Can I delete published app in alpha testing from google play?
If your app is in Alpha and no one has downloaded it. You have to unpublished your app first and then contact Google. They will delete your app for you. I had them delete 1 app for me.
If you has not published your application yet you can delete it. Once you publish it you can only unpublish it.
So you can delete it.
You can only unpublish but cannot delete it. it will not display to user but it will be in your console forever. Delete button only unpublish it.
Updated Answer
Now google added this option only if it is not suspended..