Herbicidal Activity of (L.) Cav. Essential Oil.

The bioherbicidal potential of (L.) Cav. essential oil (EO) and its main compound carvacrol was investigated. In in vitro assays, the EO blocked the germination and seedling growth of L., (L.) L., and L. at 0.125 µL/mL, of (L.) P.Beauv., L., and L. at 0.5 µL/mL, of L. at 1 µL/mL and of L., and (L.) P.Beauv. at 2 µL/mL. Under greenhouse conditions, EO was tested towards the emergent weeds from a soil seedbank in pre and post emergence, showing strong herbicidal potential in both assays at 4 µL/mL. In addition, EO, applied by spraying, was tested against , and . The species showed different sensibility to the EO, being the most resistant. Experiments were performed against testing EO and carvacrol applied by spraying or by irrigation. It was verified that the EO was more active at the same doses in monocotyledons applied by irrigation and in dicotyledons applied by spraying. Carvacrol effects on root morphology were also studied.