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In order to investigate the effects of water deficit stress effects, different rates of nitrogen and plant density on remobilization, current photosynthesis and grain yield in oily sunflower var. Iroflor, an experiment was carried out in field Agriculture and Research center of West-Azerbaijan during 2011 and 2012 cropping seasons. The experimental was conducted as split-split-plot base on Randomized Complete Block Design (RCB) with 3 replications. The main factor was consisted irrigation treatment including optimum irrigation, moderate stress and sever stress which irrigation was done after depletion of 50%, 70% and 90% of available water, respectively. Three nitrogen levels of 100, 160 and 220 kg N haG1 were considered as sub plots and sub-sub plots consisted of three plant populations of 5.55, 6.66 and 8.33 plants m2. The results of combined analyzes showed that severe drought stress reduced the grain yield by 60% compared to the optimum irrigation condition. Comparison of two-year-mean revealed that severe drought stress in compared with optimum irrigation dry matter remobilization rate decreased about 30 percent. Also, severe drought stress led to 35% reduction of current photosynthesis efficiency in compared with optimum irrigation. In each level of nitrogen fertilizer, increasing plant population led to increase contribution of remobilization but current photosynthesis contribution decreased. Therefore, due to reduction of current photosynthesis rate in severe drought stress condition, contribution of current photosynthesis decreased so that increasing of (contribution of, deleted) remobilization contribution prevented reduction of seed yield.

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This research in order to evaluate the effect of different levels of irrigation regime on yield and yield components of soybean in Urmia region at the Urmia agricultural high school Research during 2012 using split plot based on a randomized complete block design with three replications. Drought treatments (optimum irrigation 60 mm, moderate drought stress 110 mm and severe drought stress 160 mm evaporation by evaporation pan Class A) were included in main plots and the Cultivars (Clark, Williams and Onion) were allocated in subplots. The results of variance analysis showed that the effect of drought stress on seed yield, oil and protein content was significant (P<0.01), so that the maximum and minimum oil and protein value obtained by optimum irrigation and severe drought stress conditions, respectively. However, for relative water content and leaf chlorophyll, there was no significant difference. Severe drought stress reduced the grain yield by 63 and 45% compared to the optimum irrigation and moderate stress conditions, respectively. In optimum irrigation and severe drought stress conditions, the highest seed yield, oil yield and protein yield, obtained by Onion genotype. A Clark genotype in comparison with other cultivars had the minimum seed yield, in severe drought stress conditions.

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In order to investigate the effects of mycorrhizal fungi on yield and water use efficiency of eight sesame (Sesamum indicum L.) genotypes in different levels of drought stress, an experiment was conducted using a factorial split plot with three replications in the research field of the Urmia agricultural high school in 2014. The main factor was consisted of different levels of irrigation as: normal irrigation (irrigation after 70 mm evaporation of the crop (ETc), moderate drought stress (irrigation after 90 mm ETc) and severe drought stress (irrigation after 110 mm ETc), and two species of mycorrhiza fungi (Glomus mosseae, Glomus intraradices) and non-inoculated (control). Sub plots consisted of eight landraces of sesame names Jiroft13, Zanjan Tarom Landrace, Moghan Landrace, several branches Naz, TC-25, TS-3, Darab 14 and Dashtestan 5. Results showed that the effect of irrigation, mycorrhiza fungi and genotypes on studying traits was significant. Mean comparisons showed that with increasing severity of drought stress, grain yield, biological yield, water use economic and biotic efficiencies decreased significantly. Severe drought stress reduced water use economic and biotic efficiencies about 62 and 49 percent, respectively. Using two species of mycorrhizal fungi (Glomus mosseae, Glomus intraradices) in comparison with non-inoculated (control) had significant effect on all studied traits. Inoculation with G. mosseae improved seed yield, biological yield and water use economic efficiency compared to control with 33, 42 and 33 percent, respectively. Moghan landrace and Zanjan Tarom landrace based on yield and water use efficiency, had superiority on other landraces. Mycorrhiza led to improve yield of landraces and in severe drought stress conditions, sesame plants showed a higher mycorrhizal dependency.