Effect of date of transplanting and nitrogen on productivity and nitrogen use indices in hybrid and non-hybrid aromatic rice

Abstract

A field experiment was carried out during the rainy (kharif) season of 2001 at the experimental farm of the Indian Agricultural Research Institute, New Delhi, India, to study the effect of date of transplanting and nitrogen on yield attributes, yields, nutrient accumulation and nitrogen use efficiencies in hybrid and non-hybrid aromatic rice. The experiment consisted of 9 treatments with 2 varieties (Pusa Basmati 1 and Pusa Rice Hybrid 10), 3 transplanting dates (3, 10 and 17 July, 2001) and 4 nitrogen levels (0, 60, 120 and 180 kg N ha-1). Pusa Rice Hybrid 10 had significantly higher values of yield attributes (panicles hill-1, panicle weight, spikelets panicle-1, filled grains panicle-1, 1000-grain weight), yields and nutrient accumulation than the non-hybrid Pusa Basmati 1. There were significant reductions in yield attributes, yields and nutrient accumulation after delayed transplanting. Timely transplanting on 3 July led to 8.4 and 19.1% higher grain yield than transplanting on 10 and 17 July, respectively. Successive nitrogen levels had a significant effect on yield attributes (except 1000-grain weight), yields and nutrient accumulation up to 120 kg N ha-1. The maximum grain yield (5.87 t ha-1) was recorded at the highest level of N nutrition (180 kg Nha-1) and was 4.2, 15.5 and 39.3% higher than in the 120 kg, 60 kg N ha-1 and control treatments, respectively. Pusa Rice Hybrid 10 also had significantly higher values of agronomic nitrogen use efficiency (ANUE) (12.5 kg grain kg-1 N applied), apparent nitrogen recovery (27.4%), physiological NUE (44.2 kg grain kg-1 N uptake), N harvest index (62.7%), N efficiency ratio (119.6 kg dry matter kg-1 N uptake) and physiological efficiency index of nitrogen (47.4 kg grain kg-1 N uptake) than non-hybrid Pusa Basmati 1.