biological control of root- knot nematode,meloidogyne javanica, by trichoderma harzianum and the study of peroxidase activitiy changes in tomato

biological control of tomato root-knot nematode, meloidogyne javanica, by the isolate bi of trichoderma harzianum was evaluated in greenhouse and laboratory conditions in tomato cv. king stone. effects of fungal spore suspensions in various densities (103 to 108 spore/ml) were studied on different disease intensities (average of gall diameters, average of root weight and average of stem weight). average number of eggs per each mass of eggs per plant and average of egg number per each egg mass were determined. the results indicated that trichoderma at 106 spore/ml concentration significantly reduced disease intensity as compared with concentrations less than 106 spore/ml (p?0.05%). inoculation of tomato seedlings with trichoderma at 106 spore/ml induced peroxidase activitiy in roots and revealed its maximum activity 7 days following inoculation. peroxidase activity in tomato seedlings inoculated with nematode+trichoderma (as treatment) significantly increased as compared with that in the only fungus inoculated seedlings (as control) reaching its maximum activity within 5 days after inoculation.