What issues should be noted in the efficient cultivation of kernel apricots?

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

1) Develop in suitable sites. Kernel apricots are drought-tolerant, tolerant of poor soil, and widely adaptable, but for efficient production, orchards must be established in locations with deep soil layers, fertile soil, and sheltered, south-facing slopes. Because kernel apricots bloom early and are susceptible to late frost damage, avoid establishing orchards on mountain ridges, wind gaps, and low-lying areas.

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

3) Adopt comprehensive measures to improve fruit set. The yield of kernel apricots mainly depends on fruit set conditions. Comprehensive measures should be adopted in production to improve fruit set. Commonly used measures include: ① Fertilization and watering. Apply a quick-acting nitrogen fertilizer once before bud break and once after fruit set, and water after fertilizing to supplement nutrients 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 about 100 g of urea per tree each time. ② Use vigorous branches for fruiting. After long branches of kernel apricots are left unpruned and laid open, they tend to form short fruiting branches with balanced vigor, forming "flower-string branches." Kernel apricots mainly bear fruit on short fruiting branches, and flower-string branches are the main fruiting sites. During the young tree stage, non-structural branches should be left unpruned and laid open more, with less heading back stimulation, to encourage the formation of flower-string branches. Flower-string branches of kernel apricots can bear fruit continuously for many years, but after a long fruiting period, the short branches weaken, fruiting capacity declines, and yield improvement is hindered. Therefore, after entering full fruiting stage, flower-string branches that have fruited for 4--5 years (a) should be promptly retracted, ultimately retracted to a strong vigorous fork at the rear or to latent buds at the base of rear branches, to encourage new branching, keep fruiting branches robust, and help improve fruit set. ③ Protect leaves and increase nutrient accumulation. In production, leaf diseases and insect pests should be controlled more intensively to improve the leaf's ability to produce photosynthates. After flowering, use 2.5% Decis 4000x solution to kill adult apricot seed wasps and tent caterpillar larvae. Spray 1000x Sujieke to control globular scale insects, and spray 14.5% carbendazim 500x solution to control scab and shot-hole disease. ④ Spray fertilizer during flowering. Spraying 0.2% borax or boric acid, or 0.3%--0.5% urea plus 0.5% monopotassium phosphate during flowering 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 enlargement stage. Focus on phosphorus and potassium fertilizers, applying 2--3 times, each time about 100 g urea, about 150 g diammonium phosphate, and about 300 g potassium sulfate per tree. Where irrigation conditions exist, water promptly; where they do not, apply after rain while soil moisture is available to give full play to fertilizer efficiency and promote plump kernels. ② Strengthen pest and disease control. Strengthen control of leaf diseases and insect pests, promptly prune dried diseased branches, and control the occurrence of apricot scorch disease. In mid-to-late May, scatter phoxim capsules on the tree canopy to control globular scale insects, and spray 20% green kungfu 4000x solution during the larval fruit-boring period. ③ Harvest at the proper time. Be sure to harvest when the fruit is fully ripe, and strictly prevent early harvesting.

5) Maintain vigorous tree vigor. Under poor site conditions, kernel apricot tree vigor tends to weaken, leading to slender fruiting branches, increased dead branches, and reduced fruiting capacity. In production, fertilizer and water management should be strengthened, yield strictly controlled, and excessive fruiting prevented, which severely weakens tree vigor. Renewal of branches after fruiting should be strengthened to maintain vigorous branch growth. Transformation and utilization of water sprouts within the canopy should be strengthened, and by bending branches they can be converted into flower-string branches to promote fruiting and extend the fruiting life of the tree.

6) Prevent the fruiting zone from moving outward. Kernel apricot fruiting branches have a short lifespan and die easily, making it easy for the fruiting zone to move outward and for fruiting to become superficial. In production, improve ventilation and light conditions within the canopy to encourage all-around fruiting. Pay attention to controlling competing branches; competing branches can be controlled through a combination of winter pruning to thin branches and summer bud removal to prevent disruption of tree shape. Each year, promptly retract weak slender branches in the inner canopy, appropriately heading back some branches where there is space to encourage new growth amounting to 1/3 of the total branch number, and thin out aged branches that have fruited for many years, to help stabilize the fruiting zone and prevent it from moving outward.