Grafting technology of ginkgo biloba
Seedlings cultivated by ginkgo seeds are called seedlings. Ginkgo trees grown from seedlings not only bloom and bear fruit late, but also have low seed yield. Moreover, due to the great variability of seedlings obtained from seed breeding, they often cannot maintain the excellent characteristics of the original plants. This shortcoming can be overcome by grafting. The so-called grafting is to graft the branches or buds of excellent mother trees to the appropriate parts of seedlings. The combination of the two forms an ideal ginkgo plant. There are many grafting methods of ginkgo biloba. Grafting time can be all year round, as long as it is used properly, it can have a high survival rate.
Grafting height
The specification of the rootstock of grafted ginkgo depends on the grafting height, which depends on the purpose and requirements of cultivation. Ginkgo biloba is different from other fruit trees. The grafted buds of Ginkgo biloba are actually short branches of Ginkgo biloba. Therefore, after grafting, the branches extracted from the grafted buds are inclined and long, and it is difficult to stand upright. The older the bud, the greater the slope. Generally speaking, the grafting height of ginkgo biloba is a fixed stem height. In Xufang area, such as Yunnan, Guizhou, Guangxi, Sichuan and other provinces, due to high temperature and much rain, it is customary to graft with low stem. In order to make the trunk upright, it is often supplemented by columns, and then fixed after it grows into a big seedling. However, if the grafting fails, the growth potential of seedlings will obviously weaken, the stress resistance will be reduced, and even the rootstock will die. In the northern region, due to the dry weather and low temperature, the growth of the year after low stem grafting is very small, and the branches are oblique.
Second, the grafting time
Spring grafting of 1
Grafting can be carried out from early spring thawing to rootstock germination. However, different grafting methods should be selected according to the peeling state of rootstocks. Generally speaking, before peeling rootstocks, methods such as splitting grafting, cutting grafting, abdomen grafting, tongue grafting and budding with xylem can be used. After the rootstock is peeled, grafting, T-bud grafting and other methods can be added. When the rootstock and scion can be peeled off, square sleeve bud grafting and tongue grafting can be added.
2 summer grafting
Summer grafting is also called green branch grafting. The time can be from mid-June to early September. The survival rate here is the highest from mid-June to mid-July. From mid-July to mid-August, the effect is poor after mid-August. Splitting, cutting and bud grafting are commonly used in green branch grafting. If single bud grafting is used, it is easy to form partial crown, and double bud or triple bud grafting is often used in production. The top of the scion should be strictly sealed with wax to prevent water loss.
3 autumn grafting
The time is from mid-September of 10 to early of 10. Mainly bud grafting. But after grafting, the buds can only fuse in the same year and cannot germinate. Practice has proved that sealing wax in autumn can not only improve the survival rate, but also make the branches flourish in the coming year. Grafting in autumn is mostly used in warm winter areas south of the Yangtze River. But it is less used in the north. Because the temperature is too low in winter, grafted buds are easy to freeze to death. For example, 1990 in Hegou Township, Pizhou City, Jiangsu Province, grafted to a garden for 2hm2 in autumn, the survival rate can reach 95%, while 199 1, due to the influence of low temperature, all the seedlings grafted to seed breeding garden and urban courtyard in autumn failed.
3. Scion selection
In recent years, short-stem and low-crown close planting of Ginkgo biloba has played an important role in breaking the ideological understanding that Ginkgo biloba can not benefit in the short term. However, from the overall benefit of Ginkgo biloba, it is necessary to re-study this cultivation method. Therefore, as of 20 12, many places in China or Gao Qian have turned to grafting. The specifications of ginkgo rootstock seedlings also depend on the cultivation purpose and grafting height. At present, the grafting height of seedlings in high-yield ginkgo orchards tends to L2 ~ 1.5 Ni. If it is a high-yield garden intercropping vegetables, medicinal materials or low-drought crops, the grafting height can be raised to 2.0 ~ 2.5 m, and if it is a high-yield garden intercropping mulberry, fruit or picking ginkgo leaves, the grafting height can be raised to 2: 5 ~ 3. Well, the grafting height of trees planted around courtyard greening trees should be higher than the fence height, and the layered grafting method should be adopted to achieve the goal of double harvest of trees and fruits and benefit generations. For urban roads, the grafting height should be above 3.0m, and urban roads should be dominated by male plants. Village roads can be dominated by female plants and a small number of male plants. As for ginkgo bonsai, the rootstock should be old and thick, and the grafting part should be as low as possible. The specific height should be determined according to the plastic requirements.