Uso de água salobra e frequência de recirculação de solução nutritiva para produção de coentro hidropônico

Abstract

The hydroponic cultivation is an alternative that has stood out in all the territory of Brazil, providing high quality products, and for enabling farmer to produce throughout the year and thus guarantee a regular supply of products with less water, and low inputs - agricultural fertilizer and manpower. In this context, the present work aimed to evaluate the production of coriander in hydroponic profiles with different diameters and seeding densities and interaction between different intervals of recirculation of the nutrient solution and use of the fresh and brackish water. Two experiments were conducted in randomized blocks, with five replications. In Experiment I, the treatments were studied in 2x5 factorial design, totaling 50 plots: two hydroponic profiles of diameters 50 and 75 mm and five seeding density (12, 24, 36, 48 and 60 seeds per recipient). In Experiment II, the treatments were installed in a 2x4 factorial design, with 40 plots: studying the use of two types of water (fresh and brackish) and four frequencies of recirculation of nutrient solution (at intervals of 0.25, 2, 4 and 8 hours). The control frequency (0.25 h) was consisted of the following programming: 6:00 to 20:00 hours the system functioned 15 min at 15 min interval, from 20:00 to 6:00 hours the recirculation was proceeded every 2 hours, with a duration of 15 min; in the second, third and fourth frequency, the recirculation was performed every 2, 4 and 8 hours, respectively, with a duration of 15 min. It is concluded from the information in Experiment I that the best response in growth and yield per plant of coriander was with the density of 12 seeds in 75 mm diameter hydroponic profile. In Experiment II, the best response in growth and yield of coriander was obtained using fresh water; increasing the time interval every 8 hours is adequate for recirculation of the nutrient solution.