Abstract:
An experiment was conducted at the Tamil Nadu Agricultural University. Coimbalore dunn£ the kharif and rahi seasons of l'J'M-"96. lu study the time CIHIISC leaf N cmicetnraiion in lowland ria under diilercntN timings. Application of I 50 kg N ha"1 m six staggered sPllts/rom planting to heading or m tnree splits Irom early tillering Ul heading suslamed the leal'N eoncenlration at increased levels for higher grain yields. Early N application and limitation of N supply at later stages decreased the plant N con contrail on during grain filling stages and reduced the grain yield. Continued application ol Fertilizer N until heading stage favoured maintenance of N concentration in leaves during ilic posl-anlnests period, resulting in high grain yields. Based on the natural behaviour of time course leat'N concentration, simulation models «cre evolved based on the prediction ability and test of significance
