Seed propagation and cultivation techniques of Eucommia ulmoides

Eucommia ulmoides is a plant of Eucommia ulmoides family, also known as silk skin, silk skin, with the functions of tonifying liver and kidney, strengthening muscles and bones, calming stocks, lowering blood pressure and so on. It originated in China and has been cultivated for nearly a thousand years. The growth rate of Eucommia ulmoides is relatively slow at the beginning, the rapid growth period appears in 10 ~ 20 years, the growth rate of trees slows down gradually in 20 ~ 35 years, and then almost stagnates. The growth process of bark is almost consistent with the tree height, and the bark yield varies with tree age, and is also affected by environmental conditions. Eucommia ulmoides likes light, does not have strict requirements on soil and temperature, and can safely survive the winter when the temperature is-20 ℃. However, it grows rapidly in humid and high temperature areas. The seed has a certain dormancy, after low temperature stratification of 8: 10 ℃ for 50: 70 d, the germination rate can reach about 90%, the seed life is shorter, generally less than 1 year, and it is easier to lose the germination ability after drying, so it is appropriate to sow the seed immediately after harvest.

1 selection of nursery land

Select land with loose, moist, fertile and well-drained land. Before raising seedlings, the nursery was ploughed deeply and carefully, weeds were removed, basal fertilizer was applied, and cake fertilizer was applied for 2 250 ~ 3 000kg/hm2. At the same time, cooked lime 150~225kg / hm2 was applied to disinfect the soil and kill underground pests. Then the ground is fined and made into a fine bed 1m wide.

2 sowing

It can be propagated by seed, cuttage, striping and grafting, and seed propagation is the main method in production. When collecting seeds, the trees that are more than 15 years old and grow sunny on fertile soil should be selected as the mother tree. The mature, fresh, full and yellowish brown glossy seeds should be sowed in November-December or February-March when the monthly average temperature is more than 10 ℃. Generally, they should be sowed in winter in warm areas and sowed in autumn or spring in cold areas to meet the low temperature conditions needed for seed germination. Seeds should not be dry, so it is appropriate to sow seeds while they are fresh. If spring sowing is needed, the seeds should be stratified after seed collection, the ratio of seeds to wet sand is 1 ∶ 10, or the seeds should be soaked in 60 ℃ water before sowing, naturally cool down, keep 20 ℃, soak for 2 days, change water twice a day, when the seeds expand and the pericarp soften, mix with plant ash and dry soil after slightly drying, mix and sow seeds evenly. Strip sowing row spacing 20~25cm, seed amount 120~150kg/hm2, covering grass after sowing and watering water to keep the soil moist to facilitate seed germination. After the seedlings were unearthed, the cover grass was removed on a cloudy day, and 45 ~ 600000 seedlings / hm2 could be produced.

3. Nursery management

3.3.The seedlings with overdense seedlings were transplanted separately to keep the plant distance 8~10cm, and it was better to transplant before opening the true leaves after basically coming out of the seedlings, and there was almost no root in the roots without the true leaves. Gently pick it out with hard bamboo slices in cloudy days or evening (bring mud as far as possible), plant as soon as possible, water after planting, and fertilize once with very light human urine feces or urea point after 7-10 days.

3.2 pull up the grass and loosen the soil after the seedlings are unearthed to prevent grass famine; loosen the soil and weed after 4 true leaves. Early hoe can increase the soil temperature and counteract the source of the disease, loosening the soil and weeding 4 times in the whole seedling stage, pulling grass but not loosening the soil in the high temperature period in August. Can also be combined with deep ploughing, forest-grain intercropping, ploughing instead of caressing.

3.3 fertilization at seedling stage should be "eat less and eat more", farm manure and compound fertilizer are better, fertilization should be light, it is appropriate to pour thinly after each loosening soil, and ammonium bicarbonate should not be used to prevent fertilizer damage. After seedling height 30cm, urea can be sprinkled on rainy days, each time the dosage of 60~75kg/hm2. After seedling height 40cm, urea can be lightly sprinkled once every 15-20 days. Eucommia ulmoides seedlings grow sharply in autumn, and fertilizers catch up, and the big ones can grow 1.0-1.1 m high in that year, and high-quality seedlings can be cultivated. Topdressing can be applied with nitrogen fertilizer 120~180kg/hm2, phosphate fertilizer 120~180kg/hm2, potassium fertilizer 60~90kg/hm2, or farm manure 25kg per plant, ring trench depth 15~18cm, and soil mulching after fertilization.

4 colonization

When the one-to two-year-old seedlings are more than 1m high, they can be planted after defoliation and the following spring. Row spacing 1.5m × 2.0m, hole diameter 70cm, deep 70cm, transplanting at the same time. In the year of transplanting, it was generally ploughed for 3 to 4 times, combined with fertilization. Farm manure was applied once before sprouting and once after defoliation in spring, and the high quality barnyard manure was 30.0 ~ 37.5 t/hm2. In the northern region, fertilization was stopped in August to avoid overgrowth in the late stage and reduce the cold resistance.

(5) Disease and pest control

The main diseases and insect pests are blight, root rot, leaf blight, leopard silkworm moth and so on. In the prevention and control of blight, ferrous sulfate powder 105 ~ 150kg/hm2 or 40% formaldehyde solution 45kg / hm2 was sprayed during soil preparation, and then covered with grass to disinfect the soil; when sowing, 50% carbendazim 37.5kg/hm2 was mixed with fine soil and sprinkled on the seedbed or in the sowing ditch; 50% carbendazim 1000 times solution was used to irrigate the initial stage of the disease. In the cultivated land with high groundwater level or poor drainage, Eucommia ulmoides is prone to root rot and the whole plant dies, so it is necessary to strengthen drainage, dig out diseased trees and burn them and disinfect the tree holes with 50% formalin. Leaf blight harms the leaves and dies when the leaves are serious. The nursery should be cleaned and 1 ∶ 1 ∶ Bordeaux solution should be sprayed during the growing period. In the prevention and control of leopard silkworm moth, the countryside is cleaned in winter; in early June, the tree trunk is painted with whitening agent before the adults lay eggs, and 40% dimethoate emulsion is sprayed on the tree trunk during the larval incubation period.

6. Harvesting and processing

Eucommia ulmoides can not be peeled until it has been planted for more than 10-15 years, and the peeling will take place from April to June. Use a saw to saw a ring on the ground, deep to the xylem, and then saw the second ring at the upward interval of 80cm. Cut all the openings between the two rings and gently peel the edges at the cuts to peel off the bark and xylem. After harvesting, the bark is scalded with boiling water and flattened, and the inside of the bark is pressed layer by layer around the grass to make it sweat. After about 7 days, the endothelium is dark purple-brown, take out and dry, scrape off the rough skin.