Allelopathic Potential of Daphne mucronata Royle on Seed Germination and Early Seedling Growth of Convolvulus arvensis and Asphodelus tenuifolius in Relation to Total Phenolic Content

Weed-related crop losses and increasing herbicide resistance in Pakistan necessitate eco-friendly alternatives for sustainable weed management; however, the allelopathic potential of Daphne mucronata Royle, a medicinally important native shrub of Balochistan, remains scientifically unexplored. The present study investigated the allelopathic effects of D. mucronata against two problematic weeds, Convolvulus arvensis and Asphodelus tenuifolius. Plant specimens were collected from two ecologically distinct regions of Balochistan i.e. Hazarganji and Ziarat, and aqueous leaf extracts were prepared at concentrations of 0%, 8%, 16%, and 32% to evaluate their inhibitory effects on seed germination and early seedling growth under controlled laboratory conditions. The results demonstrated significant concentration-dependent suppression of germination percentage, root and shoot elongation, and fresh and dry biomass in both weed species. Extracts obtained from Ziarat exhibited comparatively stronger phytotoxic effects than those from Hazarganji, while C. arvensis showed greater sensitivity to the treatments in comparison to A. tenuifolius. In addition, total phenolic content (TPC) increased with increasing extract concentration, indicating a strong association between phenolic compounds and allelopathic activity. The findings suggest that D. mucronata contains potent allelochemicals with promising potential for the development of natural bio-herbicides and sustainable weed management strategies. However, further field-based investigations are necessary to validate these laboratory findings and to understand the physiological mechanisms underlying the observed phytotoxic effects.