Bioherbicidal Potential of Eucalyptus and Clove Oil and their Combinations on Four Weedy Species

Ahmed Almarie

doi:10.24996/ijs.2021.62.5.13

Abstract

Essential oils of eucalyptus leaves and clove buds were isolated and tested for their bioherbicidal potential on different annual weed species. Gas Chromatography-Mass Spectrophotometry analysis (GC-MS) identified thirteen compounds representing around 87.11% of the total isolated eucalyptus oil. The main constituent was 1,8-cineole, which accounted for 68.15% of the total identified compounds. As for clove oil, eleven compounds were identified, representing 90.03% of the total compounds. Eugenol was the dominant compound and accounted for 73.89%. The bioherbicidal efficacy of the two oils and their combinations by three concentrations (2.5, 5, and 10%) were tested on four weedy species, namely Chenopodium album, Raphanus raphanistrum, Melilotus indicus, and Sisymbrium irio. The isolated oils significantly affected the dry weight and inhibited the seedling growth of the four weedy species. Using the two essential oils, individually or within their combinations, showed the highest bioherbicidal efficacy against the targeted weeds in comparison with the synthetic herbicide. In addition, utilization of the two essential oils as natural bioherbicides caused an electrolyte leakage as a result of membrane disruption and loss of integrity of weed seedling tissues. The results showed the possibility of using eucalyptus and clove essential oils individually or in combination as a desirable alternative to synthetic herbicides for sustainable weed management.

Highlights

The term of ―weed‖ or ―weeds‖ refers to unwanted plants that grow in undesirable places and cause negative impacts on agricultural production due to their competition with the economic crops on the basic growing requirements such as water and available nutrients
The synthetic herbicides have become an integral part of the global agricultural production complex, as inputs required in a modern production system and accepted by farmers around the world as an integral part of the crop production [3]
Allelopathy comes at the forefront of possible solutions to provide natural solutions that are less harmful to the environment than the synthetic herbicides

Summary

Introduction

The term of ―weed‖ or ―weeds‖ refers to unwanted plants that grow in undesirable places and cause negative impacts on agricultural production due to their competition with the economic crops on the basic growing requirements such as water and available nutrients. The synthetic herbicides played a dominant role in the fight against the weeds and increase crop production qualitatively and quantitatively, as compared to other, including conventional, methods [2]. The accumulation of glyphosate (s systemic nonselective synthetic herbicide) was found in groundwater and sources of fresh drinking water as a result of leaching by irrigation water and rainfall It could be one of many reasons, which are responsible to decrease microorganisms and biomass activities, including those of plants, fish, and birds. Allelopathy comes at the forefront of possible solutions to provide natural solutions that are less harmful to the environment than the synthetic herbicides They are used as defence mechanisms in some plants when exposed to external potential threat from the surrounding environment, including nearby plants. The current research aims to examine the bioherbicidal ability of eucalyptus and clove oil, and their combinations, on the growth development of four weed species and their possible use as natural weed killers

Materials and Methods

11 Other components

Findings

Conclusions