Now that I have been syncing my ownCloud address book to my mobile devices and my laptop I was missing this address book in mutt. But using pyCardDAV and the instructions at http://got-tty.org/archives/mutt-kontakte-aus-owncloud-nutzen.html it was easy to integrate the ownCloud address book in mutt. As pyCardDAV was already packaged for Fedora it was not much more work than
yum install python-carddav, edit
~/.config/pycard/pycard.conf to get the address book synced.
I was already using a LDAP address book in mutt so that I had to extent the existing configuration to:
set query_command = "~/bin/mutt_ldap.pl '%s'; /usr/bin/pc_query -m '%s'"
Now, whenever I press CTRL+T during address input, first the LDAP server is queried and than my local copy of the ownCloud address book.