And real farmers have bad days and have difficulty maintaining the prescribed application conditions.
For one, you can't control what the weather does in the afternoon after you've applied it in the morning (and it might take all morning because farms are huge and you have to tank up again)
Real farmers, all 3,500 of them in local coop, take careful measures to control everything on large farms- spraying is generaly done at night for the cooler temps, rates are watched as over spray costs $$'s etc. Seed volumes are manually run through air seeder calibrate seed weight per acre, etc.
The trend today is toward AgBot / SwarmBot type boom sprayers with onboard weather stations for wind speed and air temp, coupled with computer vision to limit spray to actual weeds rather than broad area even spray for weed / non weed alike.
Again, driven by $$ watching, etc.