Carlina acaulis essential oil nanoemulsion for managing Meloidogyne incognita

Recently, plant secondary metabolites have been considered for developing new generation nematicides. Carlina acaulis L. (Asteraceae) contains an essential oil (EO) exhibiting significant insecticidal activity with limited impact on beneficial aquatic and terrestrial organisms. Herein, we report the development of a C. acaulis essential oil EO (CEO)-based nanoemulsion (CEONE) for managing the phytoparasitic nematode Meloidogyne incognita. Initially, pure C. acaulis essential oil EO (CEO) was evaluated for its toxicity against second stage juveniles (J2) of M. incognita as well as for the interruption of the nematode biological cycle into the roots of artificially inoculated tomato plants. CEO was analysed through gas chromatography-mass spectrometry (GC-MS) analysis. Therefore, CEONE was developed to ameliorate CEO efficacy, and physico-chemically characterized. GC-MS showed that the tested CEO was mainly composed by the polyacetylene carlina oxide (96%). CEO exhibited significant in vivo and in vitro activity against M. incognita. Of note, CEONE was more effective in controlling nematodes into tomato infested roots. Overall, the CEO could be practically exploited for a new class of nematicidal agents.