For most broadcast applications, 20-inch spacing is preferred. If these are not given on the pesticide label, follow Kentucky Cooperative Extension Service and chemical company recommendations. Correct selection of spray volume is important. It will influence several spray characteristics such as drift potential, the spray coverage, droplet size, acres per tank, and pesticide effectiveness. As a rule of thumb, the greater the operating pressure or the greater the spray angle, the smaller the droplets become.
Smaller droplets increase the drift potential.
As the nozzle orifice becomes larger, the droplets increase in size. Nozzle performance tables in manufacturers' catalogs will show the discharge rates at various pressures for several nozzle sizes. Several consecutive nozzles may meet your need, but select a nozzle that operates at a low pressure and still gives a range for fine-tuning. Remember, most nozzles perform only over a limited pressure range. A change in pressure does not cause an equal change in flow discharge.