Abstract: An agricultural spray system may have several nozzles oriented in an airstream. A controller may sense the presence or absence of foliage over many points, then determine which nozzle to activate and for how long. Each nozzle may spray in a fixed direction, and therefore may be assigned a zone for application. A real time calculation may be made to apply product through the nozzle based on the amount of foliage in a nozzle's zone at that instant. In some cases, the amount of material demanded for a nozzle may be higher than that nozzle can deliver, leading to a situation where the demanded duty cycle may be higher than 100% for that nozzle at that time. After passing through a particular field, the duty cycle of the nozzles over the field may be analyzed, and from that analysis, recommended changes to the nozzle sizes, traverse speed, or other factors may be made to increase the coverage and spray efficiency of the spray system.