What term describes the liquid material that a pesticide is added to for application?

The term that describes the liquid material that a pesticide is added to for application is "carrier." In pesticide application, the carrier serves as a medium that facilitates the dispersal and distribution of the pesticide. It can be water, oil, or another liquid substance, depending on the formulation of the pesticide and the intended method of application. The carrier not only helps to dissolve or suspend the active ingredients of the pesticide but also assists in delivering the pesticide effectively to the target area, ensuring better efficacy in pest control.

In contrast, a solvent typically refers to a substance that dissolves a solute to form a solution, which can be used in certain formulations but is more specific than a general carrier. A diluent refers to a substance that reduces the concentration of a pesticide, often used in the preparation of the final application mix but doesn't serve the broader role of a carrier. A binder generally refers to a substance that helps in adhering the pesticide to surfaces but is not specifically related to the liquid material used for application. Therefore, the most appropriate term for the context of pesticide application is indeed "carrier."