Effects of low irrigation limits on yield and grain quality of winter wheat

In order to formulate a high quality and efficient irrigation index of winter wheat in north China, a three-year field experiment was conducted from 2005 to 2008 to investigate the effects of different low irrigation limits on crop development, grain yield and grain quality of winter wheat under water controlling conditions. Results showed that compared with traditional method (proper soil water treatment at the whole period), there was no significant negative effect on crop growth, grain yield and quality of winter wheat. 11.68%–18.18% water were saved, and water use efficiency improved by 8.33%–12.5% under water stress during sowing to early jointing stage. Under water stress at jointing to early heading stage, there was most obvious inhibitory effect on crop growth of winter wheat, which caused Flour field, protein content, dough development time and stability time of grain significantly decreased, and 24.29%–31.95% water was saved, grain yield reduced by 6.56%–9.08%, but water use efficiency was improved by 6.19%–10.63%. Under water stress at heading to flowering stage, there was no significant negative effect on crop growth of winter wheat, protein content, wet gluten content, amino acids content and flour yield of grain increased significantly, but grain yield reduced by 9.96%–11.35%, water use efficiency was improved by 4.12%–5.62%. Water stress, occurred at the filling to ripening stage, had the least influence on crop growth of winter wheat, and significantly increased protein content, wet gluten content, amino acids content and flour yield of grain, but decreased grain yield significantly, and increased water use efficiency by 1.03%–5.95%. It was concluded that adequate water stress being permitted at sowing to jointing stage could be the high quality and efficient irrigation index of winter wheat in north China, low irrigation limits at sowing to early jointing stage, at jointing to early heading stage, at heading to flowering stage and at filling to ripening stage were 50%, 65%, 70%, and 65% of field capacity, respectively.