اثر ميزان و زمان مصرف نيتروژن بر خصوصيات كمي و كيفي ، كاراي انتقال مجدد ماده خشك و نيتروژن در دو رقم گندم زمستانه

Effect of Rate and Time of Nitrogen Fertilizer Application on Quantitative and Qualitative Traits, Nitrogen and Dry Matter Remobilization Efficiency in Bread and Durum Wheat

In order to investigate the effect of different times and levels of nitrogen fertilizer application on quantitative and qualitative traits, nitrogen and dry matter remobilization efficiency in two winter wheat cultivars, a field experiment was conducted by using a split factor on the basis of randomized complete block design, with three replications, during 2001-2002 in Shiraz region. Main plots consisted of two cultivars (Falat and Yavaros) and subplots included rates and times of nitrogen application. The results indicated significant differences between cultivars in number of fertile ear, number of grain per ear, 1000-grain weight, grain yield, biological yield, harvest index and grain protein percentage, with durum wheat being superior in number of grain per ear, 1000-grain weight , harvest index and grain protein percentage and Falat cultivar in number of fertile ear, grain yield and biological yield.The effect of nitrogen application rate was observed to be different on the above traits.By increasing nitrogen application all the above traits were promoted. The best method of nitrogen partitioning was obtained in T2 as well as T3. There were significant differences between cultivars in nitrogen remobilization efficiency. Durum wheat demonstrated a greater efficiency in nitrogen remobilization from flag leaf to grain. Also, this factor was promoted by increase in rate and time of nitrogen application. In general as an indicated by the results, durum wheat (in qualitative traits) and bread wheat in quantitative traits were superior.