Impact of Seedling Age and Nitrogen Application on Submergence Tolerance of Sub1 and Non-Sub1 Cultivars of Rice (Oryza sativa L.)
Of the three growth stagesviz., seedling establishment, maximum tillering and flowering, complete submergence of plant at flowering stage was found to be most critical followed by seedling estabilishment and maximum tillering stages. Among the three stages of reproductive growth phase, booting stage was found to be most susceptible to complete submergence followed by flowering and post-flowering. The submergence at booting for 4 days was equally detrimental as that of 6 or 8 days at flowering. Irrespective of the growth stages, the plants subjected to complete submergence showed higher nitrogen content (in plant as well as in grain) as compared to those grown under control conditions (5±2 cm) and increased with the increase in duration of submergence. The P and K contents in the plant decreased under submergence.