Allelopathic potential of essential oils isolated from local plants on common weeds found in Malaysian croplands

Doctor of Philosophy in Biosystem Engineering

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Main Author: Almarie, Ahmed Abdulwahid Ali
Other Authors: Ibnu Hajar, Rukunudin, Prof. Ir. Dr.
Format: Thesis
Language:English
Published: Universiti Malaysia Perlis (UniMAP) 2017
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Online Access:http://dspace.unimap.edu.my:80/xmlui/handle/123456789/78022
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spelling my.unimap-780222023-04-04T02:02:36Z Allelopathic potential of essential oils isolated from local plants on common weeds found in Malaysian croplands Almarie, Ahmed Abdulwahid Ali Ibnu Hajar, Rukunudin, Prof. Ir. Dr. Allelopathic agents Weeds -- Control Allelochemicals Weeds -- Biological control Essences and essential oils Doctor of Philosophy in Biosystem Engineering Continuous use of the synthetic herbicides to control weeds in agricultural production can have an adverse impact on the environment and the ecosystems creating safety and health concerns to the operators, consumers and the community. However, it is the resistance to the synthetic herbicides that developed in the targeted weeds and its consequent that provide strong justification for the need to develop an eco-friendly, natural and low risk but effective alternative bioherbicides. The study thus explores the benefits of using plant’s allelopathic potential that manifested in its essential oil, as an alternative herbicide. The research involved the isolation of the essential oils from eight selected plant species of Cupressus macrocarpa Hartweg. (Goldcrest), Melaleuca bracteata F. Muell. (Tea tree), Plectranthus amboinicus (Lour.) Spreng (Spanish thyme), Cymbopogon nardus L. (Lemongrass), Pelargonium radula Cav. (Radula geranium), Baeckea frutescens L. (Cucur atap), Murraya koenigii L. (Curry tree) and Persicaria odorata (Lour.) Sojak (Kesum plant) by steam distillation. Isolated essential oils were screened for their herbicidal activity as preemergence applied at three concentrations on two major weed types (2 grassy and 2 broad leaves weed species) grown under bioassay laboratory and pot culture conditions. The compounds were characterized using GC-MS. The phytotoxic effects of the eight essential oils were also evaluated on the four weeds as postemergence by analyzing the total chlorophyll content, relative electrolyte leakage, cellular respiration and stomata mechanism in the leaf membrane. The most effective essential oils were then evaluated as postemergence by applying singly and in a combination of two essential oils on widely known weed grown in the open field and compared with the known synthetic herbicide, Halexone (H130) as a control. The best essential oils were selected based on their efficacy of more than 70 % inhibition. The results showed that the oils isolated from C. macrocarpa, C. nardus and P. radula were the most effective in inhibiting seed germination and seedling growth completely in laboratory bioassay and caused the most severe effects on weeds grown under the pot culture. GC-MS analysis showed monoterpene was the most dominant and effective component of all essential oils followed by sesquiterpene and phenylpropanoids. The phytotoxic experiment showed total chlorophyll content, relative electrolyte leakage and cellular respiration were significantly affected by the application of the bioherbicides. The effects increased by increasing the oil concentration. There was a significant influence of the essential oils on plant membranes affecting the stomata mechanism, rupturing cell membrane, dissolution of its contents which eventually kill the weeds. The application of essential oils as postemergence herbicides to weed grown in the open field showed desirable efficiency against the weeds as non-selected contact bioherbicides comparable with the performance of the conventional synthetic herbicides H130. Application of the essential oils formulated in combinations improved the phytotoxic effects as compared to using oils singly. The combination of C. macrocarpa and P. radula at 5% each proved to produce the best phytotoxic effects in suppressing weed population. 2017 2023-03-07T00:53:08Z 2023-03-07T00:53:08Z Thesis http://dspace.unimap.edu.my:80/xmlui/handle/123456789/78022 en Universiti Malaysia Perlis (UniMAP) Universiti Malaysia Perlis (UniMAP) School of Bioprocess Engineering
institution Universiti Malaysia Perlis
building UniMAP Library
collection Institutional Repository
continent Asia
country Malaysia
content_provider Universiti Malaysia Perlis
content_source UniMAP Library Digital Repository
url_provider http://dspace.unimap.edu.my/
language English
topic Allelopathic agents
Weeds -- Control
Allelochemicals
Weeds -- Biological control
Essences and essential oils
spellingShingle Allelopathic agents
Weeds -- Control
Allelochemicals
Weeds -- Biological control
Essences and essential oils
Almarie, Ahmed Abdulwahid Ali
Allelopathic potential of essential oils isolated from local plants on common weeds found in Malaysian croplands
description Doctor of Philosophy in Biosystem Engineering
author2 Ibnu Hajar, Rukunudin, Prof. Ir. Dr.
author_facet Ibnu Hajar, Rukunudin, Prof. Ir. Dr.
Almarie, Ahmed Abdulwahid Ali
format Thesis
author Almarie, Ahmed Abdulwahid Ali
author_sort Almarie, Ahmed Abdulwahid Ali
title Allelopathic potential of essential oils isolated from local plants on common weeds found in Malaysian croplands
title_short Allelopathic potential of essential oils isolated from local plants on common weeds found in Malaysian croplands
title_full Allelopathic potential of essential oils isolated from local plants on common weeds found in Malaysian croplands
title_fullStr Allelopathic potential of essential oils isolated from local plants on common weeds found in Malaysian croplands
title_full_unstemmed Allelopathic potential of essential oils isolated from local plants on common weeds found in Malaysian croplands
title_sort allelopathic potential of essential oils isolated from local plants on common weeds found in malaysian croplands
publisher Universiti Malaysia Perlis (UniMAP)
publishDate 2017
url http://dspace.unimap.edu.my:80/xmlui/handle/123456789/78022
_version_ 1772813090450046976
score 13.214268