HERBICIDAL ACTIVITY OF Datura metel L. AGAINST Phalaris minor Retz

Present study was undertaken to investigate the herbicidal potential of aqueous and organic solvent (methanol and n-hexane) extracts of shoot and root of Datura metel L. (Syn, Datura alba Nees.) against Phalaris minor Retz., one of the most problematic weeds of wheat in Pakistan. In laboratory bioassays, aqueous, methanol and n-hexane extracts of 0, 5, 10 and 15% (w/v) were applied. Extracts in different solvents exhibited markedly variable herbicidal activities against the target weed species. Germination was significantly reduced by methanol root extract of 5-15% concentrations. Similarly, 15% n-hexane root extract also significantly decreased germination. Root length was significantly suppressed by all the employed concentrations of aqueous as well as organic solvent extracts. Shoot length was significantly declined by all the concentrations of methanol and n-hexane root extracts. The highest concentration of 15% of aqueous and methanol shoot extracts also reduced shoot length significantly. Aqueous shoot extracts were proved highly toxic to plant biomass where all the employed extract concentrations significantly reduced biomass.. The present study concludes that root and shoot extracts of D. metel contain herbicidal constituents. Further studies are suggested to isolate and identify the effective herbicidal constituents from D. metel which can be used as structural lead for the preparation of natural product based herbicide for the management of P. minor.