Which agent reduces drift in pesticide applications?

Thickening agents are substances added to pesticide formulations to increase the viscosity of the spray solution. This increased viscosity helps to reduce drift during application because thicker solutions are less likely to form fine droplets that can be carried away by the wind. By creating larger droplets, thickening agents help ensure that more of the pesticide reaches the target area rather than being dispersed in the air.

In contrast, surfactants are primarily used to improve the spreading and penetration of the pesticide on the target surface but do not inherently reduce drift. Compatibility agents assist in ensuring that different formulations mix well together, while pens are not related to pesticide applications. Each of these other choices serves a different purpose in pesticide formulation and application, thus not addressing the specific need for drift reduction as effectively as thickening agents do.