Effects of rhizobacteria on Meloidogyne javanica infection on eggplants

The effect of two rhizobacteria, Pantoea agglomerans and Bacillus subtilis on parasitism of the root-knot nematodes, Meloidogyne javanica on eggplants was evaluated in laboratory and greenhouse experiments. The impacts of the bacteria application as seed treatment, root dipping, and soil drench on early nematode penetration into plant roots, as well as, on eggplant growth were tested. The number of penetrated second stage juveniles of M. javanica was significantly reduced after P. agglomerans and B. subtilis application at concentration of 108 CFU ml-1. P. agglomerans increased the eggplant fresh shoot and root weight following seed treatment. In the greenhouse experiment the bacteria were applied alone and in combination with a carbamate nematicide, Oxamyl (Vydate®). P. agglomerans was able to suppress M. javanica development into plant roots through a first half of eggplant cropping season. At the end of cropping season B. subtilis significantly reduced root gall index and number of nematode juveniles in soil and roots. This bacterium applied in combination with Oxamyl was the most efficient against M. javanica reproduction. Thereby, B. subtilis might be considered as a good candidate for biological or integrated control of the root knot nematodes. Key words: Bacillus subtilis, Pantoea agglomerans, biological control, plant growth, gall index, root knot nematode.