Effect of Nursery Nutrient Management on Plant Survival, Physiological Traits and Yield of Rice (Oryza sativa) Genotype Swarna-Sub1 Under Submerged Rainfed Lowland Ecosystem

Abstract

An experiment was conducted to characterize nursery nutrient management by assessing morpho-physiological traits and yield attributes at different crop growth stages for improving submergence tolerance in Swarna-Sub1, a mega rice cultivar for Southeast Asia. Seven nutrient treatment combinations were applied at two different stages, one at after 10-day seeding and second at the time of transplanting (25-day-old seedlings) in cemented submergence tank. Fifteen days after transplanting, the plants were submerged for 13 days. Maximum plant height after submergence and at recovery was observed with T5 (N0:P0:K40). In leaves, ‘N,’ ‘P’ and ‘K’ content was highest in T1 (N40:P40:K40) followed by T6 (N0:P60:K40) and then with T3 (N0:P40:K40), respectively, at all crop growth stages studied. Highest seedling/plant dry weight before submergence and after submergence was recorded for T3 (N0:P40:K40) and T5 (N0:P0:K40). Submergence treatments significantly reduced nitrate reductase activity in leaves in all treatments. Maximum panicle length, panicle weight/hill, grain per panicle and biomass/hill were obtained in T6—N0:P60:K40. Positive correlation was found between survival and potassium content of shoot (r = 0.90**) followed by shoot total soluble sugar (TSS) (r = 0.52**). The finding of this experiment may be of use for balanced application of nutrient for improving submergence tolerance in rice.