Biological Management of Root Knot Nematode, Meloidogyne incognita through Bacterial Antagonists Infecting Tomato

Root-knot nematodes have wide host range, causing damage to many annual and perennial crops. More than 100 species of Meloidogyne are known in which Meloidogyne incognita (Kofoid and White) Chitwood is one of the most common and important plant parasitic nematode in tropical and subtropical regions of the world including Pakistan. This study was planned to investigate the interaction of Plant Growth Promoting Rhizobacteria and Pasteuria penetrans for the management of root knot nematode M. incognita on tomato in green house at 30 + 4 0C. Earthen pots 20 cm dia. having sterilized soil was mixed with Pasteuria penetrans root powder @ 103 spores per gm of soil. Three week old seedlings of tomato Money Maker were transplanted singly in pots. One week after transplanting, 30 ml of bacterial (Bacillus subtilis, Pseudomonas fluorescens and Enterobacter cloacae) suspension were applied in root zone. Seven days after application of PGPR, 2000 J2 were applied at root zone. The experiment was arranged in Completely Randomized Design and six treatments were replicated tenfold. Pasteuria penetrans alone or in different combinations with PGPR were applied.  Pots with nematode and without PGPR, Pp and nematode were kept as control. Sixty days after nematode application, plants were harvested carefully. Data were recorded on plant growth parameters and nematode reproduction in terms of number of egg mass, number of females, number of galls and galling index (0-10). The plant treated with Enterobacter cloacae + Pp significantly suppressed the number of egg mass 69.38%, number of galls 68%, number of females 66.21% and galling index 56.82% compared to control resulting in improved growth over control. The treatments   B. subtilis + Pp and P.  fluorescens + Pp showed intermediary effect on both nematode reproduction and plant growth..Pasteuria penetrans was least observed effective in suppressing number of egg mass 57.53 %, number of females 55%, number of galls 55.73% and galling index 47.73%.