Uso de água residuária para a produção de girassol ornamental

Abstract

This study aimed to determine the responses of ornamental sunflower varieties irrigated with different percentages of wastewater and tap water, cultivated in greenhouse. Two experiments were carried out at the Federal University of Recôncavo da Bahia (UFRB), on the campus of Cruz das Almas - BA, Brazil, in the experimental area of the Agricultural Engineering Graduate Program (PPGEA). In the first one, treatments consisted of five wastewater levels (0, 25, 50, 75 and 100%), mixed with tap water from the local water supply, and two ornamental sunflower cultivars (Sunspot dwarf and Evening sun), with six replicates, totaling 30 experimental unities for each cultivar. The experiment was set in a completely randomized design. The following growth variables were evaluated: plant height (PH), number of leaves (NL) stem diameter (SD) and shoot fresh and dry matter (SFM and SDM).In addition, the following production variables: capitula internal and external diameters (ID and ED). In the second experiment, besides the same 5 wastewater levels used in the first one, it was studied 4 percentages of evaporation of a Class A tank (60, 90, 120 and 150%), forming a 5x4 factorial scheme with four replicates, totaling 80 experimental unities. The analyzed variables were PH, NL, SD, SFM, SDM, days for flower buds appearance (FBA), flowering period (FP), total opening of capitula (TOC), ID, ED and the capitula fresh and dry matter (CFM and CDM), besides plant water consumption. For the first experiment, there was no statistical difference for any of the analyzed variables. For the second one, except for PH, the other studied variables were influenced by either evaporation depths or wastewater levels. However, there was no significant difference for the interactions, for any of the studied variables. The blade of 110% ECA showed higher means compared with other blades, especially during the 35 DAD and end of cycle.