Yield and quality of lettuce cultivars irrigated with treated domestic sewage effluent

Given the scarcity of water resources in semi-arid regions and the potential of water reuse as a strategy to solve this problem, this study aimed to evaluate the effects of domestic sewage effluent on growth, yield, and quality of two crisp lettuce cultivars. The research was carried out in greenhouse conditions utilizing an experimental design with randomized blocks in a 5 x 2 factorial scheme, with five concentrations from treated domestic effluent blended with tap water (0, 25, 50, 75 and 100% of treated domestic effluent) and two crisp loose lettuce cultivars (Scarlet and Cristal) done in triplicate with five plants per trial. The lettuce plants were growth in trapezoid-shaped PVC channels filled with coconut fiber substrate and organic compost (2:1) for 35 days after transplanting. The experimental results indicated that irrigation with 30% sewage effluent diluted in tap water gives higher growth and yield of lettuce. The Cristal cultivar shows growth, soluble solids, and chlorophyll higher than the Scarlet cultivar. The application of treated domestic effluent does not affect the post-harvest quality of the lettuce to both cultivars.