- Title
- Comparative study of phytochemical composition and insecticidal properties of Lemon species from Eastern Cape and KwaZulu-Natal
- Creator
- Nodola, Phumelele
- Subject
- Phytochemical -- Insecticidal properties Lemon - - Species – Eastern Cape - - South Africa Citrus limon
- Date Issued
- 2019
- Date
- 2019
- Type
- Thesis
- Type
- Masters
- Type
- M Sc
- Identifier
- http://hdl.handle.net/11260/1348
- Identifier
- vital:32261
- Description
- Citrus limon commonly known as lemon is the third most cultivated citrus genus in South Africa mainly cultivated for its juice. This study aims at analysing the chemical composition of Citrus limon waste (leaf and peel) and evaluation of their insecticidal properties. Leaves and peels of Eureka lemons were collected from three South African citrus farms (Addo, Riverside and Mystic), while Lisbon lemons were only collected from two citrus farms (Addo and Riverside) in 2017 and 2018. A total of 36 essential oils were extracted using the Clevenger like apparatus. Analyses of these oils were done using GCMS. An infusion extract of C. limon was prepared according to the standard method and subjected for phytochemical screening to detect and quantify secondary metabolites present. D-Limonene was the major compound identified in all the 36 oils from Eureka and Lisbon peels and leaves (27.9-74.8%). Other dominant compounds identified in Eureka leaf and peel oils were -pinene (5.8-13.2%), -terpinene (4.8-6.7%), geranial (4.0-15.4%), z-citral (6.7-11.7%), sabinene (4.5-6.3%), nerol (4.0-5.4%) and neryl acetate (6.3-9.5%). Some compounds were however present only in some oil such caryophyllene (6.5%) in Mystic dry leaf oil, geraniol (8.0%) in Addo dry leaf oil, as significant compounds. Lisbon leaf and peel essential oils -pinene (4.4- 11.8%), p-cymene (4.2-6.3%), -terpinene (4.4-6.9%), geranial (8.6-17.3%), z-citral (7.1-13.6%), neryl acetate (4.7-9.1%) (5.4-5.9%) were the other prominent peaks identified in the oils. These C. limon essential oils were further tested for insecticidal activities against maize weevils by conducting repellent assay, fumigant assay and contact toxicity; also plant viii powder was used against maize weevils. In general, for all the bioassay, mortality of the insect increased as the contact days with the oil increased. Contact toxicity assays of C. limon peel essential oils were most effective against S. zeamais in which all weevils were dead by day 3 (100% mortality) at 300 μL, while at other concentrations (50, 100, 200 μL) over 50% mortality was observed. The fumigant potential was high with the peel oil with over 50% mortality at 32 and 40 μL in day 4. The oil had moderate repellent effect on the maize weevil. Riverside Eureka dried powder peel was the most effect in all. These results unveil the medicinal potential of South African citrus waste in post-harvest crop protection and good sources of some chemical compounds which are of medicinal value. Furthermore, this study also reveals the economic potential of these wastes in job creation.
- Format
- xx, 160 leaves
- Format
- Publisher
- Walter Sisulu University
- Publisher
- Faculty of Natural Sciences
- Language
- English
- Rights
- Walter Sisulu University
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WSU Department of Chemical and Physical Sciences
| Thumbnail | File | Description | Size | Format | |||
|---|---|---|---|---|---|---|---|
| View Details Download | SOURCE1 | Modola, P 2019 MSc. pdf.pdf | 3 MB | Adobe Acrobat PDF | View Details Download |