When adding surfactants, what is the expected effect on the spreading of pesticide droplets?

Adding surfactants to a pesticide formulation has a significant impact on the spreading of droplets on target surfaces. Surfactants serve as surface-active agents that modify the surface tension of the liquid. When surfactants are included, they reduce the surface tension of the pesticide solution, allowing the droplets to spread out more effectively when they come into contact with surfaces such as leaves, soil, or other target areas.

This improved spreading results in a larger contact area for the pesticide, which can enhance the efficacy of the application by increasing the likelihood of the active ingredient being absorbed by the target organism or surface. Enhanced spreading can also lead to better coverage, reducing the risk of pesticide runoff.

In contrast, without surfactants, droplets may remain more spherical due to higher surface tension, leading to less effective coverage. This is particularly important in aerial applications where achieving uniform coverage can be challenging. Thus, the inclusion of surfactants is beneficial for achieving more effective pesticide applications through improved droplet spreading.