Field experiments were carried out at Tamil Nadu Agricultural University, Coimbatore, India during samba (August-December) seasons of 2012 and 2013 to find out the optimum crop geometry, age and number of seedlings on growth and physiological characters in relation to yield of low land rice. The experiment consisted of three mainplot treatments viz., M1-25 x 25 cm, M2-25 x 20 cm and M3-25 x 15 cm and six sub-plot treatments S1-14 day old seedlings (DOS)+1 seedling/hill, S2-14 DOS+2 seedlings/hill, S3-14 DOS+3 seedlings/hill, S4-21 DOS+1 seedling/hill, S5-21 DOS+2 seedlings/hill and S6-21 DOS+3 seedlings/hilland replicated thrice in a split plot design. The results revealed that plant spacing, age and number of seedlings/hill showed all physiological parameters highest under this combination of M1S1 and recorded higher grain yield (7191 and 7414 kg/ha) during 2012 and 2013, respectively, and it was statistically comparable with M2S1, M2S5 and M3S5.