Application of wastewater for production of lettuce (Lactuca sativa) in hydroponic system

Abstract

The study aimed to evaluate the agronomic performance of three varieties of lettuce subjected to different treatments of wastewater. The experimental design was a randomized block in a 7 x 3 split-plot with three replicates. The factors were 7 hydroponic and 3 cultivars of crisp lettuce. The solutions were formulated and optimized by considering Furlani solution as reference nutrient. The experimental portion consisted of the nutritive solutions (S). S1 = Furlani solution; S2 = domestic wastewater; S3 = optimized domestic wastewater; S4 = well water; = S5 optimized well water; S6 = wastewater from the UASB reactor and S7 = wastewater optimized from the UASB reactor, the subplot was constituted of three lettuce cultivars (Verônica, Vanda and Thais). The results showed that solutions with domestic wastewater (S2), optimized domestic wastewater (S3), optimized well water (S5) and the solution wastewater from the UASB reactor (S6) promoted the highest number of leaves per plant for the three cultivars. Solutions with enhanced domestic wastewater (S3), optimum water well (S5) and the solution formulated from the wastewater from the UASB reactor (S6) promoted the highest stem diameter in three cultivars. The highest value of total production was obtained from Vanda cultivar, when the wastewater from the UASB reactor (S6) was used as nutritive solution.