In vitro evaluation of botanicals against Ralstonia solanacearum E.F. Smith (Yabbuchi et al., 1995)

The antibacterial activity of 23 botanicals were investigated against the bacterial wilt pathogen, Ralstonia solanacearum under in vitro by well diffusion method. Of the 23 botanicals tested, only four, viz., Allium sativum, Lawsonia inermis, Piper betle and Syzygium aromaticum exhibited antibacterial activity against R. solanacearum. S. aromaticum showed maximum inhibition zone of 52.0 mm diameter followed by A. sativum, L. inermis and P. betle, exhibiting inhibition zone of 49.0, 16.0 and 15.0 mm diameter, respectively. The antibacterial activity of S. aromaticum and A. sativum was significantly high as compared to the commercial bactericide, Streptocyline. Whereas, the bacterial activity of L. inermis and P. betle as compared to Bronopol, another commercial bactericide, was superior and on par, respectively. Since, Betel and Henna are cheap commodities and have high bactericidal activity against R. solanacearum, their potential can be exploited for the management of bacterial wilt in solanaceous and other crops as an alternative to the existing commercial bactericides.