در تاريخ هاي كاشت نشاءكاري ORYZO SATIVA L مطالعه انتقال مجدد ماده خشك و نيتروژن در ارقام برنج

Study on dry matter and nitrogen remobilization in rice (Oryza sativa L.) genotypes under different transplanting dates

In order to study dry matter and nitrogen remobilization in rice genotypes under different transplanting dates and determination of their proportion in grain yield, a field experiment was carried out in Rice Research Institute (Amol, Iran) during 1998 cropping season. A factorial experiment was arranged in completely randomized block with three replications, in which transplanting date at three levels (including May 13. May 23 and June 1) and rice genotypes at four levels (Tarom, Nemat, Sahel and Fajr) were the factors. Results showed that different genotypes remobilized different amount of dry matter. Among the genotypes, Fajr and Tarom remobilized the highest and the lowest amount. of dry matter from stem and flag leaf, respectively. However, Fajr was the lowest in case of other leaves. Stem and flag leaf remobilized different amount of dry matter under different transplanting dates, but other leaves were similar under different conditions. In terms of nitrogen remobilization, different genotypes also showed significant differences. in general, dry matter remobilization from stem to grain was more than other parts (flag leaf and other leaves) of the plant. However, nitrogen remobilization to grain, from leaves (flag leaf and other leaves) showed higher contribution than stem. Nitrogen remobilization showed a. significantly positive correlation with grain yield while correlation between grain yield and thy matter remobilization was not significant.