What standard principles should be followed in the shaping and pruning of fruit tree bonsai?
Fruit tree bonsai has ornamental value throughout all four seasons: delicate flowers in spring, lush foliage in summer, abundant fruit in autumn, and upright, vigorous form in winter, making it full of the joy of life. China is extremely rich in fruit tree resources. Various wild fruit trees and their rootstock resources in the mountains and wilds can all be utilized, and native bonsai with local characteristics can also be developed according to local conditions. There are many varieties of fruit trees, and materials can be sourced locally, which facilitates production and management, requires relatively small investment, and can generally be cultivated by ordinary households.
According to the characteristics of fruit tree species and varieties, fruit tree bonsai can be shaped into many forms, such as the natural round-head form, pagoda form, two-branch antler form, three-branch cup form, weeping willow form, dragon-curve form, and so on. In shaping the tree form, it is necessary both to favor fruit production in potted fruit trees and to have ornamental value. The measures commonly used to promote flowering and dwarfing, and for shaping and pruning, include: bud removal, pinching, branch bending, branch twisting, ring girdling, renewal pruning, and branch pulling. Light exposure can also be enhanced by opening the angle of branches and thinning out water sprouts, densely growing branches, and ineffective branches, so as to shape the fruit tree bonsai into an ideal form.
After grafting has taken and normal growth has begun, in order to enhance the aged appearance of the bonsai, a grafting knife can be used to carve several curved lines on the trunk. During the growing season, wire can be wrapped around the fruit tree branches to fix the desired tree form. In addition, medicines can be used to promote dwarfing of the tree body; for example, during the growing period of fruit tree bonsai (summer), spraying the leaves with plant growth retardants (such as paclobutrazol, B9, chlormequat, etc.) 2 to 3 times can make the branches sturdier, the internodes shorter, and the plant dwarfed. In addition, the fruit load of fruit tree bonsai should be kept moderate.
When the number of flower buds on a fruit tree bonsai is too large, flowers should be thinned during the bud stage, or fruit should be thinned after the physiological fruit drop period; if the number of flower buds is small, a few more flower buds can be retained appropriately, and manual pollination can be carried out to increase the fruit set.
Standard shaping and pruning principles for fruit tree bonsai:
1. Shaping and pruning techniques must favor the formation of the canopy. Dwarf and close-planted trees likewise require a certain amount of growing branches in a short period to ensure the fruiting volume for early high yield.
2. Shaping and pruning techniques must promote the conversion and accumulation of nutrients, favor flower bud formation, and achieve the goals of early fruiting, early high yield, and stable yield.
3. Shaping and pruning techniques must favor light exposure. Dense planting orchards easily cause canopy shading, so shaping and pruning must be used to make densely planted trees well ventilated and well lit. Therefore, different planting densities require different shaping methods, and through shaping and pruning the goal is achieved of dense trees without dense branches and good light exposure.
4. Densely planted trees must be shaped and pruned to control tree size and reduce tree height. Pear trees have strong apical dominance, and because the spacing between plants and rows is small, the tree body very easily grows upward. Shaping and pruning should be used to dwarf the tree body.