Detailed explanation of the latest management techniques for apple trees

1. Water and fertilizer management

Water and fertilizer are the foundation and root of apple tree growth and fruit enlargement. Only when water and fertilizer are sufficient can vigorous tree growth and abundant fruit be ensured. The method is: every winter, spring and summer, ensure the orchard is watered once. Meet the water requirements of the fruit trees and fruit at each growth stage. In fertilization, follow the fertilization concept of “reduce nitrogen, control phosphorus, increase potassium”, and adopt the method of: “root application, foliar spray, trunk painting” as a three-in-one model. For 3—5 year old young trees, mainly apply nitrogen fertilizer, with an appropriate increase in phosphorus and potassium fertilizer to promote rapid tree growth and rapid canopy expansion. Generally in autumn, while there is moisture, apply 0.5 kg urea per tree and 0.5 kg potassium fertilizer, and apply the same amount once in spring with irrigation. With this water and fertilizer management, scattered fruiting can occur in two or three years, and full production can be achieved after five years. Full-bearing orchards are exactly at the time of pursuing high yield, creating high benefits, and also high investment. At this time, fertilization should adopt the method of combining “root application and foliar spray”. In autumn, apply 3000—5000 kg of decomposed farmyard manure per mu as base fertilizer, 2—3 kg of three-element fertilizer plus 1-2 kg of humic acid or probiotic fertilizer. In spring fertilization, increase nitrogen fertilizer, and other fertilizers can be appropriately reduced. In summer at the end of May and beginning of June, according to the fruiting situation, apply 2—3 kg of phosphate fertilizer with less nitrogen and more potassium as a top dressing, and starting from the end of June, spray once every 10-15 days with potassium dihydrogen phosphate plus Shuofeng 481 or Tianda 2116, Yiguosu, Guoyou, Qixin amino acids. In August, during the last fruit enlargement stage, apply top dressing once more to ensure the last rapid fruit enlargement. With this water and fertilizer management, the tree vigor can be ensured to be “strong but not excessive, vigorous but not water-sprouting, stable trees with green leaves and large fruit”, achieving “no fertilizer deficiency, no leaf drop, no water sprouts”. After harvesting, promptly spray the orchard with 0.3%-0.5% urea. This accumulates nutrients for next year's blooming and lays the foundation for later high yield. 

2. Flower and fruit management

Flowering period management must be meticulous and serious, with no carelessness at all. In order to make flowering uniform, first, spray once with Tianda 2116 or Aiduoshuo at the initial flowering stage. Shuofeng 481 to prevent spring frost; at full bloom, spray once with 0.2%-0.3% boron fertilizer plus 0.2%-0.3% urea, and spray once more 7 days after flowering. Second, reasonable load. Adhere to the principle of “thinning flowers is not as good as thinning buds, thinning fruit is not as good as thinning flowers”. According to the tree condition, leave as few fruits as possible to ensure that later every fruit is above 85. As the saying goes, “whatever vine you leave, whatever fruit you get”, so how to leave fruit and what fruit to leave has a great impact on fruit quality and yield. Be sure to leave high-shaped fruit, leave fruit with greenish fruit surface, and thin out skewed fruit and fruit with smooth surfaces. Leave fruit with broad, flat shoulders, and remove fruit with different sizes at the two ends. Leave fruit with long stalks, and remove fruit with thin, short stalks. Leave hanging fruit, and remove upward-facing fruit on water sprouts. Leave fruit with moderate fruiting spur secondary shoots. Remove fruit without secondary shoots. Only strict flower thinning and fruit retention can ensure the common growth of both tree and fruit. 

3. Fine pruning

Good tree vigor is the key to producing high-grade, high-quality fruit. What kind of tree vigor to select and retain and what pruning method to adopt must be determined according to your own orchard appearance, tree vigor and variety. Young orchard pruning should be carried out with the goals of early high yield and later high quality. Adopt the method of no heading back, continuous long release with timely renewal pruning, and single-axis extension to achieve three-dimensional fruiting. Mature orchards should adopt dynamic management of thinning out, lowering, and sparse thinning. That is, make the tree body achieve light and ventilation at every branch, control tree height within 2.6—3 m, with 2.8 m being most suitable, and leave 5—7 large branches per tree. It is best to leave 60,000—80,000 branches per mu. On the retained 5—7 large branches, all side branches larger than 0.5 cm should be removed. Leave all small branches, and give all the nutrition of the idle, food-consuming large branches to these small branches. This is called “raising sons is not as good as raising grandsons”. These small branches produce shoots in one year, flowers in two years, and fruit in three years, cycling in fruiting, with basically no alternate bearing, and the fruit produced is of high quality. Second, every spring when buds sprout, notch buds on bare branches. The method is: for upward buds on horizontal branches, notch behind the bud; for side-downward buds, notch in front of the bud. In summer from May—July, for branches about as thick as chopsticks, hold the branch with the left hand, grip the middle-rear part of the branch tightly with the right hand, and use the thumb to apply force reasonably downward until a sound is heard from the branch. This method is very effective, and the flower formation rate is also very high. For orchards with a large fruit load the previous year, do not prune in winter. This is because the tree body is weakened and resistance is reduced. If winter pruning is carried out, the tree body will be unable to overwinter and canker disease will occur frequently. Pruning should be carried out in spring. In addition, for trees with a large fruit load, in spring before flowering, promptly shorten long flowering branches, renew prune clustered flowering branches, and remove weak flowering branches. In summer, absolutely do not carry out ring-barking. If this method is not done properly, it will lead to weakened tree vigor, severe disease, and affect yield and quality. Reasonably using conventional methods such as shoot control, shoot twisting, and pinching is enough. 

4. Disease and pest control

Disease and pest control is the key to ensuring the production of high-quality fruit. In particular, the 2—3 pesticide applications before bagging are very critical. The first application ten days after flowering should use a smaller amount because the young fruit surface is highly sensitive. Pesticides can include Dasheng M-45, Anzhi, Jinlishi, Beibo, Haolaoli, Aike, Nongkang 120 and other high-quality fungicidal and insecticidal drugs. The most important thing is to grasp this pesticide application at the end of May and beginning of June. This is the key period for ensuring a year of leaves. For this application, choose tebuconazole, Namixin, Thiophanate-methyl, Beibo, abamectin, and tetradifon, which can control early defoliation disease. When applying pesticides, a compound formulation method can be used, which can achieve twice the result with half the effort in control.