Biomass partitioning and yield components of individual tillers of rice (Oryza sativa) at different nitrogen levels

An experiment was conducted during winter season (rabi) 1995-96 with rice ( Oryza sativa L.) to investigate the distribution pattern of biomass among d ifferent tillers. The productive potential of individual tillers of 2 culti vars ('IR36' medium tall and 'Swarnaprabha' tall) at 4 different nitrogen l evels (N-0, N-30, N-60 and N-90) were studied in terms of biomass partition ing, harvest index and proportion of high density grains. Vegetative phase partitioning of biomass in the mother shoot of 'Swarnaprabha' was more in t he order of culm > leaf sheath > and leaf blade. But in 'IR36' higher propo rtion was in leaf sheath followed by culm and leaf blade. High levels of ni trogen application resulted in more partitioning to leaf sheath than to cul m. In general, mother shoot and primary tillers had high number of filled g rains, harvest index and yield in both varieties. Increasing levels of nitr ogen application resulted in more secondary tillers which contributed littl e to grain yield resulting in low harvest index.