The Performance of Three Submergence-Tolerant Rice Varieties at Different Agro-ecological Submergence Zones in a Riverine Grassland

Abstract

The study was conducted in a riverine grassland along the river Taia/Jong, Njala university, Southern Sierra Leone. It was undertaken with the aim of investigating the performance of three submergence-tolerant rice varieties at different elevation zones in a Riverine grassland. The experimental design had two factors (three rice varieties and six elevation zones) arranged in a Randomized Complete Block Design (RCBD) in each of two blocks. The rice varieties were Indochine Blanc (Deepwater Floating Rice), FARO 66 and FARO 67 respectively. Yield responses to submergence depth were non-linear and variety?specific: FARO 66 and FARO 67 peaked at intermediate depths (76–143 cm), while Indochine Blanc shows a flatter, lower response with slight improvement under deep water. The study concluded that the strong variety?by?submergence interaction (p < 0.05) revealed that flooding did not act as a blanket constraint, but rather as a filter that distinguished genotypes by their tolerance capacity. While the FARO varieties generally performed best at 143 cm, these average trends were conditional on statistical context. For growers in flood?variable environments, the path to optimal yield lay in deliberately pairing water-depth management with the natural submergence?tolerance strengths of the chosen rice variety. FARO 66 is recommended for areas with stable shallow to medium flooding (up to 150 cm), while FARO 67 is preferable where water levels fluctuate frequently. Indochine Blanc is not suitable for commercial production under the tested conditions due to consistently low yields.