Abstract

                                Identification of rice genotypes, which are efficient in absorbing and utilizing N from soil-flood water system, is the recent focus of research related to nitrogen use efficiency (NUE). Our research attempted to identify the genotypes that support maximum grain production and having higher nitrogen absorption efficiency (NAE). From the field experiments conducted in three growing periods, different genotypes exhibited consistent and significant variations in the NAE. Ranking of genotypes were done using different NAE parameters like, N concentration, uptake, crude protein yield etc. Individually the genotypic performance were compared between different growing periods and between growth duration. Statistically significant difference among genotypes were observed and short duration genotypes showed higher efficiency with respect to both grain yield and N absorption parameters. Genotypic variations also manifested by different growing periods, which have differences in weather conditions. The results could be used in the genetic improvement of rice towards evolving efficient genotypes that would have higher N use efficiency.

Key words : Nitrogen use efficiency, Seasonal influence, Genotypic variation, Transplanted rice.