Evaluation of Different Sources and Dosage Levels of Slow-Release Urea on Growth, Yield and Quality Parameters of Wet Direct-Seeded Rice (Oryza sativa L.)

A field experiment was conducted during kharif, 2022 at research farm of ICAR- Indian Institute of Rice Research, Rajendranagar, Hyderabad. The experiment was laid out in a randomized block design with ten treatments that consisted of nitrogen management practices allocated randomly and replicated thrice. Slow-release urea fertilizers such as silicon coated urea and cedar wood oil coated urea are developed at ICAR-IIRR laboratory were evaluated in wet direct seeded rice under field condition. Significantly highest plant height at panicle emergence and flowering stages (94.2 and 100.0 cm, respectively), higher number of tillers m -2 (395.3 and 384.0) and similar trend in dry matter production were registered in plots with application of 100 % RDN through silicon coated urea and cedar wood oil coated urea. Significantly, the highest and statistically comparable grain yield (6183 and 6025 kg ha -1 ) was recorded in plots applied with 100 % RDN @ 120 kg N ha -1 through silicon and cedar wood oil coated urea. The lowest grain yield (2320 kg ha -1 ) was observed with no application of nitrogen. Among the nitrogen management practices, Si-CU @ 120 kg N ha -1 recorded the highest head rice recovery, hulling percentage, milling percentage and amylose content however it was at par with CWOCU @ 120 kg N ha -1 and 100% RDN @120 kg N ha -1 neem coated urea. While, the lowest values were recorded in control plot with no application of nitrogen. It can be concluded that RDN applied through silicon coated urea and cedar wood oil coated urea @ 120 kg/ha found to be a suitable alternative source to neem coated urea in increasing the grain yield and profitability of wet direct seeded rice.