1, pruning of young apple trees with short branches should focus on promotion.
Because short-branched varieties are easy to bloom, their pruning methods are completely different from those of long-branched varieties. Because of the high germination rate, strong branching, vigorous branching and difficulty in flowering, long-branched varieties mainly prune slowly on young trees, and generally emphasize how long to put them in, and pull branches early to promote flowering; However, short-branched varieties should not pull branches too early in the young tree period, which will affect the crown expansion. Before entering the fruiting period, the vertical growth of branches should be used to promote the formation of strong branches and the rapid formation of crown.
Therefore, the pruning of short-branch apples in the first and second years is mainly based on pruning, and the new shoots are not moved. Using the advantage of vertical growth of branches, we can promote the growth of strong branches, accelerate the formation of leaf area, increase the accumulation of photosynthetic products, and lay a good foundation for high yield and high quality. In the third year of planting, flowers began to bloom, and branches with standard growth length (1.5m) were pulled out to change the top advantage, disperse nutrition, promote the growth of strong and short branches, and lay a good foundation for the results. Because short-branch varieties have many short branches and few long branches, they often show insufficient nutrient accumulation. Therefore, in the growing season, bud cutting should be adopted to stimulate the growth of long branches, so as to expand the leaf area and increase the accumulation of photosynthetic products.
2. The key to pruning short-branch apple trees is to prevent weakness.
The main measures adopted in production are as follows.
(1) Prune the flower buds within 30cm. Because the short-branched red Fuji is easy to blossom, one branch can generally blossom from the top to the base. On the one hand, excessive flowers will consume a lot of nutrients, which is not conducive to the vigorous growth of branches and is easy to weaken, on the other hand, it will inhibit the elongation of branches. Therefore, the flower buds within 30cm should be pruned to ensure the effective extension and vigorous growth of branches.
(2) Abortion promotes germination
Short-branched varieties often stop growing early, with short branches, small leaf area and limited fruit expansion, and the fruit is generally small in production, especially after entering the full fruit stage. Obviously, attention should be paid to promoting the germination of branches in production, so as to expand the leaf area and increase the accumulation of photosynthetic products, thus increasing the proportion of large fruits. When pruning, the pruning method can be used. Every 5~7 buds are left 1 bud, and the remaining buds are knocked off, which on the one hand reduces the consumption of buds, on the other hand promotes the growth of short and medium branches, increases the leaf area and improves the high-quality fruit rate.
(3) The opening angle of short branch varieties should not be too large.
Generally speaking, the angle between branches is negatively correlated with the branching potential. The smaller the included angle, the more vigorous the branches are, and the larger the included angle, the weaker the branches are. After the short branch varieties enter the fruiting period, the tree vigor is easy to weaken, and the branch opening angle should not be too large. Generally, the base angle is 60, the waist angle is 80 and the sharp angle is about 70, so as to prevent the branches from being too flat, which will lead to the rapid decline of tree potential and affect the expansion of crown and the improvement of yield and quality.
(4) control the number of branches
Too many branches will inevitably lead to the dispersion of nutrients, which is not conducive to the vigorous growth of trees. Therefore, the number of branches should be strictly controlled, and the number of branches per mu should be controlled between 60,000 and 70,000. Extra branches should be properly thinned out, especially oversized branches and old branches after fruiting. Short-branched varieties are easy to bloom and often have too many fruits.
(5) Strictly control the output.
Too much fruit is the most direct cause of tree weakness, so the yield should be controlled in production to prevent tree weakness. The yield can be controlled by controlling the number of flower buds, which requires that the number of flower buds per mu should be controlled at 654.38+0.52 million before careful pruning; Leave inflorescences with fruit stones at a spacing of 25 cm, and after fruit setting, sparse individual fruits, and control the number of fruits per mu to 65438 0.5 million ~ 20,000.
(6) Strengthen the regeneration of fruiting branches and prevent them from aging.
After the short branch varieties enter the fruiting period, they need to shrink the fruiting branches again, stimulate and promote the growth of new branches, and equip the fruits with strong backup branches to replace the aging fruiting branches and maintain vigorous fruiting. Prune strictly according to the three sets of branches, and master that the bearing branches, preparatory branches and nutrient branches each account for about 1/3, and transform the three types of branches once a year to prevent the bearing branches from aging and improve the bearing capacity of short-branch varieties.