Grain Yield Performance of Selected Lowland NERICA and Modern Asian Rice Genotypes in West Africa

Six lowland experiments were conducted over three years in southern Benin to assess yield differences in 28 rice (Oryzaspp.) genotypes grown under nonfertilized and fertilized conditions. These included the interspecifi c hybrids, the lowland New Rice for Africa (NERICA) genotypes developed from crossing O. sativa and O. glaberrima. Fertilizer rates were 70–86N: 30–37P2O5: 30–37K2O kg ha–1. Fertilizer applicationincreased average grain yield across all genotypes and experiments by 39% (154 g m–2increase). Considerable genotypic differences existed in grain yields under both nonfertilized and fertilized conditions, and in yield response to fertilizer application. Two lowland NERICA genotypes (‘NERICA-L-6’ and ‘-54’) outyielded‘IR 72’ and ‘WITA4’ (standard checks) acrossnonfertilized and fertilized conditions in fourexperiments with favorable water availability inwet seasons (651 vs. 575 g m–2). The high grainyields resulted from large spikelet number m–2and biomass accumulation. In contrast, threeindicagenotypes from Asia (‘B 6144F-MR-6-0-0’, ‘IR 70181-32-PMI-1-1-5-1’, and ‘PSBRc 80’)outperformed the checks in two experiments,one straddling wet and dry seasons and theother with no standing water during most of theusual wet rice-growing season. These resultsindicate that while specifi c adaptations arelikely to provide significant yield advantage inparticular environments, interspecifi c breedingstill offers an effective approach to improvinglowland rice productivity.