Growth, productivity and profitability of aromatic hybrid rice (Oryza saliva) as affected by essential oil coated urea under aerobic condition

A field investigation was carried out at New Delhi during kharif seasons of 2010 and 2011 to evaluate the effect of combinations of different levels and sources of nitrogen on aromatic hybrid rice (Oryza sativa L.) ’PRH- 10′. Eleven treatments consisting of ten combinations of two nitrogen levels (75 and 150 kg/ha), three essential oils coated prilled ureas {uncoated prilled urea, citronella (Cymbopogon nardus L. Rendal) oil coated urea (CCPU) and palmarosa (Cymbopogon martinii) oil coated prilled urea (PCPU)} at two coating thicknesses (500 and 1,000 mg/kg prilled urea), and an absolute control, were allocated in a randomized block design with three replications. Averaged over the two years, CCPU₁₀₀₀@N₁₅₀ recorded the highest values of plant height, tillers/m²and leaf area index at 60 and 90 days after sowing (DAS), panicles/m², panicle length, grain weight/panicle, 1,000-grain weight, and grain (4.16 t/ha) and straw yields. On an average, CCPU₁₀₀₀@N₁₅₀ recorded 9.7 and 8.3% higher panicles/m² and grain yield, respectively over PU@N₁₅₀. Appreciably higher grain yield of CCPU₁₀₀₀@N₁₅₀ over other treatments and control was mainly due to a considerable improvement in most of the yield attributing characters over other treatments. The highest net returns (63 x10³/ha) and B:C ratio (2.35) were also recorded with CCPU₁₀₀₀@N₁₅₀, which were 12.9 and 11.9% higher, respectively over PU@N₁₅₀.