What is the purpose of a foliar application in herbicide application?

The purpose of a foliar application in herbicide application is to treat foliage when trees and brush are in full leaf. This method is effective because it allows the herbicide to be absorbed through the leaves, where it can then be translocated throughout the plant's system. When the plants are fully leafed out, they are actively photosynthesizing, and the uptake of the herbicide can be maximized, ensuring that the chemical reaches its intended targets in a timely manner. This approach is particularly useful for controlling established vegetation that may be resistant to other application methods, as the leaves serve as an efficient entry point for the herbicide to circulate within the entire plant.

Other methods, like targeting freshly cut tree stumps or applying herbicide to specific parts of a tree, serve different purposes, such as preventing regrowth or addressing specific growth patterns, but they do not capitalize on the advantages present in full foliage conditions.