Herbicides that are applied and mixed into the soil before crop planting are called ______ herbicides.

• A. Preplant incorporated
• B. Preemergence
• C. Broadcast
• D. Postemergence

Answer: (A)

Herbicides that are applied and mixed into the soil before crop planting are known as preplant incorporated herbicides. This type of herbicide is designed to be worked into the soil to ensure that they can effectively control weeds before the crop emerges. Incorporating the herbicide into the soil allows for better distribution and makes it more effective at targeting weeds that may compete with the crop once it is planted.

This approach helps to minimize the herbicide's exposure to sunlight and reduces the risk of volatilization or degradation by microorganisms, which can happen with surface applications. Additionally, by applying these herbicides prior to planting, farmers can create a weed-free environment for the seedlings as they germinate and emerge.

Other options, such as preemergence herbicides, are applied after planting but before the crop emerges, while postemergence herbicides are used after the crop has already grown. Broadcast refers to the method of application, which relates to how herbicides are spread rather than the timing of their use in relation to planting. Thus, preplant incorporated herbicides serve a specific purpose in early weed management, making them an essential tool for effective crop production.