Phenotyping Rice (Oryza sativa. L) Genotypes for Nitrogen use Efficiency

Abstract

Aim: Global food security has become a serious issue, nitrogen fertilizer use has increased agricultural productivity globally, but at a significant environmental cost. The present study was aimed to identification of rice genotypes from the existing germplasm or development of rice cultivars that can make the best use of N in low nitrogen soils is essential for the sustainability of agriculture
 Study Design: The experiment was laid out in split plot design with three nitrogen levels as main plots and twenty five rice genotypes as subplots.
 Place of Study: The screening experiment was conducted in December 2021April 2022 at wetland, Tamil Nadu Agricultural University, Coimbatore.
 Methodology: Twenty five rice genotypes were cultivated with three nitrogen levels 0% Recommended Dose of Nitrogen (RDN) (T0), 50% RDN (T1), 100% RDN (T2) as control under field conditions, morphological traits such as plant height, leaf area; the number of tillers, total dry weight and leaf nitrogen were recorded along with leaf nitrogen and photosynthetic nitrogen use efficiency (PNUE).Two-way ANOVA and Cluster analysis were used to analyze the data.
 Result: The results revealed that among twenty five rice genotypes, G3 recorded the highest photosynthetic nitrogen use efficiency (25.10) followed by G7 (22.62) under 0% RDN (T0). The lowest PNUE was recorded in G11 (5.99) 100% RDN (T2). Across the genotypes G3 and G7 genotypes exhibited the highest NUE.
 Conclusion: Observations relies upon that the rice genotype G3 and G7 exhibit high nitrogen use efficiency and G11 shows low nitrogen use efficiency.