Turfgrass Pest Management Category 3A Practice Test

Rainfall can increase herbicide action by which mechanism?

May help to move a pre-emergent herbicide to the roots of germinating seeds It reduces germination It deactivates the herbicide It washes away nutrients

Correct Answer:

May help to move a pre-emergent herbicide to the roots of germinating seeds

Explanation:

Rainfall provides the moisture needed to activate and move a pre-emergent herbicide into the soil zone where weed seeds germinate. A pre-emergent forms a chemical barrier in the topsoil, and water dissolves and transports the active ingredient to the root zone so the young roots or shoots encounter it as they emerge. This delivery increases the likelihood the weed will take up the herbicide right as it is trying to establish, improving control. Other ideas don’t fit this mechanism. Rainfall doesn’t inherently reduce germination in this context, it doesn’t deactivate the herbicide, and washing away nutrients isn’t the primary way rainfall affects herbicide action.

Access more questions from this quiz

Continue to Turfgrass Pest Management Category 3A Practice Test for more practice questions and the full quiz experience.

Access More Questions