Which treatment should be applied to actively growing plants?

The most suitable treatment for actively growing plants is a postemergence application. This type of application is specifically designed to target weeds or pests that have already emerged and are currently visible and growing. Postemergence treatments can effectively manage these plants when they are in their growth phase, ensuring that the herbicides or pesticides are absorbed or taken up effectively, leading to optimal control.

Preemergence applications, on the other hand, are intended to be applied before the target plants germinate or emerge, making them unsuitable for actively growing plants. Frill and stump treatments are methods typically used for controlling woody plants and are not designed for actively growing herbaceous plants. Hence, postemergence application is the correct choice for managing actively growing foliage.