Eugenol-inhibited root growth in Avena fatua involves ROS-mediated oxidative damage.

Plant essential oils and their constituent monoterpenes are widely known plant growth retardants but their mechanism of action is not well understood. We explored the mechanism of phytotoxicity of eugenol, a monoterpenoid alcohol, proposed as a natural herbicide. Eugenol (100-1000 µM) retarded the germination of Avena fatua and strongly inhibited its root growth compared to the coleoptile growth.

β-Pinene inhibited germination and early growth involves membrane peroxidation.

β-Pinene, an oxygenated monoterpene, is abundantly found in the environment and widely occurring in plants as a constituent of essential oils. We investigated the phytotoxicity of β-pinene against two grassy (Phalaris minor, Echinochloa crus-galli) and one broad-leaved (Cassia occidentalis) weeds in terms of germination and root and shoot growth. β-Pinene (0.