Accumulation of cations in lettuce cultivars under low-cost hydroponic system with brackish waters

HIGHLIGHTS: Lettuce plants of the cvs. Betty and Mimosa in hydroponic system with brackish water reduce Na accumulation after 4.5 dS m-1. There is a greater impact on Mg absorption compared to K and Ca due to the increase of Na accumulation in lettuce. In hydroponic lettuce the salinity increase causes greater reductions in the accumulation of K compared to Ca and Mg.