What are the key technical points of apple tree management in the spring of 2020?

After the apple tree is harvested in autumn, it will enter the dormancy period in winter. The dormancy period refers to the period from the natural defoliation in late autumn and early winter to the sprouting in the second spring, so what are the key points of apple tree management in spring 2020?

First, topdressing at flowering stage

To supplement part of the nitrogen fertilizer, the amount of fertilizer application accounts for about 1/4 of the total amount of the whole year, that is, 22 kg of urea per mu. If possible, appropriate amount of potash should be applied, 200kg of plant ash or 16.5kg of potassium chloride should be applied per mu, and radial ditch or furrow topdressing should be used.

2. Irrigation from bud germination to pre-flowering

For example, the local spring drought should be irrigated once, and irrigation is needed when the soil moisture is less than 60% of the field capacity.

Third, ploughing to preserve soil moisture

After topdressing, the whole garden is ploughed, the soil is broken and raked flat, and the soil is loosened and preserved after irrigation.

Fourth, pre-flowering re-cutting

The angle of the ① branch is opened, the spindle-shaped main branch is pulled into 70-80 degrees, and the auxiliary branch is pulled apart.

If the number of ② flowers is large, the branches that affect the light will be thinned and shrunk, and 3-4 flower branches will be shrunk; the middle flower and fruit branches will hit the head lightly and leave strong short fruit branches to bear fruit. When the number of flowers is insufficient, keep flowers as far as possible, sparse and shrink the branches that are left without flowers; ③ should retract properly the branches that have become flowering after slow release in previous years; ④ planting density is high and the crown has been handed over should be properly retracted and dug the crown (height, width).

Fifth, flower thinning

① artificial flower thinning: from budding to flowering, keeping flowers reasonably according to tree strength, generally leaving an inflorescence of about 15-20 cm and leaving only a single flower.

② chemical thinning: 1000-2000ppm was sprayed 2 weeks after full bloom, 10-20ppm naphthoacetic acid was sprayed on Golden Crown after full flowering, 1500-2000ppm carbaryl was sprayed on Guoguang and Fuji after full flowering, or 300ppm was sprayed first at the bud stage, and then 300 ethinyl + 20ppm naphthoacetic acid was sprayed after flowering.

VI. Pest control

Control of ① powdery mildew, leaf roll moth and Hawthorn red spider

Before flowering, spray 50% sulfur suspension agent 2000 times with 25% p-sulfur capsule 800x solution or 40% water amine sulfur 2000 times solution, or 20% methanolide 3000 times solution. Spray 300 times borax and 500 times urea mixture 2-3 times at flowering stage.

Control of early deciduous disease, ring streak, anthracnose, mildew heart disease and peach heart borer in ② apple trees

Spray 1 ∶ 4 ∶ Bordeaux solution at 10-15 days after anthesis, or 700x liquid of more than 50% bacteria. Or 50% acetaminophen 700 times solution. For young trees, spraying 50% phoxim 200 times or 25% 1605 capsules 200 times can control peach heart borer.

The key to the management of dormant apple trees is to maintain the assimilation function of leaves and prevent early defoliation. The quality of management during this period also directly affects the cold resistance of trees in winter and the quality of flower bud differentiation, and plays a decisive role in flowering and growth in the coming year. In addition, the spring management of apple trees also has a direct impact on the yield and quality of the fruit of the year.