How long after diquat application do treated plants die?

• A. Within a day
• B. Die within a week
• C. Within a month
• D. Within several months

Answer: (B)

Diquat is a fast-acting, contact aquatic herbicide, so it damages the tissues it touches and causes rapid desiccation of the plant. Because it works on contact rather than needing to be absorbed through the roots, the treated plants commonly die within about a week. The exact timing can vary with plant size and growing conditions—smaller, actively growing plants often die sooner, while larger or tougher growth may take a bit longer—but death within seven days is the typical outcome. Death within a day is unlikely for most plants, and waiting months would imply a persistence or systemic action that diquat does not provide.