Which of the following is a method of pesticide movement in water?

Runoff is a critical method of pesticide movement in water, especially in agricultural contexts. When it rains or when there is irrigation, water can carry pesticides that have been applied to soil or plants away from the treatment area. This occurs as water erodes the surface layer of soil and transports dissolved or suspended pesticide particles along with it into nearby streams, rivers, and lakes.

Understanding runoff is important for pest control applicators as it relates to environmental safety and compliance with regulations intended to prevent pesticide contamination of water bodies. It emphasizes the necessity for applicators to consider weather conditions, terrain, and the timing of pesticide applications to minimize runoff and protect water resources.

In contrast, while diffusion pertains to the movement of substances from areas of higher concentration to lower concentration, and drift refers to the airborne movement of pesticides during application, these are not primary means of pesticide movement through water specifically. Translocation refers to the internal movement of pesticides within a plant, which does not relate to movement in water at all.