What is a common application of stickers in pesticides?

Stickers are commonly used in pesticides to improve adhesion to plant surfaces. This is essential because many pesticides need to remain on the foliage or plant surfaces long enough to be effective against pests or diseases. When a sticker is added, it enhances the ability of the pesticide to stick to the leaves, stems, or fruits, which helps ensure consistent coverage and prolongs the effectiveness of the application by reducing wash-off from rain or irrigation.

The other options highlight different functions that are not characteristic of stickers. For example, dispersing active ingredients evenly often involves the use of surfactants or adjuvants designed specifically for that purpose rather than stickers. Increasing penetration into the soil typically relies on soil amendments or specific formulations that allow for such activity. Diluting toxic substances is not a function of stickers; rather, dilution is an important consideration in pesticide mixing to ensure safety and effectiveness, but it does not relate to the function of improving adhesion.