Journal of Experimental Biology and Agricultural Sciences http://www.jebas.org ISSN No. 2320 – 8694 Journal of Experimental Biology and Agricultural Sciences, June - 2023; Volume – 11(3) page 542 – 549 Allelopathic effects of the invasive plant Wedelia (Sphagneticola trilobata L.) aqueous extract on common beans (Phaseolus vulgaris L.) K.R.S. Perera 1 , R.M.C.S. Ratnayake 2 , U.P.K. Epa 1* 1 Department of Zoology and Environmental Management, University of Kelaniya 11600, Dalugama, Kelaniya, Sri Lanka 2 Department of Plant and Molecular Biology, University of Kelaniya 11600, Dalugama, Kelaniya, Sri Lanka Received – April 07, 2023; Revision – June 11, 2023; Accepted – June 20, 2023 Available Online – June 30, 2023 DOI: http://dx.doi.org/10.18006/2023.11(3).542.549 ABSTRACT Sphagneticola trilobata (L.) Pruski is an alien invasive weed with aggressive growth habits, environmental stress tolerance, and the ability to synthesize allelochemicals. However, in many parts of the world, this plant is still recommended for use in composting, phytoremediation, and as an ornamental ground cover in gardens. The present study investigated the allelopathic effect of S. trilobata on the seed germination, growth and yield of Phaseolus vulgaris L. To analyze the allelopathic effects of S. trilobata on P. vulgaris seed germination, hundred seeds of P. vulgaris were exposed to different concentrations of the aqueous extracts of fresh and dry S. trilobata (2.5×10 2 , 5.0×10 2 and 7.5×10 2 g/L) in Petri dishes for five days. The impact of S. trilobata aqueous extract on the growth and yield of P. vulgaris was also studied with seedlings planted in a compost soil mixture. Results of the study suggested negative impacts of S. trilobata extracts on P. vulgaris seed germination, growth and yield. P. vulgaris seed germination was significantly lower in the treatments than in the control (p<0.05). Further, P. vulgaris plants treated with fresh plant extracts at 5.0×10 2 and 7.5×10 2 g/L concentrations had significantly lower shoot height, growth rate, leaf area, fresh shoot weight, dry shoot weight, root length, pod length and yield (p<0.05) than controls. From the results of the study, it can be concluded that S. trilobata aqueous extracts have a dose-dependent allelopathic effect on P. vulgaris seed germination, growth, and yield and among the dry and fresh plant extracts, fresh plant aqueous extracts have a more significant allelopathic impact. As S. trilobata contains water-soluble allelochemical, it should not be used in biofertilizer production, phytoremediation, or as live mulch. * Corresponding author KEYWORDS Sphagneticola trilobata Allelopathy Phaseolus vulgaris Germination Growth Seed Yield Weeds E-mail: epa@kln.ac.lk (U.P.K. Epa) Peer review under responsibility of Journal of Experimental Biology and Agricultural Sciences. All the articles published by Journal of Experimental Biology and Agricultural Sciences are licensed under a Creative Commons Attribution-NonCommercial 4.0 International License Based on a work at www.jebas.org. Production and Hosting by Horizon Publisher India [HPI] (http://www.horizonpublisherindia.in/). All rights reserved.