Cherry can be cultivated in the greenhouse. It is very important to manage it. How to control the temperature?

European sweet cherry, also known as sweet cherry, big cherry and foreign cherry, originated in Caspian Sea and Black Sea, and has been introduced to China for more than 100 years. Because of its bright color, sweet and sour taste, good appearance and good internal quality, it has become the representative of high-end fruits.

Because sweet cherry belongs to seasonal fresh fruit, if it is only cultivated in the open field, the supply period will become short and concentrated. However, under protected cultivation, it not only greatly prolongs the supply period of sweet cherry fresh fruit, but also has the advantages of early maturity, preventing fruit cracking and improving yield.

In the past, farmers often asked questions about sweet cherries cultivated in facilities. This time, we mainly shared the key points of temperature and humidity management of sweet cherry cultivated in protected facilities, and later we will send a Weibo on improving fruit setting rate, fertilizer and water management, pest control and so on.

Sweet cherry needs 700~ 1400 hours below 0~7.2℃ to pass dormancy. If dormancy disorder occurs, it will lead to poor germination uniformity of branches of the same plant, early germination of top leaf buds, abnormal development of flower organs and low natural fruit setting rate; Or the phenological phases of adjacent trees are inconsistent, which makes management inconvenient.

The main goal of environmental regulation of greenhouse sweet cherry during dormancy is temperature, specifically, it is to control the temperature within the range of 0~7.2℃ and keep it for 35~40 days to meet the accumulation of cold demand.

When the temperature is higher than 7.2℃ in the early stage, cover the shed with a straw curtain or quilt, cover it during the day, avoid light and cool down, pull it up at night and open the upper and lower vents; When the temperature in the shed reaches the required low-temperature dormancy temperature, stop pulling; If it is windy at night, the upper and lower vents must be closed.

At this stage, the temperature cannot be controlled too high or too low. If the temperature is too high, it will easily lead to the phenomenon that the flowers and leaves are in reverse order and the stigma appears first, which will eventually affect the fruit setting and yield of the tree.

During the day, the temperature should be controlled at 12~ 16℃ and not lower than 3℃ at night, and the temperature should be gradually increased. Otherwise, even if it can blossom, the fruit setting rate is extremely low. It must be ensured that there is about 1 month from the beginning of temperature rise to flowering.

This period is divided into three types according to the regulation methods, namely, conservative type, steady type and anxious type (see the above table for details). No matter which management mode, the temperature is low in the first 3 ~ 7 days (the tuyere is not open, and the insulation quilt is rolled up during the day), and then the tree is heated (the insulation quilt is fully opened, and the temperature is controlled by adjusting the tuyere) until the flowering period.

The difference between each type is 10 ~ 20 days. But no matter which management method is adopted, facilities and management level should be taken into account, and there is no need to rush blindly.

During germination, the ground temperature should be kept at 8 ~ 65438 02℃, plastic film should be covered 20~30 days before the shed is closed, and the sea elf biostimulant should be applied to improve the soil temperature and promote the germination orderly.

In terms of humidity, the relative humidity in the shed should be kept at 70%~80%, not too low, otherwise the germination and flowering will be irregular.

The cold tolerance of sweet cherry at flowering stage is poor, and low temperature will affect the growth of pollen tubes, hinder fertilization and affect its fruit setting.

The temperature should be controlled at 16~ 18℃ during the day and not lower than 5~7℃ at night, so as not to freeze the flowers. Pay attention to the night temperature can not be higher than 8℃, otherwise it will cause the leaves to bloom first and intensify the nutrition competition. Spraying boron source pool and phosphorus and potassium source pool at flowering stage can improve its cold resistance and stress resistance, and at the same time improve the fruit setting rate. After the flowers wither, remove the plastic film to prevent the roots from being damaged by high temperature.

In terms of humidity, the relative humidity in the greenhouse during flowering is required to be around 50%. Too high or too low is not conducive to pollination and fertilization. When the humidity is too low, the stigma is dry, which is not conducive to pollen tube germination; When the humidity is too high, pollen grains are not easy to disperse, and the adhesion of pollen to stigma mucus is too thin, which is also easy to cause flower rot.

From fruit setting to the first fruit expansion period: 18~22℃ during the day, 10~ 12℃ at night, and the temperature during the day should not exceed 25℃, otherwise it is easy to cause fruit drop, and the temperature at night is higher at this stage, which is beneficial to fruit development. The suitable soil temperature is 15~ 18℃, too low will affect the root activity, and spraying sea elf biostimulant can improve it.

Hard core stage: the temperature is controlled at 18~20℃ during the day and 6~8℃ at night. When the temperature is too high during the day, the fruit with auxiliary chemicals will shrink because there are no seeds and the ability to absorb nutrients and water is poor. The temperature is high at night, and the new buds grow vigorously, which is easy to compete with the fruits for nutrition. The humidity in this period should not be too high, just 50%~60%, so as to avoid germs breeding and infecting leaves and young fruits.

The second fruit expansion period to maturity: the temperature is gradually adjusted to 22~25℃, with the highest temperature not exceeding 25℃, and the night temperature is 10~ 12℃, keeping a certain temperature difference between day and night, and spraying red pond foliar fertilizer to facilitate fruit coloring and sugar accumulation. The humidity is controlled at about 50%. If the humidity is too high, it will not only reduce the light transmittance, but also lead to fruit cracking.

Harvest time: 3~5 days before picking, the temperature can be reduced to 20℃ to increase the hardness and elasticity of the fruit and facilitate storage and transportation.