Nematicidal Activity of White Mustard Seeds as Promising Biofumigants for Control Root-Knot Nematodes, Meloidogyne spp., Infecting Solanum lycopersicum L. under Field Conditions

This study evaluates the nematicidal potential of white mustard seeds (Sinapis alba (S. alba), family Brassicaceae) in vitro and as a biofumigant against root-knot nematodes, Meloidogyne spp., infecting tomato plants under field conditions. In vitro assays revealed that S. alba extract has effectively inhibited Meloidogyne incognita egg hatching after 4 days with 94% and increased the mortality rates of juveniles by 77 and 90% after 24 and 48 h. respectively. In field experiments, three doses of mustard seeds were applied, results showed a significant reduction in nematode populations, including galls, egg masses, and second-stage juveniles, as the treatment doses increased. In addition to nematode suppression, plant growth parameters, such as shoot and root length and fruit weight, were significantly enhanced with higher doses of white mustard seed treatment. The treatments also improved the defense mechanisms of the tomato plants, elevating antioxidant levels, antioxidant enzyme activities, and the content of flavonoids and phenolic compounds. Chemical profiling of the white mustard seeds by LC-HRESI-MS/MS revealed the presence of various compounds, mainly phenolic acids and their derivatives and flavonoids, which may contribute to the observed nematicidal effects.