Minnesota Pesticide Applicator Practice Test

Which property of a pesticide increases its likelihood to move with water in surface runoff?

1. High volatility

2. High absorption

3. High surface tension

4. High solubility

The correct answer is: High solubility

The property that increases a pesticide's likelihood to move with water in surface runoff is high solubility. When a pesticide is highly soluble, it can dissolve easily in water and therefore be transported along with water during events like rainfall or irrigation. This means that as water moves across surfaces, it can pick up and carry dissolved pesticides, leading to potential runoff into nearby water bodies. In contrast, a pesticide that has low solubility tends to remain in the soil or on the surface rather than mixing with water, which minimizes its movement in runoff. High volatility, while it refers to the ability of a substance to evaporate, does not directly relate to movement with water in runoff. High absorption describes how well a pesticide is taken up by soil particles or plants, which also tends to reduce its movement with water. High surface tension, which affects how water interacts with surfaces, is not a factor in increasing the solubility of a pesticide in water. Therefore, high solubility is the key property that directly influences a pesticide's movement with water in surface runoff.