Increasing sprayer travel speed causes the controller to increase boom pressure (and decrease droplet size). If field conditions have you running behind and your sprayer travel speed has increased 20–25%, consider using one size larger nozzle tip to minimize drift potential. For example, if self-propelled sprayer speed increases from 12 to 15 
mi/hr and #4 tips are used at 12 mi/hr, substituting #5 tips at 15 mi/hr allows similar boom pressure to what was used with #4 tips at 12 mi/hr.
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Sprayer Speed Affects Drift Potential
Spray Drift Potential Increases During Warm Weather Applications
Spray Volume is Critical for Postemergence Herbicides
Selecting Nozzles for Postemergence Herbicides
Photo by Daren Mueller