wget: command not found

Problem:
Error “wget: command not found” occurs when you try to run scheduled tasks (cronjob) on Plesk.

Solution:
/usr/local/psa/bin/server_pref -u -crontab-secure-shell /bin/sh

Reference:
https://plus.google.com/+AlmogKoren/posts/LupxQciM9Wc
http://forum.parallels.com/showthread.php?110192-php-command-not-found