Dwarf planting of apples is mainly realized through the following ways: using dwarf rootstocks to promote tree dwarfing; Or select short-branch varieties with dwarfing characteristics; Or use chemicals to control the crown, and finally use artificial dwarfing measures to achieve dwarfing. Each of the four approaches has its own advantages and disadvantages, among which the use of dwarf rootstocks to update dwarfing culture and its varieties is particularly superior.

(1) Selection Skills of Dwarf Rootstock

There are three main types of apple dwarfing rootstocks, which can be divided into semi-dwarfing rootstocks, dwarfing rootstocks and extremely dwarfing rootstocks according to the degree of promoting tree dwarfing, and the first two are commonly used in production. Dwarf rootstocks include M and B series, and semi-dwarf rootstocks include M and MM series and 77-34. You should choose the right rootstock according to your own needs.

(2) Skills of selecting dwarf varieties

Dwarf varieties are also divided into three types according to the strength of growth potential. The first is a triploid variety with big trees and vigorous growth, such as Jonakin and Fuji. The second category is the early fruit varieties with slightly poor growth, such as Jinguan and New World. Third, short-branch varieties with small trees and weak growth, such as Red Star, Shouhong and Short-branch Red Fuji.

Colonial technology

1. Planting density and planting mode

The suitable planting density should be determined according to the species, varieties, growth potential, site conditions and management level of dwarf rootstocks, and the coverage rate after crown formation should be about 70% to intercept light energy to the maximum extent. Taking dwarf rootstock as an example, the planting density of Fuji is 1.8×3m, and the number of plants per mu is about 1.20. Golden crown varieties can be densely planted, the row spacing is 1.5×3m, and the number of plants per mu is about 1.50. The spacing between Shouhong and emerging plants can reach1.2× 3m, and the planting per mu can reach about 260 plants.

Dwarf apple trees have two planting methods: single row and multi-row strip. Single row planting is mostly rectangular, with large row spacing and dense plant spacing. Single row planting management is convenient, with sufficient sunshine and good fruit quality. Multi-row strip planting can increase the number of plants per mu, save land and improve the early yield of orchard.

2. Dwarf apple planting method

Dwarf apple trees have high planting density, high yield and weak growth potential compared with trees. Therefore, it is particularly important to create a good environment for root growth.

First of all, choose a gentle slope or flat land with good small environment, sunny lee and fertile soil to build a garden, and establish a shelter forest on the northwest side of the orchard. Before planting (the first autumn), dig planting ditches. Generally, the depth of the ditch is about 0.8m, and the width of the ditch is about 1 m.. Combined with fertilization to improve soil, 3500~5000 kg of high-quality farm organic fertilizer is applied per mu. In mountainous and hilly areas, terraces should be renovated to conserve water and soil. In the beach along the river, it is necessary to dig deep into the land, use soil to suppress sand or improve exotic soil, build drainage facilities and create a fertile and breathable ecological environment.

Three: Dwarfing apple planting depth

The planting depth should be suitable for the planting depth of dwarf rootstocks and should be treated differently. Self-rooted seedlings, after water infiltration, the interface should be flush with the ground. If it is too deep, the interface will be buried, and after the scion variety takes root, the tree will easily restore prosperity and lose the role of dwarfing rootstock. Dwarf intermediate rootstock seedlings can be deeply planted even if they are buried.