Effect of different levels of nitrogen fertilizer on yield and yield components of high yielding cultivars and hybrid (Bahar 1) rice in Ahwaz region

In order to evaluate the effects of nitrogen fertilizer on yield، yield components of high yielding cultivars and hybrid (Bahar 1) rice، a field experiment was carried out in the experimental field of Agriculture and Natural Resources university of Ramin during 2005 2006. A Split-plot Layout in the basis of randomized complete blocks design with three replications was used. Four nitrogen levels، including of 0، 150، 175، and 200 kg urea/ha as the main plots and three rice cultivar including of Danial (LD183)، Shafagh and hybrid (Bahar 1) rice as the sub plats were applied. The results showed that different amount of nitrogen on traits such as Grain yield، Biological yield، Harvest index، tillers total number، fertilized tillers percent، grain number panicle، panicle fertilized percent، plant height and grain protein percent have significant differences. Also we did not see any significant differences in the effect of cultivars on all of the treats but not، tillers total number. The interaction between nitrogen treatments and genotype had significant effects on grains fertilized percent، 1000 seeds weight، fertilized panicle percent and grain protein percent. Optimum level of fertilizer for tested cultivars treatment of N with 175 kg/ha pure nitrogen had the most seed yield and had the high level than the other level of fertilizer. The most seed yield pertained to Danial (LD183) cultivar with medium seed yield (6390. 7 kg/ha) that it was more Compare to the other two cultivars. Danial cultivar with a treatment fertilizer N2 (175 kg/ha pure nitrogen) had most seed yield in considering quality features we saw significant difference among level of no and the other treatments. We did to saw any significant difference.