Biomass and essential oil production of basil at recirculation intervals of nutrient solutions prepared with treated domestic effluents

Considering the growing water crisis, using wastewater helps reduce the pressure on good-quality water consumption. In this context, this study aimed to evaluate the growth, production, and essential oil content of Alfavaca Basilicão and Grecco a Palla basil genotypes with a DFT (deep flow technique) hydroponic system adapted to PVC tubes at different recirculation intervals of nutrient solutions prepared with treated domestic effluents. The experiment was performed in a greenhouse with Alfavaca Basilicão and Grecco a Palla basil genotypes analyzed individually. It was a completely randomized design with four replicates in a 2 x 3 factorial scheme: two types of water (public-supply water and wastewater) and three recirculation intervals of nutrient solutions (2, 4, and 6 hours). At 35 days after transplanting, the study evaluated plant height, stem diameter, shoot fresh mass, shoot dry mass, water consumption, water use efficiency, and essential oil content and yield. The types of water did not significantly influence the variables of growth, production, and essential oil content of the basil genotypes. Basil cultivation with the DFT system in tubes is technically feasible with nutrient solutions prepared with treated domestic effluents and recirculation every 2 and 6 hours for Grecco a Palla and Alfavaca Basilicão genotypes, respectively. The means of essential oil content were 1.6 and 1.7% (v/m) for Alfavaca Basilicão and Grecco a Palla genotypes, respectively.