Effects of essential oils distilled from some medicinal and aromatic plants against root knot nematode (Meloidogyne hapla)
Essential oils of medicinal and aromatic plants are important and promissing to manage the nematological problems in agriculture. In this study, five of the plants including Origanum onites, Salvia officinalis, Lippia citriodora, Mentha spicata and Mentha longifolia for egg hatching inhibition and four of the plants including Mentha piperita, Foeniculum vulgare, Coriandrum sativum and Ocimum basilicum for juvenile mortality were tested on Meloidogyne hapla under laboratory conditions. The oils were achieved by using water distillation method with a Clevenger apparatus. As the results of egg hatching trial, the highest egg hatching inhibition rate was found as 54% for O. onites. In addition, the other inhibition rates varied as 31.4%, 21.6%, 23.8%, 25.7% for the other plants, S. officinalis, M. longifolia, M. spicata and L. citriodora, respectively. Essential oil of each plant components were determined by gas chromatography (GC). Carvacrol was found as the main component (68.8%) of O. onites followed by Thujone 27.7% for S. officinalis, I-Menthone 76.9% for M. longifolia, Carvone 27.1% for M. spicata and Citral 19.3% for L. citriodora. For the juveile mortality, Mentha piperita showed the highest mortality rate as 93.2% and was followed by F. vulgare 72.9%, C. sativum 69.3% and O. basilicum 64.9%. The main component of the used plants were Carvone 39.3%, Anethole 40.2%, Linalool 81.3% and Linalool 54.6%, respectively.
Keywords: Essential oil, Medicinal and aromatic plants, Meloidogyne hapla