The short answer
No, you can't at install time.
The long answer
You can restrict the installation on devices by two ways:
- Using the uses-feature meta tag in the manifest. Check out the doc here.
- Via the android console, where you can manage restrictions on any model by excluding or including some of them as target for the install of your application.
Since the root is not a feature implemented as part of the device, it is a software restriction, you might accept users to install the application and check it at runtime if the device is rooted. Here is a link on how you can try to do it, but there is not an official way or consistent for all devices as far as I know.