In agricultural areas irrigated with water of unsatisfactory quality, plants that are tolerant to the salinity in water and soil are needed. The purpose of this work was to evaluate the influence of the salinity of irrigation water and soil mulch on the vegetative development of amaranth (Amaranthus spp) in a greenhouse. The experiment was carried out from March to May 2006 in PVC columns with 30 kg of soil with silt loam texture. The non-use of mulch and four salinity levels of the irrigation water (0.147; 1.5; 3.0; 4.5 dS m-1, to 25 °C) was evaluated in a completely randomized design with eight treatments and four replications. Mulch reduced the beginning of flowering and increased the leaf area, plant height, stalk diameter and biomass production. The increase of the saline concentration did not reduce the calcium and magnesium concentrations in the leaf tissue. The higher salt concentration of the irrigation water delayed amaranth flowering, but the species was tolerant up to 4.5 dS m-1, since dry biomass production was not affected by the higher water salinity.
irrigation water; leaf area
