| A study is made on the photosynthesis rate(Pn), transpiration rate(Tr), water use efficient(WUE) and water producing efficiency of crop in different growth stages of winter wheat(jointing, booting and filling stages) and different treatments with various amount of water retaining agent, including 45.0,52.5,60.0 kg/hm2 and 0 kg/hm2(CK). The result indicates that the Pn, Tr and WUE of winter wheat are ranged in order from higher ones to lower ones as follow: booting, filling and jointing during the growth stages. In each growth stage, the Pn, Tr and WUE all augment with the increase of water-retaining agent. In other treatments such as 45.0, 52.5 and 60.0 kg/hm2, the water producing efficiency of winter wheat all excels that in CK by 5.4, 5.5 and 10.4 kg/(mm·hm2) respectively after harvest. |