Yield of Rice As Influenced By Plant Population Density in Igbaja, Guinea Savanna Ecological Zone of Nigeria

Optimizing plant population density is critical for improving rice productivity in sub-Saharan Africa, where yield gaps persist due to suboptimal crop management. Two experiments were conducted during the wet seasons of 2022 and 2023, to evaluate the effect of three plant population densities (444,444, 250,000 and 160,000 plants ha-1, achieved at 15cm × 15 cm, 20 × 20 cm, and 25 × 25 cm spacing levels, respectively) on key yield components and grain yield of lowland rice (Oryza sativa L.) in Igbaja, Guinea savanna ecological zone of Nigeria. A split-plot design was used, and data were analyzed for combined years. Results showed that higher plant population density of 444,444 plants ha-1 significantly increased tiller count and panicles per stand, but intermediate density of 250,000 plants ha-1 produced the highest grain yield (5.23 t ha⁻¹). Low plant density of 160,000 plants ha-1produced more spike per panicle and heavier grains (1000-grain weight), but resulted to lower yield per hectare. These findings suggest that an intermediate density of 250,000 plants ha-1 optimizes rice yield under the Guinea savanna ecology.