Small drops take time to hit target.
A tiny droplet 100 microns in diameter (about the diameter of a human hair) takes 11 seconds to fall 10 feet. At 50 microns, it takes 40 seconds to fall that far, because of the drag that air friction puts on them. That’s a long time for a wind current to move that droplet to an unintended target.
“Those tiny droplets really slow down when they leave the nozzle,” says Hanna. “The other important part of that is that you may think you can crank up the pressure and drive those small droplets down into the crop canopy. It doesn’t work because they slow down so fast.”
[ Idea Link: http://goo.gl/hxjoLG ]