Investigation of the Response of onion (Allium Cepa L.) to continuous deficit irrigation as smart approaches to crop irrigation under Mediterranean conditions

Aziz Abouabdillah,Rachid Bouabid,Mohamed Bourioug,Omnia El Bergui,Youssef Brouziyne,Nabil El Jaouhari,Ahmed Bouaziz,L El Youssfi,Y Ouaggajou,S.I Cherkaoui,O Seidou,A Aghzar,E.S.P Assèdé,D.R Salazar,A.G Faundez

doi:10.1051/e3sconf/202233704001

Abstract

Water is a crucial resource for food production and its scarcity associated with frequent droughts has increased the need for a more efficient use of it along with new irrigation management technologies. This study addressed onion crop responses to continuous deficit irrigation with trigging thresholds of readily available water content. The experiment was conducted on an experimental plot in open field in Morocco. Three water regimes were applied T1 control (100%), T2 (75%) and T3 (50%) of crop evapotranspiration ETc combined with two trigging thresholds (10% and 5%). This is a complete random block device with four repetitions. The measurements concerned the monitoring of vegetative, Eco physiological and yield parameters. The results obtained show that: (i) 100% ETc irrigation at a threshold of 5% of RAW recorded the maximum bulb diameter and weight, thus achieving the best marketable bulb yields. However, in terms of yields, this treatment is not significantly different from the other irrigation regimes with the exception of the irrigated treatment at 50% daily ETc and at a threshold of 10% RAW. The latter recorded the lowest values in terms of production parameters. (ii) For the ecophysiological parameters, significant effects of irrigation dose were observed for proline content, stomatal conductance and leaf temperature, and the effect of the trigging threshold was clearly observed for the moisture content of the leaves. (iii) Water restrictions have minimized the rate of premature run and population density of Thrips tabaci in the onion. (iv) Finally, the best agronomic efficiencies in the use of irrigation water were recorded in treatments with a water restriction of 50%.

Highlights

Decrease in water resources has become a worldwide problem and there may be insufficient water for food production by 2025 (Girona et al, 2010), especially in Mediterranean region which is a climate change "hot spot" (Abouabdillah et al, 2010)
A distinction is made between two types of deficit irrigation that can be applied: Sustainable Deficit Irrigation (SDI) which means the application of continuous water restriction throughout the entire crop cycle (Goldhamer et al, 2006), or a water stress during particular crop developmental periods (RDI: Regulated Deficit Irrigation) (English et al, 1990; Chalmers et al, 1981; Hueso and Cuevas, 2004)
Another study, published by Kanton et al (2003), who examined the effect of irrigation frequency on onion crop, indicates that as irrigation intervals increased, plant height decreased significantly

Summary

Introduction

Decrease in water resources has become a worldwide problem and there may be insufficient water for food production by 2025 (Girona et al, 2010), especially in Mediterranean region which is a climate change "hot spot" (Abouabdillah et al, 2010). Major challenges exist in maximizing water use efficiency (WUE) and increasing crop productivity per unit of water applied. Within this context, deficit irrigation (DI) is used as a practice that provides water below optimal crop water requirements leading to increased WUE (Pereira et al, 2002; Costa et al, 2007; Fereres and Soriano, 2007; Capra et al, 2008; Evans and Sadler, 2008; Sharma et al, 2014 : Chai et al, 2016). The objectives of this study were to determine optimal irrigation parameters for yield optimization and increased water use efficiency, as well as to study the combined effect of deficit irrigation and irrigation frequencies on the onion crop

Objectives

Methods

Results

Conclusion