Abstract：Through monitoring the pH and EC（electrical conductivity）value of nutrient solution，effects of 3 different renewal frequencies——F10，F15，F30（i. e. the renewal frequencies were 10 days，15 days and 30 days，respectively）of the nutrient solution on the yield and quality of lettuce（Lactuca sativa L.）in soilless culture were studied．The results showed that compared with F10 treatment, no significant variation existed among F15，F30 treatments in terms of aboveground fresh weight，leaf number and other morphological characters，and in contents of soluble protein，VC．The contents of nitrate and soluble sugar were lower in F15 and F30 treatments．The contents of soluble sugar in F15 and F30 were increased．The F30 treatment was better than that of F15．
李嘉佳, 宋世威, 陈日远, 刘厚诚, 孙光闻. 营养液更换频率对水培叶用莴苣产量和品质的影响[J]. 中国蔬菜, 2012, 1(24): 69-72.
LI Jia-Jia, SONG Shi-Wei, CHEN Ri-Yuan, LIU Hou-Cheng, SUN Guang-Wen. Effects of Nutrient Solution Renewal Frequency on Yield and Quality of Lettuce in Soilless Culture. , 2012, 1(24): 69-72.
