Effects of different water depths on the physiological develoment and yield of lettuce applied by trickle irrigation

Abstract

The effects of different water depths, applied by trickle irrigation, on the development and crop yield of lettuce (Lactuca sativa L.), cv. Floresta, were evaluated under field conditions. The study was carried out at the Experimental Arca, FEAGRI - UNICAMP, Campinas, SP, Brazil. Four daily water depths were used, based on the percentage of daily evaporation depths measured at a Class A pan (120%, 100%, 80%, 60%). The irrigation arrangement consisted of a completely randomized design with five replications. Due to the high experimental data variability, the results showed no significant difference among treatments for the physiological parameters at different sampling data. However it was possible to conclude that the crop development was affected by the different water depths applied, mainly in its final growth stage. The 120% treatment showed the best results for the total fresh weight, number of leaves per plant and leaf area. The highest average yield (3,582.6 g/m²) and the best marketing quality yield were also obtained in this treatment.