USE OF REJECT BRINE FROM DESALINATION ON DIFFERENT DEVELOPMENT STAGES OF HYDROPONIC LETTUCE

Resumo

In order to evaluated the impact of the high salinity reject brine from reverse osmosis desalination on hydroponics lettuce cultivated in greenhouse an investigation was carried out in Mossoro, Northeast of Brazil (5º11’S, 37º20’O and 18m above sea). Two lettuce cultivars (‘Verônica’ and ‘Babá de verão’) were cultivated with a basic nutrient solution with 1.1 dS m-1 (control) during the crop cycle (1-28 days after transplanting – DAT) – T0 and with basic nutrient solution containing 50% of the reject water from desalinization with 4.8 dS m-1 exposed during 1-7, 21-28, 7-14 e 1-28 DAT (T1, T2, T3 and T4, respectively). The addition of 50% of brine reject from desalination into the hydroponic nutrient solution allows grow only ‘Verônica’ lettuce with no reduction in fresh biomass. This lettuce cultivar shows to be more tolerant to salinity for all exposure time with reject brine in the nutrition solution, despite the fact that ‘Babá de Verão’ cultivar is more productive.