Abstract
Because of its known anti-bacterial properties, we explored the potential ofXanthium strumarium, an invasive, enormous mass-producing weed, for the control ofRalstonia solanacearumwhich causes bacterial wilt (BW) of tomato. Both in-vitro andin-plantaexperiments were conducted, using different concentrations of the dried powders of the plant parts applied to infested soil at different times. Addition of a 20% (w/v) aqueous extract of leaf powder or succulent shoot powder to wells cut in nutrient agar inhibited growth ofR. solanacearum. Inin-plantaexperiments, 4.5% (w/w) leaf powder applied to artificially infested soil 10 days before transplant (DBT), produced the best effect and enhanced root length, shoot length, and plant fresh bio-mass by 64%, 37%, and 42%, respectively, as compared to inoculated control. Leaf powder also lowered the area under disease progress curve (AUDPC) by 38%, and the pathogen counts (g(-1)dry soil) by 1.202 log(10)units. Succulent shoot powder (4.5% w/w) applied 20 DBT proved to be better than other application times and increased root length, shoot length, and plant fresh bio-mass by 55%, 42%, and 57%, respectively, as compared to inoculated control. Succulent shoot powder also decreased AUDPC by 35%, and the pathogen counts (g(-1)dry soil) by 1.294 log(10)units. Our data strongly suggest that 4.5% (w/w) of leaf or succulent shoot powder, applied 20 DBT, can be an effective component of the integrated disease management (IDM) against BW.