When do greenhouse nectarines usually grow? What cultivation techniques should be mastered?

Nectarine is a kind of peach, the skin is smooth and hairless, the taste is sweet and sour, the meat is very crisp, which is much smaller than the average peach. Although it is not as good as other peaches, it is indeed a variety with high nutritional value. In recent years, in order to increase the yield of nectarines, greenhouse planting has been set up in many places. When are nectarines usually planted in the greenhouse? What cultivation techniques should be mastered?

First, how to build and select the site of the greenhouse?

The address of the greenhouse should be in the place of leeward facing sun, good drainage and irrigation, fertile soil and sandy loam, which is a simple solar greenhouse, with a span of about 10m from north to south and a length of about 60m. The back wall and both sides of the wall are brick-concrete structure, thick 50cm, the height of the back wall is 2.5m, the ridge height is 3m, and the distance from the ridge to the back wall is 1.5m. The pillars are reinforced concrete columns and the frames are made of bamboo and wood. There is a ventilation window on each side of the wall and a ventilation window every 3m interval on the back wall. Greenhouse film with good light transmittance, low polyhydraulic PVC drip-free film, phase pressure between the membrane, covered with hand-pulled straw felt. The nectarine can break dormancy and heat up when the cooling capacity is reached. In the first ten days of December every year, the straw blankets are usually opened at 8 ∶ 00 in the morning to improve the light conditions in the shed and improve the nutrition level of the trees, and 16 ∶ 00 in the afternoon to keep the temperature in the shed.

When will it be planted?

The main cultivated variety in Hefei area is Yanguang. Planting from January to April, in order to make full use of the land area in the shed and increase the yield per unit area, high density planting was adopted, the plant spacing was 1m and the row spacing was 1.5m. The planting ditches of 70cm and deep 70cm were dug, and the topsoil and subsoil were placed respectively, and the high quality and mature organic fertilizer 60t/hm2, calcium superphosphate 1800kg/hm2 and potassium sulfate 7500kg/hm2 were applied. The topsoil fills the bottom of the ditch, the subsoil and fertilizer are fully mixed and filled in the planting ditch, and after watering, the soil is covered and watered, and the ditch is ridged by filling soil.

Third, how to control the temperature in the shed?

Controlling the temperature and humidity in the greenhouse is the key link to improve the fruit setting rate and achieve premature delivery, high yield and high quality. The temperature in the shed is mainly controlled by ventilation windows, openings and straw blankets. In the daytime within 5 days, the grass felt pulled up a small amount of light and warmed up gradually, which was beneficial to the slow activity of peach trees and the balance of hormones and nutrients. After 5 days, all the grass blankets should be pulled up, the temperature should be controlled at about 15 ℃ during the day, not less than 5 ℃ at night, 15 ℃ at the budding stage during the day, and not less than 5 ℃ at night, 15 ℃ at the flowering stage and 8 ℃ at night, 20 ℃ at day and 10 ℃ at night in the young fruit expansion period, and 20 ℃ at day and 5 ℃ at night during the fruit coloring period. Between the plants, the dark trenches of 30cm were dug wide in the north-south direction, poured dark water, and covered with plastic film. This can reduce the humidity in the shed, increase the light, and reduce the occurrence of diseases and insect pests. The air relative humidity should be kept at about 75% in the budding period, 55% in the flowering stage and 65% in the young fruit stage.

IV. The necessity of shaping and pruning

Choose the happy shape of the tree. In order to enhance the light, the fixed trunk mode of low in the south and high in the north can be adopted, and the height of the fixed stem is 20cm, 30cm, 40cm and 50cm respectively. Three strong main branches can be selected for each plant, and 3-4 lateral branches and 8-10 fruit branches are left on the main branch. during the growing period, the crown is controlled between 1.2 and 2.0m, which makes the crown lower than the greenhouse film 30~50cm. During the budding period, the buds below the trunk and the over-dense buds on the fruiting branches should be erased in time, and the lateral buds should be retained. Pull the main branch or side branch with a smaller opening angle into an angle of 45 °to 70 °. During the growing period, dense branches, cross branches and parallel branches were thinned, and the strong new shoots were cut short to promote the germination of secondary branches, so as to enrich the branches and serve as fruiting branches in the following year. Winter shearing is mainly to remove dense branches, thin and weak branches, upper dorsal branches, light cutting of medium and long fruit branches, leaving more flower buds in the middle and upper parts to bear fruit. It should be noted that the nectarine dense planting in the greenhouse often appears the phenomenon of strong on the top and weak on the bottom, so it is necessary to re-cut the upper branches to remove the strong and stay weak and inhibit the growth.

5. How to manage flowers and fruits?

During the growing period, 15% paclobutrazol 500 × 600 times was sprayed twice at intervals of 2 weeks to control the vigorous growth and promote the crown to form flowers. The humidity in the greenhouse is high, the pollen is not easy to spread, and there are few pollinating insects. In order to increase the fruit setting rate, artificial pollination (usually smearing, releasing bees) or letting out the air in the greenhouse is needed; spraying 0.3% borax + 0.3% urea solution during flowering can increase the fruit setting rate; remove concomitant flowers, thin flowers and abnormal flowers during flowering. When thinning fruit, it is necessary to remove deformed fruit, small fruit, disease and insect fruit, keep fruit reasonably according to the load, leave leafy fruit, lateral fruit, strong branch fruit, sparse few leaf fruit, lower fruit, upward fruit, weak branch fruit. Greenhouse nectarine flower thinning and fruit thinning should be carried out in accordance with the principle of light flower thinning and fruit thinning.

6. Soil fertilizer and water management

In spring topdressing, 0.3 kg diammonium or compound fertilizer was applied per plant during early flowering and young fruit period; 0.3% urea was sprayed during fruit expansion, and potassium dihydrogen phosphate 0.2kg was applied to each plant. After fruit harvest, deep ploughing and fertilization should be carried out to compensate for the nutrient consumption caused by a large number of results. After the nectarine leaves were defoliated, before the soil was frozen, combined with the pruning of postharvest fruit trees, a trench was dug and fertilized. Dig wide ditches of 40cm and deep 40cm between rows, apply fully mature farm manure 75t/hm2 and three-element compound fertilizer 1800kg/hm2, and irrigate through water after fertilization. When digging fertilizer ditches, clean the plastic film in the shed, and then loosen the soil. There are more Rain Water in Hefei in summer and autumn, so it is necessary to drain water and prevent waterlogging in time.

7. Pest control

The principle of giving priority to prevention and comprehensive control is adopted in the prevention and control of diseases and insect pests. The main diseases are bacterial perforation and Botrytis cinerea, which can be controlled with fungicides such as chlorothalonil, 70% methyl topiramate, and mancozeb. The main pests are aphids, mites, etc., which are controlled by 5 °B é stone sulfur mixture, methamphetamine, 2000 times wettable powder and so on. In winter, it is necessary to remove fallen leaves, residual branches and weeds in time, dig deep into the soil and whiten the trunk. It is worth noting that the temperature in the greenhouse is larger than that in the open air, the air flow is small, the number of times of medication should be increased, and the dose should be appropriately reduced to prevent drug damage.