Characterization of radiation environment in relation to growth variables in rice under shallow water ecology

Sharp variation were observed in radiant energy over the rice canopy during its main growing season (July to November) under shallow water ecology. Low radiation environment led to high leaf area index (LAI), but poor crop growth rate (CGR). The cultivars studied showed wide variation in energy interception (E_i), energy utilization (E_u), harvest index (HI) and grain yield under defined environment. Maintenance of population pressure beyond 50 hills m⁻² did not bring any significant influence on aforesaid parameters. The cv. IET 13901 and IET 14339 were found to be highly promising for their efficient E_i, E_u and dry matter partitioning thus enhanced productivity.