Effects of plant and row spacing and nitrogen levels on growth, yield and economics of onion (Allium cepa L.) in Khost, Afghanistan

Abstract

Poor soil fertility management and inappropriate plant and row spacing are the main factors constraining onion production in Khost. Therefore, it was felt necessary to develop a package to recommend nitrogen (N) levels and plant and row spacing in the study area. Hence, this study was initiated to assess the effect of plant and row spacing and N levels on the growth, yield and economics of onion at the Agricultural Research Farm of Shaikh Zayed University (SZU), Khost. A randomized complete block design (RCBD) with three replications was used to set up the experiment, which was a factorial combination of three plant and row spacings (10×10, 15×10, and 20×15 cm) and four levels of nitrogen (0, 50, 100, and 150 kg N/ha). The analysis's findings showed that the growth and yield attributes of onion were significantly influenced by the main and interaction effects of N levels and spacing. Higher growth and yield components were recorded with higher N levels and wider spacing, but significantly higher bulb yield and net returns over the control were obtained with the application of 150 kg N/ha combined with narrow plant and row spacing (10×10 cm). The control group with no nitrogen produced the lowest growth and yield attributes across all spacing treatments. Therefore, 10×10 cm plant and row spacing combined with 150 kg N/ha is recommended for optimum bulb yield and economically attractive benefits in the study area.

Keywords

• plant geometry
• nitrogen levels
• onion performances and profitability