Several propagation techniques of Populus tomentosa in Hokkaido

There are many ways to reproduce Hokkaido Buxus. Here are a few commonly used methods:

1. Cuttage law: Cuttage law is divided into hardwood and softwood cuttage law. Hardwood cuttings are carried out between October and the end of March. For units with sufficient provenance, the cuttings can be cut slightly longer, and for units lacking provenance, the cuttings can be slightly shorter, the cuttings are 8 to 15 cm long, the cutting depth is generally 3 to 5 cm, and roots can grow after 1 month. As long as the cuttings are carried out according to the following methods, better seedlings can be quickly obtained:

1) Lay a sand bed with good water permeability, and disinfect the sand bed with potassium permanganate or carbendazim two days in advance.

2) Prepare alcohol, plant rooting powder, and prepare the solution according to the instructions.

3) Do not choose too tender branches when cutting ears. Those with high lignification degree are easy to take root and sprout.

4) When pruning, leave the trunk to cut the lateral branches, and leave at least one bud root for the next time.

5) Remove the lower leaves of the cuttings and leave 2 to 3 leaves on the upper part. After the cuttings are repaired, they are soaked in rooting water.

6) Draw a trench on the sand bed with a small shovel, put the cuttings in 5 to 10 cm, and cover them with soil and compact them. Row spacing 10 to 20 cm.

7) Cutting process needs to maintain appropriate temperature and humidity, watering according to temperature, humidity, to always keep leaves wet. Do not overwater, extend the rooting time, seedlings can reduce watering after rooting.

8) After cutting, it will take root in about 30 days, and it can also be installed in a timely manner. Bowl nutrient soil can be sand, soil and peat soil accounted for one-third of the preparation, in order to facilitate ventilation, do not load bowl too full.

2. Single bud cuttage method: Single bud cuttage method can be used to rapidly propagate seedlings of Buxus chinensis. Cuttings are carried out between 5 and October, buds are 1 to 2 cm long, one bud and one leaf, and good leaves should be retained. The knife that cuts bud child must be sharp, bud piece cuts good hind undertake cuttage in time. 500 to 1000 seedlings can be cut per square meter, rooted 1 month after insertion, sprouts begin to sprout 40 to 45 days later, and seedlings can reach 10 to 15 cm high after 2 months.

3. Leaf cuttage method: select mature leaves for cuttings, cuttage leaves petioles must be complete, take leaves, do not use scissors, it is best to break the petioles from the bud base, take with the plug, or put the leaves in a clear water basin. Leaves stored too long will cause cutting survival rate decreased. Cutting depth 2 to 3 cm. After 20 days of cuttage, callus can be produced from petiole base, new roots can grow from callus after 30 days, buds can be formed on root primitive after 50 to 60 days, and new plants can be formed from buds after 70 to 80 days. 1 square meter cutting bed can cut 1000 to 1500 leaves, the survival rate can reach more than 95%.

4. Seed sowing method: Hokkaido Buxus fruit early, large seed yield, high seed germination rate. When the pericarp cracks, harvest it in time, otherwise the mature seeds are easy to be eaten by birds. After seed harvest, remove the red aril in time. When removing the aril, the force should be light, and the force should be too heavy. It is easy to crush the seed. The seeds are dried in the shade and stored in wet sand. Sand degree can not be too big, humidity big seed easy mildew rot. Storage room temperature should not exceed 15 degrees, room temperature exceeds 15 degrees, seeds are easy to germinate ahead of time. After the soil thaws, it is necessary to sow as early as possible, sowing should be early rather than late, sowing late, temperature and ground temperature rise, seeds take root and germinate quickly, seed roots are long, seeds are easy to break when sowing, causing damage to seeds. The seedlings bred from seeds have obvious variation phenomenon, especially the shape of leaves. 50% to 60% of the seedlings have the same leaves as the female parent, 20% to 40% of the seedlings have sharp leaves, and 1% to 10% of the seedlings have wide leaves. No matter how the leaf shape changes, the seedling's arborization character and habit of rapid growth are almost the same as the female parent. However, it should be noted that when breeding seedlings, do not easily throw away those with pointed leaves.

5. Grafting method: Although Hokkaido Buxus is arborization character, growth speed is 3 to 5 times faster than ordinary Euonymus, to let Hokkaido Buxus grow into 5 to 6 cm DBH large-scale seedlings, at least 6 to 8 years, more than 10 to 15 years or longer. In order to cultivate large-scale and large-scale seedlings in 5 to 6 years, it is necessary to cultivate silk cotton trees as rootstocks. The root system of silk cotton tree is developed, the survival rate of transplanting is high, the growth speed is fast, and the seedlings with DBH of 5 to 6 cm can be cultivated in 3 to 4 years. Buxus hokkaido grafted with yucca as rootstock has early crown formation and strong cold resistance.