Must you Tank Combine Your Pesticides? The Solutions are “Combined”. – ONfloriculture

Will tank mixing pesticides provide you with higher efficacy? Prevent cash? Can tank mixing HURT your crop in any approach? How have you learnt if two merchandise are appropriate? And, how have you learnt in the event you’re legally ALLOWED to tank combine two merchandise?

This submit covers all these questions and extra, with some nice hyperlinks to different assets as well!

This text was written by Jason Deveau (OMAFRA Utility Expertise Specialist) and Mike Cowbrough (OMAFRA Weed Administration Specialist – Area Crops). The unique submit will be seen on the Sprayers 101 web site. New steering on Well being Canada’s federal tank mixing coverage will be discovered right here.

What’s Tank Mixing?

Tank mixing is the follow of mixing a number of registered agricultural merchandise within the sprayer tank for software in a single move.

The Professionals of Tank Mixing

  • Effectivity: If the timing is smart, a single move saves time and reduces trample/compaction. E.g. A “weed-and-feed” software of fertilizer and herbicide in corn.
  • Resistance administration: A number of modes of motion assist stop resistance improvement and fight present issues.
  • Improved efficiency: Labels could require adjuvants to situation service water or cut back drift (utility adjuvants) or to enhance the diploma of contact between droplets and the plant floor, or improve product uptake or rainfastness (activator adjuvants).
Prowl meets Roundup – A ravishing photograph by Peter Smith, College of Guelph

The Cons of Tank Mixing

Tank mixing requires warning and cautious investigation. Ought to tank combine companions show to be incompatible, the results will be refined or dramatic, however are at all times destructive. There are two sorts of incompatibility.


This type of incompatibility might not be instantly obvious following an software. Some degree of crop harm or impaired efficacy happens, which can impression yield or warrant an extra “clean-up” software. That is the results of product synergism or antagonism.

Synergism (Crop harm)

When merchandise synergize, the appliance turns into too potent. For instance, an adjuvant might have an effect on crop retention or uptake, exposing it to extra lively ingredient or overwhelming crop metabolism. The result’s harm to the crop we try to guard.

Antagonism (Decreased efficacy)

When merchandise antagonize, the appliance turns into much less potent. There are a number of examples:

  • pH adjusters in a single product could cut back the half-life of one other product (e.g. The fungicide Captan has a half-life of three hours at a pH of seven.1 and solely 10 minutes at a pH of 8.2.)
  • Lively substances could get tied-up on the clay-based adjuvants in different merchandise (e.g. glyphosate tied up by Metribuzin).
  • One product adjustments the uptake/retention of one other. For instance, a contact herbicide burns weed foliage past its capability to take up a deadly dose of systemic herbicide.


Bodily incompatibility impacts work price and efficacy. Merchandise type solids that intervene with, or halt, spraying. It could possibly additionally make sprayer clean-up tougher. For instance, weak-acid herbicides decrease the pH of the spray combine, decreasing the solubility of Group 2 herbicides (i.e. imidazolinones, sulfonylureas, sulfonanilides). The oily formulation then adheres to plastic and rubber surfaces in tanks, connectors and hoses.

There are numerous types of bodily incompatibility:

  • Liquids can curdle into pastes and gels that clog plumbing to such an extent that flushing can’t clear it and a handbook tear down is required.
Clogged screens
  • Dry formulations don’t hydrate or disperse, turning into sediment that clogs screens and nozzles. Even when they’re sufficiently small to spray, they cut back protection uniformity. For instance, a dry product added behind an oil will get coated, stopping it from hydrating.
  • Sure product mixtures could trigger settling, or one accomplice is extra susceptible to settling. If the sprayer sits with out agitation, settled merchandise could or could not resuspend. Even when they do resuspend within the tank, they might stay as sediment in traces.
Residue in hoses – Picture courtesy of Fred Whitford, Purdue College
Clay-based merchandise could or could not resuspend simply in a tank. Even then, they might not resuspend in plumbing traces.
  • Sure product mixtures could trigger foaming, or one accomplice could also be susceptible to foaming, inflicting overflows or breaking pump suction. When merchandise foam, dry merchandise added via the froth could swell, stopping hydration.
The Foamover Blues
  • Section separation happens when merchandise layer within the tank. Contemplate oil and water. Even with agitation, the lively substances might not be uniformly suspended within the tank and protection uniformity might be lowered throughout spraying.
Salad dressing left to relaxation is a superb instance of separation and stratification (left). Agitation helps emulsify it (proper)

Due Diligence – Stopping Tank Mixing Errors

Incompatibility is commonly a operate of the inert substances in pesticide formulations (e.g. thickeners, adjuvants, defoamers, stabilizers, solvents, and so forth.) and never the lively substances. The extra merchandise you add to the tank, the extra doubtless you’ll encounter a problem. It’s prudent to carry out a jar take a look at to substantiate bodily compatibility. Bear in mind, even when registered tank combine companions assist mixing, your tempo, mixing order, and water high quality/temperature might trigger points.

Don’t determine to attempt a new-to-you registered tank combine throughout loading. Even in the event you’ve used these merchandise efficiently prior to now, formulations change with out discover. Plan as a lot as doable off season when there may be time to do the next:


Pesticide labels are at all times the primary level of reference. They need to be obeyed even when they contradict standard practices. Booklet-style labels that include the merchandise are lengthy, troublesome to look and might not be up-to-date.

In Canada, it’s quicker and simpler to go to the PMRA Label Search web site and search labels in PDF format. In different international locations, seek the advice of the producer’s web site for label data. For every tank combine accomplice, use <CTRL>+F to search out the next key phrases:

  • Do Not Combine
  • Combine
  • Hours
  • Agitation
  • Fertilizers


You’re doubtless not the primary to think about a sure tank combine. Study from these which were there already:

  • Seek the advice of your chemical gross sales consultant. They know their merchandise greatest and wish to see you succeed. They might have perception that’s not discovered on the product label.
  • Seek the advice of native authorities or tutorial extension packages for an unbiased opinion.
  • Enlist the assistance of an expert crop advisor.

It’s a good follow to get tank combine suggestions in writing. If one thing ought to go incorrect, legal responsibility is a crucial concern.

For those who’ve made a multitude – The Reverse Jar Check

It occurs. We’ll use this real-world state of affairs for example:

“I blended up a batch of MCPA 500 A and Glyphosate at ¾ beneficial label price, however then acquired delayed on software with a caught drill. I got here again to the sprayer and located a nasty chemical precipitate – like waxy chunks. Agitation didn’t break them down. I dumped the tank out as I didn’t wish to pump it via the booms. How do I clear up the chunks within the system?”

We forwarded this query to ag chemists Dr. Eric Spandl (Land of Lakes) and Dr. Jim Reiss (Precision Laboratories) and developed this response:

“Carrying acceptable private protecting gear, bodily take away the “chunky” materials. A variety of time will be wasted (and rinsate water created) by experimenting with numerous concoctions, however in the event you do select to attempt a compatibility agent, first attempt it in a mason jar. If it really works to dissolve the fabric, it may be added to the tank with water and agitated. If not, you’re right down to handbook cleansing: scorching water underneath strain.”

We dubbed this course of “The Reverse Jar Check”. Don’t add scorching water, cleaners or compatibility brokers till the reverse jar take a look at confirms success. It’s possible you’ll create a bigger drawback. In fact, one of the best recommendation is to not put your self on this place to start with. As soon as once more, don’t make mixing selections on the inductor bowl – make them earlier than ordering product.

Tank mixing rules in Canada (Up to date December 2022)

The next legislative framework is restricted to Canada, so readers in different international locations ought to seek the advice of their very own regulatory authorities.

Paragraph 6(5)(b) of the Pest Management Merchandise Act (PCPA) states that no individual shall use a pest management product in a approach that’s inconsistent with the instructions on the label. In 2020, a public session was held to consolidate and make clear tank mixing necessities. This led to Regulatory Proposal PRO2020-01 (Streamlined Class B Submissions and Tank Combine Labelling – July 3, 2020). Primarily, it said that tank mixing can be allowed if there was textual content on the product label that particularly permitted it. This could possibly be a particular tank combine mixture, a normal assertion allowing mixing, or each.

A brand new normal label assertion that allows tank mixing was proposed to consolidate tank mixing data in a single place on the label and permit higher flexibility by way of tank mixing choices. The prohibition towards tank mixing merchandise with the identical mode of motion was eliminated, and the reference to tank mixing with a fertilizer is now an non-obligatory element of that assertion. The overall label assertion reads as follows:

“This product could also be tank blended with (a fertilizer, a complement, or with) registered pest management merchandise, whose labels additionally permit tank mixing, offered everything of each labels, together with Instructions For Use, Precautions, Restrictions, Environmental Precautions, and Spray Buffer Zones are adopted for every product. In circumstances the place these necessities differ between the tank combine accomplice labels, essentially the most restrictive label have to be adopted. Don’t tank combine merchandise containing the identical lively ingredient except particularly listed on this label.

In December of 2022, Well being Canada launched a steering doc describing the federal tank mixing coverage (discovered right here). This doc shouldn’t be a part of the PCPA, however is an administrative doc meant to facilitate compliance by all stakeholders. There’s a two-year transitional interval for registrants to replace labels and advertising to mirror this new streamlined method.

All stakeholders might be afforded the identical 2 12 months interval to transition to the brand new tank combine steering. Which means that growers will be capable of proceed with unlabelled tank combine practices in the course of the two 12 months interval (ending December 2024) that registrants might be updating the labels and supplies.

After this 2 12 months interval, applicators in Canada can solely apply tank mixes that seem particularly on a product label, or tank mixes of merchandise whose labels embody the brand new normal tank mixing assertion.


Tank mixing shouldn’t be permitted when a possible tank combine accomplice’s label has some exclusionary assertion, comparable to:

  • Forbidding mixing. E.g. “Don’t combine or apply this product with every other additive, pesticide or fertilizer besides as particularly beneficial on this label.”
  • Limiting tank mixes to solely these particularly listed on the product label.

Throughout the label transition, steering referring to tank mixing could also be discovered underneath a piece particular to tank mixing, and/or underneath different sections as within the following examples:

  • Instructions to be used: E.g. “When tank-mixes are permitted, learn and observe all label instructions, together with charges and restrictions for every product used within the tank-mix. Comply with the extra stringent label precautionary measures for mixing, loading and making use of said on each product labels.”
  • Buffer Zones: E.g. “When tank mixes are permitted, seek the advice of the labels of the tank-mix companions and observe the biggest (most restrictive) spray buffer zone of the merchandise concerned within the tank combination and apply utilizing the coarsest spray (ASABE) class indicated on the labels for these tank combine companions.”
  • Resistance Administration: E.g. “Use tank mixtures with [fungicide/bactericides/insecticides/acaricides] from a distinct group that’s efficient on the goal [pathogen/pest] when such use is permitted.”

If there aren’t any instructions on the labels, don’t tank combine them.

In case your state of affairs doesn’t match these examples, Appendix A (the desk on the backside of the Steering Doc), lists a number of different examples examples of various tank combine wording eventualities for registered pest management merchandise.


The label for at the very least one tank combine accomplice should specify using an adjuvant, and solely registered adjuvants labeled for the crop and for tank mixing are permitted. For instance, tank mixing the herbicide Reflex with a registered soybean oil adjuvant not labelled for the use, or with an unregistered meals grade adjuvant, wouldn’t be acceptable.

Whereas the PCPA doesn’t reference adjuvants particularly, they’re prescribed to be pest management merchandise within the rules (Pest Management Merchandise Laws s.2(b)). The overall reference within the PCPA that applies is s.6(5)(b).

And so, within the case of adjuvants, you have to observe the label.


For extra data, please contact Well being Canada’s Pest Administration Info Service.

Educational Sources

Even when merchandise are doubtlessly appropriate, points can come up from errors in mixing order, temposervice quantityservice high quality and agitation. These are mentioned in our article on sprayer loading and jar testing.

In 2018, Purdue College revealed “Keep away from Tank Mixing Errors”. It is a superb reference.

In late 2022, Australia’s GRDC launched a complete information on pesticide mixing and batching (throughout the context of the Australian agronomic setting, after all), which will be downloaded totally free, right here.

Lastly, you may watch a 2021 presentation on tank mixing (under). It was delivered to a grape rising viewers, however a lot of the content material applies throughout agriculture. There are a couple of “oops” moments the place I didn’t say fairly what I meant. I misinterpret the Sencor dissolution / filtration work. And, I actually didn’t reply the final query about mixing herbicides. The reply ought to have been to seek the advice of labels and native assets, comparable to OMAFRA’s Crop Safety Hub. Be aware that any dialogue of Canadian regulatory coverage could have modified in mild of the brand new 2022 Steering Doc.

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