Propagation methods of Populus tomentosa

Populus tomentosa, also known as boxwood, melon seeds, boxwood, Jinshu boxwood, etc., is mainly produced in Shaanxi, Gansu, Hubei, Sichuan, Guizhou, Guangxi, Guangdong, Jiangxi, Zhejiang, Anhui, Jiangsu, Shandong and other places. The main methods of reproduction are sowing and cutting propagation. Let's take a look at the breeding methods of Populus tomentosa.

Growth environment of Populus tomentosa

Populus tomentosa grows mostly in high mountains, steep cliffs, mountainous and stony places, tolerant to shade, likes warm and humid climate and loose and fertile soil, can grow in acidic, neutral and alkaline soil, developed root system, strong sprouting ability, weak cold resistance and anti-pollution.

Sowing and propagation of Populus tomentosa

1. Seeding bed: at the beginning of September, sandy soil with loose and fertile soil and good drainage was selected as sowing ground, and base fertilizer (organic fertilizer) was applied and mixed with insecticides and fungicides such as carbendazim.

2. Sowing rate: the sowing rate is 50-60 grams per square meter. after mixing the seeds with the right amount of sand, spread evenly on the seedbed, cover with fine soil 1-1.5 mm, and cover with a layer of grass curtain to moisturize.

3. Post-sowing management: after sowing, the seeds only grow radicles and do not germinate in the same year, in order to prevent frost injury, cover 5-8 cm of soil on the grass curtain before the soil is frozen in the middle and last ten days of November. In the middle and last ten days of March, the grass curtain and covering soil are removed, and the plastic arch shed is built on the seedling bed, and the temperature is controlled at 25-30 ℃. About 20 silkworm germs grow out of the soil surface, and then the temperature in the shed is controlled between 20-25 ℃ and properly watered. When the temperature is stable in late April, the plastic arch shed will be removed. At seedling stage, grass should be pulled to loosen the soil, timely irrigation, spraying 2% potassium dihydrogen phosphate solution for foliar topdressing, and timely prevention and control of diseases and insect pests.

Cutting Propagation of Populus tomentosa

1. Nursery bed: the cutting seedbed should choose the land with high topography, deep soil layer, loose soil and good drainage and irrigation. After removing the grass roots and stones, the beds were formed into a high border of about 1-1.2m and irrigated with 1000 times of imidacloprid and 1500 times of mancozeb to remove underground pests and harmful germs. After leveling the nursery bed, flatten it with a spade, pour 10% rotting rare human feces and urine, and then cover the bed with a layer of sifted coke ash or yellow soil, about 5 cm thick.

2. Cuttage: the cuttage propagation of Populus tomentosa can be carried out at any time, but the survival rate of cuttings with young branches growing in the same year is high in summer. The cuttings select the excellent branches that are lignified or semi-lignified in the same year. After cuttings are collected, cutting and cutting should be carried out in a cool leeward place, and the knife and scissors should be sharp. When cutting, the branches that have grown branchlets at the internodes are cut off at 0.5 cm above and below the nodes, and then the stem nodes are cut into two halves according to the location of the branchlets, and the branches that do not grow branchlets must be cut into 2 knots. the upper end is cut into a flat section at 1 cm above the bud, and the lower end is cut into a horseear or flat section at 0.5 cm from the bud.

3. Cuttage: the cuttings should be shallow rather than deep, the cuttings of branchlets should be cut flat and face down, the depth of the mother plant should be 1 cm, the depth of big branch cuttings should be 1 cm in the upper middle of the next stem node, and the cuttings should be tilted to about 45 degrees with the ground. Shallow oblique cutting is conducive to the early rooting and survival of cuttings. After cutting, the soil around the cuttings should be compacted and watered once, so that the lower part of the cuttings is close to the soil. The row spacing of cuttings is generally 12-15 cm, and the plant spacing is 6-8 cm. When cutting, the leaves on the cuttings should not be left too much, nor should they be completely cut off. The lower leaves can be completely cut off with the petioles, and the upper leaves can be left with 2 leaves. According to the size of the leaves, each leaf should be cut slowly by 2 to 2 times, so as to reduce the excessive consumption of water and nutrients.

4. Management: after cutting, boxwood is required to set up a shed for shade in order to reduce transpiration and direct sunlight on the seedbed. When cutting in early spring or late autumn, it should be covered with film to prevent winter damage. After cutting, the soil of the seedling bed should be watered frequently to keep the soil moist and the soil on the surface of the seedling bed should not show whiteness. Topdressing of cutting seedlings can be combined with watering, or foliar spraying can be carried out with potassium dihydrogen phosphate plus urea. The weeding work should be very meticulous and do not collide with cuttings.

5. Transplantation: it can take root in about one month, and be transplanted into the nursery in about 2 months. The summer and autumn of the first year should be properly shaded, and after the second year, it can be managed generally. During the peak growth period, nitrogen fertilizer and water were applied twice a month, and fertilizer was stopped after autumn. Cultivate 2-3-year-old seedlings, can be planted in a small pot, 4-5-year-old seedlings, only for flower bed edge or ground planting.