I have found reference to everything from bud break to early summer shoot extension.

The one time I tried it was more like bud swell and results poor. I also only scored the cambium and I now understand a small bit of removal is neccesary. Along the lines of a1/16"?

I have young apple that went straight up as a whip to 7' last year I would rather encourage a few lower branches this way than cut it back hard

I also have a young pear whip that I wish to attempt espalier. It would be nice to force a few low scaffolds on it as well. Even better if I can pick where with precision.