I was thinking of the early years when some inexperienced, but well meaning, applicators sprayed some crabgrass escape plants with MSMA by aiming the nozzle at the center of the plant while holding the nozzle about 4 inches high. They probably shouted, "Take that!" before releasing the trigger. 48 hours later we had calls about some kind of disease spot. Easy to diagnose--there was a dead crabgrass plant in the center of each spot. I am not saying it never happened to me--I've done it. What I mean is move the nozzle across the weedy spot--in a manner similar to the motion when you calibrated your hand sprayer. Do not sweep the nozzle back and forth. Not accurate--its approximate. Since my test used trigger sprayers. I used one squirt and tried to cover a half sqft. (9.6" diameter circle). (Then three times; then five times over)--(only for purposes of the phytotoxicity test). I am not worried about dandelions. I never liked to be called back for resprays on oxalis, veronica, ground ivy, spurge and wild violets. I found these weeds tough to kill, particularly when in the tough mature growth stage.