What is a substance used to dilute a pesticide concentrate called?

The term used for a substance that dilutes a pesticide concentrate is "diluent." A diluent is specifically designed to reduce the concentration of the active ingredient in a pesticide formulation, making it easier to apply or handle. This is crucial for achieving the desired effectiveness of the pesticide while ensuring safe handling and application.

In the context of pesticide use, the other terms may have different meanings or uses. For instance, "adjuvant" refers to a substance added to a pesticide formulation to enhance its effectiveness, such as improving adhesion or spreading properties but it does not serve the primary purpose of diluting the product. "Solvent" usually refers to a liquid that can dissolve a solute, but this term can imply various uses beyond dilution, such as being a part of a chemical formulation rather than strictly as a dilutive agent. "Carrier," while it can refer to a medium that transports the pesticide to the target site, does not specifically denote a substance intended for dilution, but rather for delivering the active ingredient.

Therefore, the correct identification of "diluent" as the substance used to dilute a pesticide concentrate reflects an accurate understanding of the terminology used in pesticide application.