Seedling raising techniques of Cucumber in overwintering stubble

Overwintering cucumber refers to the cucumber which is sown in autumn and harvested in winter in the solar greenhouse until the end of the second year in late spring and early summer, also known as overwintering stubble, or "winter and spring stubble". The production of overwintering cucumber has experienced the worst sunshine and the lowest temperature of the year, which is technically difficult and strict, but the economic benefit is the best.

? I. basic conditions for production

The production of cucumber overwintering in solar greenhouse is based on no heating or almost no heating (limited temporary heating). Therefore, the construction and management of greenhouse are strict. No matter what structure form of high-efficiency and energy-saving solar greenhouse is adopted, the temperature must meet the most basic needs of cucumber growth in severe winter. Under normal management, the lowest temperature of the greenhouse should not be lower than 8 ℃. In areas with high cold and poor sunshine conditions, temporary warming measures can be taken to ensure that the indoor temperature reaches the limit or slightly higher than 1 Murray 2 ℃.

? II. Varieties

At present, grafted seedlings are commonly used in overwintering cucumbers, in which scion varieties are required to bear melons normally at low temperature and weak light energy; at the same time, they should be resistant to high temperature and high humidity, and have strong ability to bear melons under high temperature and high humidity conditions. In addition, it also has good disease resistance and strong adaptability to the greenhouse environment. At present, it is mainly used in production, including Changchun thorn, Xintai thorn, Shandong thorn, Jiza No. 1 and No. 2, Beijing 102, Jinlu No. 3 and so on.

? Third, sowing date

The seedling age of overwintering cucumber is about 35 days, and the harvest begins about 35 days after planting, and it takes about 70 days from sowing to harvest. Overwintering cucumbers are generally required to be harvested before and after New Year's Day in order to enter the peak period of yield around the Spring Festival. As a result, it is estimated that the normal sowing date should be from the first ten days to the middle of October. Sowing in this period is beneficial to the healing of grafting wounds and the establishment of high yield shelves before the arrival of severe winter. In order to increase the yield before winter and reduce the risk of overwintering stubble, the sowing date can also be advanced appropriately.

? 4. grafting and raising seedlings

The cultivation of overwintering cucumber seedlings is generally carried out in the solar greenhouse. Generally, cucumber seeds should be sowed in advance for 7 days, pumpkin cotyledons are flattened to the first true leaf, and cucumber with two leaves and one heart is the suitable time for grafting. When the black-seeded pumpkin seedlings are too large and hollow, it will affect the survival rate of grafting. At present, the method of relying on grafting is widely used in raising cucumber seedlings in overwintering stubble, and there are three ways of raising seedlings by grafting: first, cucumber and black seed pumpkin are sowed and raised separately, and the seedlings are dug up and planted on another border after grafting. The other is that in the sand bed where the cucumber seeds are sown, the black-seeded pumpkin is germinated and sowed in a nutrition bowl (in the middle position). When grafted, only the cucumber seedlings are dug, and then the roots of the cucumber seedlings are pseudo-planted on one side of the nutrition bowl and placed in the seedling bed for culture. it can be managed by moving the nutrition bowl according to the seedling condition, and the seedlings are easy to carry and not easy to hurt the roots when planting. The third method is to sow pumpkin seeds directly on the ridge, dig up cucumber seedlings during grafting, and then pseudo-plant the roots of cucumber seedlings to one side of the ridge. These three methods have their own advantages and disadvantages, but the latter two methods use slow seedling, but require skilled grafting technique to ensure the survival rate of grafting. In the first 3 days after grafting, the temperature should be maintained at 25 ℃ and 95% humidity, and then the temperature and humidity should be reduced gradually. through fine management, a robust seedling with a height of 15 cm, a thickness of 0.6 mi, a heart of 4 leaves and a seedling age of 35 Mel for 40 days was cultivated.