Pruning and Flower and Fruit Management Techniques for Dense Planting of Apricot Trees

I. Training and Pruning

1. Training The apricot is a light-loving fruit tree; for dense planting orchards, a "V" shape with good ventilation and light penetration is recommended. The training method is as follows: plant at a row spacing of 3 m x 1 m; in the planting year, shorten the trunk by cutting to 40 cm; when new shoots reach 30 cm in spring, select and retain two symmetrically growing branches that extend toward the row middle, grow vigorously, and form a 30-60 degree angle with the trunk as the main branches, and let them grow naturally. Select and retain another 3-4 new shoots as auxiliary nurturing branches, remove the remaining new shoots, and at the beginning of May when the auxiliary nurturing branches are 20 cm long, pinch out the growing tips; in late June, pull all auxiliary nurturing branches to a horizontal position to promote flower bud differentiation. For the main branches, pinch out the growing tips when they are 50 cm long to promote branching, and select one vigorous branch as the extension branch.

2. Pruning (1) Pruning of young trees. In winter pruning, the principle of retaining more and cutting less should be adopted. Because young trees differentiate flower buds relatively late, they should be shortened less and left to grow longer more, and techniques such as propping, pulling, and hanging should be combined to adjust the angle of the main branches so that the canopy opens appropriately, thereby improving light and favoring early fruiting and early high yield. (2) Pruning of high-yielding trees. In winter pruning, appropriately retain fruiting branches and properly thin out overly dense branches. When the rows close in, appropriately retract the extension branches of the main branches so that a 50-80 cm ventilation and light penetration strip is kept between rows and the plants within the row do not cross. In summer pruning, remove overly dense branches.

II. Flower and Fruit Management

1. b2 crown flower-promoting technique In the first 1-2 years after planting, flowers should be promoted. The common method is to spray 200-300 times diluted 15% paclobutrazol solution once in late June, and a second time in early to mid-July. From late June to late July, open ditches for drainage so that the soil remains moderately dry, both of which help flower bud differentiation. After the apricot tree enters the high-yield period in the 3rd year, in order to control excessive canopy growth, combined with fruit retention, spray 300 times diluted 15% paclobutrazol solution twice in late April and early May.

2. Measures to protect flowers and fruits The commonly used methods are: (1) Plant pollinizer trees at a ratio of 1:1 or 2:1 and place bees during the flowering period. (2) Artificial pollination is very effective, especially in years with warm winters when there are many abortive flowers, so artificial pollination should be carried out even more. (3) Spraying water during the flowering period. Spray clean water at full bloom, and 0.1% borax and 0.1% urea solution can be added to the water. (4) Use plant growth regulators to retain fruits. Spray 50 x 10 x E-6 concentration gibberellin solution in mid-to-late October to increase the fruit set rate the following year. Spray 20 x 10 x E-6 concentration gibberellin solution at full bloom to increase the fruit set rate in the current year. Spray 300 times diluted 15% paclobutrazol in late April to control excessive growth and fruit drop.

3. Fruit thinning technique Fruit thinning is carried out after the first physiological fruit drop half a month after petal fall (at this time the young fruit diameter is between 1.0-1.5 cm). When thinning fruit, first remove all diseased and insect-damaged fruits, deformed fruits, and small fruits, and remove overly dense fruits so that the remaining fruits are evenly distributed on the tree, with fewer retained on weak trees and more retained on vigorous trees. Keep to a density of 1 fruit per 5-8 cm of branch tip, and control the yield per mu at about 2000 kg.

4. Measures to prevent fruit cracking In order to prevent fruit cracking, while selecting varieties that are not prone to cracking, drainage work should be strengthened from April to June, potassium fertilizer should be added in spring, and bagging should be carried out after fruit thinning. During the fruit expansion period from April to May, spray 0.2% potassium dihydrogen phosphate solution or 0.2% potassium sulfate solution on the leaves multiple times.