Multi-Component Adjuvants

By Brian de Villiers

June 2024

There are six major groups of adjuvants, namely salt adjuvants, buffers, surfactants, oils, stickers, and deposition agents. However, there are also many other types of adjuvants such as humectants, compatibility agents, anti-foamers etc. Many of these products are
available unmixed but they can also be purchased as multi-component products. There are many versions of pre-mixed products like ammonium sulphate or buffers that also contain surfactants, humectants, or antifoaming agents in the same formulations. Multicomponent adjuvants are convenient because they reduce the need to use multiple adjuvants in a single tank mixture, but they also may have some limitations if not used correctly. Therefore, it is necessary to address two important questions.

Are all the Ingredients necessary?

Crop protection products (CPPs) that require adjuvants have limitations that must be addressed, such as inadequate retention or spreading, poor absorption, alkaline hydrolysis or salt antagonism. For instance, if a herbicide is antagonized by cations in spray water, an ammonium sulphate adjuvant is required. This can be addressed by a single-component spray-grade ammonium sulphate adjuvant or by a multi-component product that contains ammonium sulphate. Multicomponent ammonium sulphate adjuvants may also contain other ingredients such as acids, surfactants, humectants, and compatibility agents. It is important to determine if all these additional ingredients are necessary and if some of the components are antagonistic to the tank mixture. If all the ingredients are beneficial, the multi-component product will be the best option. However, if it contains unnecessary or antagonistic components, it may be more effective to use single-component adjuvants

Is there enough of each Ingredient?

Multi-component adjuvants normally contain one or two core components such as salt adjuvants, buffers, or any of the main adjuvant groups. The aim of the other ingredients is to further enhance the CPP or to modify the spray mixture. Adjuvant formulations have limited space available for all these active ingredients. Therefore, it is important to ensure that the product contains enough of each active ingredient for the CPP in the specific water quality or crop situation. For instance, buffers that contain a surfactant in the formulation may have enough spreading ability for use on certain fruit crops, but not nearly enough for weed control in row crops!

Villa’s stance

Multi-component adjuvants are useful products to use with certain CPPs. They provide multiple adjuvants in one product and are convenient and cost effective. However, these adjuvants also have limitations and should be used wisely. They may contain unnecessary or antagonistic ingredients that limit their use with certain spray mixtures. They may also not contain enough of one or more active ingredients to be effective in certain situations. Only use registered multi-component adjuvants that are backed up by solid research. Contact your Villa agronomist for more information about adjuvants and water quality.