ارزيابي اثرات كود نيتروژنه بر عملكرد، اجزاء عملكرد و انتقال مجدد ماده خشك در سه ژنوتيپ برنج

Evaluation of nitrogen fertilizer effects on yield, yield components And dry matter remobilization of three rice geno type

In order to evaluate the effects of nitrogen fertilizer on yield, yield components and dry matter remobilization of different rice genotypes, a field experiment was carried out in the Rice Research Institute (Rasht/lran) during 1999-2000. A split-plot lay out in the basic of randomized complete blocks design with four replications, was used. Three nitrogen levels, ibcluding of 0,150 and 300 kg/ha as the main plots and three rice genotypes including of 424, 506 and 507 as the sub plots were used. The results showed that grain yield and dry matter remobilization had significant differences among rice genotypes and different levels of nitrogen. Grain yield and dry matter remobilization in 424 genotype was more than others, and the highest dry matter remobilization was obtained under 300 kg.ha level of urea. Moreover the interation between nitrogen treatments and genotype had significant effects on grain yield and dry matter remobilization. Different rice genotypes and also different plant parts showed different responses related to remobilization of dry matter. 424 and 506 genotypes showed the highest dry matter remobilization under 300 kg.ha and 507 under 0 kg/ha level, of urea. In general, contribution of grain dry matter from stem was more than other parts(like flag leaf and other leaves). There were positive and singnificant correlations between grain yield and 1000-grain weight and fertile tillers number. Correlation voefficient between grain yield and dry matter remolilization was not significant.