What type of application targets only the lower part of brush or trees?

The correct application that targets only the lower part of brush or trees is the basal application. This method involves applying pesticide or herbicide to the lower portion of tree trunks or the stems of brush at the soil line. The basal application is specifically designed to control unwanted vegetation or pests by delivering the treatment directly where it is most effective without affecting the entire plant or surrounding area. This localized approach minimizes chemical exposure to other plants and organisms, making it a more environmentally responsible choice.

In contrast, other application methods serve different purposes. A band application typically involves treating a strip or band around the plant or area, which encompasses a broader section than just the base of the plant. A broadcast application refers to spreading chemicals broadly over a large area, affecting many plants or the entire environment, rather than a focused lower section. A crack and crevice application targets specific narrow spaces or gaps to manage pests hiding there, which is not relevant to areas like the lower parts of trees or brush. Thus, the basal application is clearly distinguished by its targeted approach.