Which describes a residual herbicide?

Study for the Ontario Pesticide Training and Certification CORE Test. Prepare with multiple-choice questions, get hints and explanations. Ensure readiness for your certification!

Residual herbicides are designed to stay active in the soil after application, providing weed control for an extended period as seeds germinate or young weeds emerge. Their lingering presence means you get ongoing suppression, not just a one-time kill. If a product breaks down quickly, it won’t offer long-term control, which is the opposite of what residuals do. If a product only kills weeds on contact or only affects surface foliage, it won’t persist in the soil to prevent future weeds, so it isn’t describing a residual herbicide. In short, the defining idea is persistence in the soil that yields lasting weed control.