Using allelopathic effects of drought-tolerant plant extracts to produce natural weed controllers

Environmental and human health requirements necessitate replacing chemical herbicides with natural ones for weed control. Allelopathy is a form of interaction among plants that may assist in producing natural herbicides, but less research has been conducted in this important area. Allelopathic effects of extracts of five drought-tolerant plant species widely used in urban landscapes were examined using five completely randomized design experiments with four replications. The species were Rosmarinus officinalis, Lavandula officinalis, Salvia sclarea, Atriplex halimus, and Atriplex canescens. The plant species' soluble extracts were prepared at 0, 2.5, 5, and 7.5%. The seeds' germination percentage and rates of Taraxacum officinale, Conyza canadensis, and Tragopogon major were measured daily after being affected by these extracts. Increasing the concentrations of all the extract types was associated with germination percentages and rate declines. The most outstanding allelopathic effects were related to Atriplex halimus and Salvia sclarea extracts, respectively. Tragopogon major was considered the most sensitive weed species in reducing its germination rate when affected by the landscape plant extracts, except for R. officinalis extract. The reduction in germination percentage of T. major and C. canadensis under A. halimus extract compared to the control was the highest. A. halimus and S. sclarea extracts can be used as natural weed controllers for important weeds such as Taraxacum officinale.