By definition a spray additive or adjuvant is a material added to the spray mixture to aid or enhance the functionality of the pesticide. Spray additives or adjuvants function in a few different ways when added to pesticides and herbicides. They help by wetting the foliage and/or pest, improve the uniformity of the spray deposited and enhance the penetration and movement of the herbicide or insecticide.
There are a several different classes of spray additives that are used to improve the function of pesticides. Surfactants, emulsified oils, ammoniated salts, acidifier and buffers, drift and foam retardants. Nonionic Surfactant acts to break down the waxy cuticle layer and to allow the herbicide or insecticide to be more easily absorbed. Spray pattern indicators are also listed in spray additives, the colorants added to pesticide application will allow you to mark the areas that have been treated. Spray pattern indicators are designed for use with pesticides, fertilizers, and many other liquid chemical applications. Spray dyes helps indicate position and coverage. Know where you have been and where you are going with a good spray pattern indicator.