Comparative Biochemical and Phytotoxic Effects of Prosopis juliflora and Morus alba Methanolic Extracts on the Germination and Burrowing of Radish Plants

Abstract

This study investigated the phytotoxic, toxicological, and phytochemical aspects of the methanolic extracts of Prosopis juliflora and Morus alba. Phytotoxic activity was measured using radish (Raphanus sativus) seed germination and root growth inhibition assays, whereas toxicity was tested using Indian night crawlers (Perionyx excavatus). Both extracts had strong, concentration-dependent inhibitory effects on seed germination and seedling growth. In P. juliflora, root growth inhibition increased from 12.63% at 10 ppm to 67.70% at 10,000 ppm, whereas the germination index decreased from 46.64% in the control to 29.54% at 10,000 ppm. Similarly, M. alba demonstrated greater phytotoxicity, with root inhibition increasing from 12.20% to 76.66% and the germination index decreasing from 46.12% to 28.11% across the same dose range. The extract concentration significantly affected root inhibition and the germination index (P < 0.001). Toxicity tests revealed that the mortality rate of Indian night crawlers increased considerably with increasing extract concentration, with P. juliflora having greater toxic effects than M. alba did (F = 20.167, P = 0.001). Both species contained alkaloids, flavonoids, saponins, coumarins, and phenols, but no tannins were detected through qualitative phytochemical screening. The findings show that both plant species have strong allelopathic and toxicological effects because of their diverse secondary metabolite compositions, emphasizing their ecological importance and possible applications in natural weed management.

Keywords: Allelopathy, Prosopis juliflora, Morus alba, Phytotoxicity, Seed Germination, Root Growth Inhibition, Perionyx excavatus, Phytochemical Screening