Most boom sprayers seem to be mounted on the back or towed. However some, such as the Gregson-Clark Spreader-Mate and some ground powered units are walk-behind. TurfEx also has a front mounted ZTR sprayer. Isn't there a problem walking or driving over fresh spray? Maybe worse if there is a marker dye in the spray? If it is possible, I'm thinking the FIMCO ATV Deluxe sprayer with 3.8gpm pump, 25 gallon tank, and 10' boom with 7 TeeJet nozzles, and a hand boom with 15' hose could be adapted to the front of walkbehind floating deck mower.