Allelopathic effects and insecticidal activity of aqueous extracts of Satureja montana L.

Abstract

Extensive use of synthetic insecticides, herbicides and other pesticides has negative effects on the environment and on human and animal health. Therefore, scientists are turning towards natural pesticides, such as active components of plant extracts. The effect of two concentrations (0.1 and 0.2 %) of a Satureja montana L. aqueous extract on the lipid peroxidation process, as well as on the activity of the antioxidant enzymes superoxide dismutase (SOD), guaiacol peroxidase (GPX), pyrogallol peroxidase (PPX) and catalase (CAT) in the leaves and roots of pepper and black nightshade seedlings were examined 24, 72 and 120 h after treatment. The results showed that the higher concentration of S. montana aqueous extract induced lipid peroxidation in black nightshade roots. Furthermore, significant increases of pyrogallol and guaiacol peroxidase were detected in black nightshade leaves treated with 0.2 % of the S. montana aqueous extract. The second aim was to evaluate effectiveness of the aqueous extract as a contact toxicant against whitefly. It was observed that the 0.2% aqueous extract exhibited a toxic effect with 68.33 % mortality after 96 h.