Darn the sprayer unit, I want that John Deere towing it.
Stamper,
Can you talk about the pump you’re using? And do you have close ups of the pump and the pulley connection? Thanks
I made something very similar to spray my pecan. The tank came from Northern Tool. I sealed the lid and added a shrader valve (tire valve) to charge it with a couple lbs of air to give positive feed to the pump. I also use a spray nozzle with a zero degree spray angle but sized for a flow twice what my pump will do. This keeps the stream more intact and will go higher.
GREAT MINDS THINK ALIKE 
Mike