Phytotoxic activity and variation in essential oil content and composition of Rosemary (Rosmarinus officinalis L.) during different phenological growth stages

Phytotoxic activity and variation in the quantity and quality of the essential oil (EO) of Rosmarinus officinalis L. (Lamiaceae) were examined at different phenological growth stages of full flowering (FF), fruit set (FS) and full ripened fruit (FRF). The EO yields (w/w %) at different stages were in the order of: FF (0.94%), FS (0.98%) and FRF (1.15%). The EO samples were analyzed by gas chromatography (GC) and GC–mass spectrometry (GC–MS). The main oil components at different phenological stages were found to be α-pinene (25.8–27.7%), camphor (8.6–9%), camphene (6.5–7.7%) and 1, 8-cineole (9.4–9.6%). The EO phytotoxicity activity of the mentioned stages was determined at 0, 300, 600, 900, 1200, 1500 and 1800 µlL−1 concentrations on a weed plant, prickly lettuce (Lactuca serriola L.), and a crop, radish (Rhaphanus sativus L.). The inhibitory effect of rosemary was found to be depended on the plant's phenological growth stages and EO concentrations.