The Main Compounds of Bio-Fumigant Plants and Their Role in Controlling the Root-Knot Nematode Meloidogyne incognita (Kofoid and White) Chitwood

Meloidogyne spp. are important parasitic nematodes affecting a variety of plants worldwide. We investigated the nematicidal properties of specific compounds found in bio-fumigant plants, particularly linalool, nonanal, methylene chloride, and 2-Decanal. Laboratory findings revealed that methylene chloride and 2-Decenal effectively reduced populations of second-stage juveniles (J2s). Additionally, the research explored the effects of tomato ( Solanum lycopersicum L.) on M. incognita J2s, observing that tomato leaves significantly increased J2 mortality for all time measurements and different temperatures, while the opposite results were observed for root-stems. In the study, leaf treatment resulted in a maximum mortality response (MR max ) and half-maximal effective concentration (EC 50 ) of approximately 100% and 4.0 µg/mg, respectively, at a temperature of 35 °C by week 8. In contrast, the root-stems treatment showed an MR max of 13.5% and an EC 50 of 3.0 ± 1.7 µg/mg. GC-MS analysis identified key compounds in tomato leaves and root-stems, such as α-pinene, d-limonene, and linalool. The results suggest that tomato leaves have potential as effective bio-fumigants for controlling root-knot nematodes.