Abstract
This study examined how light exposure, soil composition, and plant associations influence biomass and the accumulation of secondary metabolites in Eclipta prostrata (L.) L. (Asteraceae), a medicinal plant with significant ethnopharmacological value. Plants were grown under controlled conditions across different soil types and shade and in association with Arachis repens Hando or intraspecific association. Metabolite profiles were analyzed using HPLC-DAD and HPLC-DAD-ESI-MS/MS. The results revealed that light exposure, soil quality (especially Carolina soil), and plant associations significantly enhanced the production of key secondary metabolites. Interestingly, metabolite accumulation was not directly correlated with biomass, highlighting the influence of abiotic and biotic factors on the plant's phytochemical plasticity.