Seed propagation:
In the past, it was propagated by dividing plants, which resulted in low seedling yield and was only suitable for scattered cultivation; Seed propagation can provide a large number of seedlings, which can meet the needs of intensive cultivation and great development of Toona sinensis. The germination ability of Toona sinensis seeds is about .5a, and the seeds above .5a hardly germinate. Therefore, fresh capsules collected in that year should be selected, air-dried and crushed, and winnowed to remove impurities. The key points of seed propagation are: selecting nursery land; Carefully soaking seeds to accelerate germination; Sow in time to prevent cold and drought; Low bed drilling to moisten the bottom of the ditch; Timely fertilization by stages; Scientifically use water to survive the spring drought; Do a good job in the prevention and control of pests and diseases as soon as possible.
1- Soaking seeds to accelerate germination: the required amount of seeds per hectare is 371kg. Before sowing, the seeds are soaked in warm water at 2-3℃ for one night according to the ratio of 1: 3, and then washed out with clear water. The seeds are placed in a mud basin with no water at the bottom, covered with two layers of gauze, and germinated in a warm and dark place. The temperature is controlled at 2-25℃, and the thickness of seeds should not exceed 3cm. When 3% of the seeds crack and shoot white buds, mix them with fine sand or fine soil and sow them evenly in the furrow.
2- timely sowing: the suitable sowing period of Toona sinensis is generally from the end of March to the beginning of April. Sowing early in time and careful management can make seedlings grow in spring and transplant with leaves in autumn. The appropriate sowing spacing is 4cm, with 18, ~ 3, plants per hectare, the appropriate sowing furrow depth is 4cm, and the soil is 2 ~ 3 cm after sowing.
ramet propagation:
Also known as tillering or root tillering propagation. It is the most common propagation method of Toona sinensis, which is suitable for sporadic cultivation. Toona sinensis has strong tillering ability, and its lateral roots are distributed in the topsoil layer of 1cm, and most of them grow horizontally, so it is easy to sprout and form tufted plants. After defoliation in autumn or before germination in spring, ditching or digging holes around the mother tree can promote the germination of roots and tillers, and the plants can be planted in autumn or spring of the following year.
Rooting propagation:
Rooting propagation is to propagate seedlings by using the characteristics that Toona sinensis roots are easy to form adventitious buds. This is a seedling raising technology with easy operation, low investment, high survival rate, fast seedling formation and wide application. The key points are: deep soil preparation and application of organic fertilizer to keep the soil in the nursery loose and moist; Selecte robust and high-yield trees or seedling in nurseries, digging roots with a thickness of .5-1. cm, cut into 15-2 cm segments as cuttings, and inserting as the cuttings are harvested, and covering the soil with a thickness of 2-3 cm; When the height of the seedling is 1cm, choose a strong bud to fix the seedling; Spraying urea 2 ~ 3 times in seedling stage, and spraying phosphate fertilizer and potash fertilizer 2 ~ 3 times in September to promote lignification of seedlings; The rainy season should be drained and loosened in time; Don't water the newly cut roots to prevent rot.
Cutting propagation:
There are two kinds of cuttings: soft cuttings and hard cuttings. The key of soft branch cutting lies in the fullness of cutting tissue. Rooting of fully lignified branches is difficult or slow; Branches are too tender and will rot easily after being inserted. The survival rate of semi-lignified or mostly lignified branches as cuttings is high. It is easier to take root and survive by using budding branches on the roots or stems as cuttings than branches on the crown. The specific method is: from late June to early July, select the lignified branches whose trunk is 2cm away from the ground, cut them into small pieces of 2cm or 1 ~ 15 cm, cut the lower end into oblique mouths, keep 1 ~ 2 pairs of leaflets at the base of compound leaves on the upper part of the cuttings, and cut off the rest leaves. Dip the cuttings into 5mg/L NAA or vitamin D12 solution, insert them into loose, fertile and moist soil at a density of 4cm×4cm, put a small arch shed on the border, keep the relative humidity of 85% ~ 9% and the temperature of 2 ~ 3℃, and take root for about 5 days. After hardwood cuttings are planted on the fallen leaves of Toona sinensis in early winter, 1-2-year-old branches are selected and cut into 15-2 cm segments, with the upper opening cut flat, the cutting opening is about 1.5cm away from the last bud, and the lower end is an oblique opening. Bundle cuttings and bury them in a sand pit for the winter. Take them out in the following spring. Soak the lower end of cuttings in NAA5mg/L solution for 2 ~ 4 hours. After cleaning, insert them into a bed with pure sand in the bed, cover them with plastic film, put a small arch shed on the bed, and keep the temperature at about 25℃ and the relative humidity above 85%. After a series of management, the nursery can be planted in the same year or the following year.