| Cucumber is annual climbing herb belongs to cucurbitaceae Cucumis. It was widely cultivated in protected cultivation in China because it has high quantity and relatively high economic benefits. Seedling raising is one of the important and characteristic parts of vegetable production. At present, a widespread use of factory plug seedlings realized factory production and changed the traditional cultivation system, however, there are still some problems such as: the small nutrition volume, obvious magrginal utility, fertilizer and water difficult to precisely control, non-renewable main seedling media. To solve the problems, Beijing Vegetable Research Center developed a new type of nutrient solution seedling system. In this system, roots are covered by nutrient solution, seedlings can be fertilized precisely. It can provide equal nutrient condition to the seedlings and improve the degree of uniformity and robustness. In the research, cucumber was studied as material to screen nutrition solution, to research the effect of CCC to the seedlings, to study the effect of cooling system to growth and development to the seedlings, in order to research and improve the new seedling system and provide a reference for cultivating strong seedlings. The main findings are as follow:1.Four kinds of nutrition solution formulae were tested in this paper. The results showed that the nutrient content of Hogland and Arnon nutrient solution was moderate. With the Hogland and Arnon nutrient solution, the root activity of the cucumber was stronger, the ratio of root to shoot was higher. The seedling index of the plants in Hogland and Arnon nutrient solution is 50.7%、18.28% and 20.88% higher, respectively than the others. It is the suitable nutrition solution for cucumber seedling.2.Seedling culture in nutrient solution without substrate is a new seedling technology for vegetables. As the plants are grown in nutrient solution in the entire seedling stage, how to control excessive growth and how to cultivate strong seedlings are the problems to be solved, especially in summer. To study the effect of chlormequat chloride(CCC) on inhibition of spindling and cultivation of sound seedlings with cucumber in summer, different concentrations(5, 10, 15 mg/kg) of CCC were added in nutrient solution. The results showed that adding CCC in nutrient solution can apparently reduce hypocotyl length, plant height as well as internode length. With CCC treatment, the color of leaves became greener, the ratio of root to shoot was higher. Compared to the control, the seedling index of 5, 10, 15 mg/kg treatments increased 27.3%, 45.5% and 15.2%, respectively. Among the three treatments, adding 10 mg/kg CCC in nutrient solution has the best effect on inhibition of the excessive growth and cultivation of strong seedling with cucumber in summer.3. Refrigerating machine was used to keep the temperature of nutrient solution 25℃ at daytime and 20℃ at night. Taking “Lvbo sixth F1” cucumber as material, and normal temperature nutrient solution as control, the effect of the cooling system of cucumber seedling growth and reproduction was studied. The results showed that the cooling system promoted the growth of cucumber seedlings, improved the seedling index and root activity, reduced the first female flowers festival, increased the number of female flowers and the proportion of female flowers, and enhanced the cucumber production. Cooling system can be used as a new way of nutrient solution seedling in high temperature seasons to further research. |
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