Abstract: An experiment was conducted to study the effects of water deficits in the different growing stages,and to analyze the water use,yield and its components,and yield response factor(Ky) of two maize varieties,Ludan 981 and Zhengdan 958.The results showed that effects of water deficits on yield in every stage were different.The highest effect was in the flowering stage,while the lowest effect was in the jointing stage.There was significant difference between yield response factors of both genotypes during flowering stage,which were 1.40 and 1.20 respectively.

Key words: Maize, Maize, Yield response factor, Yield components