Detailed Explanation of Winter Pruning Experience and Methods for Apricot Trees

Winter pruning of apricot trees is an extremely important technical step in the year-round management of fruit trees. Reasonable pruning can regulate the relationship between vegetative growth and reproductive growth, determine a reasonable crop load, overcome alternate bearing, and extend the life of the fruit tree. Pruning of apricot trees is no exception; the pruning methods and strategies differ at different stages of the apricot tree. In production practice, the following pruning methods are adopted:

1. Winter pruning of young trees and trees in their first fruiting stage: Young apricot trees and those in the first fruiting stage generally grow vigorously, with the canopy expanding rapidly, a large amount of new shoot growth, and they often produce secondary and tertiary shoots. Pruning at this stage should take into account both training and fruiting. The extension shoots of the main and lateral branches should be pruned lightly and left long, generally leaving 2/3 of the full branch length for heading back. Remove crowded branches, multi-forked branches, overlapping branches and vigorous branches that disrupt the tree form, and control the growth of competing shoots and upright vigorous shoots. For moderately vigorous growing shoots with relatively open angles, leave them unpruned to encourage the sprouting of medium and short shoots, increasing the number of fruiting branches; after they form flower buds or bear fruit, promptly cut them back to train them into fruiting branch groups. Medium and short branches with wide angles form flower buds easily, so retain them as much as possible to favor fruiting. For weaker-growing young trees, heading back appropriately is advisable; remove overly dense and thin weak branches, retain more healthy branches, and bend upright vigorous branches flat to serve as auxiliary nurturing branches, so as to promote the growth of thick, strong medium and short fruiting branches.

2. Winter pruning of trees in full fruiting stage: The training of trees in full fruiting stage is basically complete. As the tree age increases, the yield rises and then gradually stabilizes, growth vigor weakens, and the tree condition gradually moderates. The main task during pruning is to adjust the relationship between growth and fruiting, maintain tree vigor, and extend the number of years of fruiting in the full fruiting stage. When pruning, according to the growth vigor of the branches and the space conditions of each part of the canopy, thin out and cut back appropriately to maintain a stable fruiting position and growth vigor. For extension branches at all levels, generally carry out moderate heading back (cut off 1/3--2/3 of the current year's shoot) so that they continue to produce healthy new shoots. For weakened main branches, lateral branches, perennial auxiliary nurturing branches, fruiting branch groups, and drooping branches, cut back for renewal at positions with strong branches or raise their angles to restore their growth vigor. For branches at the lower part of the canopy and inside the canopy, pay attention to timely renewal and rejuvenation so that they continuously produce new healthy fruiting branches. For overly dense and vigorous branches at the upper part and outer periphery of the canopy, cut back or thin out to improve light penetration inside the canopy. Apricot trees have weak branching ability; for fruiting branch groups in all positions, long fruiting branches, and moderately vigorous growing shoots, as long as they are not overly dense, generally do not thin them out; heading back can be used to promote a small number of long shoots, so that the middle and lower parts produce medium and short shoots that bear fruit alternately.

3. Winter pruning of trees in the aging stage: In the aging stage, the growth of extension branches of apricot trees weakens, new shoots are short, skeletal branches begin to droop, the interior of the canopy begins to become bare, fruit is borne almost only on the surface of the canopy, and yield decreases. The main task of pruning is to renew skeletal branches and branch groups, strengthen tree vigor, and extend the number of years of economic fruiting. Use vigorous back branches with small angles at the middle and lower parts to replace the leader. Or cut back at relatively upright branch sections to promote the sprouting of latent buds for renewal. For water sprouts in appropriate positions, use them and train them into skeletal branches and fruiting branch groups. For fruiting branch groups and fruiting branches, following the principle of removing the weak and keeping the strong, select and retain strong branches and strong buds for renewal pruning. If the tree vigor is extremely weak and renewal is difficult to achieve, on the premise of strengthening fertilizer and water management, carry out a whole-tree major renewal of the main and lateral branches and large branch groups at the 10--15-year-old in one operation; a large number of new shoots can sprout that same year, and through summer bud removal and pinching plus winter training and pruning, they can flower and bear fruit the following year, restoring a certain yield.