* Present address: Deptt. of Botany, Osmania University, Hyderabad.
** Central Rice Research Institute, Cuttack
Increased population pressure in rice decreased the sustenance period particularly at 100 and 200 hills per square meter. On the other hand, increased population density reduced the volume, weight and number of roots per hill, but the same root parameters increased per square meter of land. The cultivar, N 22 maintained its superiority for deeper root penetration at higher plant densities, while the root diameter decreased and became at par with thin rooted Cauvery. This suggests the need for using an optimum population of 100 hills per square meter to capitalize advantages on thickness and length of roots in N 22.
