This research was conducted to study the interaction between root-knot nematode Meloidogyne javanica and tomato Fusarium wilt Fusarium oxysporum f. sp. lycopersici to show the effect of nematode biology stages on severity of tomato Fusarium disease and probability of translocation of susceptibility, to fungus, caused by nematode, to the other parts of the plant. Results indicated that 15 days after penetration of nematode (young adult stage), in comparison to other stages, induced more susceptibility to Fusarium. Four, as well as 21 days after penetration also induced susceptibility to Fusarium, but no significant differences were observed between them. In this research it was also found that susceptibility caused by nematode to Fusarium can be transfered to other parts of the plant such as root and stem. Disease symptom was exhibited in these parts, in comparison to control (without nematode inoculation), with a significant diference. The traits studied were leaf index (0-10), xylem browning, root fresh weight as well as fresh weight of plant aerial parts.
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