Response of lettuce (Lactuca sativa var. crispa) to salinity of irrigation water

Abstract

This study was conducted in a greenhouse to assess the response of lettuce (Lactuca sativa var. crispa) to increasing salinity of irrigation water (0.75, 1.5, 2.5, 3.5, 5.0, and 7.0 dS m(-1)). Soil salinity increased linearly with increasing salinity of irrigation water. The threshold value was determined as 1.1 dS m(-1) and the relative yield decrease in slope after this threshold as 9.3%. The results showed that L. sativa var. crispa was moderately sensitive to salinity. In contrast to yield, plant dry matter content increased with increasing salinity for the salinity range studied. The taste of lettuce was not affected by salinity. The results further showed that the variables of leaf number per plant, plant height, water use efficiency, and accumulation of calcium (Ca) and iron (Fe) in the leaves decreased with salinity, whereas accumulation of potassium (K), nitrogen (N), copper (Cu), manganese (Mn), and zinc (Zn) in plant leaves was unaffected.