Ibimirim in Pernambuco is a municipal district located in the Brazilian semiarid region and most of its wells produce brackish water. The use of this water has been avoided since it may cause human diseases (such as hypertension and kidney stones) and crop yield reduction (with soil degradation). The objective of this work was to evaluate the utilization of brackish groundwater and the waste from its desalination for hydroponic production of two lettuce varieties (Vera and AF-1743). Six levels of water salinity (CEa: 0.2, 1.2, 2.2, 3.2, 4.2 and 5.2 dS m-1) were analyzed. The waters were used in overall production process (to prepare the nutrient solution and to restore the water consumed). The salinity increase caused a linear reduction in the growth lettuce of plants. The plants exhibited general chlorosis at the beginning of the cycle, but this symptom was not verified at the harvest. The variety 'Vera' had a lower absolute growth and yield than the 'AF-1743'. On the other hand, the percent reduction for both varieties was similar - the shoot fresh matter accumulation was decreased by 17.06 and 15.74% (dS m-1)-1 for 'Vera' and 'AF-1743', respectively.
salinity; soilless; vegetables; reverse osmosis; irrigation
