Plants of ornamental sunflower 'Sol Vermelho' were grown under hydroponic conditions aiming to evaluate the effects of use of brackish water on its yield and inflorescence (capitulum) quality. The brackish waters were utilized to prepare nutrient solution and to replace water due to evapotranspiration loss. The experiment was carried out in a completely randomized experimental design with five levels of water salinity: 1.51; 2.56; 3.86 and 6.19 dS m-1, obtained by addition of NaCl to local fresh water; this fresh water (0.47 dS m-1) was also studied as control treatment. Each treatment was replicated four times and each experimental unit had four plants in an independent NFT (nutrient film technique) hydroponic system. A linear reduction was observed with increasing water salinity on plant height, stem diameter and fresh and dry matter of plant shoot. Both plant height and stem diameter were decreased by 3.2%, shoot dry matter was decreased 5.78% with per unit increase of water salinity (dS m-1). On the other hand, water salinity did not affect sunflower capitulum size. Systematic toxicity symptoms caused by salinity were not registered. These findings support the technical feasibility for hydroponic ornamental sunflower production using brackish waters.
Helianthus annuus L; water salinity; soilless cultivation; ornamental plants
