Influence of Plant Density and Nitrogen Fertilizer Rates on Yield and Yield Components of Beetroot (Beta vulgaris L.)

Ethiopia is endowed with diverse agroecologies suitable for the production of tropical, subtropical, and temperate vegetables. Agronomic practices such as plant density and fertilizer management are known to affect the crop environment, which influences the growth and ultimately the yield. So far limited research has been done on plant density determination and rate of nitrogen fertilizer in Ethiopia in general and the study area in particular. Thus, this experiment was carried out to evaluate the influence of plant density and nitrogen fertilizer rates on the yield and yield components of beetroot (Beta vulgaris L.). Four plant densities (133 333, 100 000, 80 000, and 66 666 plants per hectare) and four nitrogen (N) fertilizer rates (0, 46, 92, and 138 kg N ha−1) were arranged in a factorial combination in a randomized complete block design with three replications. The results revealed that the main and interaction effects of plant density and nitrogen fertilizer rates on total root yield, root length, root fresh weight, root diameter, and total soluble solute of beetroot were significant. The highest root yield of beetroot was achieved from the combination of 66 666, 80 000, and 10 0000 plant ha−1 with 92 kg N ha−1, whereas the lowest root yield of beet was obtained from the combination of 0 kg N ha−1 with a planting density of 133 333 plants ha−1. The economic analysis showed that higher net benefit and marginal rate of return were obtained from the application of 92 kg N ha−1 with plant densities of 66 666 plants ha−1. In order to prevent excessive production costs, the use of 66 666 plants ha−1 combined with the application of 92 kg N ha−1 is recommended.