Bactericidal Properties of the Leaf Extracts of Psidium guajava and Psidium guineense against Ralstonia solanacearum by two Analytical Methods

Extracts of two medicinal plants—Psidium guajava and P. guineense were evaluated in vitro in different organic solvents, viz., benzene, acetone, chloroform, methanol, petroleum ether, ethanol, ethyl acetate and aqueous extracts. All these preparations displayed bactericidal effect againstRalstonia solanacearum which causes bacterial wilt in Solanaceae plants. Among them, the ethanol part of leaf crude extracts prepared from the leaves of Psidium guajava and P. guineense shows maximum inhibition as compared to aqueous extract as control and Tetracycline and Streptomycin as standards. The inhibition of P. guajava against Ralstonia solanacearum equalizes near about toP. guineense in both disc diffusion and silica cotton method but less than the both standard antibiotics.