What characteristic of water can inactivate pesticides?

The characteristic of water that can inactivate pesticides is its hardness. Water hardness refers to the concentration of calcium and magnesium ions present in the water. These minerals can interact with certain pesticide formulations, particularly those containing active ingredients that may bind with the ions, leading to a decrease in the effectiveness of the pesticide. This interaction can render the pesticide less available for action against pests, as it may become physically or chemically bound in a way that prevents it from performing its intended function.

This is especially crucial when mixing pesticides with water for application, as using hard water may significantly affect the pesticide's efficacy. In contrast, the other characteristics such as water temperature, clarity, and color do not typically result in the inactivation of pesticides in the same direct manner. While extreme temperatures might impact the stability of some formulations and clarity might influence application efficacy, hardness specifically and reliably affects the chemical behavior of pesticides in water.