Pasture Sprayer

[Rch]

At Fleet Farm the big catalog for the Delavan pumps and nozzles has a protocol in the front section for calibrating output. I'm sure other suppliers have similar sections in their literature. I had to mark off a 100' or 2, put the tractor in the gear(combination) used for field travel, set the pressure( 35 to 45 lbs usually) run the course at PTO speed collecting the output from one of the nozzles. You plugged this into an equation and it gave the volume of water sprayed per acre. Then it is a simple conversion from the herbicide brochure on how much herbicide to put into whatever the gallons your sprayer holds. I user a paint marker (its like a fat ballpoint pen that has yellow paint in it available at hardware stores) and put this data on the tractor tool box lid i. e., up gearshift 3, lower gear 2- 14.7 gallons/acre at 540 PTO mark on tachometer for future reference. A disavantage of a HST tractor is there is no exact way to set the same speed.
One piece of advice, put 2 filters in series above and beyond those little screens at each nozzle on the sprayer and be fanatical about keeping it clean, clean up with ammonia solution right after use and make up fresh mixes. Sprayer nozzles clog very easy.