4.1. In vitro study and identification of rhizobacteria
Certain beneficial plant growth promoting rhizobacteria are
known to employ an array of mechanisms to inhibit the growth
of pathogens (Compant et al., 2005). The antagonistic bacteria we
selected and tested under in vitro conditions against R. solanacearum
on KB-medium showed different levels of antagonism. Among
the thirteen isolates, Bacillus spp. BC1AW, BC2BA, BC3AW, BC4SS
and Pseudomonas spp. PP3WT had the highest zones of growth
inhibition of 16.9–21.5 mm and were selected for greenhouse experiment. Similarly, Lemessa and Zeller (2007) and Alyie et al.
(2008) found growth inhibition of R. solanacearum by Pseudomonas
spp., Bacillus spp. and Paenibacillus macerans under in vitro
conditions.