From an environmental perspective, the facilities will promote cultivation of fruit trees. The earlier the time is, the earlier the mature market will be, and the higher the benefits will be. However, there is a limit to the time for the sheds in the cultivation of facilities, and it is not infinitely advanced and arbitrarily determined. Because the deciduous fruit trees have a natural dormant habit, if the accumulation of low temperature is not enough, it cannot reach the required cooling capacity of fruit trees, and does not pass through natural dormancy. Even if the insulation of the shed is given suitable environmental conditions for growth and development, the fruit trees will not sprout, sometimes In spite of the budding, flowering is often irregular, the production cycle is long, and the fruit setting rate is low. Therefore, the need for refrigeration is the primary basis for determining the time for the shed. Satisfying the required cooling capacity of the fruit tree and allowing it to pass through the natural dormancy is the basis for the successful cultivation of the facility. Only in this way can the fruit tree grow and develop normally under the conditions of the facility.
At present, most experts point out that the effective temperature for natural dormancy of fruit trees is 0 to 7.2°C, the cumulative number of hours of low temperature (called cooling demand), and the temperature of 10°C or more or 0°C or less for low temperature cumulative hours. invalid. In general, the required cooling capacity of peaches is 800 to 1200 hours, the cooling capacity of apricots is 500 to 900 hours, the required cooling capacity of Lee is 700 to 1000 hours, and the required cooling capacity of grapes is 1000 to 1500 hours.
In production practice, artificial low-temperature concentration treatment method is often used to break the dormancy of fruit trees. When the average temperature of the outside is below 10°C, generally 7°C to 8°C, the insulation of the shed is started, the film is covered and covered with straw, but the grass The exposing of the cockroach is the opposite of normal protection. At night, the grasshopper is opened, the air outlet is opened for low temperature treatment, and the grasshopper is closed during the day and the air outlet is closed to keep the temperature at night low. Most deciduous fruit trees are treated in this way for 20 to 30 days, and they can pass through natural dormancy, and can be protected and cultivated later.
At present, lime nitrogen is used to break the dormancy in the cultivation of grape plants in production. Lime nitrogen scientific name of calcium cyanamide, grapes treated by lime nitrogen, can be 20 to 25 days before the untreated and germinate and neat. Every kilogram of lime nitrogen needs to add 5 kg of warm water at 40°C to 50°C. When used, put lime nitrogen and warm water into a bucket or pot, stir continuously, and soak for more than 2 hours to make it evenly paste. Add appropriate amount of spreading agent, and then use a small brush to take appropriate amount, evenly spread on the top of the grapes and on both sides of the bud, apply a length of 2/3 of the vine, spread the vine on the surface and cover the film after moistening 3 ~ 5 days.