Impact of Irrigation Deficit on Yield, and Water Productivity of Quinoa

Abstract

A field experiment was carried out to ivestigat the impact of irrigation deficit on Quinoa (chenopodium quinoa Willd) variety Chipaya. The sowing date was Nov. 11, 2018, and the harvesting date was March. 17, 2019.The irrigation regimes (irrigation deficit) were in the rate of 40, 60, 80, and 100% of the reference evapotranspiration (ET0) as compared with rainfed irrigation as control. The experimental design was a Randomized Complete Block Design with three replicates. The results indicated that the irrigation regimes had a significant effect on Quinoa productivity. The best effect of irrigation regimes on the gross seed yield of quinoa was recorded with 100% of ET0 irrigation regime corresponding to an increase by 155.56% over the rainfed irrigation. Seed yield reached the highest values of 0.616 ton/fed at 100% of ET0,.Also, there were no significant differences between irrigation at 100 and 80 % of the ET0 irrigation regime. Seed weight per plant, and per m2 had the highest values with 100% of ET0. It increased by about 216.70 and 216.68% over the rainfed irrigation. The total applied water (TAW) were 931.4, 796.6, 658.0, 523.3, and 285.6 m3/fed for irrigation treatments of 100, 80, 60, and 40% of ET0 and rainfed irrigation, respectively. The irrigation water-use efficiency (IWUE) or water productivity (WP) as kg grain/m3 of applied water reached the values of 0.681, 0.655, 0.806, 0.778, and 0.712 kg/m3 for 100, 80, 60, 40% of ET0, and rain-fed treatments, respectively.Irrigation at 100 or 80% of ET0 gave the highest seed yield. Nevertheless, irrigation at 60% of ETO gave the highest water productivity (IWUE).