Interactive Effect of Nitrogen Fertilizer and Plant Density on Yield of Nerica 4 Upland Rice using Dibbling Method

The experiment was conducted at the JICA-Tsukuba International Center Experiment Field during the April –October 2015 cropping season. The objective of this experiment was to evaluate the influence of Nitrogen fertilizer and plant density on growth and yield of NERICA 4 upland rice. In this study, a split-plot experimental design was used with three replications. The treatments comprised of Nitrogen fertilizer at 0 and 60 Kg N/ha; while planting was done using the dibbling method at spacings of 30cm x 30cm, 30cm x 15cm, and 20cm x 15cm which resulted into plant densities of 11.1 hills/m2, 22.2 hills/m2 and 33.3 hills/m2 respectively. Results showed that Nitrogen application increased tiller number, plant length, leaf area index and SPAD Value at both maximum tillering and heading stages. The analyzed data on yield and yield components at (HSD 5%) showed no significant difference in panicle number/m2, spikelet number/panicle, percentage of ripened grains, 1000 grains weight and paddy yield between plant densities at both 0, and 60 kg N/ha. However, plant density of 22.2 hills/m2 resulted in the highest paddy yield of 2.79 t/ha and 3.77 t/ha at both Nitrogen levels 0, and 60 kg N/ha respectively. Plant density S2 (22.2 hills/m2) was the optimum for NERICA 4 upland rice for increased growth and yield