Root-knot nematodes are one of the important plant pathogens that cause significant damage on crops in the world. It is necessary to use environmentally friendly methods and suitable alternatives for chemical compounds to control this nematode. In present research, the antagonistic effect of Heterorhabditis bacteriophora in 10, 50 and 100 larvae and Abamectin and Rugby nematicides in 5 ppm, 25 ppm and 50 ppm on the tomato root-knot nematode (Meloidogyne javanica) was investigated in vitro. Two characteristics including; non-hatching of eggs and mortality rate of larvae were evaluated at four times of 48, 72, 96 and 120 hours. The results of the trend of egg non- hatching at 48 to 120 hours showed, at 48 hours, all treatments had the lowest rate of egg non- hatching, and after 24 hours ,that is, in 72 hours, the rate of all treatments was steep. increased. Then, rate of increase has slowed down (96 hours) and finally after 120 hours, this process started to stabilize. The highest rate of non- hatching of eggs was observed in 100 larvae of biocontrol nematode then 50 larvae was in the next rank. The lowest level of non- hatching of eggs was observed in the treatment, 5 ppm concentration of Rugby and 25 ppm of Abamectin concentration. In larval mortality, all treatments also showed a trend similar to that of non- hatching.
