Abstract: The purpose of this work was to study the effect of the
irrigation using waste water with various electric conductivities (T(0,92ds/m), EC3 (3ds/m) and EC6 (6ds/m) on three varieties of
quinoa cultivated in a field south of Morocco. The follow up of the evolution of the chemical and agronomic parameters throughout the
culture made it possible to determine the responses to the saline stress in arid conditions. Results showed that the salinity caused the
depression of plant-s height, and reduced the fresh and dry weight in
the different parts of the three varieties plants. The increase of the irrigation water EC didn-t affect the yield for the varieties. Thus,
quinoa resisted to salinity and proved a behavior of a facultative halophyte crop. In fact, the cultivation of this using treated wastewater is feasible especially in arid areas for a sustainable use of
water resources.