Beautiful tree and composition, although i would have used mild post processing, or shot in brackets and do an HDR image, because your sky lost a lot of its beauty (although i realize you were trying to capture the tree as the most important aspect, but you don't wanna lose quality in your background!

the highlights are a bit blown

lovely yellows, but the highlights appear very blown, too bad...nice try

I agree with what other said but honestly this is an easy fix. Just drop out the top where the sky looks blown out (too bright) and I would suggest crop some of the bottom to focus more on the tree and you will have a great entry. I'll come back and vote later.