Herbicidal activity of flavonoids of mango leaves against Parthenium hysterophorus L.
Arshad Javaid, Shazia Shafique, Qudsia Kanwal, Sobiya Shafique
Author Affiliation: Institute of Mycology and Plant Pathology, University of the Punjab, Quaid-e-Azam Campus, Lahore, Pakistan.
Natural Product Research 24 : 1865-1875
Abstract : This study was undertaken to investigate the herbicidal activity of mango (Mangifera indica L.) leaves against parthenium weed (Parthenium hysterophorus L.). The aqueous leaf extract at 15% concentration (on fresh weight basis) significantly reduced germination, shoot length and the shoot and root biomasses of parthenium seedlings. In a leaf residue incorporation pot trial, 2% residue incorporation treatment significantly suppressed the root and shoot biomasses of parthenium, while a 5% residue treatment completely stopped the growth of the weed. Five flavonoids, namely (--)-epicatechin-3-O-?-glucopyranoside (1), 5-hydroxy-3-(4-hydroxyphenyl)pyrano[3,2-g]chromene-4(8H)-one (2), 6-(p-hydroxybenzyl)taxifolin-7-O-?-D-glucoside (tricuspid) (3), quercetin-3-O-?-glucopyranosyl-(1 -> 2)-?-D-glucopyranoside (4) and (-)-epicatechin(2-(3,4-dihydroxyphenyl)-3,4-dihydro-2H chromene-3,5,7-triol (5)) were isolated from mango leaves. In a laboratory bioassay, 50 ppm solution of compounds 3 and 4 caused yellowing of the parthenium seedlings. A 250 ppm solution of compound 4 also significantly reduced germination and the root and shoot lengths of parthenium seedlings. This study concludes that compound 4 exhibits herbicidal activity against parthenium weed.