When you download a torrent in Vuze, it connects to an available list of torrent trackers. Public torrents are often shared among various trackers to increase the seed range. If you want to remove an individual tracker from the list, you can do so by editing the trackers list. Then you can target where you are sharing to and downloading from.
Click "My Torrents."
Right-click the torrent. Click "Advanced," "Tracker" and "Edit Tracker URL(s)."
Select the tracker you want to remove and press "Delete."
Close the trackers list.