Evaluation of drought stress on grain yield and yield components in some winter cereals under controlled conditions

In order to evaluate the effect of drought stress on grain yield and yield components in some winter cereals, a factorial experiment in completely randomized with 3 replications was conducted in greenhouse at Faculty of Agriculture and Natural Resources, Gonbad Kavoos University. The treatments were winter cereals with 6 levels included bread wheat cultivar Kohdasht, durum wheat cultivar Seimareh, six-row barley cultivar Sahra, two-row barley cultivar Khorram, and hull less barley Line 17 and triticale cultivar Javaniloo and drought stress with 3 levels i.e., full irrigation as the control (-0.4 bar), slight water stress (-1 bar) and intensive water stress (-4 bar). Drought stress was imposed in flowering stage. The results showed that the effect of species and drought had a significant effect on all the studied traits while interaction on all studied were not significant. The results of mean comparison showed that the range of grain yield changes between species varied from 1.25 to 2.58 g per plant. The results showed that grain yield in triticale is  more than durum wheat (73%). Also, the comparison between different levels of drought stress showed that with increasing drought stress, all measured traits decreased in the studied species. The results showed that grain yield, biological yield and harvest index decreased by about 32, 72 and 45%, respectively in severe stress conditions compared to the control. The results of this study showed that high biological yield and high harvest index can be considered as important criteria in breeding cultivars of plant species.