Detailed Explanation of Key Technical Points for Greenhouse Peach Cultivation and Management

I. Early training, early shaping, early fruiting

Because greenhouse peach trees are planted at high density, in order to obtain relatively high early income, shaping and flower bud development must be completed within one year: vigorously promote growth in the early stage for early shaping, then control growth in the later stage to produce more flowers. When shaping, whether using the slender spindle form or the "Y" form, yield must be given top priority. Not only should pinching be done multiple times under the premise of adequate fertilizer and water supply to promote more secondary and tertiary branches, but permanent fruiting must also be considered, that is, the branches being trained should not be tipped so they maintain a certain growth vigor. Otherwise, because peach trees have a high budbreak rate, strong branching ability, and large shoot and leaf growth, if the lower branches are quickly shaded by the upper shoots and leaves, it will be very difficult to train them later. Therefore, when the trunk height is about 40 cm, the framework branches should be selected in time, and branches that affect the growth of framework branches should be pulled, bent, or twisted to change their position.

II. Root control and canopy control

Container cultivation and root pruning are effective methods for controlling root growth. To obtain benefits earlier in greenhouse peach production, the peach trees can first be planted in containers such as flower pots or woven bags. Because the nutritional area is small, growth will not be excessively vigorous, and a method of fewer thinning cuts and more pinching can be adopted. For peach trees planted directly in the greenhouse, root pruning should be carried out after two years, that is, after fruit harvest, trenches are dug between rows for fertilization to cut off some fine roots, thereby achieving the effect of root pruning.

III. Open up the light path

Greenhouse cultivation involves high-density planting, and with the early use of paclobutrazol, branches grow toward the lower sides. If the tree form is spindle-shaped, it is easy for the upper and outer branches to droop downward, shading the lower and inner canopy branches, resulting in a flattened fruiting plane and low yield. Therefore, dense upper branches should be thinned out to open up the light path. In addition, vigorous branches should be "blocked" so that lower branches receive more nutrients and water, forming three-dimensional fruiting.

IV. Thinning and reshaping

The high density in the first two years is for obtaining early yield. As branch volume increases and crowding occurs, the individual trees and the overall structure must then be adjusted accordingly through methods such as thinning, heading, and renewal pruning. Horizontally, every other tree or every other row can be removed to improve ventilation and light conditions; vertically, one side can be thinned, "inserting" where there is space and "yielding" where there is none, making full use of space, and when necessary the trunk can also be transformed into a delayed open-center form.

V. Careful winter pruning, frequent summer pruning

The main purposes of summer pruning for greenhouse peaches are to control excessive branch growth, solve ventilation and light penetration problems, and promote flower bud differentiation and fruit ripening. Upright branches on the back and parallel branches should be removed as early as possible; when branches and their orientation are unsuitable, adjust the angle by pulling branches; when there is space but new shoots are too vigorous, pinch the tips or twist the shoots; remove overly dense branches. After fruit harvest, heavily renew and severely head back the fruiting branch groups to promote canopy formation. During the fruit coloring stage, fruit branches should also be tied up, pulled, and a small number of leaves removed to enhance coloring. The focus of winter pruning is to maintain the tree form, select and retain reserve branches, and carefully prune all types of fruiting branches. Generally, long fruiting branches retain 4-8 pairs of flower buds; moderate fruiting branches retain 3-5 pairs of flower buds; short fruiting branches are not pruned; flower-bouquet fruiting branches are renewal-pruned according to position and the length and thickness of the fruiting mother branch. Pay attention to the training and renewal of branch groups and retain good reserve branches; otherwise, the branches and trunk easily become bare and weaken quickly.