People are not going to want to measure their canopy, so it’s just land area meant there. AI’s can say some pretty stupid things as we are all learning. I did ask ChatGPT and it supports the per land area view. It says “per acre of TRV” sometimes is used for the other interpretation: per acre of tree row volume. Personally I’ve never seen that on any label, but that might have gotten your AI confused.
Often the labels also have a pounds per hundred gallons or the like recommendation and I usually follow that, just divide by 100. If not I do the acre guess thing. Did you look at the Spray amounts guide here?
This is based on my and others’ calculations and experiences.
BTW if any data are missing from there please edit to add them, it’s still a bit spotty. I should add a few things myself that I have been using recently.