Combined effect of Metarhizium anisopliae and Pseudomonas fluorescens CHA0 on root-knot nematode, Meloidogyne incognita in tomato

Root knot nematodes are one of the most important plant parasitic nematodes with worldwide distribution and wide host range. Regarding to the hazards of synthetic chemicals, this is necessary to use other measures, such as biological control. In some studies, the separate, as well as the combined effects of two biocontrol agents, Metarhizium anisopliae and Pseudomonas fluorescens CHA0, on Meloidogyne incognita were studied. In a laboratory test, it has been showed that there is no non-volatile inhibitory effect of P. fluorescens CHA0 on M. anisopliae. In case of In vitro assay of culture filtrate and suspension of both biocontrol agents, the mixture of culture filtrates and culture filtrate of the bacterium caused about 95% and 80% larval mortality, respectively. Maximum inhibitory in egg hatch (93-98%) observed in those treatments in which culture filtrate of one or two agents were included. In the experiment that was designed to compare the application methods, the growth factors of tomato plants considerably increased and the nematode-related factors considerably decreased, in those M. anisopliae spore suspension were applied as soil drench. Soil drench of the trade formulation of M. anisopliae to the soil and foliar spray of P. fluorescens CHA0, improved the plant-related factors and decreased up to 30% of gall formation and up to 75% of reproduction factor. This is the first report of nematicidal effect of M. anisopliae on M. incognita.