Response of three lowland rice (Oriza sativa L.) variety to seedling age under different plant populations in a derived savanna agro-ecology of Nigeria

Anotace: Field trials were conducted during rainy season of 2019 and 2020 at Teaching and Research Farms, Directorate of the Federal University of Agriculture, Abeokuta, Nigeria (Latitude 7o12′54′′N – 7o9′17′′N; Longitude 3o20′24′′E – 3o27′68′′E). The trials were laid out in a split-split plot arrangement in a Randomized Complete Block Design with three replicates. Main plot treatment was three lowland rice varieties (NERICA L-34, ARICA-3 and WITA-4), sub plot treatment (three plant populations: 250,000, 160,000 and 111,111) plants/ha and the sub-sub plot treatment (three seedling ages: 7, 14 and 21 days). Data collected on growth, yield and yield components were subjected to analysis of variance (ANOVA) and treatment means separated using 5% least significant difference (LSD at p ≤ 0.05). The results showed that there was 36% and 120% increase in hill count when rice was planted at 160,000 plants/ha and 250,000 plants/ha, respectively compared to 111,111 plants/ha in both years. Planting 7 days old rice seedling resulted in lower hill count compared to planting 14 and 21 days olds seedling. In both years, NERICA L – 34 produced longer rice grains, more grains per panicle and higher grain yield than ARICA – 3. Our findings also revealed that rice grain yield increased with plant population with the highest yield recorded with 250,000 plants population. Highest grain yield was recorded with planting 21 days old rice seedling. Therefore for maximum rice yield, 21 days old seedling of NERICA L – 34 should be planted at 250,000 plants/ha.