Allelopathic effect of Origanum syriacum var. bevanii (Holmes) (Lamiales: Lamiaceae) and Rhododendron ponticum L. (Ericales: Ericaceae) essential oils and extracts on Meloidogyne incognita (Kofoid & White, 1919) (Rhabditida: Meloidogynidae)

Abstract

In this study, the nematicidal activity of essential oils and extracts of Origanum syriacum var. bevanii (Holmes) (Lamiales: Lamiaceae) and Rhododendron ponticum L. (Ericales: Ericaceae) against the second-stage juveniles (J2s) of Meloidogyne incognita (Kofoid & White, 1919) (Rhabditida: Meloidogynidae) were evaluated in Petri dish and pot experiments. The essential oils and extracts were applied directly to J2s at concentrations of 5 and 10% (w/v). The mortality of J2s of M. incognita was recorded 24, 48, and 72 hours after treatments. The results showed that a 100% mortality rate was obtained from both concentrations (5 and 10%) of O. syriacum var. bevanii essential oil application. Moreover, the pot experiment showed that O. syriacum var. bevanii essential oil (5%) (w/v) and O. syriacum var. bevanii extract (10%) was more effective against the J2s of M. incognita on tomato plants. Results were promising in terms of testing the effects of essential oil and extracts obtained from the determined plants in laboratory conditions against M. incognita.