Nail Adjuvant Selection for Greater Pesticide Success

Spraying ( Darrell Smith )

While herbicide, insecticide and fungicide active ingredients make headlines, silent in the background are adjuvants—but they play a big role in pesticide value. Get to know these tank mix partners better so your 2020 spray season is more successful.

“When a farmer buys a tractor they know they have to put fuel and oil in it to make it go. It’s the same with pesticides—you have to put adjuvants in the tank to make it ‘go,’” says Ryan Wolf, agronomy service manager at WinField United. “Adjuvants make whatever you put in the tank—herbicides, insecticides or fungicides—do whatever it’s supposed to do better.”

Adjuvants might be an afterthought on some farm operations, but the reality is the right—or wrong—adjuvant choice could have immense impact on pesticide success. Ask the right questions, have application plans in-hand when talking to retailers and understand your water’s impact on pesticides before buying adjuvants.

Know types of adjuvants

There are four general categories of adjuvants, according to Paul Gerdes, CHS Agronomy proprietary products director:

  1. Drift and deposition—keeps the application in the field and helps penetrate through crop canopy.
  2. Plant absorption—typically an oil that penetrates the waxy cuticle and allows the application to get into the plant better.
  3. Spreader, sticker—a surfactant of some sort that helps so the application doesn’t shear off the leaf and instead sticks to the plant.
  4. Multi-functional—does any of the above and can be combinations of the above.

“What are you trying to accomplish?” Gerdes says. Know your goals and what the properties of the pesticide you’re pairing with an adjuvant are before you decide what to include in the tank.

Consider hard water implications

Most farmer applicators will mix pesticides with some kind of hard water. Without the right adjuvant or water additive, the minerals in water can tie up part of the active ingredient in the pesticide, rendering it less effective.

“Calcium, magnesium and iron can tie up pesticides so they can’t be absorbed by the plant,” says Katie Miesse, Helena adjuvant brand manager. “Test your water, find out what you need to put in it to increase the efficacy of your spray program.”

Based on the results of your water testing, locate an additive that will make sure the active ingredient keeps its potency. If you know what those are, talk to an agronomist or other advisor to ensure you’re maximizing your pesticides’ efficacy.

“A lot of chemicals react in the tank, like glyphosate and glufosinate,” Wolf says. “You could tie up 20% to 30% of your chemical in the tank before it gets out of the sprayer—that’s an extreme, but it can happen, depending on how hard the water is.”

Bust adjuvant myths

You’ve likely heard rumors of adjuvant ‘snake oil’ or other not-so-savory comments on adjuvants. What can you actually believe? Here are a few common myths you can consider busted.

“Not all adjuvants are created equal. There are over 4,000 adjuvants on the market,” says Bill Smith, Helena strategic marketing manager. “Understanding where products come from and how they’re developed is important—there aren’t a lot of regulations for adjuvants. We take pride in what we develop.”

Asking for proof will help you weed out any snake oil type of product. Ask for field trial data and other efficacy studies to see if the salesperson can prove the product actually does what it’s labeled to do.

“2,4-D and dicamba are very different,” Gerdes says. “This includes what adjuvants you can use with them. I think most retailers realize that, but downstream that can be a misconception.”

When it comes to new 2,4-D and dicamba herbicides don’t assume what works for one will work for the other. Look at their websites for up-to-date tank mix partners and talk to your herbicide representative if you have any questions.

“Be cautious about all-in-one adjuvants,” Wolf says. “Yes, they can do a lot, but they can’t always do it well. You might carry a multi-tool on your belt, but you’re not going to use that to overhaul an engine. You want the right tools. It’s the same with adjuvants.”

This boils down to making sure the adjuvant, or adjuvant mix, you choose is fit to your situation. Weather, pesticide partners and your application methods all play a part in which adjuvant is the best fit. Make sure you take those all into consideration before picking the mix.

Talk with your agronomist about your goals and application plans to pair the best tank mix partners in 2020. Don’t forget water’s role in spray applications and ask lots of questions. Every dollar counts—make sure your sprayer applications are maximizing every dollar.

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