Water use efficiency (WUE) and productivity of promising quinoa (Chenopodium quinoa Wild.) genotypes grown under three water regimes

Abstract

Quinoa is one of the most nutritious grains and currently has attention due to its adaptation to a wide range of environments and abiotic stresses. This study was conducted under field conditions of an arid agro-ecosystem to evaluate the response physiological and yield of nineteen elite quinoa genotypes grown under three water regimes (95, 65, and 35% Field capacity) using a drip system in sandy soil. The experiment design was a split-plot in a randomized complete block design during the 2019/20 and 2020/21 growing seasons. The results showed significant differences among evaluated genotypes, water treatments, and their interaction. Fluorescence chlorophyll components were sensitive to water stress and strongly decreased at low soil moisture. Fluorescence (Fo) was the most correlated with seed yield and water use efficiency (WUE) under both full irrigation and drought stress. This may be used for improving yield and WUE in breeding programs. The optimum WUE achieved from moderate irrigation (65% FC), indicated the importance of detecting water requirements. The seed production ranges between 3.8 and 2.2 t ha-1 under full irrigation, and it decreases to reach 62.8% under water regimes. The most suitable genotypes for growing under full irrigation were ‘V9’, ‘Apelawa’, ‘30TES’, and ‘27GR’ which produced 3.8, 3.7, 3.5, and 3.5 t ha-1, respectively. The highest seed yield under stream drought (1.4 t ha-1) was produced by ‘Ames 10334’ and ‘QU629-99’. However, the genotype ‘Apelawa’ could outperform under different moisture conditions. It produced 1.2 t ha-1 under stream drought thus, recommended to cultivate it, especially in zones where precipitation fluctuates.