Exploring the antifungal potential of various Tunisian essential oils against Neofusicoccum parvum Npbt67: A sustainable approach to combat grapevine trunk diseases

The increasing interest in aromatic and medicinal plants has brought renewed attention to their essential oils (EOs) as natural bioactive agents with strong potential for plant disease control. In the search for sustainable alternatives to synthetic fungicides, this study focused on the extraction, chemical characterization, and antifungal evaluation of six EOs obtained by hydrodistillation from Tunisian native species: Thymus capitatus, Eucalyptus citriodora, Cymbopogon citratus, Lavandula stoechas, Rosmarinus officinalis, and Juniperus oxycedrus. Gas chromatography–mass spectrometry (GC-MS) identified major active compounds, including carvacrol, β-citronellal, and 1,8-cineole. The EOs were tested in vitro against Neofusicoccum parvum strain Npbt67, a key pathogen associated with grapevine trunk diseases (GTDs). All EOs exhibited antifungal activity, with T. capitatus EO proving to be the most effective, achieving complete inhibition at 20 μL, with a minimum inhibitory concentration (MIC) of 250 ppm and a minimum fungicidal concentration (MFC) of 900 ppm. Carvacrol (68.84%) was identified as the main antifungal constituent, and its pure form exhibited significantly higher antifungal activity (MIC 80 ppm, MFC 200 ppm). These findings underscore the importance of EO extraction and chemical profiling for identifying potent natural antifungal agents. T. capitatus EO, in particular, stands out as a promising and eco-friendly alternative for the management of GTDs and other fungal plant diseases.