Bioefficacy of Some Aqueous Phytoextracts Against Clavibacter Michiganensis Subsp. Michiganensis (Smith), the Cause of Bacterial Canker of Tomato

The ability of some medicinal plants was explored to control bacterial canker of tomato caused by Clavibacter michiganensis subsp. michiganensis. The plants tested included Peganum harmala, Allium sativum, Withania somnifera, Melia azedarach, Calotropis procera, Mentha piperita and Nerium oleander. Aqueous extracts of P. harmala and M. piperita proved to be very effective under in vitro conditions against Clavibacter michiganensis subsp. michiganensis. In in vivo studies, the highest dose of dried powder of P. harmala and M. piperita kg−1 of soil decreased disease severity significantly. Other yield-contributing parameters were also enhanced by the application of dried powder and no phytotoxicity was observed at given concentrations. Alkaloids, tannins, glycosides, flavonoids and saponins were detected in aqueous extracts of P. harmala, W. somnifera, M. azedarach, C. procera and M. piperita. Dried powders of P. harmala and M. piperita could be incorporated as an integral part in the integrated disease management programs against Clavibacter michiganensis subsp. michiganensis.