Phytomass of lettuce cultivars under water replenishment levels

Water scarcity in the semi-arid region causes significant losses in the socioeconomic activities, with reduction in agriculture.Therefore, this study aimed to evaluate the effect of the application of irrigation depths on the phytomass accumulation of lettuce cultivars.The experiment was carried out at the Academic Unit of Agricultural Engineering, in 10 beds composed of 78 plants each, at spacing of 0.25 × 0.30 m.The treatments were set in a 5 x 3 factorial scheme, with five water replacement levels, The irrigation depths were applied based on the reference evapotranspiration -ETo, as follows: 70% (L1), 80% (L2), 90% (L3), 100% (L4) and 115% (L5) of the reference evapotranspiration -ETo, and three cultivars: Elba' -C1, 'Iceberg' -C2 and 'Looseleaf' -C3, four replicates.Irrigations were applied through a drip system with the aid of the program ETo calculator-FAO Penman-Monteith to estimate the reference evapotranspiration.The following variables were determined: fresh matter (FM), dry matter (DM), root fresh matter (RFM), root dry matter (RDM), number of leaves (NL) and plant height (PH).According to the results, the increment in irrigation depths increased leaf fresh matter, number of leaves, plant height and root dry matter.The irrigation depth of 192.4 mm cycle -1 , i.e., 100% of evapotranspiration under field conditions led to greater yield.