Which physical characteristics of a plant are best for herbicides to enter?

Herbicides are designed to penetrate the plant's protective barriers for effective uptake and action. A broadleaf plant with leaves growing parallel to the ground typically has a larger surface area and a softer cuticle in comparison to other plant types. This physical characteristic allows herbicides to be absorbed more readily through the leaves. The orientation of the leaves parallel to the ground can facilitate better coverage and contact with the herbicide, enhancing absorption.

In contrast, coniferous plants with needles generally have a much thicker and waxy cuticle. This can make uptake more difficult for some herbicides since the herbicides would have to penetrate this protective layer, which may inhibit their effectiveness. Similarly, plants with thick, waxy leaves are also designed to minimize water loss and resist penetration, making them less suitable for herbicide absorption. Flowering plants with clustered blooms might present varying leaf structures that may not be as conducive to herbicide entry as broadleaf plants. Therefore, the broader leaves and their positioning in broadleaf plants make them more favorable for herbicide absorption.