The pot- experiment was carried out in the green house at Faculty of Agronomy in autumn 2012 and spring seasons 2013 under low nitrogen (N1), intermediate nitrogen (N2) and high nitrogen (N3) to biomass accumulation of newly developed rice lines with short growth duration and of check variety IR 24. The experiments were laid out in randomized complete block (RCB) with 4 replications. At the active heading stage, 7, 14 and 21 days after heading (DAH), plants of each treatment were randomly selected to measure dry weight of leaf, stem- sheath, root and panicle
individual grain yield was determined at harvesting stage. The experimental results indicate that raising the nitrogen application levels caused increase in dry weight of root, leaf and stem - sheath at heading stage and dry weight of panicle at 14 days after heading of short growth duration line in both seasons. ILl9-4-3-8 produced accumulation grain yield and had the export percentage of the matter in stem- sheath and the transformation percentage of the matter in stem-sheath more than that in IR 24. Significant and positive correlations were revealed between percentage of :filled spikelet, weight of 1000 graihs of ILl9-4-3-8 and stem-sheath single weight at heading stages of 7 DAH and 14 DAH
whereas grain filling percentage and weight of 1000 grains of IR 24 were positively and significantly related to stem-heath single weight at heading stage.