عنوان مقاله [English]
In order to evaluate the reaction of bread wheat () to various moisture levels (supplemental irrigation) and various nitrogen fertilizer levels, an experiment was conducted on 2014-2015 cropping year at Kuhdasht town climatic conditions, Lorestan province, Iran as split-plot based on completely randomized block design. Main plots include irrigation at three levels (without irrigation, irrigation once at planting and twice irrigation at planting and stem emerging) and secondary plots include wheat varieties (Karim and Kuhdasht) and various nitrogen levels at three levels (without fertilizer application, application on planting and fertilizer application on planting and stem emerging). During experiments, grain yield, biological yield, 1000-grain weight, seed number per plant, harvest index and so on were measured. According to results of analysis of variance, Koohdash variety with twice irrigation and 120 kg nitrogen fertilizer caused increasing biological yield and grain yield up to 13060 and 5466 kg/ha, respectively and also Karim variety with two times irrigation and without N fertilizer had highest 1000-grain weight by 42.67 g. Interaction effects of nitrogen and other effective factors are of great importance at plant growth and plant N utilization. Available water content is one of the effective factors on N use efficiency. By supplying optimum irrigation water along with nitrogen application, it can be expected that yield and yield components would be increase.