Latest Key Points of High-Quality Apple Cultivation Techniques

1. Improve the variety structure. Introduce varieties such as Yanfu, Royal Gala, and Sasha for promotion, gradually replacing old, mixed, and inferior varieties. Changfu and Qiufu should also be replaced with superior Fuji lines. New apple orchards should all adopt new varieties and new rootstocks.

2. Rational close planting, scientific planting, and improving orchard establishment quality. ① Strictly prepare the land and apply sufficient base fertilizer. Before planting, dig planting holes according to the required density, with a size of 0.8m×0.8m×0.8m, or dig planting trenches along the rows with a depth of 0.6m and a width of 0.8m. Keep subsoil and topsoil separate. Apply 10000kg of base fertilizer per 667 sq m, mix it with the topsoil, and backfill until 20cm from the ground surface, then tread firm. ② Rational close planting. In order to rationally and fully utilize land resources, newly built apple orchards adopt close-planting cultivation, with a spacing of 2—3m×4—5m. ③ Scientific planting. Plant in late March to early April in spring. 3—4 days before planting, fill the planting holes with sufficient water so that the live soil settles. Use first-grade seedlings. Before planting, soak them in clean water for 24 hours, then dip them in mud slurry, treat the roots with rooting powder, and plant immediately. After planting, water promptly, cover the soil with plastic film to preserve moisture, and then cover the film with another layer of soil to protect the plastic film.

3. Scientific fertilization. ① Apply base fertilizer in autumn. The method for applying base fertilizer in autumn is to apply 3000kg of organic fertilizer per 667 sq m for non-fruiting trees, and 5000kg of organic fertilizer per 667 sq m for fruiting trees, after harvesting mid-season fruit and before harvesting late-season fruit, in combination with deep plowing of the orchard, at a depth of 20—30cm. ② Control nitrogen fertilizer and promote the use of compound fertilizer. Excessive use of nitrogen fertilizer easily causes a decline in fruit quality and soil compaction. Fruit-tree-specific compound fertilizer and three-dimensional compound fertilizer should be used. Generally, apply 0.25kg per tree for one-year-old trees, and increase by 0.25kg each year thereafter. For fruiting trees, calculate according to fruit yield: for every 100kg of fruit produced, apply 100kg of compound fertilizer. ③ Foliar spraying of fertilizer. Foliar spraying is a fertilization method with fast absorption and high fertilizer utilization rate. High-efficiency humic acid spray fertilizer is a liquid fertilizer rich in nitrogen, phosphorus, potassium and other trace elements. This fertilizer is non-toxic and pollution-free, and is an ideal fertilizer for developing green food. Usage: spray a 200-fold solution 3—5 times during the growing season.

4. Rational shaping and pruning. New orchards adopt different shaping methods according to planting density. Orchards with a spacing of 2m×4m adopt the slender spindle tree shape, and orchards with 3—4m×4—5m adopt the spindle shape. The main shaping task for fruiting trees is tree-form transformation, developing them toward improved spindle and open-center dense-layer forms. ① Shaping and pruning of young trees. Pruning of young trees is mainly for shaping, generally carried out in early spring. Skirt branches below 50cm on the trunk are not retained at all and are all removed; branches above 50cm retain one branch every 20cm, and the direction must be chosen well. Branches longer than 70cm are not pruned at all; all are slowed down, bent flat, and notched for buds; branches about 50cm long are lightly short-cut; branches less than 30cm are very heavily short-cut to promote new shoots, and treated again the following year. The central leader is generally not short-cut, but a ring cut is made every 20cm to promote uniform growth of branches. In May—June, promptly twist shoots and pinch tips to control growth. Vigorous trees should have ring cuts on the main branches to promote flower bud differentiation. ② Pruning of trees in early fruiting. Trees in early fruiting adopt combined winter and summer pruning, mainly summer pruning, changing the past practice of one-time winter pruning. Winter pruning is mainly thinning, supplemented by renewal pruning, to cultivate main branches with single-axis extension. For upright branches within the canopy, those with space should be bent flat, and those without space should be removed; water sprouts and thin weak branches must be removed; auxiliary branches affecting the growth of scaffold branches should mainly be renewal-pruned and transformed into large fruiting branch groups; for moderate branches or moderately strong branches, leave them unpruned to promote flower formation. Summer pruning mainly adopts methods such as bud notching, branch bending, shoot twisting, and ring stripping. In mid-May, when new shoots grow to 15cm, twist them promptly; those exceeding 20cm should have their tips pinched to control growth; those without growth space should be removed promptly, and those with space may be heavily short-cut to promote new shoots. In early June, carry out ring stripping. For strong trees, use trunk ring stripping; for weak trees, use methods such as ring cutting and girdling to promote flower bud differentiation and fruit enlargement. In August, carry out branch bending or branch pulling, pulling branches to nearly 80 degrees. Through rational pruning and shaping, the germination rate and flower formation rate can be increased.

5. Strengthen flower and fruit management and improve fruit quality. ① Determine fruit by flowers, thin flowers and fruit. Starting from the inflorescence separation stage, retain one inflorescence every 20—25cm, retain one central flower per inflorescence, and remove all the rest. Orchards with unstable flowering can appropriately retain more central flowers, and after fruit set, carry out fruit thinning, retaining one fruit every 20—25cm. ② Fruit bagging. Bagging starts two weeks after flowering and ends 45 days after flowering. Before bagging, spray the whole orchard once with insecticide and fungicide, and choose freely hanging central fruit for bagging. Remove bags 20—25 days before harvest. For double-layer bags, first tear open the outer layer, and remove the inner layer after 5 days. While removing bags, remove leaves near the fruit that shade it, and lay reflective film under the trees. ③ Produce selenium-enriched health-care apples. A large number of experiments have proved that selenium is the protector of important human organs. Supplementing 200μg (micrograms) of selenium daily can effectively prevent and treat various diseases of the liver and heart. One week before flowering, 10 days after petal fall, and 1 month before fruit harvest, spray foliar fertilizer with 5000-fold sterilizing fertilizer type II to produce selenium-enriched health-care apples.