Improvement Of Submergence Tolerance In Rice Through Efficient Application Of Potassium Under Submergence-Prone Rainfed Ecology Of Indo-Gangetic Plain

Potassium (K) is one of the limiting factors that negatively influenced rice growth and yield in submergence prone soils. We conducted an experiment during the wet season of 2014-15 to achieve optimal doses of K and understand the effect of K application on submerged rice in terms of survival, chlorophyll content, non-structural carbohydrates (NSC), anti-oxidant activities and yield. Results revealed that chlorophyll and NSC content were significantly (P <= 0.05) lower whereas the activity of anti-oxidants (catalase, superoxide dismutase and total peroxidase) were significantly (P <= 0.05) higher after submergence compared with pre-submergence. Further, application of K at a higher basal dose (40 kg ha(-1)) was more beneficial to improve survival after de-submergence by maintaining NSC, chlorophyll content and higher activity of anti-oxidants with lower level of lipid peroxidation. Furthermore, results showed superiority of the treatments having application of higher doses with one foliar spray (T9-40 kg K2O ha(-1) (basal) + one foliar spray at 0.5% K at panicle initiation (PI) stage) for grain yield. We conclude that application of a higher dose of K with one foliar application at PI stage is more beneficial to enhance plant survival, better recovery and yield gain of rice during complete submergence.