Yield Evaluation of Some Rice Varieties Subjected to Water Application Frequencies in In-Land Flood Plains of River Niger, Lokoja, Kogi State, Nigeria

A field trial was conducted within the inland floodplains of the River Niger in Lokoja, Kogi State, Nigeria, to evaluate the growth and yield response of seven rice varieties; FARO 44, FARO 45 (ITA 257), FARO 46 (ITA150), FARO 47, FARO 51, FARO 55 (NERICA 1), and Farmer’s Variety (Local) to four irrigation frequencies (daily, 2-day, 4-day and 6-day intervals). The experiment was laid out in a Randomized Complete Block Design with twenty-eight treatment combinations replicated three times. Irrigation frequency exerted a significant effect (p<0.05) on leaf production at 6 and 9 weeks after sowing, with the 4-day interval producing the highest leaf counts, while daily watering became superior by 12 weeks after sowing. Varietal differences were highly significant and consistent across nearly every growth and yield parameter measured, with FARO 55 (NERICA 1) consistently outyielding all other varieties in leaf number, panicle number, panicle length, filled spikelet per panicle, panicle weight, grain yield and straw yield, while the unimproved Farmer's-Variety performed poorest throughout. Although irrigation frequency alone did not significantly alter panicle-level and yield traits, a significant F×V interaction was obtained for panicle length, filled spikelet per panicle, panicle weight and grain yield, indicating that varietal response to irrigation frequencies were not uniform. Across all varieties, yield and yield components declined progressively as irrigation frequency was reduced from daily to 6-day intervals, but FARO 55 (NERICA 1) sustained the highest absolute performance at every frequency level, recording the highest grain yield (6.06 t/ha) under daily irrigation and remaining the top performer (4.30 t/ha) even under the least frequent 6-day regime. These findings demonstrate that variety selection, more than irrigation frequency alone is the primary determinant of productivity under floodplain conditions, and that FARO 55 (NERICA 1) combined with a daily to 2-day watering regime offers the most reliable pathway to improved rice productivity for smallholder farmers in the river Niger floodplain ecology.