The use of wastewater in the preparation of the nutrient solution in semi-hydroponic cultivation both increases the supply of water in regions where it is scarce and recycles the nutrients it contains, making them available to plants. Taking these aspects into consideration, the aim of this study was to analyse the growth and development of sunflower plants for ornamental purposes, when grown under a semi-hydroponic system, using wastewater in the preparation of nutrient solutions based on NPK at increasing nutrient concentrations (55, 70, 85 and 100%), and in different growth substrates (coconut fibre, washed sand and sugarcane bagasse). The treatments were arranged in a completely randomised design and analysed in a 4 x 3 factorial scheme with three replications, giving a total of 36 experimental units. It was found that even with the concentration of NPK in the nutrient solution reduced to 55%, the growth of sunflower plants for ornamental purposes remains within commercial standards, provided that wastewater is used in the preparation of the nutrient solution, and coconut fibre or washed sand as the growth substrate.
Helianthus annuus L.; Water quality; Plant nutrition
