The nematicidal activity of mustard plant against hatching, migration and mortality of
the root-knot nematode Meloidogyne javanica was investigated in-vitro and in-vivo on tomato. In vitro test found that mixing sandy clay soil with mustard at 4% as a biofumigant significantly reduced the percentage of egg hatching at all different incubation periods compared to control treatment. Laboratory results also led to high percentage of larval mortality at the different intervals periods tested. Laboratory results confirmed the highest reduction in egg hatching and larval mortality obtained after 48 hrs incubation period . Application mustard at 5% either before one week or 48 hrs. of nematode inoculation was the most effective treatment that significantly reduced all nematode parameters comparing to the check. The percent of chemical components i.e. total sugars, total amino acids and total phenols were markedly enhanced compared to positive and negative control. The highest percentage was obtained with mustard at 5% one week before nematode inoculation by 68.7, 57.3 and 45%, respectively .