Effect of aqueous extracts of selected medicinal plants on germination of windgrass [Apera spica-venti (L.) P. Beauv.] and lambsquarters (Chenopodium album L.) seeds

The study aimed to determine the effect of aqueous extracts of medicinal plants (Matricaria chamomilla, Hypericum perforatum, Achillea millefolium, and Urtica dioica) containing allelopathic compounds on seed germination in lambsquarters (Chenopodium album) and herbicide-resistant windgrass (Apera spica-venti). A Petri-dish experiment was carried out, in which the effects of five concentrations of aqueous extracts on the germination of weeds were assessed for 10 consecutive days. It was found that the dynamics of seed germination are closely related to the type and concentration of aqueous extract of medicinal plants. The 8% U. dioica aqueous extract posed the strongest inhibitory effect, limiting the germination of both lambsquarters and windgrass. Additionally, weed germination was delayed by 12–72 h in the presence of extracts, compared with the control. Summing up, the aqueous extracts of medicinal plants, especially their higher concentrations, pose a desirable inhibiting effect against the germination of lambsquarters and herbicide-resistant windgrass seeds