Malaysian Journal of Sustainable Agriculture (MJSA)

The invasions of Argemone mexicana in sub–Saharan Africa’s natural habitats negatively affect biological diversity. We investigated A. mexicana’s suppressive effects on Phaseolus vulgaris seed germination (petri dish experiments) and seedling growth (pot experiments). Phaseolus vulgaris seeds and seedlings were treated with different A. mexicana leaf (AmL) and root (AmR) crude extract concentrations to study their suppressive effects on the test plant. The results revealed that AmL and AmR crude extract suppressed P. vulgaris seed germination and seedling growth, particularly at higher concentrations (70% and 100%). At these concentrations, the seed germination inhibition percentage was twice that at lower concentrations (25% and 50%). The number of seeds that germinated at higher concentrations was lower compared to those that germinated at lower concentrations. Correspondingly, seed germination was delayed at higher concentrations compared to lower ones and controls. Moreover, P. vulgaris seedling growth vigour was negatively affected as the growth parameters (fresh biomass, root lengths, stem diameters, and heights) under 75% and 100% concentrations of AmL and AmR were lower. Though this study’s findings revealed that A. mexicana crude extract reduced P. vulgaris germination and growth, further research is required to investigate the allelopathic effects of A. mexicana on other plant species.