Technical approaches for apple dwarfing

Dwarfing apple planting is mainly achieved through the following approaches: using dwarfing rootstocks to promote tree dwarfing; or selecting short-cut rootstocks with dwarfing characteristics. Branch type varieties; or use chemical agents to control the crown, and finally use artificial dwarfing measures to achieve dwarfing. Each of the four approaches has advantages and disadvantages, among which the use of dwarf rootstocks for dwarf cultivation and variety upgrading is particularly advantageous.

(1) Tips for selecting dwarfing rootstocks

There are three main types of apple dwarfing rootstocks, which are divided into semi-dwarfing rootstocks, dwarfing rootstocks and Extremely dwarfing rootstocks, the first two are commonly used in production. Dwarfing rootstocks include M and B series, and semi-dwarfing rootstocks include M, MM series, 77-34, etc. You should choose the appropriate rootstock according to your needs.

(2) Tips for selecting dwarf varieties

Dwarf planting varieties are also divided into three types according to their growth potential. The first type is triploid varieties with large trees and strong growth, such as Jonagold and common Fuji with strong growth. The second type is early-fruiting ordinary varieties with slightly poorer growth, such as Golden Delicious, New World, etc. The third type is short-branched varieties with small trees and weak growth, such as New Red Star, Shohong, Short-branched Red Fuji, etc.

Techniques of colonization

1: Planting density and colonization method

Determine the appropriate one based on the type, variety, growth potential, site conditions and management level of the dwarf rootstock According to the planting density, the coverage rate after the canopy is formed should be about 70%, in order to maximize the interception of light energy. Taking dwarf autogenous stock as an example, the planting density of Fuji is 1.8 × 3 meters, and the number of plants planted per mu is about 120. The Golden Delicious variety can be planted appropriately densely, with a plant row spacing of 1.5 × 3 meters, and about 150 trees per mu. Shouhong, Xinhongxing, etc. can use a plant-to-row spacing of 1.2×3 meters, and about 260 plants can be planted per acre.

Dwarf apple trees can be planted in two ways: single row and multi-row strips. Single-row plantings are mostly rectangular, with large row spacing and dense plant spacing. Single row planting is easy to manage, with sufficient light and good fruit quality. Multi-row strip planting can increase the number of plants per acre, economically utilize the land, and increase the early yield of the orchard.

Two: How to plant dwarf apples

Dwarf apple trees are planted with high density and high yield. Compared with trees, their growth potential is relatively weak. Therefore, they create a good root system. The growing environment is particularly important.

First of all, choose a gentle slope or flat land with good small environment, leeward and sunny, fertile soil to build the orchard, and establish a protective forest on the northwest side of the orchard. Before planting (in the fall of the first year), dig a planting trench. Generally, the ditch depth is about 0.8 meters and the width is about 1 meter. It is combined with fertilization to improve the soil. Apply 3500 to 5000 kilograms of high-quality farm organic fertilizer per acre. In mountainous and hilly areas, terraces should be renovated to preserve soil and water. On the tidal flats along the river, it is necessary to deeply plow the land, use soil to suppress sand or carry out soil improvement, and build drainage facilities to create a fertile and breathable ecological environment.

3: Planting depth of dwarf apples

The planting depth should be suitable for the planting depth of dwarf rootstocks and should be treated separately. For self-rooted seedlings, after watering and infiltration, the interface should be flush with the ground. If it is too deep, the joint will be buried. After the scion variety takes root, the tree will easily return to strength and lose its role as a dwarfing stock. Dwarf intermediate stock seedlings can be planted appropriately deep, even if they are buried