Preemergence herbicides generally require rainfall within a week of application to incorporate the herbicide into the soil.

• A. True
• B. False

Answer: (A)

Preemergence herbicides are designed to be effective before the target weed seeds germinate. For these herbicides to work properly, they need to be incorporated into the soil where they can interact with the weed seeds and effectively inhibit their germination. Rainfall plays a crucial role in this process.

When preemergence herbicides are applied, they typically need to be activated by moisture to properly bind to the soil particles. Rainfall within a week of application helps water the herbicide into the top layer of the soil, allowing it to form a barrier that prevents weed seeds from sprouting. Without this moisture, the herbicide may remain on the surface and become less effective, leading to poor weed control.

Therefore, the statement that preemergence herbicides generally require rainfall within a week of application to incorporate into the soil is accurate. It emphasizes the importance of timely moisture after application for optimal herbicide efficacy.