Study On Artificial Light To Solve The Problem Of Greenhouse Cucumber Senescence

In order to solve the problem of greenhouse cucumber's earlier senescence, artificial light was used in study. Under different light time(everyday for 2 hours, 3.5hours, 5hours)and different light intensity (60μmol m-2?s-1, 120μmol m-2?s-1, 240μmol m-2?s-1), we studied the cucumber's plant height, leaf area, dissolution of cell's inclusion, photosynthesis of cucumber leaves, injury of cell membrane, plant's yield etc. The results were as following:1 Artificial light could increase the growth of greenhouse cucumber. Under the condition of this experiment, with the time of artificial light longer, and light intensity higher, plant height and leaf area was developed more rapidly. In the end the natural life of leaf was prolonged. There were marked difference in three light time treatments.2 Soluble protein and chlorophyll contents of senile leaves were increased by light. Light can keep the cucumber's leaves vigorous. longer time and more intense, the light effect was more obvious.Contrast with comparison, the content of chlorophyll in Ⅰ,Ⅱ,Ⅳ were marked different. Artificial light intensity was more effectively influence on protein content than time.3 Artificial light could prolong photosynthesis time of cucumbers. Net photosynthesis rate of cucumber leaves rise with artificial light intensity increased. Pn. in the morning was higher than the same time at the night. 4 Artificial light reduced damage of cell membrane of cucumber leaves, enhanced enzymes activity of scavenging free radical. There wree a great contrast at the degree of cell membrane damage between treatments Ⅵ,Ⅷ,Ⅸ and comparison. When leaves senescence, artificial light intensity had stronger effect on the relative conductivity, while time had stronger effect on the CAT activity.5 Though the yield ofⅠ,Ⅱ,Ⅲ is not markedly different with comparison, cucumber yield could increased by artificial light. The increased trend accorded to artificial light intensity and time. The production value of Ⅵ,Ⅷ and Ⅸ is markedly great than others.6 The treament Ⅸ is excellent than others,but the treament Ⅵ is most cost-efficient. We should use artificial light on greenhouse cucumber: light time is 3.5 hours every day and intensity is 240μmol m-2?s-1.