Graph one depicts the possible distance a spray droplet particle can physically drift downwind. Common to all scenarios depicted are 40 percent relative humidity, 20 degrees Celsius and an operating pressure of forty pounds per square inch. In the first scenario, a two hundred micron diameter droplet released one half metre from the ground does not drift more than a quarter of a metre, even in fifteen kilometer an hour winds. In scenario two, the same droplet released one metre from the ground can move as far as three metres with a fifteen kilometre and hour wind. In scenario three, a one hundred micron diameter droplet released half a metre from the ground drifts considerably farther: almost six metres downwind in a fifteen kilometer and hour wind. In scenario four, that same droplet released one mtre from the ground can travel as far as sixteen metres in a fifteen kilometre an hour wind. In all cases, there is a linear relationship between distance drifted and apparent wind speed.



Return to Which factors reduce pesticide drift.