Impact of Nitrogen and Spacing on Onion (Allium cepa L.) Growth in Southern Tigray, Ethiopia

The aim of the study was to evaluate the combined effect of nitrogen fertilizer rates and intra-row spacing on the growth, yield, and yield components of onion. The study was carried out using a factorial arrangement in a randomized complete block design. A field experiment was conducted in the experimental field of Alamata Agricultural Research Center kara Adishabo in 2020 with experimental treatments of Nitrogen fertilizer rates (0, 23, 46, 69, and 92 kg N/ha) and intra-row spacing (5, 10, and 15 cm) with three replications. Results indicated that the interaction effect of nitrogen and intra-row spacing significantly swayed most of the yield and yield components of the onion where the highest maturity date was recorded from the 92 Kg N/ha and 15 cm (140 days) and 69 Kg N/ha and 10 cm (127 days) respectively. The highest (40.01t/ha) and lowest (15.03 t/ha) marketable yields were recorded from the treatment combinations of 69 kg N/ha and 5 cm and 0 kg N/ha and 15 cm respectively. Application of 69 Kg N/ha and 5 cm of intra-row spacing in the study area can lead to maximum yield.