conversion of a solid or liquid into a gas or vapor.
volatilization (Wikipedia)
Pesticide drift, also known as spray drift refers to the unintentional diffusion of pesticides toward nontarget species. It is one of the most negative effects of pesticide application. Drift can damage human health, environment, and crops. Together with runoff and leaching, drift is a mechanism for agricultural pollution. Some drift results from contamination of sprayer tanks.
Farmers struggle to minimize pesticide drift and remain productive. Research continues on developing pesticides that are more selective, but the current pesticides have been highly optimized.