Cultivation techniques of Xu Changqing

Xu Changqing is the root and rhizome or rooting whole grass of Xu Changqing, a perennial herb of Asclepiadaceae, which is distributed in most parts of the country and is mostly wild in hillside or roadside grass. It is mainly produced in East China, Guizhou, Guangxi and Northeast China. In recent years, drug farmers in East China and other places have successfully carried out wild breeding experiments, including small-scale cultivation.

Growth habit

Xu Changqing is a perennial erect herb, as high as 60~80cm. It has strong adaptability to climate. It can grow normally in the mountains and plains of the north and south of the Yangtze River. It likes warm and humid environment, but it avoids stagnant water, has strong resistance to heat and cold, and can still grow normally when the temperature is above 30 ℃. Under the temperature of-20 ℃, the underground rhizome can also survive. All the plants with more than 2 years old could blossom and bear fruit, but the fruiting rate was low. The seeds are easy to germinate, the optimum temperature for germination is 25 ℃ ~ 30 ℃, the germination rate is more than 90%, and the seed life is 2-3 years.

Planting technology

It is better to choose fertile sandy loam which is rich in humus, deep soil layer and good drainage. Apply fully mature farm manure 2000~3000kg per mu, add calcium superphosphate 30kg as base fertilizer, deep 30cm, level and rake fine, make a high border, border width 130cm, length 6m 10m, or depending on the topography, the border surface is tortoise back shape, and finally open a good size drainage ditch according to local conditions.

Reproduction method

Seed propagation (seedling transplanting) and ramet propagation are commonly used in production.

1. Seed propagation. Select seeds that are more than 2 years old and are mature, full and with a germination rate of more than 80%. The sowing time of spring sowing is from February to March, and autumn sowing from September to November is mostly adopted in low temperature areas. The nursery land opened a high border with 130cm width, sowed in ditches according to the row spacing 15cm, the ditch depth was about 2cm, the bottom of the ditch should be flat, the sowing ditch was sprinkled with a layer of rotten compost powder and dung water, the seeds were mixed well with plant ash, evenly scattered in the sowing ditch, and then covered with a layer of burning soil or humus soil after sowing, finally covered with grass to keep the border moist. The seedlings can emerge after 3 weeks, and the cover grass can be removed in time after emergence. After finishing the seedlings, the seedlings can be fixed many times according to different plant spacing, and the soil can be loosened, fertilized and weeded in time. After one year of careful cultivation, the seed roots were carefully picked and transplanted after falling seedlings in winter and before germination in the following spring. The distance between plant and row was about 22~26cm, with 2 plants in each hole. When planting, the root system was straightened, the soil was compacted, and the root was fixed by dung water. The sowing amount per mu of seed seedling propagation is 1.5~2.5kg, and the transplanting field can be expanded by 8 to 10 mu.

2. Ramet propagation. In early spring, the underground rhizome of Xu Changqing was dug up, and the fresh rhizome, which was strong, dense in color and free from diseases and insect pests, was selected, and the excessively long fibrous root was cut off for medicinal use, leaving the root about 5cm, and then according to the number of bud mouth, the rhizome was cut, and the mother stalk was divided into several plants, each keeping 1 or 2 bud mouths. The planting method is the same as that of seedling transplanting. 45~80kg needs to be planted in each mu of field, and the rhizome of mother Honda can be transplanted to about 10 mu of field per mu.

Field management

1. Replenish seedlings with inter-seedlings. The seedlings emerged 20-25 days after sowing in the seedling field, and the seedlings began to grow after the seedling height was about 3cm, and then it was carried out 2 or 3 times successively. When the seedling height was 7~10cm, the method of leaving seedlings with the wrong plant was adopted, the plant spacing was 6~10cm, and the row spacing was about 15cm. When it is found that there is a lack of seedlings, it should be replanted in time.

2. Ploughing and weeding. One week before the soil preparation, the ground was sprayed with herbicides such as Roundup, and then the soil was prepared and ditched for sowing. Cover the border with a layer of raw or burning soil before emergence. The temperature at the seedling stage is low and the plant growth is slow, but the weeds are especially harmful to Xu Changqing at the seedling stage, so we must seize the opportunity to loosen the soil and weed for 2 or 3 times before closing (seedling height 15~20cm). Loosen the soil near the plant shallow loose, between the rows can be deeper, so as not to hurt the root, to protect the seedlings, to prevent being oppressed by the soil, but also not to damage the stem of the seedling. Soil consolidation should also be loosened in time after rain.

3. Cultivate the earth and choke the earth. After the seedlings survived, when the seedlings were high 20cm, the livestock manure was mixed with burning soil or other fertile soil without weed seeds, and the thickness of the plant stalk was not more than 3cm, which could promote the growth of the underground part of the plant and increase the yield.

4. Reasonable topdressing. In addition to applying sufficient base fertilizer before soil preparation, topdressing must be applied properly for 2 or 3 times. For the first time before Qingming Festival, when the seedling height was 3~6cm, 1500kg light human and animal manure water (or urea 4kg to water) was applied to the roots per mu to promote seedling growth, and the second time, in the first and middle of May, nitrogen, phosphorus and potassium fertilizers were applied simultaneously, mixed well with high quality ternary compound fertilizer 8~12kg plus rotten cake fertilizer powder 25kg per mu, and applied at holes off the seedling 10cm to meet the needs of plant branching and increasing leaves. For the third time before and after Grain in Beard, the method of seedling fertilizer application was adopted, which was mainly composed of rotten human and animal manure water, biogas fertilizer liquid and other farm organic fertilizer. Each topdressing should be combined with ploughing and weeding. In addition, if the plant was topdressing the plant with potassium dihydrogen phosphate solution and other micro-fertilizer hormones for 2 or 3 times, it could improve the disease resistance, lodging resistance and yield of the plant.

5. Drainage and irrigation. Pay attention to watering the seeds after germination so that the soil moisture is moderate. In case of drought, water should be watered in time to resist drought to prevent plants from drying up and dying; when Rain Water is concentrated in the rainy season, it is necessary to prevent stagnant water and rot roots, and attention should be paid to timely ditch drainage.

6. Set up a fight. Along the ditch, two bamboo or wooden stakes are erected every 6m (the height of the wooden stakes is about 120cm). At the height of 25cm, 45cm and 65cm from the border, pull 2 strips of cloth or plastic rope respectively, and fix the seedlings that want to lodge on both sides of the rope. Build a frame in time to solve the problem that Xu Changqing is easy to lodge and lead to low yield, promote the normal growth of branches, increase the number of branches, thicken the stem, improve the plant height, so as to increase the yield.

7. Keep the seed. The management of seed field should be strengthened to avoid plant lodging prematurely. Extra-root topdressing with potassium dihydrogen phosphate at early flowering or proper spraying of compound Guoling at flowering stage can effectively increase fruit setting rate and promote seed growth. The fruit generally matures in September, because the mature fruit will automatically crack and the seeds will fall with the wind, so it should be harvested in time. When the fruit is yellowish green and is about to crack, it should be harvested in stages and in batches. Knead the harvested fruit in a plaque, remove the shell and tassel, choose mature, full, brown seeds to store in a dry and cool place, or store in Kraft paper bags and cloth bags. Pay attention to turning the sun frequently during storage to prevent adults and larvae from eating seeds.

Pest control

1. Disease. Generally speaking, Xu Changqing rarely occurs diseases, but he should pay attention to the harm of root rot, and the injured roots are black and rotten. The disease generally begins in early May and is serious from June to July and can last until the end of October. Poor drainage or low-lying terrain is beneficial to the disease. Prevention and control methods: timely drainage and loosening of soil in the rainy season to reduce the humidity between plants on the ground; timely removal of diseased plants and treatment of diseased points with lime to prevent spread. The medicament can use 50% carbendazim 500-fold solution, 70% Tushuxiao 500-fold solution, or 58% Ruidu wettable powder 600-fold solution, 25% Gen Fuling wettable powder 500-fold solution, 75% chlorothalonil wettable powder 600-fold solution to irrigate plant roots to reduce harm.

2. Insect pests. There are mainly aphids and bugs, which mainly harm the stems and leaves of young plants and suck fruit juice. Control method: spraying 40% omethoate 2000 times liquid per mu, or spraying plants with 20% dimethoate 20ml diluted with water 50kg, once every 7 days for 2 or 3 consecutive times to control insect pests.

Harvest and processing

Xu Changqing, which is propagated by ramets, can be picked and dug in the same year after planting. After 2 years of seed breeding, the seeds were harvested. Dig up the roots that do not need to be left as roots, wash the soil and dry in the sun. If it needs to be reserved for planting seedlings, the stems, leaves and roots will be harvested in autumn and spring respectively. After harvesting the stems and leaves, remove the soil and impurities, sun to semi-dry, tie them into small handfuls, and then dry them in the sun or shade. Root picking is generally carried out in combination with sowing in the early spring of the following year, and the seed roots are cut and reserved for seedling seeding, and the remaining roots are washed and dried for sale as medicinal materials. The dry stems and leaves of the whole grass are grayish green; the dried roots and rhizomes are dark brown and brittle. To dry, hypertrophy, color, no impurities, strong smell as a good product.