Effect of planting geometry and nitrogen level on growth, yield and nitrogen-use efficiency of scented hybrid rice (Oryza sativa)

A field experiment was conducted during the rainy (kharif) season (July-October) of 2000 and 2001 at Indian Agricultural Research Institute, New Delhi, to study the effect of planting geometry and nitrogen levels on growth, yield attributes, yield and nitrogen-use efficiencies of ‘PRH 10’ scented hybrid rice (Oryza sativa L). Planting geometry did not influence growth, yield attributes, yields and nitrogen-use efficiency. However, each unit increase in N level led to significant increase in growth, yield-attributing characters, and yield of rice. The maximum grain yield (65.5 q/ha) was recorded with highest level of N. The maximum response was observed at 75 kg N/ha and thereafter it decreased with the increase in N level. The nitrogen-use efficiency (NUE), apparent recovery (%), nitrogen efficiency ratio (NER) and physiological efficiency index of absorbed nitrogen (PEIN) were significantly higher at lower level of N and decreased significantly with increasing N levels.