A Detailed Guide to Apple Tree Planting Techniques and Management Methods

The apple is also a high-yielding fruit tree with strong adaptability to soil. Generally, thin hilly land, sandy wasteland along riverbanks, and mildly saline-alkali land can all be used for block planting after proper improvement. Generally, apple trees begin to bear fruit only 2-3 years after planting. As for the length of the fruit growth period, it is generally 65-87 days for early-maturing varieties, 90-133 days for mid-maturing varieties, and 137-168 days for late-maturing varieties. Under normal circumstances, apple trees can live 15-50 years after planting.

Apple Tree Planting Conditions

1. Temperature: Apples prefer cool, dry climatic conditions with abundant sunshine. It is generally believed that an average temperature of 12°C-18°C during the growing period from April to October is most suitable for apple growth. If summer temperatures are too high, with an average temperature >26°C, flower bud differentiation is poor, fruit develops quickly, and it does not store well. The suitable coloring temperature for red varieties before ripening is 10°C-20°C. If the diurnal temperature difference is small and night temperatures are high, coloring becomes difficult. Compared with the climatic conditions of the Huaibei region, especially for mid-maturing red varieties, there is a certain gap from the most suitable temperature requirements, and further south to the Yangtze River basin, this gap becomes even greater.

2. Rainfall: The annual precipitation in the world's main apple-producing regions is about 500 mm-800 mm. During flower bud differentiation and fruit ripening, the air is required to be relatively dry with abundant sunshine, so that the fruit surface is smooth, the color is deep and vivid, and the flower buds are plump. If rainfall is excessive and sunshine insufficient, branches and leaves tend to grow excessively, flower bud differentiation is poor, yield is low and unstable, pests and diseases are severe, and fruit quality is poor. The annual precipitation in the Huaibei region is about 800 mm, but it is unevenly distributed, with occasional spring droughts, summer droughts, or autumn droughts. In most years, rainfall in July-August is too concentrated, so irrigation and drainage measures both need to be strengthened.

3. Light: The apple is a light-loving tree species. Sufficient light is beneficial to normal growth and fruiting, and helps improve fruit quality. Different varieties have somewhat different light requirements. The annual sunshine hours in the Huaibei region are more than 2,000 hours, which can basically meet the needs of apple growth and development.

4. Soil: In terms of soil, apples are suitable for deep, well-drained sandy loam rich in organic matter. The soil pH value should preferably be slightly acidic to neutral. When soil aeration is poor, root growth is hindered. When the pH is above 7.8, nutrient deficiency and chlorosis are prone to occur. Its salt tolerance in soil is below 0.15%.

Shaping and Pruning of Apple Trees

1. Shaping of apple trees: For apple tree shaping, the spindle shape is mainly advocated. The spindle shape bears fruit relatively early and is a tree form currently advocated. The tree height is 2.5-3.0 m, the crown width is 1.8 m, and the trunk height is 70 cm. On the central leader, 10-15 main branches are evenly distributed, without tiers. The spacing between main branches is 15-20 cm, and they are evenly distributed in all directions. The opening angle of the main branches reaches 60-90 degrees. This tree form has a small crown and is easy to manage. It flowers in the same year, bears fruit in the second year, and production can increase substantially in the third to fourth year.

2. Pruning of apple trees

① Spring pruning: Carried out after bud break and around the flowering period. Pruning tasks are completed using measures such as bud rubbing, branch thinning, heading back, bud notching, and girdling. For young orchards, it also includes shaping and pruning tasks such as branch bending.

② Summer pruning: Techniques such as opening branch angles, pinching, shoot twisting, girdling, thinning and cutting back, and ring cutting are used to moderate tree vigor, improve light, and expand the tree crown.

③ Autumn pruning: Measures such as bending branches, thinning upright branches, water sprouts, dense branches, and overly dense peripheral new shoots improve light conditions, promote flower bud differentiation, and enhance the tree's cold resistance.

④ Dormant period pruning: This is pruning carried out from leaf fall in early winter to bud break in spring. The main task is to remove useless branches such as diseased and insect-damaged branches, dense branches, and water sprouts. Methods include heading back the tips of scaffold branches and retracting overly long or overly large fruiting branch groups, auxiliary branches, and weakened scaffold branch tips. Its role is to adjust the angles and extension directions of scaffold branches, auxiliary branches, and fruiting branch groups, control the ratio of flower buds to leaf buds, and balance tree vigor, so as to achieve the goal of abundant and high yields.

Fertilizer and Water Management for Apple Trees

1. Fertilization management: Fertilization is generally divided into base fertilizer and topdressing. The specific timing depends on the variety, fertilizer requirement patterns, and the tree's growth and fruiting conditions. Under normal circumstances, it is advisable to fertilize 4 times throughout the year.

① Pre-flowering fertilizer or sprouting fertilizer (early April).

② Post-flowering fertilizer (mid-May). These two fertilizations can effectively promote sprouting and flowering and promptly prevent nutrient depletion caused by the large consumption of nutrients during flowering, improve fruit set rate, and promote new branch growth.

③ Flower bud differentiation and young fruit enlargement fertilizer (late May to early June). This topdressing is to meet the needs of fruit enlargement, branch and leaf growth, and flower bud differentiation. This fertilization is mainly potassium fertilizer.

④ The best time to apply base fertilizer is autumn (early to mid-September). When applying base fertilizer mainly with farmyard manure, all phosphorus is applied as the total amount for the whole year. To give full play to fertilizer efficiency, phosphate fertilizer should first be piled with organic fertilizer to decompose, then mixed evenly and applied.

2. Flower and fruit management

① Techniques for promoting flowering in young trees: For trees growing normally or vigorously, in addition to the aforementioned spring bud notching, summer girdling, and autumn branch bending, growth regulators can also be used to promote flowering. In the early and middle stages of vigorous new shoot growth and during the autumn shoot growth period, spraying 0.15%-0.2% daminozide or 0.1%-0.2% ethephon 2-3 times can effectively inhibit growth and promote flowering. If daminozide and ethephon are sprayed together or alternately, the effect is even better. In addition, from around leaf fall in autumn to before bud break in early spring of the following year, soil application of paclobutrazol at 0.5 g/sq m-0.75 g/sq m calculated by tree crown projection area (referring to active ingredient, equivalent to 15% paclobutrazol wettable powder 3.3 g/sq m-5 g/sq m), evenly broadcast within the tree plate and then turned into the soil, or applied with water in a ring-shaped trench below the outer line of the tree crown, also has good effects on promoting flowering. It is also possible to spray a 0.1%-0.15% paclobutrazol solution on the leaves when new shoots begin vigorous growth, which is likewise effective for promoting flowering. At the same time, good work should be done in autumn to protect leaves and nourish roots. Good vegetative growth is the foundation for promoting flowering and early fruiting.

② Improving fruit set rate: In years with poor climate and few flowers, artificial pollination or bee release at the early full-bloom stage of apples can ensure fruit set. For trees with many flowers or in years with many flowers, supplementary pruning is carried out when flower buds swell and begin to open, including removing weak ones and keeping strong ones, flower-blocking cuts on clustered flowering branches, and retraction cuts on clusters of short fruiting branches, and thinning flower buds. This can not only improve fruit set rate and enlarge fruit, but also help fruit spur branches form flower buds, so it is also an effective measure to overcome alternate bearing. In boron-deficient orchards, spraying boron at flowering stage has a significant effect on improving fruit set rate.

③ Flower and fruit thinning: From the early to late full-bloom stage, excessive inflorescences and flowers are thinned as required. At 1-4 weeks after petal fall, excess young fruit are thinned. This is a necessary measure to prevent or overcome alternate bearing in apples. According to the leaf-to-fruit ratio standard, it is generally controlled at (30-40):1. According to the branch-to-fruit ratio (vegetative branches/fruiting branches) standard, it is (3-4):1 for Delicious strains, 3:1 for Golden Delicious, and (2-3):1 for Ralls Janet. Weak trees should appropriately increase the ratio. In general production, leaving 1 inflorescence to set fruit out of every 6-7 inflorescences can basically achieve the (30-40):1 leaf-to-fruit ratio standard. To improve thinning efficiency, taking advantage of the uneven flowering of apples, that is, the earlier-opening central flowers have already been pollinated and fertilized while lateral flowers and axillary flower buds open later, chemical flower thinning can be carried out at the late full-bloom stage with 0.5-1 degree Baume lime sulfur mixture. After testing, it can be promoted for use in production.

④ Preventing pre-harvest fruit drop: Some apple varieties, such as Delicious, Starking, Jonathan, Fengyan, and Tsugaru, have severe pre-harvest fruit drop. Spraying a solution of naphthaleneacetic acid or sodium naphthaleneacetate at a concentration of 20 ppm-40 ppm on fruit clusters 30-40 days and 20 days before harvest, 1-2 times, can effectively reduce fruit drop.

⑤ Preventing fruit russeting and fruit cracking: Fruit russeting in Golden Delicious apples is an important factor affecting the commercial value of the fruit. It mainly occurs within 1 month after petal fall. Rainfall, high relative humidity, and spraying Bordeaux mixture all aggravate the formation of fruit russeting. Although bagging has a good anti-russeting effect, it is difficult to apply over large areas. Using other fungicides instead of Bordeaux mixture to prevent disease within 1 month after petal fall can reduce fruit russeting. In addition, strong tree vigor can also reduce the degree of fruit russeting. Fruit cracking is a common phenomenon in Ralls Janet apple varieties in the Huaibei region, reducing the commercial value of the fruit. Spraying a 0.5%-1% calcium chloride (CaCl2) solution 1-2 times 1-3 weeks before fruit harvest has a clear effect on preventing fruit cracking. In addition, varieties with light fruit cracking such as Fuji can be selected to replace Ralls Janet.