Cultivation and management techniques of apricot trees in greenhouse to avoid freezing damage

Apricot trees cultivated in greenhouse

Apricot is native to China and has a long history of cultivation. However, because most apricot trees are extensive management, the yield is low and unstable, coupled with the early flowering period of apricot, vulnerable to late frost and other reasons, affected the development of apricot. Nowadays, the occurrence of frost injury can be effectively avoided through intensive cultivation in solar greenhouse. The cultivation techniques of apricot in solar greenhouse are summarized as follows.

Apricot varieties suitable for cultivation in solar greenhouse

Varieties with early ripening, large fruit, bright color, good quality, good storage and transportation, early flowering, high yield, strong resistance, low chilling requirement and easy management should be selected, such as Kate apricot, Jinyang, Hongfeng and Xiangbai apricot.

2. Types of solar greenhouse suitable for cultivating apricot trees

1. Bamboo-soil wall structure

The thickness of the earth wall is required to be 2cm wide at the bottom. The width of the top is 1 to 1.2 meters, and the height of the earth wall inside the greenhouse is 1.5 to 1.8 meters. The cement pipe with a diameter of 25 centimeters is buried at the height of 1.2 to 1.5 meters, and one vent is used for every 4 meters. The back slope sandalwood is made of wood, the top column is made of cement columns, and the front slope is arched with bamboo poles. The upper cover has a long life without dripping film, the film is made of 3 pieces, the foot membrane is 1.2 to 1.5 meters, and the top membrane is about 1 meter. The middle membrane depends on the span of the greenhouse. The middle column can be constructed with cement column suspension beam and suspension column. The main parameters are ridge height 2.9-3.3 m, shoulder angle 1.2-1.3 m, length 50-100 m, span 6.5-10.5 m, span 7.5-8.5 m. Cover the film with a thick grass curtain of 3 cm to 5 cm.

2. Reinforced brick wall structure

The rear wall and east-west gable are 37 cm hollow or 50 cm double hollow. The wall is 1.8 meters high. Leave 30 cm × 40 cm vents at the wall height of 1.2 to 1.5 meters, one every 4 meters. The back slope uses wooden sandalwood rafter cement columns, and the front slope is welded with steel bar, except that there are no columns in the outer shed of the back slope to reduce shading. Other parameters are basically similar to the structure of bamboo-soil wall.

Apricot trees cultivated in greenhouse

III. Planting methods of apricot trees cultivated in solar greenhouse

1. Planting apricot trees after having greenhouse.

Direct colonization of ①

The farm manure was applied in the first and middle of March, and the depth was 25 cm. The planting pit was dug according to the row spacing of 1 m × 1 m. The diameter and depth of the pit were 30 cm and 30 cm respectively. Plant apricot seedlings directly. Before planting, soak the apricot seedlings in clean water for one day and night, and disinfect them with 3-5 degree stone sulfur mixture for 5 minutes. Then add 1 gram of ABT rooting powder to 20 kg of water for 15 minutes to 1 hour. When planting, pay attention to stamping, while filling, while lifting seedlings, while stepping on. The planting depth is the same as the original soil skin. After planting, the stem is fixed by 30cm in the southernmost row, each plant increases by 5cm in turn to the north, and the height of the northernmost plant is about 60cm.

Transplanting large seedlings of ②

This method can be used when vegetables are produced in solar greenhouse in winter and spring. The method is as follows: using old cement bag, chemical fertilizer bag or plastic bag (cut bottom angle) to fill nutrient soil, the proportion of nutrient soil is mature farm manure 1 to 4, garden soil 3 to 4 to mix evenly. Seedling treatment is the same as directly planting seedlings, one seedling per bag, dry after planting, placed neatly, made of 4 meters bamboo bark into a small arch shed, covered with large greenhouse film, covered with grass curtain at night. The period takes place at the initial stage of local thawing.

2. First plant apricot trees, then build a greenhouse

In this way, the site with flat terrain, convenient transportation, watering conditions and no shade in the east and west should be chosen to plan and build the garden. The method of soil improvement is to choose the east-west length of 50-80 meters. On the flat land with a width of 710 meters from north to south, 667 meters are sprinkled with about 10,000 kilograms of farm manure, and the suspension plough is used for deep ploughing. Other planting methods are the same as direct planting.

Apricot trees cultivated in greenhouse

Management of apricot trees in the first year after planting in solar greenhouse

1. Soil, fertilizer and water management

① soil management: improve soil and water before planting, loosen soil after rain, increase soil permeability and weed in time.

② fertilizer includes base fertilizer and topdressing fertilizer.

Base fertilizer: in addition to changing soil base fertilizer before planting, apricot trees in solar greenhouse should apply 5000 kg farm manure per mu from the first ten days of September to the end of October of that year. The method is to use four-toothed fork to turn 40 cm wide and 25 cm deep after surface application.

Topdressing: before the middle of July of that year, topdressing should be done about once a month. The first fertilizer was applied 100 times as much as reclamation bio-organic fertilizer when the new shoot was 10-15 cm in the same year. The plant was applied 1.5 kg to 2.5 kg. It can also apply urea 100g to 150g per plant. For the second fertilizer, when the new shoot was 25cm to 30cm, the plant applied 100g urea + 100g Sakefu. For the third time fertilizer, 400g potassium sulfate compound fertilizer was applied to the plant in late June.

Extra-root topdressing: combined with spraying, 300 times urea was sprayed before the middle of July to promote the growth of new shoots; after the middle of July, 300 times of potassium dihydrogen phosphate was sprayed every time to promote flower bud differentiation and branch maturity.

③ water seedlings should be watered once after planting, and then watered every 10 days or so. Irrigate 4 times in a row to ensure the survival of seedlings. After the seedlings survive, they should be watered every half a month or so to promote the growth of new shoots. After the middle of July, watering is stopped when the rainfall is moderate, and watering is appropriate when it is dry. When the rainfall is heavy, pay attention to drainage, irrigate fertilizer water and seal frozen water throughout the year.

2. Pruning

Apricot trees in the first year of ① summer pruning are mainly heart-picking. When the new shoot is about 25 cm in that year, pick the heart once, pick the heart again when the second shoot is 30 cm, and remove some upright new shoots when the new shoot is 10-15 square meters three times. The rest will be removed in the first ten days of September. Before and after the Beginning of Autumn, each plant left east and west to retain 60 °70 °to the two main branches, and the other branches softened to about 90 °. Careful and meticulous summer shearing can promote flower formation.

② winter shearing is carried out from before to after heating, and the erect branches, non-flowering branches, cross branches and weak branches are removed, leaving about 40 flowering branches above 30 cm per plant. The height of the tree is controlled in half of the ground to the greenhouse film.

3. Disease and pest control

The main diseases and insect pests of apricot are perforation, scab, early deciduous disease, brown rot, red spot disease, aphids, red bee spiders, almond wasps and shell insects. In production, comprehensive control is given priority to. Annual young trees use mancozeb 600x or carbendazim 800x solution to control diseases, 1500 times to control aphids, 1500 times to sweep mites or 2500 times to acaridins to control red spiders, 1500 times to control caterpillars and 1000 times to kill scale insects at a speed of 1000 times. The disease medicine is used once every half a month, and the insect pest medicine is used only when the insect is used.

Apricot trees cultivated in greenhouse

Management of apricot trees in solar greenhouse in the second and subsequent years

1. Temperature and humidity control

Do not make the temperature rise suddenly in the first week of heating. Generally, you can uncover the grass curtain of 1 / 2 / 2. The temperature control is below 15 ℃ and the relative humidity is 80%-90%. At the beginning of the second week, open all the straw curtains. The suitable temperature during sprouting period is 8: 15 ℃, the lowest temperature is 5 ℃, and the humidity is less than 80%; the suitable temperature at flowering stage is 12: 18 ℃, the lowest temperature is 7 ℃, and the humidity is less than 60%; the temperature during flowering period is not more than 22 ℃. Suitable temperature for young fruit stage is 15: 20 ℃, minimum temperature is 8 ℃, relative humidity is less than 70%: suitable temperature for expansion stage is 18: 25 ℃, minimum temperature is 10 ℃, humidity is less than 70%, suitable temperature for near-ripening stage is 22: 30 ℃, minimum temperature is 15 ℃, humidity is less than 60%. Plastic film mulching in the second week after heating is beneficial to preserve soil moisture and improve ground temperature.

2. Fertilizer and water management

From the first ten days of September to the end of October, 5000 kg of farm manure was applied to 667m 2 of ① base fertilizer, spread and turned deeply.

Topdressing of ② fertilizer in the first week. 200 grams of urea was applied to plants, 300 grams of Sakefu compound fertilizer was applied to plants 2 weeks after flowering, 300 grams of potassium sulfate compound fertilizer was applied to plants during fruit expansion, and 300 grams of urea was applied to plants after fruit harvest.

③ water poured sprouting water, pre-anthesis water and post-anthesis water, fruit expansion water and frozen water.

3. Flower and fruit management

In full bloom, the whole tree is rolled with feather duster, and the pollination effect is also good. Honeybees or wall bees can also be used to pollinate in areas where conditions permit.

② hormone spray promotes fruit setting by spraying 500x borax + 300x urea: spraying 25mg / L gibberellin (GA3) plus 0. 3% potassium dihydrogen phosphate plus glucose and 300x anti-falling colorant within 2 weeks after flowering to improve fruit setting rate.

After cutting flowers, the ③ ring cut the branches of the tree, each branch 2-3 knives, with an interval of 3-5 cm.

④ artificial fruit thinning can be carried out in two times. The first fruit thinning was completed within 2 weeks after flowering, and the basal fruit, deformed fruit, concomitant fruit, disease and insect fruit were removed. The second fruit thinning was carried out in the hard core stage, generally leaving 1 fruit in the bouquet branch, 1 fruit in the short fruit branch, 3 fruit in the middle fruit branch and 6 fruit in the long fruit branch.

4. Pruning

① summer shears are mainly sprouting, coring, branch thinning, leaf picking, thinning or retraction after fruit picking.

When the post-flowering leaf buds germinate, erase the improper buds; pick the heart when the new shoot is 20cm or 25cm, or remove it when the secondary shoot grows to 20cm. When the backbone branch grows to about 50 cm, it should pull the branch to open the angle, part of the new shoot should be cut around, twist the shoot, and remove the strong shoot and dense branch on the back in time, so as to open the light path and increase the light to promote flower bud differentiation.

When the fruit is nearly ripe, remove the leaves around the fruit to promote fruit coloring.

After fruit picking, interrow thinning was carried out to turn it into 1 × 2 row spacing. To retain trees, remove drooping branches, retract fruit branches, short truncated trunk branches, and promote new shoots for fruiting in the coming year.

The pruning principle of ② in winter is still to remove figs, disease and insect branches and cross branches. Overlapping branches and drooping branches should be separated by 1 × 2 rows, leaving 60-80 medium-long fruit branches per tree.

5. Pest control except spraying 3 °stone sulfur mixture once in the first week after heating up, other pest control was the same as in the first year.