The objective of this study was to evaluate the growth, water consumption and extraction of nutrients of lettuce (Lactuca sativa L.) in a NFT (nutrient film technique) in hydroponic system using saline water. Two experiments were conducted in a protected environment. The experiment was arranged in a completely randomized design with five replications and five levels of salinity in the irrigation water using NaCl. Increasing water salinity reduced the growth and water consumption of lettuce linearly. The salinity reduced the macronutrient concentration, but symptoms of nutritional deficiency were not observed. The lettuce yield (shoot fresh matter) was reduced by 6% and 6.5% per dS m¹, in the first and second crops, respectively. The results obtained in the NFT system indicate the possibility of using saline water as an alternative for the production of vegetables by farmers who have freshwater restriction, although with a reduction in the yield.
Lactuca sativa L.; salinity; electrical conductivity
