Growth Parameters of Onion (<i>Allium cepa</i> L. var. Cepa) as Affected by Nitrogen Fertilizer Rates and Intra-row Spacing Under Irrigation in Gode, South-Eastern Ethiopia

Abstract

The productivity of onion crop is low due to poor agronomic and management practices in Gode district. Therefore, a field experiment was conducted at Gode Polytechnic College demonstration farm in 2013 under irrigation to assess the effect of N fertilizer rates and intra-row spacing on growth parameters of onion (Allium cepa L.). The treatments were consisting of six rates of N fertilizer (0, 46, 69, 92, 115, 138 kg ha-1) and four levels of intra-row spacing (7.5, 10, 12.5 and 15 cm) and the experiment was designed in RCBD with three replications. Results of the analysis revealed that the interaction effects of N rates and intra-row spacing showed highly significant (P<0.01) effect on leaf number. Plant maturity was delayed at higher N rates and wider intra-row spacings and vice-versa. The longest plant height was obtained from 15 cm intra-row spacing and 138 kg N ha-1 where as the shortest was recorded from 7.5 cm intra-row spacing without N fertilizer application. Longest leaf length was obtained from plants spaced at 15 cm fertilized with 138 kg N ha-1. However, the shortest was recorded for plants grown in 7.5 cm intra-row spacings without N fertilizer. The overall result analysis showed thatgood growth performance of onion was obtained from 15 cm intra-row spacing combined with 138 kg N ha-1 fertilizer applications.