Not directly, no. However, you can add a Text Widget containing only a white space (or a dummy widget) to the specified sidebar. This way there will be no visible widgets (depending on your css to the Text Widget of course). Will this do?
Displaying empty sidebars might be implemented fully at a later point though.
Actually I would like to have no sidebar at all on my post pages so that my posts can move to the very of my main page. Is it possibile?
If you do what my previous post says and thereafter removes the widget again, so that the specified sidebar is empty, it is indeed possible at the moment. However, it is important that you add a widget and thereafter remove it again, or else it will not work.
The plugin was never really meant to act like this, but I guess WordPress saves a sidebar in the database once a widget has been added to it or something, I haven’t really looked into it, I just noticed it worked by accident.
As I said before though, it will be fixed at some point so that you do not have to do this extra step.
