2.In vitro screening for antagonistic activity Antagonistic activity of the rhizosphere bacteria against the virulent R. solanacearum strain To-udk2 (race1, biovar3, phylotype 1)obtained from Thailand (N. Thaveechai, Kasetsart University, Bangkok)were evaluated using the dual culture assay method on KB-medium. A water soaked sterile paper discolor was used as a negative control. Plates were kept at 28 C and the inhibition-zone around the discolor was measured after 3 days. The trial was done three times with four replicates.