Detailed Explanation of Key Techniques for High-Efficiency Cultivation of Kernel Apricot

Kernel apricot is one of the main dried fruits in northern China, with quite good economic returns. In recent years, due to the development of almonds, the comparative benefit of kernel apricot has somewhat decreased. To enhance the production efficiency of kernel apricot, comprehensive measures should be adopted.

1) Develop in suitable locations. Kernel apricot is drought-resistant, tolerant of poor soil, and widely adaptable, but for high-efficiency production, orchards must be established in places with deep soil, fertile texture, and shelter from wind facing the sun. Since kernel apricot blooms early and is susceptible to late frost damage, avoid establishing orchards on mountain ridges, at wind gaps, or in low-lying areas.

2) Pay attention to configuring pollinator trees. Kernel apricot is mostly self-incompatible, so sufficient pollinator trees must be configured, preferably with 3--4 varieties mixed. The commonly used varieties in production, Longwangmao, Yiwufeng, Youyi, and Youer, can all pollinate each other. Generally, pollinator varieties should not be less than 30% of the total planted trees.

3) Adopt comprehensive measures to improve fruit set. The yield of kernel apricot mainly depends on fruit set conditions. In production, comprehensive measures should be adopted to improve fruit set. Commonly used measures include: ① Supplementary fertilization and watering. Before germination and after fruit set, apply 1 application of quick-acting nitrogen fertilizer each time, and water after fertilizing to supplement nutrition and meet the nutrient demands of new shoot growth and flowering and fruit set. The amount of fertilizer should be determined by tree size and yield level, generally applying about 100g of urea per tree each time. ② Use vigorous branches for fruiting. After long branches of kernel apricot are left unpruned and laid open, they easily form short fruiting branches with balanced vigor, forming flower-bearing branches in a row. Kernel apricot mainly fruits on short fruiting branches, and flower-bearing branches in a row are the main fruiting sites. During the young tree stage, non-structural branches should be mostly left laid open and less shortened to stimulate growth, so as to promote the formation of flower-bearing branches in a row. The flower-bearing branches in a row of kernel apricot can bear fruit continuously for many years, but as the fruiting years lengthen, the short branches weaken, fruiting ability declines, and this is unfavorable for increasing yield. Therefore, after entering the full fruiting stage, flower-bearing branches in a row that have fruited for 4--5a(years) should be promptly retracted, finally retracting to a vigorous fork at the rear or to latent buds at the base of rear branches, to promote branching, keep fruiting branches robust, and help improve fruit set. ③ Protect leaves and increase accumulation of nutrients. In production, leaf pest and disease control should be strengthened to improve the ability of leaves to produce photosynthetic products. After flowering, use 2.5% Decis 4000-fold solution to kill adult almond wasps and tent caterpillar larvae. Spray 1000-fold solution of Sujieke to control globular scale insects, and spray 14.5% carbendazim 500-fold solution to control scab and shot-hole disease. ④ Spray fertilizer during flowering. Spraying 0.2% borax or boric acid during flowering, and spraying 0.3%--0.5% urea plus 0.5% monopotassium phosphate, is very beneficial for improving fruit set. ⑤ Place bees during flowering.

4) Promote plump kernels. The main measures used in production are: ① Timely topdressing and watering during fruit expansion. Focus on phosphorus and potassium fertilizers, fertilizing 2--3 times, each time applying about 100g of urea, about 150g of diammonium phosphate, and about 300g of potassium sulfate per tree. Where irrigation conditions exist, water promptly; where conditions do not allow, adopt the method of applying after rain while soil moisture remains, to give full play to fertilizer efficiency and promote plump kernels. ② Strengthen pest and disease control. Strengthen control of leaf pests and diseases, promptly prune diseased withered branches, and control the occurrence of apricot blister disease. In mid-to-late May, scatter phoxim capsules on the tree canopy to control globular scale insects, and spray 20% green Kung Fu 4000-fold solution during the larval fruit-boring period. ③ Harvest at the proper time. Be sure to harvest when the fruit is fully mature, and strictly prevent early harvesting.

5) Maintain robust tree vigor. Under poor site conditions, kernel apricot trees tend to weaken, causing fruiting branches to become slender, dead branches to increase, and fruiting ability to decline. In production, fertilizer and water management should be strengthened, yield should be strictly controlled, and excessive fruiting should be prevented to avoid severely weakening tree vigor. Renewal of branches after fruiting should be strengthened to maintain vigorous branch growth. Transformation and utilization of water sprouts within the tree canopy should be strengthened, and by bending branches, they can be converted into flower-bearing branches in a row, promoting fruiting and extending the fruiting years of the tree.

6) Prevent the fruiting zone from moving outward. The fruiting branches of kernel apricot have a short lifespan and die easily, making it prone to outward movement of the fruiting zone and superficial fruiting. In production, by improving ventilation and light conditions in the tree canopy, promote all-around fruiting of the tree. Pay attention to controlling competitive branches, which can be controlled by combining winter pruning to thin branches with bud removal during the growing season, preventing disruption of tree shape. Each year, promptly retract weak slender branches in the inner canopy, appropriately shorten some branches where space permits, promote new branches amounting to 1/3 of the total branch number, and remove aged branches that have fruited for many years, so as to stabilize the fruiting zone and prevent it from moving outward.