Adjuvants 101 for Fruit Growers – What You Need To Know

We can all use a helping hand every now and then. The same holds true for your crop protection tank mix. And that is why growers, pest control advisors (PCAs), and certified crop advisors (CCAs) regularly include adjuvants in spray applications. Adjuvants help herbicides, fungicides, and insecticides work better by modifying the spray pattern, droplet, deposition properties, or movement rate of the spray applications into the plant. Using the right adjuvant results in more consistent performance, whereas skipping them may lead to reduced efficacy and the need for reapplication. Check product labels for adjuvant recommendations or requirements.

Adjuvants fall into two primary categories:

• Activator adjuvants are designed to improve the activity of the pesticide and include surfactants, oils, and nitrogen-based fertilizers.
• Special-purpose adjuvants, also called utility adjuvants or spray modifiers, fix specific conditions that can negatively affect the spray solution or application. These include compatibility agents, drift control agents, deposition agents, defoaming agents, and buffering and conditional agents.

The adjuvant you choose depends on what you are trying to accomplish.

For example, water conditioners and pH adjusters help with poor spray water quality. Deposition agents help depending on the temperature and how long you need an application to be on the leaf surface. Drift control products minimize fine droplets that can be carried by the wind, helping to create uniform droplets that are large enough to stay on target but not so large that they reduce coverage. This ensures more active ingredients reach the intended spray area while limiting drift to neighboring fields.

Given current market conditions for most crops, you want to be sure each product delivers the maximum benefit. Adjuvants can help boost your return on investment for these tools and are not an area on which to skimp.

REGULATORY COMPLIANCE IMPLICATIONS

Adjuvants may have an even bigger role when it comes to regulatory compliance.

The application of the Endangered Species Act (ESA) to herbicide, fungicide, and insecticide treatments has significant implications for every farm and orchard in every county, state, and crop.

The ESA rule for herbicides was announced in August 2024. But it is still unknown how it will impact farmers and retailers, how it will be monitored, and what the true long-term impact will be.

However, one requirement for growers is to incorporate a buffer zone for crop-protection-applied acreage. The good news is that drift reduction adjuvants (DRA), specifically oil emulsions, will reduce the size of necessary buffer zones.

Eventually, other drift-reducing agent (DRA) formulations will likely be added as options.

The Council of Producers and Distributors of Agrotechnology (CPDA) and other organizations have been championing this effort, working with the EPA and providing data to show that adjuvants, specifically DRAs, can help growers and retailers navigate these changes.

The ESA rules are expected to be applied to fungicides and insecticides, and the use of DRAs is also expected to positively impact these tools.

ALL ADJUVANTS NOT CREATED EQUAL

Before including any adjuvant in your tank mix, check the label of the crop protection products you are using. Some labels include directions for adjuvant use, and many have specific instructions on what type of adjuvant to use and how to use and mix it with the product. For sensitive crops, choose an adjuvant with a proven use of low phytotoxicity.

Be sure to use only high-quality adjuvants. Look for products with proven results and purchase from a reputable manufacturer. The CPDA website is a great resource for high-quality adjuvants; it lists many adjuvants that have been CPDA-certified. When users purchase these products, they know that the product meets the functionality claims indicated on the label according to a specified set of standards and that the ingredients used in the product meet EPA regulations for approved ingredients for use in pesticide tank mixes.

Also, test water sources several times a year as pH levels and other water hardness parameters may fluctuate. For this reason, keeping a pH meter handy is a good idea.

However, adjuvants are not designed to fix everything. And they cannot fix human error. If you are going to make an application that you have never made before and do not know how those chemistries, water, and anything else added to the tank are going to mix, consider a jar test before applying. It is much easier to solve an issue in a pint-sized container versus a spray tank.