What is a good practice for linking managers compensation to their efforts and abilities to training and development their staff? What other ideas do you have that hold managers accountable for the development of their employees?

Wow, I don't knwo that I ahve ever seen comp linked to training directly. Many organizations do expect that managers "recruit, develop and retain" employees as part of their job description.

Advanced companies will have actual measures to hold managers accountable. i.e. time to hire, employee development hours, retention etc.

I have seen this work well in the past and I have seen companies base bonuses based on the manager's ability to fulfill those objectives.

Suggested, but there is one catch:
Managers can't be the ones to "certify" the development of the employees outright.

We had a system where managers were "certifying" that employees had completed certain training- and yes, the horror was that a minority of folks were not honest in fears that their performance scores would suffer. By moving the true "completion" of key training to an objective medium (compliance trainer, course attendance completion validated by approved instructors, and LMS online course completion), we removed this issue (it was mandated by an audit group). Not one issue since.

Managers still do get to comment on development, key areas to improve, etc... but "hard" completion measures are done from an objective medium.