How to Disable root Login in phpMyAdmin ?

This how to guide will help you to restrict root login through phpMyAdmin. Edit phpMyAdmin configuation file config.inc.php and update following parameters.

# cd /usr/share/phpmyadmin
# vim config.inc.php

$cfg['Servers'][$i]['auth_type'] = 'cookie';
$cfg['Servers'][$i]['AllowRoot'] = FALSE;

If there are no config.inc.php file found, create it by copying config.sample.inc.php file at same location.

# cp config.sample.inc.php config.inc.php

References:
How to Install phpMyAdmin on CentOS using Yum
Setup phpMyAdmin on CentOS, RHEL and Fedora Using Source Files