Study On Water-saving Irrigation Index For Greenhouse Cucumber During Springtide

The experiments were performed on greenhouse cucumber (Cucumis Statirus L. Jinyou 1 hao), to study the optimum irrigation index for greenhouse cucumber at seedling, bloom and fruit-bearing stages, on the basis of previous research of soil water irrigation starting point. Under different soil water irrigation maximum (81%, 85%, 90%, 95%, 100%), the following items were measured: plant height, stem diameter, leaf area, dry weight and fresh weight of root, stem, leaf and total, chlirophl, root activity, relative water content of leaf, free water and bound water, water saturated deficit, cell sap concentration, net photosynthesis rate, transpiration rate, stomatic conductance of cucumber seeding; plant height, stem diameter, yield and qualtity of cucumber at bloom and fruit-bearing stages. The result showed that different soil water irrigation maximum had remarkable influence on plant height and leaf area of cucumber seedling, and were correlated with irrigation maximum which was line relation (Rph=0.9978, Yph=18.5x―2.552; Rsd=0.9662, Ysd=128.11x+30.91). Stem diameter, dry weight, root top ratio, chlirophl, rool activity net photosynthesis rate, transpiration rate, stomatic conduetance, which were the largest at 90 percent irrigation maximum, significant differences existed in these index of seedling. Index of good seedling were in four function curve relation with the irrigation maximums, the regression equation and relative coefficient were: R=0.999, y=78.667x4―284.67x3+385.1x2―30.82x+51.742. Cell sap concentration and relative water content of leaf change with the irrigation maximum chanage, that can show condition of plant water. Different irrigation maximums also influenced plant significantly at blooming and fruit-bearing stage. Plant height, leaf numbers, fruit length, fruit weight, water content of fruit increased when the irrgation maximum increased. Chlirophl.,net photosynthesis rate, dissoluble sugar, coarse protein, which were the largest at 90 percent irrigation maximum. The yield of 90 percent is the largest, it is 30 kg, more than 100 percent treatment 17 percent, than 80percent treatment 30 percent. Yield were in cubic function curve relation with the irrigation maximums, the regression equation and relative coefficient were y=866.67x3―2885.7x2+3093.1x―1048.2, R=0.992.In conclusion, the 90 percent irrigation maximums for seedling, can promote the plant growth, increase dry weight, save water, make a good basic of high yield and good quality of cucumber. Statistics show, index of good plant was correlaled with yield: y=1442.6x―14.009, R=0.8402. So, 90 percent irrigation maximum for seedling, can produce goodseedling; in blooming and fruit-bearing stage, 90 percent irrigation were favorable to the increase quality and yield.