Effects of Irrigation Stage and Rate on the Components of Starch,Grain Yield and Water Use Efficiency in Wheat

This research was carried out from 2004 to 2005,using a strong wheat cultivar,namely Jimai 20.The aim was to study how the starch components,grain yield and water use efficiency(WUE) changed under different water irrigation stage and rate.The results were as follows.After anthesis,the photosynthetic rate of flag leaves and amylase content in grain of the treatment W0 were significantly lower than those of other treatments(W1,W2,W3);in the middle of grain filling stage,the photosynthetic rate of flag leaves and amylase content in grain of W1,W2 and W3 took such order: W3W2、 W1.The amylopectin content and total starch content of W0 were significantly higher than those of W1,W2 and W3.From 21d after anthesis to maturity,the amylopectin content and total starch content of W1 and W2 were significantly higher than those of W3.As to grain yield,the order was W1,W2W3W0,and there were no significantly differences between W1 and W2.The above results indicated that irrigation in winter didn’t affect grain yield significantly and irrigation during grain filling stage made grain yield decrease.The order of WUE among different treatments was W0W1W2W3,and water pro-duction efficiency was W1W2W3.The order of the rate of amylase to amylopectin was W0W1,W2W3.According to the analysis of above indices,the treatment of W1 was the best one in this experiment.