The backbone branches are the main part of the tree structure, including the main trunk, main branches, lateral branches, fruiting branches, extension branches, etc. (Figure 6).

Figure 6 Tree structure of a peach tree

1. Main trunk

The part of the tree that runs from the rootstock at ground level to just below the first main branch.

2. main branches

Permanent skeletal branches attached directly to the main trunk

3. lateral branches

Fixed skeletal branches attached to the main branches, which are subordinate to the growth of the main branches.

4. Extension branch

The main branch, lateral branches and other trunk branches at the apex of the continued extension and expansion of the crown of the annual branches.

5. Fruiting branch group

Bearing in the main branch, lateral branches and other trunk branches of the perennial branch group, consisting of a number of fruiting branches, is the main part of the fruit, fruiting branch group is divided into large, medium and small three categories.

6. Large fruiting branch group

Multi-branching, fruiting branches more than 16, height and distance 70 ~ 80 cm, strong, long life, can be renewed. Composition: small branch group + medium-sized branch group + branch group + fruiting branches. Position: main branch dorsal slant, interlaced with lateral branches.

7. Medium-sized fruit-bearing branch group

More branches, fruit-bearing branches 6 to 15, height and distance 40 to 70 centimeters, branch age 4 to 7 years. Composition: small branch group + branch group + fruiting branches. Position: main lateral branches dorsal or both sides, straight or oblique.

8. Small fruit-bearing branch group

Few branches, 2 to 5 fruit-bearing branches, height and distance 30 cm, branch age 2 to 3 years. Composition: branch group + fruiting branches. Position: on large and medium-sized fruiting branch groups and main lateral branches, filling in the gaps (Figure 7).

Figure 7 Types of fruit-bearing branch groups