| This article has been：Browse 1829Times Download 2643Times |
|
|
|
| DOI： |
|
| Effects of Dissolved Oxygen on Growth, Photosynthesis and Yield of Leaf Lettuce |
|
MA Jimei, TIAN Juncang, ZHANG Ruiwan
|
|
College of Civil and Hydraulic Engineering ,Ningxia University, Yinchuan 750021, China;Ningxia Research Center of Technology on Water-saving Irrigation and Water Resources Regulation, Yinchuan 750021, China; .Center of Engineering Research of Education Department on Efficient Utilization of Water Resources in Modern Agriculture in Arid Regions, Yinchuan 750021, China
|
| Abstract: |
| We studied the impact of dissolved oxygen concentration in irrigating water on growth, photosynthesis, fresh weight,dry weight and yield of leaf lettuce grown in a greenhouse. Four concentrations were examined: 6.8 mg/L (T1), 8 mg/L (T2), 7.4 mg/L (T3) and 1.2 mg/L(T4). The findings were as follows: ①The dissolved oxygen concentration has a significant impact on lettuce height, leaf numbers and stem diameter; both height and leaf number of the lettuce under different treatments decreased in the order of T2> T3> T1>T4. ②The dissolved oxygen concentration also has a significant effect on chlorophyll content, net photosynthetic rate, transpiration rate, and stomatal aperture, but has less impact on intercellular CO2 concentration. ③The dissolved oxygen has remarkable impact on fresh and dry plant weights. The highest fresh weight and dry weights were in T2, being 56.25 g and 10.71 g respectively. The lowest fresh and dry weights were in T4, being 42.64 g and 3.52 g respectively. The yield in T1, T2 and T3 increased by 13.2%, 22.6% and 28.3% respectively compared with that in T4. The results showed that a combination of dissolved oxygen concentration of 7.4 mg/L with amount of irrigation of 45 m3/hm2 achieved the highest yield. |
| Key words: water saving irrigation; dissolved oxygen concentration; leaf lettuce; photosynthesis indexes; yield |
|
|
