According to the planting and sales experience of Huanren Hexing Nursery Professional Cooperative in Northeast China with five-pointed maple as the core in recent years, due to the special climatic conditions in the north, many introduced and domesticated tree species have been defeated in the face of severe cold, and seedling breeders can only aim most of their hopes at local colorful tree species. However, there are few varieties of colored-leaf tree species in the north. As a local five-pointed maple, especially the five-pointed maple ball, people pay more and more attention to it. Because of its slow growth, it takes at least 15-20 years from seedlings to green seedlings. As a dwarfing product of the five-pointed maple, the five-pointed maple ball can play the role of greening and beautifying in the early stage, greatly shortening its production cycle, thus becoming one of the indispensable color-leafed tree species in the northern greening project, and the demand is increasing day by day.
However, the growth of five-pointed maple bulbs is slow, and there is only one growing season in the north, which leads to less annual growth and longer production cycle. However, the development of northern cities has advanced by leaps and bounds. A large number of greening projects have increased the demand for five-pointed maple balls, resulting in a shortage of supply. This requires us to shorten the molding cycle, improve the cultivation techniques and master the cultivation points, so that the five-pointed maple balls can be quickly molded and used in a large number of greening projects. Through years of practice, I personally think that there are three key periods in the cultivation process of pentagonal maple ball. As long as we master the cultivation points in these three periods, we can not only shorten the emergence period of five-pointed maple balls, but also improve their molding quality.
The first critical period is the seedling stage, which is the period from the first year to the third year. In order to quickly mold seedlings, when Acer truncatum seedlings grow to the third year, at the peak of seedling growth (about June and July every year), the terminal buds of seedlings are pruned, that is, the central branches are shortened to one-fifth of the height of the whole tree, and the short branches are left under the incision as high-growth extension branches. In order to cultivate spherical backbone branches, 3-4 short truncated tops should be left at the same time to eliminate the top advantage of seedlings and promote their growth. That is, the initial crown expansion, in addition to erasing the buds below 50CM, makes them concentrate nutrition, promotes the growth of lateral buds, and maintains the top advantage of lateral buds to achieve the effect of controlling longitudinal growth and developing transverse crowns. During this period, attention should be paid to prevent the susceptible damping-off disease in seedling stage, which mainly occurs in wet places in nursery or in rainy season, mainly in June and July. At this time, it is best to take carbendazim as a protective agent for seedlings in advance to prevent them in advance. Otherwise, if the cataplexy occurs in the rainy season, it will spread rapidly because of the suitable weather, and the spread of the disease cannot be controlled because of frequent rain or because the drug effect cannot last for a long time. This will lead to the death of seedlings in a large area, so it is best to take preventive measures in advance.
The second critical period is from the fourth year to the sixth year of seedlings, and the technical points of this period are mainly plastic surgery and fertilization. The technical requirements of plastic surgery are as follows: firstly, the crown should be enlarged continuously, and the top edge should be removed to help the lateral buds grow, and the lower buds should be removed. No bud points should be left below 60CM, 80CM or 1M from the ground (depending on the height of seedlings or the height required for cultivation), so as to cultivate a straight trunk. At this time, although the branches are a little early, it can let the seedlings concentrate their nutrition on the growth of the seedlings and promote the seedlings to grow taller and thicker. At the same time, more attention should be paid to the application of compound fertilizer combined with nitrogen fertilizer to promote the growth and thickening of its branches. Fertilization should be given priority in spring, appropriate topdressing in summer, and never fertilization in autumn to prevent the tops and shoots of tender branches from freezing due to low temperature in winter and cold or cold in the following spring.
The third critical period is after the seventh year, and the seedlings can come out of the nursery one after another. The technical point is to finely prune the seedlings, that is, to finalize the nursery. Pruning in this period is also the focus of technical points. If well pruned, the nursery can be formed earlier. If it is not trimmed well, the molding effect will be bad. The focus of pruning is light pruning, which can speed up the growth of the sphere and basically trim it into a sphere. Trim once every 10 day and a half to be light and diligent. However, the disadvantage of this method is that Acer truncatum has dense branches and leaves and is prone to powdery mildew, especially after the rainy season in late July and early August, which is the high incidence period of powdery mildew. If it is not controlled at this time, the disease will continue until the leaves fall, which will not only affect the growth of seedlings in that year, but also affect the emergence of seedlings in that year. At this time, triadimefon should be given at the early stage of the disease, once every ten days, and it can be basically prevented for three consecutive times. Or take carbendazim to prevent it when there is no disease. In winter, infected fallen leaves should be burned to prevent the bacteria from overwintering on the fallen leaves and causing reinfection in the next year. Another disease is plaster disease, which is basically caused by high planting density and high humidity. It mainly occurs in the part of the stem near the ground, which makes the branches rot and eventually leads to the death of the whole plant. The easiest way is to scrape it off by hand.
Mastering these three critical periods can basically shorten the time for the five-pointed maple ball to leave the nursery by about three to five years. Of course, the longer you grow in the nursery, the better the molding effect will be. When the crown width of the ball reaches about 600, we should pay attention to the ventilation and light transmission in the crown, remove the dense branches and thin inner branches, and strictly control the branches under the crown. So as to achieve a more perfect spherical green leaf tree species-pentagonal maple leaf ball.