Evaluation of Yield and Water Productivity of Lettuce under Drought andSalinity Stress in Greenhouse Conditions

The aim of this research was to investigate effect of deficit irrigation and salinity of irrigation water on yield, yield components and water productivity of lettuce (Red Salad Bowl) in greenhouse conditions, in 2017 in Faculty of Agriculture, Shahid Chamran University of Ahvaz. The experiment was conducted in a completely randomized design with factorial arrangement with three replications, with water of irrigation at three levels (I1:100%, I2:80% and I3:60%) and salinity of irrigation water at four levels (S1:0.5, S2:2 , S3:3.5 and S4:5 dSm-1). The results showed that, The effect of irrigation water on all of the studied parameters was significantly different than stem diameter at 5% probability level. Also, its effect on water productivity was not significant. The highest fresh weight was 148 g per plant, related to I1 . Irrigation water salinity effect was significant only on leaf area, plant length, stem length and water productivity at 5% level. The highest fresh weight was related to S4 , which was 127 g per plant. The interaction effect of irrigation and salinity stress was not significant on any of the parameters except stem length. The results showed that this cultivar has the ability to tolerate of salinity.