(1) Main branch pruning
In order to prevent baldness in the lower part of the crown and increase the effective fruit area, the main branches should generally keep an opening angle of 45 ~ 50. The pruning of the extension branches of the main branches generally adopts the method of long shearing or light short shearing. By light short cutting or long cutting, a large number of elongated branches can bear fruit and increase yield. In addition, because there are many fruits with extended branches, the growth of extended branches can be effectively controlled and the growth rate of extended branches can be delayed, so as to adapt to the characteristics of high planting density of protected peach trees.
(2) Pruning of fruiting branches
A fruiting branch group consists of more than two fruiting branches, which are directly planted on each main branch. According to the space occupied and the number of branches, the fruiting branches are divided into big fruiting branches, middle fruiting branches and small fruiting branches. Large fruit branches occupy large space, have strong growth potential, stable fruit and long life; Small fruit branches occupy small space, have weak growth potential, are not easy to update and have short life; Medium-sized fruit branches are in between. When pruning, it is necessary to cultivate and configure all kinds of fruiting branches in a planned way, so that the large, medium and small fruiting branches can cooperate with each other, make full use of space and achieve three-dimensional effect.
Under the condition of close planting, the bearing branches of peach trees are mainly middle branchlets. A certain distance must be kept between branches, the distance between large bearing branches in the same direction should be 50 ~ 70 cm, the distance between medium bearing branches should be 30 ~ 50 cm, and the small bearing branches should be arranged between large and medium bearing branches. In short, we should ensure the principles of light transmission, balanced growth, clear division between master and slave, uneven height, compact arrangement, no crowding and no baldness.
The purpose of pruning fruiting branches is to arrange all kinds of fruiting branches on the main branches, maintain the growth potential of branches and prevent baldness at the lower part of the crown. Pruning of fruiting branches of protected peach trees is accomplished by post-harvest pruning and winter pruning. When pruning in winter, the degree of pruning should be determined according to the growth potential of branches, that is, the ability to bear fruit. For branches with strong growth potential, large growth space and good fruiting branches, solid fruiting branches can be used instead of retraction pruning; For those branches with weak growth potential, and all branches on the branch group are short fruit branches or bouquets, they should be retracted to enhance the growth potential of the branch group. In the case of high branch density, the branches that are too dense should be properly sparse to ensure good light reception under the crown during the growing season.
(3) Pruning of fruiting branches
Therefore, the principle of pruning is still "guide the situation, the strong stay long, and the weak stay short". In the specific pruning, we should first arrange the density and spacing of fruit branches, generally calculated from the cut, and the spacing between adjacent fruit branches is about 20 cm. The extension direction should be staggered. Secondly, according to the growth and fruiting ability of different fruit branches, appropriate short cutting is carried out. Generally,1/3 ~1/2 of the branch length can be cut off on the basis of ensuring that there are leaf buds at the lower part; Pruning the average fruit branches of gold1/2 ~ 2/3; Cut off 2/3 of the top fruit branches or lift them lightly (or even lengthen them).