Management of root knot nematode Meloidogyne incognita by plant growth promoting rhizobacteria Bacillus spp. on Gerbera jamesonii

A pot culture experiment was conducted under glasshouse conditions for the evaluation of Bacillus spp. against root knot nematode, Meloidogyne incognita (Kofoid and White) Chitwood in Gerbera jamesonii (Hook) 'Valletta'. Earthen pots of 5 kg capacity were used for the experiment. Each pot was inoculated with M. incognita (1 J g^-1 of soil). Efficacy of liquid and talc formulations of B. subtilis strain BG 42, B. subtilis strain BG 37 and B. amyloliquefaciens strain B4 with a propagule load of 10⁸ cfu g^-1 were tested. The results indicated that soil drenching of liquid formulation of B. subtilis strain BG 42 at 1% m^-2 gave maximum reduction of juveniles 250 g^-1 soil (67.40%), number of adult females 5 g^-1 root (73.46%) and gall index (1.67). Liquid formulation of B. subtilis strain BG 37 and talc formulation of B. subtilis strain BG42 were next in line in efficacy. Further liquid formulation of B. subtilis strain BG42 had a positive influence on gerbera quality parameters viz., flower diameter and stalk length.