Nematodes belonging to the Meloidogyne genus pose a significant threat to a wide range of crops, both in open fields and under protected environments. Two experiments were conducted to assess the nematicidal efficacy of essential oils (EOs) derived from Sage (Salvia officinalis), Atlas cedar (Cedrus atlantica), Warionia saharae (Warionia saharae), and Calendula (Calendula officinalis) on Meloidogyne javanica. The EOs were evaluated on the second stage juveniles (J2s) mortality and egg hatching inhibition under in vitro conditions, meanwhile nematode development was tested on tomato plants under in vivo conditions. During in vitro experiment, concentrations of 50, 100, 200, 400, and 800 µl/L were examined, while in vivo experiment focused on doses of 400 and 800 µl/L. The obtained results indicate that the tested EOs effectively killed J2s and inhibited M. javanica egg hatching, with outcomes dependent on oil type, exposure duration, and concentration. Notably, treatments of C. atlantica, C. officinalis, and W. saharae at 800 µl/L achieved significant J2s mortality rates exceeding 80% mortality within 72 h. The lowest egg hatching (20.1%) was recorded with S. officinalis oil at 800 µl/L. However, during in vivo assay a substantial reduction in gall index, egg masses, eggs/g of root and J2s nematodes/100 cm3 of soil were also observed. Additionally, significant increases in tomato shoot and root length were observed. Further research exploring their impact on diverse crop systems will be essential for practical implementation and broader adoption of these natural control strategies in agriculture.
