Which type of herbicide application typically involves contact or translocated substances?

The choice related to wiper treatment is accurate because this method specifically involves the use of contact or translocated herbicides applied to the foliage of plants. A wiper treatment applies herbicides using a absorbent material, like a sponge or cloth, that comes into contact with the target vegetation, allowing the herbicide to be directly absorbed by the leaves. As a contact herbicide, it acts upon the plant it touches, while translocated substances can move within the plant to disrupt growth processes more comprehensively.

In contrast, preplant treatments generally involve applications made before planting and are usually incorporated into the soil, targeting weeds before crops emerge, which may not always involve direct contact with plant foliage. Directed sprays are often used to apply herbicides precisely to plant foliage while minimizing drift to non-target areas, but typically do not use the contact methodology that characterizes wiper treatments. Soil-incorporated applications specifically focus on distributing herbicides within the soil to affect germinating weeds and roots, again differing from the contact emphasis of wiper treatments.