تأثیر تنش خشکی انتهای فصل بر عملکرد و اجزای عملکرد گندم نان

Drought is one of the most important global threats on food production that make restriction on plant growth and crop yield. The aim of this study was to identify the impact of terminal drought stress on traits associated with grain yield. Four bread-wheat cultivars (Karim, Orum, Pishgam, Sivand and two lines DN-11 and Cross of Sabalan) and also Sardari (as check) were planted as Randomized Complete Block Design (RCBD) with three replicates on two separate sites as full irrigation (control) versus terminal drought stress (irrigation cut at boot stage). Grain yield, biological yield, harvest index, seed number per spike, thousand kernel weight, hectoliter weight and plant height were measured. The results of combined analysis showed, biological yield, harvest index and thousand kernel weights were decreased significantly by irrigation cut at boot stage. Pishgam and Cross of Sabalan had the most grain yield at normal and terminal drought stress conditions respectively, but Sardari and Karim had the least grain yield at normal and terminal drought stress sites respectively. It seems that Sivand was the most tolerant variety to terminal drought stress than rest. Harvest index, thousand kernel weight and biological yield were more effective variables on grain yield.