Nematicidal Effects of Two Volatile Organic Compounds, 3-Octanone And 1-Octen-3-ol Against Five Plant Parasitic Meloidogyne Species

Root-knot nematodes (RKNs) of the genus Meloidogyne are major plant pests causing severe crop losses. Microbial volatile organic compounds (VOCs) have emerged as promising biopesticides. In this work, we evaluated the nematicidal activity of two fungal VOCs, 1-octen-3-ol and 3-octanone, against five Meloidogyne species (M. incognita, M. javanica, M. hapla, M. arenaria, and M. luci). Plate assays showed near-complete (95–100%) juvenile mortality at 500–1000 ppm within 24 h. At lower concentrations, mobility declined and species-specific effects appeared: 1-octen-3-ol was more effective against M. arenaria, while 3-octanone strongly affected M. hapla and moderately M. incognita and M. javanica. Egg differentiation was significantly inhibited across time points, with up to 80% reduction at 1000 ppm and effects persisting at 125 ppm. Egg hatching from egg masses was reduced up to 95% in a concentration-dependent manner, irrespective of compound type. Soil-like assays confirmed enhanced efficacy at low doses, with >90% mortality at 125 ppm after 24 h, suggesting prolonged activity. These results show that fungal VOCs are potent nematicides at low doses and short exposures, highlighting 1-octen-3-ol and 3-octanone as eco-friendly candidates for sustainable nematode control.