Effect of induced moisture stress and growth regulators on physiological traits and yield of transplanted rice (Oryza sativa L.) at critical stages

A field experiment was carried out at the wetland farm of SRM college of Agricultural Sciences, Baburayanpettai during the season Sornavari (April - May) 2024, to assess the performance of growth regulating compounds for mitigating moisture stress in transplanted rice. Split plot design experiments with three replications. The main plot treatments (3) comprised of Conventional Irrigation (control) (M1), moisture stress during panicle initiation stage (M2) and moisture stress during flowering stage (M3). The sub-plot treatments (4) were foliar application of growth regulating compounds including Control (No spray) (S¬1), potassium silicate @ 1% (S2), seaweed extract @ 2% (S3), brassinolide @ 0.04% (S4). The moisture stress free control is implemented by irrigating the field with 5 cm of irrigation each day after the disappearance of previously ponded water. The experimental results revealed that as stage of rice crop is concerned, the panicle initiation stage is more sensitive to stress compared to flowering stage. The MS period of 10 days from panicle initiation significantly reduced all physiological parameters, including rice yield. This finding concluded that the treatment combination of moisture stress free control with 1% potassium silicate registered higher physiological traits and grain yield.