LAUSR

BACKGROUND As a common abiotic stress, water deficit stress has a negative impact on the growth and yield of many field crops worldwide. In this study, a mobile rain shelter experiment was conducted in the 2017-2019 growing seasons to investigate the effects of water stress at different growth stages on various traits in winter wheat, including plant height, leaf area index (LAI), biomass, radiation use efficiency(RUE), leaf photosynthetic traits, and yield. RESULTS Three different limited irrigation treatments were applied: no irrigation at all stages (T0), no irrigation at the reviving and jointing stages (T1), and no irrigation at the heading and grain filling stages (T2). In all treatments, 2-year averages showed that T1 resulted in the highest grain yield (6470 kg ha-1 ). The plant height and LAI of winter wheat increased the order of T0 < T1 < T2. In addition, T1 increased post-anthesis biomass. The net photosynthetic rate and RUE were significantly higher in T1 than in other treatments. T1 could improve leaf photosynthetic traits by increasing Gs, Fv/Fm, ΦPSII, and qP, thus increasing RUE and grain yield. CONCLUSION We propose that irrigation at the heading and grain filling stages was the optimal limited irrigation practice for efficient radiation use and high yields in winter wheat in the arid and semi-arid area of Northwest China. This article is protected by copyright. All rights reserved.