Illinois Pesticide Operator General Standards Practice Test

Before spraying, focus on conditions that directly affect where the spray goes and how well it stays where you intend. The most important factors are wind, temperature, and droplet size. Wind speed and direction determine drift risk—strong or gusty winds can carry droplets off-target into unwanted areas. Temperature and air stability influence how the spray behaves in the air and how droplets may evaporate or volatilize, which changes deposition. Droplet size controls how far droplets travel—finer droplets drift farther, while coarser droplets tend to deposit more on the target. Time of day, soil texture, and crop type matter for other reasons, but they don’t regulate drift and deposition as directly as wind, temperature, and droplet size.