Comparative nitrogen use efficiency in hybrid and indigenous cultivars of rice

A field experiment was conducted during kharif 2001 in an Entisol soil to study the comparative nitrogen-use efficiency in hybrid and indigenous cultivars of rice under sub-tropical climatic conditions. Two hybrid varieties PHB-71 and KRH-2 and two indigenous varieties PC-19 and Jaya were tried in a factorial randomized block design with four nitrogen levels (0,50,100 and 150 kg ha⁻¹) in the main-plots and varieties in sub-plots. Hybrids responded upto 150 kg N ha⁻¹, while locals responded only upto 100 kg N ha⁻¹. Further hybrids recorded higher uptake of N, P and K at harvest as compared to local varieties. Apparentnitrogen recovery, nitrogen-use efficiency and physiological N efficiency decreased with increased levels of nitrogen. Nitrogen-use efficiency was highest in the hybrids, while reverse was the case with regard to physiological N-efficiency.