Biological control of tomato root knot nematode, Meloidogyne javanica by Talaromyces flavus and Trichoderma harzianum in the greenhouse conditions

To study the antagonistic effects of two antagonistic fungi, Talaromyces flavus and Trichoderma harzianum in the control of root knot nematode, Meloidogyne javanica in tomato, experiments were carried out in two years (2013-2014). The experiments were conducted and executed with eight treatments and five replications using pots with a completely randomized design under greenhouse conditions. To prepare treatments, 2×107 spores of T. flavus and T.harzianum (originally isolated from tomato roots) per gram soil, were added to the pots containing three kg of pasteurized soil. After transplanting four leaves seedlings of tomato, pots were inoculated with 15000 eggs and juveniles of the nematode per pot. The uninfected control pots contained only pasteurized soil without root knot nematode and antagonistic fungi. Two months after inoculation of the nematode, the growth parameters of the plants including foliar height, root weight, and some nematode- related parameters including the number of galls and egg mass, final population and reproduction factor were measured. In the combined statistical analysis, the differences were observed in data and analysis was performed separately for two years. The results showed that the antagonistic fungi were effective in increasing the plant growth and there was significant decrease of nematode population up to 80% in comparison with the infected control (α=0.05). According to the results, T. harzianum was more effective than T. flavus in increasing plant growth and decreasing the population of the nematode (78 and 67%, respectively), but differences were not significant. Furthermore, the combination of two fungi was more effective than other treatments in increasing plant growth characteristics and controlling the root knot nematode such as reduction of the number of galls and reproduction factor.