These docs are for an old release.
Info on upgrading to v4
removeEventSource
Dynamically removes an event source.
.fullCalendar( ‘removeEventSource’, source )
Events from the source will be immediately removed from the calendar.
The source parameter is rather flexible. You can provide an event source’s id/Array/URL/Function or you can specify the full Event Source Object.
To remove multiple event sources at once, resulting in a single re-render, use removeEventSources.