(1) seed breeding

① Seed treatment: stratification treatment.

② Seedling raising in the open field: First of all, you should make a bed, either in autumn or spring. Select a flat plot, turn it loose and thin, apply 3 meters of decomposed farmyard manure and 50 kilograms of NPK compound fertilizer per mu, and then make a bed with a width of 1.2 meters and a height of 10 cm. When the bed is ready, you can sow, and the sowing time is determined to arrive in Tomb-Sweeping Day in late March. The seeds of tender thorn buds are very small. In order to improve the sowing quality and make the sowing uniform, the dosage of fine sand per mu should be 10 ~ 15 kg. As for the sowing amount, due to the differences of seed plumpness, seed treatment level and other factors, the germination rate is very different, generally 20% ~ 60%, so it is safer to use a large amount of seeds, at least the dry seed amount per mu should not be less than 0.5 kg. Cover the soil immediately after sowing, preferably mountain bark soil, because mountain bark soil contains less grass seeds and has strong permeability, which is conducive to improving sowing quality. Cover the soil as shallow as possible so that you can't see the seeds. In order to prevent surface dryness from affecting germination, the ground must also be covered with pine leaves, sawdust and other things. After careful management of 1 year (such as weeding and thinning seedlings, etc. ), the seedlings can grow in autumn and be planted in the following spring.

(3) Pot-tray seedling: Plastic pot-tray seedling can be used in the greenhouse in advance, and the time can be set at about 2 months before transplanting. The specifications of bowls and plates are 128 holes. According to the calculation of 18000 ~ 20000 mu per mu, 150 boards shall be prepared per mu. Before seedling raising, a bench with a height of about 0.8 meters should be built in the greenhouse, and the width of the bench can be exactly five boards placed side by side. The substrate can be crushed peat, and a small amount of decomposed high-quality farm manure and compound fertilizer should be added. In order to increase the viscosity, each transplanted seedling can carry mud, and a small amount of yellow mud should be added to the substrate. When sowing, first fill the bowl with 3/4 depth matrix, and then sow the treated seeds after watering. For safety, it is best to sow 15 ~ 20 seeds per hole on average. After sowing, cover it with a thin layer of matrix or mountain bark soil, and then lay a thin layer of vermiculite powder on it. Management mainly pays attention to moisture and temperature, the surface should be moist frequently, and the temperature in the shed should be kept at about 28℃. After emergence, tweezers and other equipment can be used to plant seedlings, one in each hole, and the seedlings can be transplanted to the nursery when they are about 5 cm long.

Before transplanting, the nursery needs to do soil preparation, fertilization and other operations, and it is best to cover it with plastic film, and design the plant spacing according to 6.5438+0.8 million plants per mu, and then transplant. The quality and seedling rate of seedlings cultivated by this method are much higher than that of direct seeding in the open field.

One disadvantage of seed seedling raising method is that the period is too long, because the seedling raising period takes one year, and only 60% of the stems can be used in greenhouse after the second year of planting; It can only be fully utilized in the third year. Second, there are many varieties with large natural variation, so it is difficult to maintain the purity of varieties.

(2) Tissue culture and seedling raising

This method is to remove the shoot tip tissue of the tender bud by biotechnology and cultivate it in vitro in the laboratory, but ordinary farmers do not have the conditions, so I will not introduce it here for the time being.

(3) Planting method

Seedlings can be planted in early spring, usually on hillsides or gently. The method is the same as planting trees. Spine buds are positive plants with developed roots and lush foliage. Narrow row spacing will inevitably affect ventilation and light transmission, leading to excessive stem growth. According to various density experiments, it is reasonable to plant one plant per square meter, and the row spacing can be appropriately wider. The best design method is row spacing 1.8m and plant spacing of 0.6m, so that 700 holes can be planted per mu. In the second year, 2 plants were sent out from each hole, and in the third year, 4 plants were sent out from each hole.