Abstract:

In order to explore the effects of regulated deficit irrigation at different growth stages on the yield and water use efficiency of seed-producing maize in Hexi Corridor, full irrigation (CK) was selected as the control, two deficit adjustment gradients of mild water deficit (accounting for 60%-70% of field capacity) and moderate water deficit (accounting for 50%-60% of field capacity) were set up, and different deficit adjustment gradient tests were carried out at seedling stage and jointing stage. In total, six treatments were set including control. Leaf area index and dry matter accumulation of maize were measured at each growth stage, and the yield and its components were measured after harvest. It was shown that the yield, water use efficiency, and irrigation water use efficiency of maize under mild water deficit at seedling stage were not significantly higher than those of CK (P>0.05). While, the yield of maize under moderate water deficit at seedling stage, mild water deficit at jointing stage, moderate water deficit at jointing stage, mild water deficit at seedling stage+moderate water deficit at jointing stage was significantly (P<0.05) lower than that of CK by 7.07%-23.90%. Given yield and water use efficiency, the regulated irrigation of mild water deficit at seedling stage, i.e. soil water content was maintained at 60%-70% of field capacity at seedling stage and 70%-80% at other growth stages, was suitable in the cultivation of seed-producing maize in the irrigation area of oasis in Hexi Corridor.

Key words: regulated deficit irrigation, seed-producing maize, plant growth, yield