ALLELOPATIC EFFECTS OF SOME ESSENTIAL OIL COMPONENTS OF THYME AND ROSE ON GERMINATION: CASE STUDY OF BARLEY

The study was carried out to determine whether different concentrations of essential oil components (geraniol, carvacrol, thymol, and alpha terpinene) and essential oil of thyme (Thymus vulgare) have any allelopathic effects on the germination of barley seeds. The study was carried out in the laboratory environment according to the divided plots experimental design in random plots. At the end of the experiment, the effects of allelochemical types of carvacrol, thymol and geraniol doses on germination rate and seedling dry weight were found to be statistically significant (p<0.01). It was determined that geraniol (0.00245 g), carvacrol (0.01790 g) and thymol (0.02590 g) had the most negative effects on seedling dry weight, respectively. As a result, it was determined that some of the herbal allelochemicals used were effective on the germination of barley seed and seedling growth, and the effect rate increased as the dose increased. Thymol, geraniol and carvacrol showed the most negative effects on the germination rate of barley seed at all doses. On the other hand, adverse effects were determined at high doses of alpha terpinene. All doses of thyme essential oil and low doses of alpha terpinene showed similar effects with the control. As a result; It is thought that essential oil components, which have a negative effect on the germination of barley seed, can be used in the production of plant-based bio-herbicides.