What size of spray droplets poses the greatest drift hazard?

Droplets smaller than 150 microns are known to pose the greatest drift hazard due to their size and the way they behave in the atmosphere. These tiny droplets are more susceptible to being carried away by wind currents, making them more likely to drift off-target and potentially impact non-target areas, including homes, waterways, and other sensitive environments.

The aerodynamic characteristics of smaller droplets allow them to remain airborne longer than larger droplets, which tend to settle to the ground more quickly. This extended flight time increases the likelihood that they will be influenced by gusts of wind or other atmospheric conditions, further exacerbating the drift issue.

In contrast, droplets larger than 300 microns tend to fall more quickly due to gravity, thus reducing their potential for drift. Droplets in the range of 200-250 microns and exactly 150 microns also do not present as significant a risk as those smaller than 150 microns. Understanding these dynamics is crucial for applicators to minimize pesticide movement beyond the intended application area and to enhance environmental safety.