[tgeb]

Northern tool has some sprayers and you might be able to rig one up to work for you.

http://www.northerntool.com/shop/tools/category_lawn-garden+sprayers+broadcast-spot-sprayers

I like the look of this one, you would have to make a mount and probably set up some sort of boom and nozzle system to spray, but everything else is there, pump switch, hose....

http://www.northerntool.com/shop/tools/product_200578563_200578563

Farmtek.com is another source

http://www.farmtek.com/farm/supplie...rchDefaultPerPage=50&searchQuery=tank+sprayer