Response of onion crop to bulb set size and planting date under mulching in dry Mediterranean environment

Ibrahim Mubarak

doi:10.14720/aas.2021.117.3.818

Abstract

The present pot experiment under open field conditions was conducted to evaluate the response of onion crop to bulb set size and planting date using mulching. Two different sizes of onion sets at planting (large (6-10 g) and small (2-6 g)) and three different planting dates (February, March, and April) with two soil coverings (with and without straw mulching) were tested. Treatments were replicated three times. Onion was not exposed to any drought stress during the course of the experiment.Results indicated that the larger bulb sets which were planted earlier under mulching, maximised the total bulb yield (Yield, 44.0 t ha-1), water use efficiency (WUE, 8.37 kg m-3), and irrigation water use efficiency (IWUE, 9.57 kg m-3). Moreover, findings revealed that onion crop appreciably respond to smaller bulb sets when they were planted earlier under mulching. Onion bulb responses were predicted to be linearly increased with the earliness in planting date, with an obvious better preference under mulching and heavier bulb sets. Hence, adopting early planting date with mulching is suggested for sustainable crop production and for enhancing water use efficiency in dry Mediterranean area.

Highlights

Onion (Allium cepa L.) is one of the most important crops worldwide. The ecological conditions such as temperature and photoperiod largely affect its growth and production. The cultural practices such as planting date, size of onion bulb sets at planting, and irrigation water availability have an impact on crop production (Brewster, 2008; Khokhar, 2014; Mubarak and Hamdan, 2018a)
Two indicators were used in this study to represent the shape of onion bulbs: bulb diameter (BD) and the shape index (Sh I)
Both indicators were found to be highly affected by the main effects of all studied factors according to the ANOVA (Table 2)

Summary

Introduction

Onion (Allium cepa L.) is one of the most important crops worldwide. The ecological conditions such as temperature and photoperiod largely affect its growth and production. The cultural practices such as planting date, size of onion bulb sets at planting, and irrigation water availability have an impact on crop production (Brewster, 2008; Khokhar, 2014; Mubarak and Hamdan, 2018a). Late-date-planted onions start forming bulbs before reaching satisfactory plant growth to support the final size of bulbs. This would produce very small bulbs, and decreasing the bulb yield (Brewster, 2008; Rohini and Paramaguru, 2016)

Methods

Results

Conclusion