Key cutting techniques of Purple Leaf Dwarf Sakura in Autumn and Winter

Purple leaf dwarf cherry (prunsxcistenena) Rosaceae, plum belongs to deciduous small trees, about 2.5m high, the leaves are long ovate or ovate long oval, 4-8cm long, the leaves are red or purple, the back color is more red, the top of the new leaves are fresh purple, landscaping and beautification are very beautiful. The flowers are light pink and the florescence is from April to May. Like light, like warm and humid climate, do not have high requirements for soil. Cold-resistant, drought-resistant, high survival rate of transplanting, more resistant to pruning, can be made into a ball, can also be made into a ribbon group planting. The wood is fresh purplish red, showing leaves from the middle of April to the first ten days of May, and falling leaves in late November, all purplish red from budding to falling leaves. It is a world-famous foliage tree species, often planted in streets, parks and courtyards.

Purple leaf dwarf cherry is generally propagated by grafting, but it has the advantages of high cost, slow reproduction, easy variation and short life span. In recent years, the author has carried on the technical experiment of hardwood cutting in autumn and winter on purple leaf dwarf cherry. The results show that this method has the advantages of low cost and high speed, and the survival rate of cutting is more than 95%.

The key techniques of hardwood cutting in autumn and winter are briefly introduced as follows:

1. Cuttings selection: cuttings are prepared to select 2-3 years old plants with strong growth as mother trees. After defoliation in late autumn, the annual branches free of diseases and insect pests are cut from the mother tree, and the sturdy, full buds, disease-free and mechanical damage-free branches can also be used as cuttings combined with shaping and pruning. Cut the selected cuttings into branches of 25-45 cm, bind them according to 100-150 branches, bury them in wet sand and store them with a layer of sand, and seal them well to prevent the branches from sprouting or losing water through ventilation.

2. Nursery site selection and arrangement: nursery land selection and soil preparation should choose places with convenient drainage, irrigation and transportation, and the soil layer should be deep, fertile and loose sandy loam. Before soil preparation, 1.2-1.5 tons of rotten farm manure was evenly spread per mu (1 mu = 1/15ha), and 1.6kg of 50% carbendazim was scattered in the soil for soil sterilization and disinfection, and then 4 kg of 50% zinc and parathion granules were used to kill underground pests. Then deep ploughing, fine raking, leveling the land, removal of weeds, waste agricultural film and other debris, to make beds. Purple leaf dwarf cherry likes the wet environment, but is not resistant to stagnant water, should be planted in high dry places, do not plant in low-lying places, border length according to the nursery, border width of 1-1.5 meters, 30 cm high, leaving a ditch between the border, 40 cm wide and 30 cm deep. After a little suppression, the border surface will be ploughed and raked flat, ready for cutting.

3. Cutting time: from mid-November to mid-December.

4. Cutting method: before cutting, cut off the branches that have just been cut or stored in wet sand, cut off the weak branches and dry parts, and then cut the long branches from bottom to top to grow 15-18 cm with 5-8 buds. The lower end of the cuttings was cut into a horseshoe-shaped smooth slope near the bud to increase the contact surface between the cambium and the soil, which is beneficial to rooting. The upper end of the cuttings is cut into a plane 0.8-1 cm from the bud hole. After the cuttings are cut, the lower slope of the cuttings should be immediately soaked in clean water for 15-20 hours, so that the cuttings can fully absorb enough water, and the cut base should be put into a 10-fold mixture of 10% concentration of B-indoleacetic acid and B-indolebutyric acid, dipped in it for 12 seconds and then dried to be inserted to facilitate rooting. The cuttings are inserted obliquely into the soil, the plant row spacing is 6 cm × 8 cm, and the buds at the upper end are 0.5-1 cm above the ground. Immediately after cuttage, water must be irrigated thoroughly, which is conducive to the close connection between cuttings and soil. After the ground is slightly dry, it is covered with double-layer thin plastic film to preserve soil moisture, and at the same time, a small plastic arch shed with a height of 1 meter and the same width as the border surface is built on the border surface, which can be covered with grass curtain or Reed curtain for heat preservation and cold protection.

5. Cutting seedling management: shading must be done after cutting, and the illuminance is about 30%. The seedbed with plastic film and a small arch shed can be maintained without irrigation for a long time, such as the soil under the plastic film is dry, and then irrigate once along the border ditch. The temperature is best controlled between 16 and 25 ℃ and the humidity is about 80%. When the lowest temperature drops to minus 5 ℃, the grass curtain should be added to the arch shed to prevent freezing and heat preservation; after the minimum temperature rises to 0 ℃, the grass curtain should be opened during the day and put down at night; when the lowest temperature reaches more than 5 ℃, the arch shed should be opened during the day to prevent high temperature burns. In order to prevent the matrix and cuttings from producing mold, it is necessary to spray antibacterial drugs regularly, such as carbendazim, topiramate and so on. At the beginning of March, when the seedling was 3-5 cm high, the root system was basically formed, and the young root could grow to 1-3 cm. The seedlings were ventilated and trained with plastic film during the day, and the ventilation rate gradually increased with the seedling growth. From mid-late March to early April, pay attention to keep the seedbed moist. Take off the greenhouse film in the middle of April and fertilize, weed and water in time. Transplant the upper basin at this time, it is best to transplant to a simple thin-walled soft plastic basin, and the soil in the basin should be compacted so that the soil in the basin can become a lump when planting. Shading, watering, placed under the shade shed, can be planted after 1 week.

6. transplant seedling management: in late April, transplant will be carried out after 4: 00 p. M. on a rainy or sunny day. Before raising the seedling, the plastic basin should be filled with enough water to facilitate the seedling to reduce root damage, and the root system should take soil. At the time of transplantation, the row spacing was 30 cm × 50 cm. Before transplanting, apply 4-5 tons of mature farm manure and 15% ternary compound fertilizer 50 kg per mu, plough deeply and then transplant. Pour enough water after planting, keep the seedling land not dry but not too wet, and strengthen the prevention and control of diseases, pests and weeds. In early June, before rainy days or before soil drought irrigation, 25 kg of urea per mu was applied to promote seedling growth. It should also be fertilized properly during the growing period. Nitrogen, phosphorus and potassium compound fertilizer was applied once in early spring and early summer, and circle fertilizer was applied again at the end of autumn. For newly planted seedlings and seedlings that do not grow well due to lack of fertilizer, foliar fertilization can be carried out with a concentration of 0.5%. It is selected to be sprayed in the early morning or evening, and it is not suitable to be sprayed at noon when the light is sufficient and before and after the rain. The appropriate spraying times is 3 times with an interval of 10-15 days. In the same year, the average height of the transplanted seedlings can reach 1.2-1.5 meters, and the ground diameter is 1-1.5 cm.