Phytotoxic Effects of Three Natural Compounds: Pelargonic Acid, Carvacrol, and Cinnamic Aldehyde, against Problematic Weeds in Mediterranean Crops

Marta Muñoz,Rosa Peiró,Rubén Guijarro,Natalia Torres-Pagán,Mercedes Verdeguer,Adela M. Sánchez-Moreiras

doi:10.3390/agronomy10060791

Marta Muñoz, Rosa Peiró + Show 4 more

Open Access

https://doi.org/10.3390/agronomy10060791

Copy DOI

Abstract

Weeds and herbicides are important stress factors for crops. Weeds are responsible for great losses in crop yields, more than 50% in some crops if left uncontrolled. Herbicides have been used as the main method for weed control since their development after the Second World War. It is necessary to find alternatives to synthetic herbicides that can be incorporated in an Integrated Weed Management Program, to produce crops subjected to less stress in a more sustainable way. In this work, three natural products: pelargonic acid (PA), carvacrol (CV), and cinnamic aldehyde (CA) were evaluated, under greenhouse conditions in postemergence assays, against problematic weeds in Mediterranean crops Amaranthus retroflexus, Avena fatua, Portulaca oleracea, and Erigeron bonariensis, to determine their phytotoxic potential. The three products showed a potent herbicidal activity, reaching high efficacy (plant death) and damage level in all species, being PA the most effective at all doses applied, followed by CA and CV. These products could be good candidates for bioherbicides formulations.

Highlights

One of the main challenges for the agriculture in this 21st century is to be capable to feed the increasing world population in a sustainable way, because natural resources are becoming even more scarce [1]
The objective of the present study was to evaluate the herbicidal potential of the natural compounds pelargonic acid, trans-cinnamaldehyde, and carvacrol against important cosmopolite weeds (Amaranthus retroflexus L., Portulaca oleracea L., Erigeron bonariensis L., and Avena fatua L.) as an alternative to synthetic herbicides to reduce the abiotic stress that they cause on crops
They were previously tested in the plant growth chamber described before (30 ± 0.1 ◦ C, 16 h light and 20 ± 0.1 ◦ C 8 h dark) to assure their germination capability and after that, sown in plastic pots filled with a mix of three-fourth peat and one-fourth perlite instead of soil because it was very difficult to germinate the seeds on the soil, as E. bonariensis germinates better in lighter soils [60] and, the properties of the soil collected from the citrus orchard (Table 1) did not fit the needs for their germination

Summary

Introduction

One of the main challenges for the agriculture in this 21st century is to be capable to feed the increasing world population in a sustainable way, because natural resources are becoming even more scarce [1]. Crop protection measures can prevent yield losses due to pests [2]. Herbicides have been the most used method to control weeds since their development, at the end of the Second World War because they are effective and economical [3,4]. Herbicides cause stress in crops and can make them more susceptible to other pests [5]. In the latest 10 years, integrated weed management (IWM) strategies have been promoted worldwide [7,8] to control weeds. They consist of a combination of methods: cultural, mechanical, physical, biological, biotechnological, and chemical

Objectives

Methods

Results

Conclusion