wasp was controlled with 2.5% Kung Fu EC 3000 times during the peak period of adult and egg hatching.

6. When the leaves die and the underground tubers stop growing, the yam can be dug and listed on the market. The average yield per mu is 1200-2000 kg.

7. When the introduction starts to develop the production of Chinese yam, it must be introduced to the producing area and suitable varieties should be introduced according to consumption habits or uses. First, a small amount of introduction was made to observe its adaptability, economic characters and cultivation benefits, and then it could be developed in a large area.