Allelopathic effect of imperata cylindrica (L.) beauv. extracts on the germination of weeds

• Main Author: A Salim, Mohamed Ali
• Format: Thesis
• Language: English; English; English
• Published: 2020
• Subjects: TA401-492 Materials of engineering and construction. Mechanics of materials
• Online Access: http://eprints.uthm.edu.my/909/1/24p%20MOHAMED%20ALI%20A%20SALIM.pdf; http://eprints.uthm.edu.my/909/2/MOHAMED%20ALI%20A%20SALIM%20COPYRIGHT%20DECLARATION.pdf; http://eprints.uthm.edu.my/909/3/MOHAMED%20ALI%20A%20SALIM%20WATERMARK.pdf; http://eprints.uthm.edu.my/909/
• Institution: Universiti Tun Hussein Onn Malaysia

In this study, the allelopathic effect of Imperata cylindrica has been investigated. Aqueous extracts of Imperata cylindrica were tested at concentrations of 31.25, 62.5, and 125 mg/ml to study different parameters on Cucumis sativus and Lolium perenne Similarly, allelopathic effect of Imperata cylindrica root and shoot 70 % ethanol extract fractions (obtained by different polarity solvents), that is, A, B, C, and D, were also tested at 0.125, 0.25, and 0.5 mg/ml concentrations on four different plants; Linum usitatissimum, Lolium perenne, Macroptilim lathyroides, and Phalaris canariensis. Distilled water and glyphosate were used as negative and positive control, respectively. Various factors were studied to determine the inhibition and growth of root and shoot length, percentage germination, and fresh and dry weight. Results indicated that the extracts of Imperata cylindrica may contain allelochemicals which may contribute to its invasiveness and extreme competitiveness. While the gas chromatography-mass spectroscopy analysis (GC�MS) of active fractions revealed the presence of allelochemicals including phenolic acid, fatty acids, and organosilicon compounds. Although phenolic acids [butyl phenol, phenyl 3-methylbut-2-enoate, p-coumaric acid, and p-coumaric acid methyl ester], fatty acids [phytol, methyl isohexadecanoate, palmitic acid, palmitic acid methyl ester, (9,12-Octadecadienoic acid, ethyl ester), (9Z, 12Z, 15Z�Octadecatrienoic acid, ethyl ester)], and organosilicon compounds [silicic acid, diethyl bis(trimethylsilyl) ester and cyclotrisiloxane, hexamethyl] detected in shoot and root extract were similar in some compounds, however, they show difference in phytotoxicity. 125 mg/ml of shoot aqueous extract and 0.5 mg/ml of fraction (B) shoot were the highest concentrations that affected the germination of weeds. The results show that Imperata cylindrica contains allelochemical compounds that are released from the root and shoots parts under different favorable conditions have the capability to contribute towards inhibition and stimulation in germination, lengths growth and decrease in the biomasses of other plant species.