Abstract

                                The genotype difference in the grain yield and N acquisition led to the differences in N requirement for maximum grain yield. Efficient genotypes achieved maximum yield with less N acquisition compared to inefficient one. Therefore to identify the efficient genotypes in utilizing absorbed crop N towards different production parameters, this study was carried out with two groups of rice viz. short and medium duration genotypes. Ranking of genotypes were done using different crop absorbed N use efficiency (CNE) parameters individually and the genotypic performance were compared. Statistically significant differences among genotypes were observed and short duration genotypes showed higher efficiency. Based on the normalized values, ADT 39, ADT 38, CO 43, CO 45, CORH 2, TNRH 19, TNRH 21 and TNRH 31 in medium duration group and ADT 42, ADT 36, ASD 20, CO 37, IR 36, IR 72 and TKM 9 in short duration group were identified as efficient genotypes in utilizing absorbed N towards protein yield in transplanted rice.

Key words : Nitrogen use efficiency, Growth duration, Genotypic variation.