Assaying the effects of some essential oils on Root-knot Nematode [Meloidogyne javanica (Treub 1885) Chitwood 1949] in the laboratory

Abstract

Nematodes are man’s faceless enemy whose activities encourage hunger and poverty. This study was conducted to determine the efficacy of selected plant oil extract in the control of root knot Nematode [Meloidogyne javanica] in the laboratory. The experimental design used was Complete Randomized Design (CRD) with fourteen treatments, replicated three times. Egg hatch inhibition test on M. javanica eggs and juvenile mortality test were separately performed by exposing the eggs and juveniles to different dosage of the essential oils. Neem seed oil statistically proved effective in inhibiting egg hatch followed closely by Garlic clove oil and then Moringa seed oil. All the essential oil treatments were more effective than carbofuran treatment. The surfactant Sodium Lauryl Sulphate was shown to have nematicidal properties as it also recorded zero egg hatching at all the doses applied. The second stage juveniles of M. javanica recorded a higher mortality rate (100%), when they were treated with Neem seed oil, closely followed by Garlic clove oil and then Moringa seed oil. All Surfactant treatments caused 100% juveniles’ mortality. The higher the doses of the essential oils, the higher the juvenile mortality rate. Neem seed oil at all the dosage proved effective in controlling Meloidogyne javanica causing high rate of juvenile mortality and suppressing M. javanica egg hatch. The nematicidal characteristics exhibited by the essential oils might be due to the phytochemicals present in the oils.