Mark Glady, an agronomist with WinField United, highlights how crop inputs encounter numerous hurdles on their journey from tank to leaf.
“High-quality adjuvants act as crucial facilitators, ensuring inputs reach their intended target and maximize activity, ultimately boosting ROI potential,” Glady says. “The active ingredient is what kills the weed, but if it can’t get to the site of action, it can’t do it’s job.”
From his territory across southwest Minnesota, Glady reports there are four key reasons to put an adjuvant in the spray tank:
- Enhance Efficacy
- Preserve Potency
- Target Precision
- Optimize Uptake
“Just putting on more of the herbicide isn’t the answer,” Glady says. “Full rates need to be used with the appropriate adjuvants to ensure the herbicide is delivered to the plant.”
Glady highlights the role of drift deposition agents.
“With a flat fan nozzle at 40 PSI, roughly 25% of the spray volume can be a driftable fine. I’ve seen years when up to 1/3 of the acres didn’t have waterhemp killed after the herbicide pass. That was an opportunity to use drift deposition aids to help.”
Drift deposition aids aren’t just tools on windy days.
“When droplets are small and light, they don’t have the velocity to reach the target,” he says. “Small driftable fines, even without wind, they won’t go more than 10 inches from the nozzle, and you can minimize the small droplets and make them heavier to have more velocity to reach the target.”
He also shares how WinField’s InterLock can reduce off target movement from 25% to 8%.
Another priority is maintaining the water quality in the tank to keep active ingredients stable.
“Water conditioners are essential in preventing herbicide tie-up in the tank, preserving the potency throughout the application,” he says.
As an example, Gladys explains how AMS based water conditioners provide the necessary sulfate for glufosinate and glyphosate applications.
“Glufosinate and glyphosate have weak negative charges, which can be tied up in hard water, which has a positive charge. You need sulfate, which is also negatively charged to keep from deactivating 10% to 20% of the herbicide,” he says.
Takeaways From Last Year
Specific lessons from the 2024 spray season are to ensure the product can cut through the plant’s waxy outer cuticle, which was thicker last year and in any year with drought stress.
“Here’s where surfactants and humectants are key,” Glady says.
Surfactants help spread out on the droplet on the leaf to cover more surface area. Humectants provide a slower dry out time for the droplets, giving it more of a chance to soak into the plant.
“You have to keep the product liquid to get into the plant,” he says. “Surfactants and humectants are key players in breaking through natural leaf barriers, facilitating improved plant uptake, and ensuring that every applied nutrient or protective agent counts.”
Another tool is to use an methylated seed oil (MSO).
“This is what melts the waxy cuticle and helps get more product in the plant,” he says. “The plant’s defensive mechanism is to put a waxy layer. And we need an MSO to break through that waxy layer.”
More Recommendations
“In my territory, I estimate 80% of soybeans are Enlist tolerant. The best recommendation for a 2,4D choline mix is that it responds to an AMS water conditioner and add an MSO product to melt the waxy cuticle. That combination helps get more in the plant,” he says.
He emphasizes that spraying Enlist with an MSO will not burn soybeans as may have been seen when paired with other chemistries such as those in Cobra, Blazer and others.
