Effect of stress on grain yield and dry matter accumulation in three spring barley genotypes

In order to study effect of water deficit on growth، yield and yield components on three spring barley (Hordeum Vulgare L.) genotypes، an experiment was conducted in Ardabil Agricultural Research Station، Iran in 2003-2004. The experiment was split plot as complete block design with three replications. Water treatment including: Well watered (Normal)، No irrigation in all growth stage (stressed) and Water stress induction after anthesis were arranged in main plots and three barley genotypes: LB-IRAN، N-81-7 and N-81-14 in sub plots. In all water treatments dry matter accumulation trend was sigmoid figure، however the value had variation under water treatment affected. Maximum and minimum LAI obtained from well watered and stressed in all growth stage treatment respectively. LB-IRAN genotype had the highest values of growth parameters. There was no significantly different on tillage per plant and grain number per ear between non- irrigated and exposing of water stress after anthesis، but 1000- grain weight of them was significantly affected. Final grain yield of non-irrigated treatment decreased compared to well watered and water stress exposing after anthesis (63. 7 and 17. 2 percent، respectively). Maximum grain number per ear obtained from LB-IRAN and N-81-14. The highest 1000- grain weight was belonging to LB-IRAN and N-81-7 genotypes. The grain yield in LB-IRAN genotype (2034 kg. ha-1) was higher than others genotypes. According to Fernandez tolerance index، N-81-14 genotype had high yield stability.