Response of rice (Oryza sativa) varieties to nitrogen levels in flash flood conditions

A field experiment was carried out during wet season of 1993 and 1994 to st udy the response of new rice (Oryra sativa L,) genotypes to nitrogen levels in flash flood conditions. The results revealed that variety 'Barh Avarodh i' recorded the maximum grain yield (2.28 tonnes/ha) which was 11.8, 32.6 a nd 45.2% more than the grain yield of 'NDGR 24', 'Madhukar' and 'Chakia 59' , respectively. Application of 90 ka N/ha gave significantly higher grain y ield over 30 kg N/ha and control, however, yield differences between 60 and 90 kg N/ha was non-significant. 'Barh Avarodhi' fertilized @ 90 kg N/ha ga ve the highest grain yield of 2.82 tonnes/ha. Agronomic efficiency of 'Barh Avarodhi' at 30 kg N/ ha was the maximum (31.0 kg grain/kg N applied). The optimum economic dose of nitrogen was worked out to be 74.5, 81.9, 76.6 an d 69.8 kg/ha with corresponding profit Rs 7,971, 7,076, 5,443 and 4,965/ha for 'Barh Avarodhi' 'NDGR 24','Madhukar' and 'Chakia 59', respectively.