1Department of Botany, Punjab Agricultural University, Ludhiana-141 004, Punjab
2Department of Soil Science, Punjab Agricultural University, Ludhiana-141 004, Punjab
3Department of Plant Breeding and Genetics, Punjab Agricultural University, Ludhiana-141 004, Punjab
*Corresponding author: rupinderkaur2088@gmail.com
Online published on 27 December, 2018.
Dry-direct seeded rice (Oryza sativa L.) (DDSR) is emerging as an alternative crop production system to overcome water crisis and labor shortage associated with the conventional method of puddled transplanted rice (PTR). Studies on nitrogen (N) nutrition, uptake, and N use efficiency (NUE) indices of rice genotypes are crucial for the development of high yielding genotypes under DDSR system. We investigated yield, its components and NUE indices of selected genotypes in response to variable N application. The experiment was laid out in a complete randomized block design with genotypes AAUDR, MAS 946, Dhan 202 and IET 23455 and N levels 0, 75, 150, and 225 kg N/ha. Significant differences in grain yield, N uptake and NUE indices were observed among genotypes. The genotype IET 23455 was found to be superior among all the tested genotypes in terms of grain yield, grain N uptake, N uptake efficiency and NUE traits. It was concluded that N uptake and N uptake efficiency are predominant factors in determining grain yield. Because of genotypic differences in NUE, it may be possible to develop genotypes that are efficient even at low N application. Such genotypes may be used for selection of high yielding and N-efficient rice genotypes for DDSR.
Correlation, Genotypic differences, Nitrogen uptake, Nitrogen dynamics, Quadratic response
