Allelopathic Influence of Lantana camara Leaf Extracts on Germination and Seedling Growth of Phaseolus vulgaris

Abstract

Allelopathic interactions caused by invasive plant species can significantly influence crop establishment and productivity in agricultural ecosystems. Laboratory and greenhouse experiments were conducted to evaluate the allelopathic effects of Lantana camara leaf extracts on seed germination and early seedling growth of Phaseolus vulgaris. Aqueous leaf extracts of different concentrations were prepared and applied to bean seeds under controlled conditions to assess their influence on germination percentage, germination rate, root elongation, shoot growth, and seedling biomass. Results demonstrated a concentration-dependent inhibitory effect of L. camara extracts on all measured growth parameters. Higher extract concentrations significantly reduced seed germination and delayed germination initiation compared with untreated controls. Root growth was more severely affected than shoot growth, indicating greater sensitivity of belowground tissues to allelochemicals present in the extracts. Seedlings exposed to concentrated extracts exhibited reduced vigor, chlorosis, and impaired biomass accumulation, suggesting interference with normal physiological and metabolic processes. The inhibitory effects were attributed to the presence of phenolic compounds and other secondary metabolites released from L. camara leaves. Lower concentrations produced comparatively mild effects, although slight reductions in seedling development were still observed. Environmental persistence of allelochemicals and accumulation of plant residues in agricultural fields may contribute to suppression of neighboring crop species and alteration of plant community composition. The findings highlight the ecological significance of L. camara as an invasive species capable of negatively affecting crop establishment through chemical interference.