Abstract

One significant medicinal plant in the Bignoniaceae family is Tecoma stans. The study was carried out in the greenhouse of the National Research Centre, Giza, Egypt in two pot experiments. The experiments were to investigate the effect of aqueous fresh leaf extract of Tecoma stans plant on the two weeds Amaranthus viridis (broad leaf weed) and Echinochloa colonum (grassy weed) growth associated Gerbera jamesonii plants during 2022 and 2023. Spraying the leaf water extract of T. stans at concentrations 5, 10, 20 and 30% caused significant reduction in the fresh and dry weight of the two weeds. The reduction in fresh and dry weight of the two weeds reached maximum with spraying the leaf water extract of T. stans at 30%. The weed growth inhibitions was concomitant with increase in the growth and flowering of Gerbera jamesonii. Qualitative examination of T. stans' leaf extract for secondary metabolites revealed the presence of alkaloids, tannins, phenols, flavonoids, carbohydrates and saponins. When T. stans leaf extract was fractionated by sephadex LH-20 column and applied to TLC glass sheets seven flavonoids and seven phenolic acids were separated. Our work plainly indicated that the water extract of T. stans can be a promising as biohrbicide for weed management and good effect on growth of ornamental plant Gerbera jamesonii.