Phytobiocides are a good alternative to chemicals in managing bacterial diseases including bacterial wilt of tomato caused by Ralstonia solanacearum. In the present research study, finely ground dried powders of seven widely available medicinal plants/weeds species viz., Peganum harmala (esfand or wild rue), Calotropis procera (sodom apple), Melia azedarach (white cedar), Allium sativum (garlic), Adhatoda vasica (malabar nut), Tagetes patula (marigold) and Nerium oleander (oleander) were assessed for their anti-microbial activity, both in-vitro (10% w/v) and in-vivo (10, 20, 30, and 40 g/kg of potted soil) against R. solanacearum. Aqueous extracts (prepared as 10% w/v, soaking for 48-72 h and filtering) of C. procera, A. vasica, and T. patula inhibited the in-vitro growth of the bacterial pathogen over 60% of that produced by the standard antibiotic streptomycin. A. sativum, N. oleander and P. harmala aqueous extracts were less effective while M. azedarach showed no effect against R. solanacearum. The higher dose (40 g/kg of soil) of C. procera, A. vasica and T. patula decreased disease severity quite effectively and increased yield and plant growth characters as much as the standard antibiotic did. No phytotoxicity of medicinal plants powder was observed on tomato plants. Alkaloids, flavonoids, tannins, saponins and terpenoids were detected in the aqueous extracts of T. patula and A. vasica whereas C. procera was found to have only alkaloids, flavonoids, tannins and saponins. Our data suggest that dried powders of T. patula, C. procera and A. vasica (40 g/kg of soil) could be used as an effective component in the integrated disease management programs against bacterial wilt 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.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.