Biocontrol effect of Trichoderma harzianum isolates on root knot nematode Meloidogyne javanica on greenhouse cucumber

Root-knot nematodes(Meloidogyne spp.) are the most important parasitic nematodes infecting cucurbits plants. These nematodes cause 5% loss in crop production and also provide favorable conditions for co-infection with other plant pathogens. Trichoderma harzianum Rifai is a potential bio-control agents for controlling the plant pathogens, including plant parasitic nematodes. In order to find the effective isolate/s of T. harzianum for management of root-knot nematodes on cucumber, a suspension of 107 spores/ml of four isolates of T. harzianum with 36, 39, 42 and 43 codes was evaluated by soil drenching method. Twenty four hours after soil drenching of fungus isolates, four leaf stage seedlings of cucumber (cv. Super Dominus) were inoculated with 2000 eggs and second stage juveniles of Meloidogyne javanica and kept for two months in the greenhouse and the experiment was conducted as a completely randomized design with four replicates. The results showed that the isolate Th42 was the most effective isolate on reducing the biological activity of nematode as compared to other treatments. The isolate Th42 reduced the number of eggs, galls, egg masses and reproductive factor by 69.2, 81.8, 88.6 and 70%, respectively, as compared to control treatment.