Phosphorus fertilization in inbred and hybrid rice

Abstract

Five phosphorus rates (0, 5, 10, 20 and 30 kg P/ha) were tested with four rice genotypes in Boro (BRRI dhan36, BRRI dhan45, EH₁ and EH₂) and T. Aman (BRRI dhan30, BRRI dhan49, EH₁ and EH₂) season. Phosphorus rates did not influence grain yield irrespective of varieties in T. Aman season while in Boro season P response was observed among the P rates. Application of P @ 10 kg/ha significantly increased the grain yield. But when P was applied @ 20 and 30 kg P/ha, the grain yield difference was not significant. The optimum and economic rate of P for T. Aman was 20 kg P/ha but in Boro rice the optimum and economic doses of P were 22 and 30 kg/ha, respectively. Hybrid entries (EH₁ and EH₂) used P more efficiently than inbred varieties. A negative P balance was observed up to 10 kg P/ha.