Effect of irrigation periods on the yield of two Agropyron species

To study the effect of irrigation periods on the yield of two Agropyron species in climatic conditions of Damghan, an experiment was conducted as split plot in a randomized complete block design with four replications at the Ahvano rangelands. Main plots consisted of four irrigation periods: no irrigation and irrigation periods of 20, 40 and 60 days and the subplots were devoted to two A. elongatum and A. desertorum species. Analysis of variance along with mean comparison between treatments indicated that there were significant differences among irrigation regimes for plant species. There was also considerable variation observed among species in dry matter yield. Maximum dry matter yields for the 20-day period with 141.5 kg/ha belonged to A. desertorum. For the latter treatment, dry matter yield was reduced by 22.8 % as compared with the non irrigation conditions. Minimum dry matter yield was 96.4 kg/ha obtained from A. elongatum in non irrigation conditions, however, at 20 days periods dry matter yield increased by 34.8 %.