Allelopathic potential of essential oils from four Satureja spp.

Abstract

Potential damage to human health and to the environment from herbicides is regarded today as a real problem. It has resulted in an increased interest in alternative strategies leading to the development of biodegradable compounds. In this study, allelopathic effects of four essential oils (EOs) of Satureja spp., S. khuzestanica, S. bachtiarica, S. rechingeri and S. spicigera, were investigated against tomato (Lycopersicon esculentum) and rye (Secale cereale). The concentrations 0, 100, 200, 400, 600, 800 and 1000 μl l− 1 of the EOs were tested in vitro against seeds, and their effect on germination, root and shoot length, fresh and dry weight, proline content and relative membrane permeability was determined. EOs from S. khuzestanica and S. rechingeri showed high inhibitory effect against rye and tomato seeds, respectively, at 400 μl l− 1, whereas S. bachtiarica showed the least inhibitory effect on the tested plants. S. spicigera and S. bachtiarica, which significantly decreased rye germination and growth at high concentrations, stimulated the growth at lower concentrations compared with the control treatment. The main components of the examined EOs were carvacrol and thymol. Findings of this study showed that EOs from the tested Satureja species have allelopathic effects on tomato and rye plants and have potential as natural herbicides.