Purple-leaf dwarf cherry is generally propagated by grafting, but it has high cost, slow propagation, easy variation and short life. In recent years, the author conducted experiments on hardwood cutting techniques of Prunus humilis in autumn and winter. The results show that this method is low cost and fast, and the survival rate of cutting is over 95%. The key techniques of hardwood cutting in autumn and winter are briefly described as follows:
Cuttings selection
Cuttings are prepared to select 2-3 year-old and vigorous plants as mother trees. After defoliation in late autumn, the annual branches without pests and diseases are cut from the mother tree, or the cut branches with thick buds, no pests and diseases and no mechanical damage can be used as cuttings with plastic pruning. Cut the selected cuttings into branches of 25 ~ 45 cm, bind them according to 100 ~ 150, bury them in wet sand for preservation, and seal the cuttings layer by layer to prevent the buds from sprouting or losing water due to excessive temperature.
Selection and arrangement of nursery land
Nursery should be selected in a place with convenient irrigation and drainage and transportation, and the soil layer should be deep, fertile and loose sandy loam. Before soil preparation, spread 1.2 ~ 1.5t decomposed farmyard manure evenly on every 660m2 of land, and conveniently spread it in the soil for soil sterilization and disinfection; Then, the underground pests can be killed by spreading the pest level. Then plough deeply, rake finely, level the land, remove weeds, waste agricultural film and other sundries, and make a good border. Purple-leaf dwarf cherry likes humid environment, but it is not resistant to stagnant water. It should be planted in high drought places, not in low-lying places. The length of the border depends on the nursery. The border width is 1 ~ 1.5m and the height is 30cm. There is a ditch between the boundaries, 40 cm wide and 30 cm deep. When it's done, press it a little, level the border and prepare for cutting.
Cutting time
165438+1from mid-October to mid-February.
Cutting method
Before cutting, the branches that have just been cut or stored in wet sand should be cut off, and then the long branches should be cut from bottom to top into 15 ~ 18 cm long with 5 ~ 8 buds. Cut a horseshoe-shaped smooth slope at the lower end of the cutting near the bud to increase the contact surface between the cambium and the soil, which is beneficial to rooting. The upper end of the cutting is cut into a plane at a distance of 0.8 ~ lcm from the bud eye. Immediately after cutting, immerse the downhill surface in clean water 15 ~ 20h to make the cuttings fully absorb water. Put the cuttings in the rapid rooting solution (or the mixed solution of 1000% B- indoleacetic acid and B- indolebutyric acid is 10 times), soak them in 12s, and then take them out to dry. The inclined plane of the cuttings is inserted downward into the soil, the row spacing is 6cm×8cm, and the upper buds are exposed to the ground for 0.5 ~ lcm. Water the cuttings immediately after cutting, and be sure to water them thoroughly, which is beneficial to the close combination of cutting and soil. When the ground is slightly dry, cover it with a double-layer thin plastic film to preserve moisture, and build a small thick plastic arch shed with the height and width of lm at the edge, which can cover the grass curtain or reed curtain to keep warm and keep out the cold.
Cutting seedling management
After cutting, you must do a good job of shading, and the illumination is about 30%. The seedbed with plastic film and small arch shed can be kept without irrigation for a long time, such as the soil under the film is dry, and then irrigation along the border 1 time. The temperature should be controlled between16 and 25℃, and the humidity should be about 80%. When the minimum temperature drops to MINUS 5℃, the arch shed should be protected from freezing and warmth with straw curtains; When the minimum temperature rises to O℃, open the straw curtain during the day and put it down at night; When the lowest temperature reaches above 5℃, the arch shed should be opened during the day to release air properly to prevent high temperature from burning seedlings. In order to prevent the substrate and cuttings from producing mold, it is necessary to spray antifungal drugs regularly, such as You Le Jing and Green Shield. At the beginning of March, when the seedling height is 3 ~ 5 cm, the root system is basically formed, and the young root can grow to 1 ~ 3~5cm. During the day, the plastic film is removed to ventilate the seedlings, and the ventilation rate increases gradually with the growth of the seedlings. From the middle and late March to the beginning of April, pay attention to keep the seedbed moist. In mid-April, the shed film was removed, and timely fertilization, weeding and watering were carried out. At this time, it is best to transplant the upper pot into a simple thin-walled soft plastic pot, and the soil in the pot should be compacted so that the soil in the pot can become a lump when planting. Shade, water, and put it under a shade shed. It can be planted after 1 week.
Transplanted seedling management
In late April, transplantation was carried out after 4 pm in rainy or sunny days. Before seedling emergence, plastic pots should be filled with enough water to facilitate seedling emergence and reduce root damage, and roots should be covered with clods. When transplanting, the plant spacing is 30cm×50cm. Before transplanting, apply 4 ~ 5 tons of decomposed farmyard manure and 50 kg of ternary compound fertilizer per mu, 15%, and transplant after deep ploughing and fine harrowing. After planting, it is necessary to pour enough water, keep the nursery dry and not too wet, and strengthen the prevention and control of diseases, pests and weeds. At the beginning of June, before rainy days or dry irrigation of soil, 20 kilograms of Oolong bamboo were sown on each mu of land to promote the growth of seedlings. Appropriate topdressing should also be done during the growth period. Topdressing NPK compound fertilizer 1 time in early spring and early summer respectively, and applying ring fertilizer 1 time in late autumn. For newly planted seedlings and seedlings that lack fertilizer and grow poorly, foliar fertilization can be carried out at a concentration of 0.5%, and should be sprayed in the morning or evening. It should not be done at noon when the light is sufficient and before and after the rain. It should be sprayed three times, with an interval of 10 ~ 15d. The average height of transplanted seedlings in that year can reach 1.2 ~ 1.5m, and the ground diameter1~1.5cm. ..