Should you feed fruit trees just before they go dormant at the outset of winter?
Depends on the zone. In zones 3 4 and 5 you shouldnt feed anything 6 weeks before average last frost. It can encourage green growth which will get killed during the winter, leaving the plant open to stress, therefore diseases.
Sure, it isnt as simple as that, but that is the jist of it
No. The weather is already unpredictable this year (/At least in our area-metro Georgia) as things are starting to bloom again that already bloomed, etc. We have had a lot of rain this summer season going into fall and it has somehow got the plants all mixed up. LOL. In any case, I would not suggest you fertilize anything right now. It is time for the trees and plants to rest, for them to go dormant...