Management of Ralstonia solanacearum (Smith) Wilt in Tomato Using Green Manure of the Medicinal Plant Adhatoda vasica (L.) Nees

Aqueous extracts and green manures of different parts of Adhatoda vasica, a wild medicinal shrub plant, were tested in vitro and in vivo for the control of bacterial wilt (BW) in tomato. Higher concentration (14%, w/v) of aqueous extracts of leaf, succlent shoot and stem were more effective than the lower concentrations and inhibited the in vitro growth of the pathogen by 94, 89, and 65% respectively, of the growth inhibition produced by streptomycin (200 ppm). Green manure dose of 30 g kg⁻¹ soil strongly suppressed the BW pathogen, reduced disease severity and promoted the yield-contributing plant growth parameters. Green manure of leaves, when applied to soil 4 weeks before the transplantation of tomato seedlings, controlled BW more effectively and significantly increased plant growth parameters as compared to the green manures of other parts of the plant and other application times. It can be clearly concluded from our data that Adhatoda vasica leaves green manure dose of 30 g kg⁻¹ soil (or possibly higher) could be included as an effective and nature-friendly component of the integrated disease management (IDM) against BW and possibly other similar diseases.