It’s odd to begin an article by suggesting the reader consult another, but Dr. Tom Wolf wrote a great summary about adjuvants for SaskPulse in 2023 and you can and should download it here. While I’m at it, also grab this article by Rich Zollinger, Emeritus Extension Weed Scientist, North Dakota State University.
OK, back to the article at hand. An adjuvant is “any substance in a formulation or added to the spray tank to modify the biological activity or application characteristics”. This means they have an array of functions, such as masking pesticide odor, conditioning carrier water, improving mixing and reducing drift (Utility modifier adjuvants). They can also improve the degree of contact between droplets and the plant surface, or enhance product uptake or rainfastness (Activator adjuvants which include a subset of products referred to as Surfactants [SURFace ACTive agENTS]).
For example, this short video was filmed in 2015 to demonstrate how a sticker surfactant reduces runoff and how a penetrant surfactant can help a product pass through a waxy plant surface. This video was filmed and edited by former OMAFA summer student, Victoria Radauskas.
Generally, pesticides already come preformulated with the requisite inerts, which include the utility modifier and activator adjuvants that ensure ease of use and optimal product performance. But sometimes the pesticide label requires the operator to add a particular name brand or category of adjuvant. In this case, the pesticide does not include the adjuvant because it might negatively impact product stability, increase bulk and/or increase expense.
Canada is seeing an increase in the number of adjuvants for purchase (particularly utility modifiers). Claims of improved performance make it tempting to reflexively and proactively throw them in the mix. The grower is free to use any adjuvant provided it is registered for use on the crop and in combination with the pesticide being applied. You can learn more about the regulatory realities in our tank mix article.
We suggest that adding any adjuvant is an optional last step in optimizing a sprayer’s performance. Dialing in all other aspects tend to reap the greatest rewards. Here are a few general guidelines when using surfactants in horticultural crops:
Do not use penetrant surfactants (including oils) with copper, sulphur or captan fungicides.
Do not use penetrant surfactants with contact or surface pesticides.
Stickers may impede the movement of systemic products.
Stickers may prevent redistribution to newly emerging leaves early in the growing season (but they may be desirable during wet springs).
Deposition utility modifiers may negatively affect canopy penetration when employing multi row or alternate row traffic patterns.
Spreaders are more likely to incur runoff so adjust volumes accordingly.
Additional Resources
The following video presentation was recorded for a 2021 adjuvant conference in Argentina. It’s a primer to introduce what adjuvants are and why we might consider using them. You’ll note that I speak slowly during the presentation – that’s because it was being translated and I wanted to make that process as easy as possible. Also, I think I mistakenly said captan was an insecticide – in fact it’s a fungicide. Oops.
And here’s a 2022 interview from Real Agriculture’s “The Agronomists” featuring Tom Wolf of Agrimetrix, and Greg Dahl of Winfield United. For the adjuvant-related part of the conversation, you can pan ahead to the six-minute mark.
And here’s a 2025 interview from Real Agriculture’s “The Agronomists” featuring Jason Deveau and and Austin Anderson of Helena.
The decision on which application method is best for herbicides boils down to two main factors: (a) target type and (b) mode of action. In general, it’s easier for sprays to stick to broadleaf plants on account of their comparatively larger leaf size and better wettability compared to grassy plants. There are exceptions, of course – at the cotyledon stage, broadleaf plants can be very small and a finer spray with tighter droplet spacing may be needed. Water sensitive paper is a very useful tool to make that assessment. Imagine if a tiny cotyledon could fit between deposits – that could be a miss!
Some weeds are also more difficult to wet, and those may also need a finer spray or a better surfactant for proper leaf contact. An easy test is to apply plain water to the leaf with a spray bottle. If the water beads off or the droplets remain perched on top in discrete spheres, the surface is considered hard to wet. Most grassy weeds are hard to wet, while most broadleaf weeds are easy to wet.
Grassy weeds are an especially difficult target because they have smaller, more vertically oriented leaves, and almost without exception are more difficult to wet than broadleaf species. All these factors call for finer sprays for effective targeting and spray retention.
Broadleaf weeds usually have more horizontally oriented leaves which also happen to be larger. As a result, they can intercept larger droplets quite efficiently.
There are about thirty mode of action (MOA) groups among the herbicides with about ten accounting for the majority in Canadian prairie agriculture. It’s probably an over-simplification to categorize them into just two groups – systemic and contact. But that grouping goes a long way to making an application decision.
Contact products (MOA Group 5, 6, 10, 14, 22, 27) must form a deposit that provides good coverage. Good coverage is an ambiguous term that basically means that droplets need to be closely spaced and cover a significant proportion of the surface area because their physiological effects occur under the droplet, and don’t spread far from there. One way to generate more droplets is to reduce droplet diameter, another is to add more water. A reasonable combination of both is ideal because simply making droplets smaller creates issues with evaporation and drift.
Systemic products (MOA Group 1, 2, 4, 9) will translocate within the plant to their site of action after uptake. As a result, coverage is less important as long as sufficient dose is presented to the plant. In practice, this means coarser sprays and/or less water may be acceptable.
When two factors are combined, either in a tank mix or a weed spectrum, the more limiting factor rules. Application of a tank mix or product that is active on both broadleaf and grass plants will be governed by the limitation placed on grass targets. A tank mix comprised of both systemic and contact products is governed by the limitations placed on contact products.
A factor we should also consider is soil activity and the presence of residue. Studies have shown that soil-active products are relatively insensitive to droplet size. But if they have to travel through a layer of trash to get to the soil surface, more application volume is the best tool.
Below are some recommended spray qualities and water volumes for use in Canada. The spray qualities listed in the table can be matched to a specific nozzle by referring to nozzle manufacturer catalogues, websites, or apps. Note that Wilger also offers traditional VMD measurements on their site, allowing users to be a bit more specific if necessary.
This work was performed with Mike Cowbrough, OMAFA Field Crop Weed Specialist.
In the early summer months, many field and specialty crop operations collect rainwater (or possibly pump water from holding ponds) into storage tanks for use as a carrier in spray applications. These tanks may be stationary, or they may be part of a nurse or tender truck that delivers both water and chemistry to the field as a means of improving operational efficiency.
In the case of translucent poly tanks, which are commonly used because of their light weight, custom shape, and low price point, light exposure will grow algae. Algal populations multiply exponentially and will clog spray filters and negatively affect filling. In response, growers use home-grown algicides such as copper sulfate, lengths of copper pipe, household bleach, chlorine, bromine, etc. They do so with little or no guidance and therefore little or no consistency. Beyond the obvious questions surrounding efficacy, it is unknown whether these adjuncts create physical or chemical incompatibilities in the tank mix. If so, there is the potential for reduced efficacy and/or crop damage.
We tested popular methods for algae control by inoculating a series of 10 L translucent plastic jugs with an algal population sourced from a southern Ontario holding pond. The population was left to acclimate and generally establish itself (aka colonize) before we introduced some form of control. Each jug was then gently stirred and emptied through a sieve for qualitative assessment.
In a parallel experiment, we introduced the same algicides to fill water and conducted spray trials. 10 L volumes were mixed with a field rate of glyphosate and sprayed on RR soybeans. Weed control was assessed and soybean yield measured for each treatment.
Algicide Efficacy Experiment
In each treatment, tap water was mixed with a micronutrient growth media (from the Canadian Phycological Culture Centre at the University of Waterloo). This was an unsterilized 10% WC(ed) solution intended to provide micronutrients for algal growth while minimizing fungal and bacterial growth.
The source algae were collected from the bottom of a holding pond from a farm in Guelph, Ontario. Algae were homogenized and equal parts added to each jug. The jugs were former 10 L pesticide containers thoroughly rinsed and sprayed with Five Star’s “Star San” non-rinse sterilizer. Tank solutions were gently bubbled (one bubble every 10-15 seconds) with air from an aquarium pump. Air was balanced using a manifold and introduced via diffusion stones at the bottom of each jug.
Algae sourced from a farm’s holding pond near Guelph, Ontario. Algae was homogenized before inoculating treatment jugs with equal parts.
Treatments
Each treatment was tap water plus growth media inoculated with algae and exposed to a natural diurnal/nocturnal cycle unless otherwise indicated.
Container was spray-painted black to exclude light
Ammonia
“Scotch Bright” copper-coated scour pad. (copper is often introduced as copper sulfate at 1 cup / 1,000 US gal. or a short length of copper pipe)
Bromine (sourced from a local pool supply store)
Treatment Number
Treatment Name
Rate (/US Gal.)
Rate (% v/v)
Rate (/10 L final volume)
1
Control (no algicide)
2
Shaded
3
*Household bleach
1/4 tsp
0.00033
3.3 mL
4
Black container
5
*Ammonia solution
1/4 tsp
0.00033
3.3 mL
6
Copper-coated scour pad
7
Bromine
1/32 ml
0.000004
0.04 g
Table 1. *Bleach and ammonia should never be added together as they produce toxic chloramine gas.
Method
On July 12, jugs were loaded with water and growth media and inoculated with algae. They were bubbled gently for one week to establish a stable algal colony. On July 19, algicides were added, or transferred to shade or black-out conditions. On August 31 (approximately six weeks later), jug contents were gently stirred and filtered through white cloth for qualitative assessment.
Building up algal population for each jug. Note air lines through lids for slow, intermittent bubbling. Algae was not moved to black container or to the shade until after the first week of acclimation.Almost six weeks after algicide was added, jug contents were gently stirred and poured through white cloth to collect algae and establish how easily the liquid passed through.
Observations
The results of all seven treatments, plus photos of the copper-coated scour pad.
(1) Control. Liquid poured slowly through cloth. Algae was still alive and healthy. It formed some clumps but was not as thick as other treatments.
(2) Shaded. Liquid poured fast and easily through cloth. Was particulate in texture rather than clumpy or gelatinous. Very little mass and entirely brown, suggesting it was dead.
(3) Household bleach. Liquid poured easily through cloth until the clump of algae sitting at the bottom of the jug came out (i.e., most algae were not suspended). Thick mat of healthy-looking algae (note profile photo #3 below). Much greener and thicker than the control (1).
(4) Black container. Liquid poured fast and easily through cloth. Algae retained a little green coloration (more than the shaded condition (2)) but was particulate and not as healthy as the control (1). We intended for this treatment to exclude all light, but it was still able to enter at the bottom where the jug wasn’t completely painted. This may have kept the algae alive.
In an oversight, the jug was not completely painted. This left a source of light at the bottom edge that may have helped sustain algae.
(5) Ammonia. Very difficult to pour liquid through the cloth (note profile photo #5 below). The only condition where a mat of algae was floating at the top of the jug rather than settled at the bottom. It was healthy, green and thick.
(6) Copper. The most gelatinous of all conditions, the liquid took the longest to pass through the cloth filter. While the algae seemed brown and dead, the gel would be very problematic during sprayer filling and spraying. Note that the copper scouring pad (shown unrinsed) has nothing growing on it.
(7) Bromine. Like the household bleach condition, liquid poured easily until the healthy mat of algae at the bottom of the jug came out (i.e., most algae were not suspended). Note profile photo #7 below.
Profile shots of treatment 3 (Bleach), 5 (Ammonia), and 7 (Bromine).
Spray Efficacy Experiment
Ideally, adjuncts added to carrier water are inert. That means they don’t reduce a herbicide’s effectiveness on susceptible weeds or increase crop injury. For example, hypochlorite (found in bleach and in chlorinated water) reduces the biological effectiveness of low concentrations of isoxaflutole (the active ingredient in herbicides such as Converge and Corvus). However, when added to higher, agriculturally-relevant concentrations, the reduction in efficacy wasn’t considered significant (Lin et al., 2003). Conversely, bromide has been added to certain herbicides to improve performance (Jeschke, 2009).
There’s precious little information about synergistic or antagonistic effects from adding bleach, ammonia, copper or bromine to herbicide carrier water. To learn more, we added each of these adjuncts to the standard rate of glyphosate (900 gae/ha – 0.67 L/ac). Using a CO2-pressurized plot sprayer, the solution was applied to <10 cm tall weeds at 150 L/ha (15 g/ac) in glyphosate tolerant soybean at the 2nd trifoliate stage of growth (Elora Research Station, Ontario).
Visual crop injury was evaluated at 7 and 14 days after application. Weed efficacy was evaluated at 14 and 28 days after application. Soybeans yields were collected using a Wintersteiger plot combine and adjusted to a moisture content of 14%.
Weed Control
All treatments provided excellent control (>90%) of the weeds emerged at the time of application. Table 2 (below) presents the % visual control 28 days after application.
Carrier Treatment (glyphosate 540 g/L at 900 gae/ha or 0.67 L/ac)
Lamb’s-quarter
Green pigweed
Witch grass
Green foxtail
1) Control
0
0
0
0
2) Shaded
100
100
100
100
3) Household bleach
100
100
100
100
3a) Household bleach – added prior to mixing
95
97
100
100
4) Black container
100
100
100
100
5) Ammonia
100
100
100
100
6) Copper-coated scour pad
100
100
100
100
7) Bromine
100
100
100
100
Table 2. Visual control of lamb’s-quarter, green pigweed, witch grass and green pigweed at 28 days after the application of glyphosate 540 g/L at 900 gae/ha mixed with various carrier treatments intended to prevent algae growth. Treatment numbers correspond with the soybean injury and yield image below.
Soybean Injury and Yield
There was no noticeable crop injury from any treatment (figure below) and yields were not significantly different from the control treatment (Table 3). However, when bleach was added prior to mixing, we did observe a trend in reduced soybean yield. We’re unable to explain this observation, but suggest it may be an unrelated issue (such as field variability). There were no obvious signs of crop injury, and the treatment provided excellent weed control.
Photographs of each plot 14 days after application. The number/letter in each inset image corresponds to treatments in Tables 2 and 3.
Carrier Treatment (glyphosate 540 g/L at 900 gae/ha or 0.67 L/ac)
Crop Injury (%)*
Avg. Yield (bu/ac)
Significance**
4) Black container
0
40.0
A
7) Bromine
0
39.6
A
2) Shaded
0
38.1
AB
3) Household bleach
0
37.6
AB
1) Control
0
37
ABC
5) Ammonia
0
36.9
ABC
6) Copper-coated scour pad
0
36.1
BC
3a) Household bleach – added prior to mixing
0
34.0
C
Table 3. Visual control of lamb’s-quarter, green pigweed, witch grass and green pigweed at 28 days after the application of glyphosate 540 g/L at 900 gae/ha mixed with various carrier treatments to prevent algae growth. *7 days after application. **Duncan’s multiple range test. Soybean yields that don’t share a letter in common are significantly different.
Discussion
We elected to use an extreme situation where a single application of algicide was applied to an established, healthy colony. It’s possible that regular applications of algicide in a volume of water with little or no algae could maintain that condition.
A treatment was considered effective if it slowed or halted algal growth, especially if it also degraded algal populations, causing them to become brown, thin, and/or particulate. Once in the spray tank, the shear forces created by circulation should disperse any dead or degraded algal masses, making it easier to pass them through filters and nozzles.
The shade treatment appeared to kill algae as well as cause degradation. Second place went to the black-out treatment, where some light was unfortunately allowed in. This would have continued to fuel photosynthesis in the unpainted portion at the bottom of the jug. Conversely, the black exterior likely raised temperatures above >20 °C, which depresses most algal growth and may have contributed to the degradation.
Copper appeared to kill the algae but also created a gel that would pose problems to filters. Unlikely to be bacterial, as copper is known to suppress bacterial growth, it could have been caused by diatoms; certain invasive species are known to form brown jelly-like material endearingly referred to as “brown snot” or “rock snot”. Alternately, and according to work by J. Rodrigues and R. Lagoa, alginate polysaccharide can form viscous aqueous dispersions (such as gels) in the presence of divalent cations (such as copper).
No treatment appeared to reduce herbicide efficacy or affect crop health. However, unexpectedly, the household bleach added prior to mixing may have reduced soybean yield. Given the limited number of replications and the single plot location, we suspect this was a field effect, unrelated to the treatment.
Take Home
Based on these results, a combination of shade and light-excluding materials (e.g. black paint) would be the ideal approach to algae control. It’s cheap, effective, and doesn’t require periodic management. Buying black tanks is a good choice, or you can paint them. What you should paint them with is a matter of debate and there’s a very good Twitter thread on the subject if you’re interested.
An Aside: Algae in Ponds and Dugouts
We didn’t test this, but the question has come up and the best we can do is share some long-standing farmer wisdom. Some have used Aquashade dye to absorb the photosynthetic wavelengths and reduce algae buildup. Reputedly it is moderately successful. Another option is adding aluminum sulfate to the pond, and with a lot of agitation it should clarify in about 48 hours. Still others have added a few square barley straw bales to the water and found it to work surprisingly well (possibly an allelopathic response). Tie a rope to them and float them in the pond.
Citations
Jeschke, Peter. 2009. The unique role of halogen substituents in the design of modern agrochemicals. Pest Manag Sci, 2010; 66: 10–27
Lin, C.H., Lerch, R.N., Garrett, H.E. and M.F. George. 2003. Degradation of Isoxaflutole (Balance) Herbicide by Hypochlorite in Tap Water. J. Agric. Food Chem. 2003, 51, 8011-8014
No sprayer operator is more preoccupied with work rates, sprayer cleanout and tank mixes than the custom (aka contract) applicator. Perhaps this is why we’re seeing more direct injection systems on their sprayers in recent years.
Injection systems employ additional tanks and pumps to introduce undiluted product directly into the carrier just prior to the boom. They are designed to maintain the product concentration in the boom (they are not for variable rate prescription spraying within in a field). This permits the operator to change tank mixes between fields without having to clean out or refill.
This generic plumbing diagram depicts an injection system that can create custom tank mixes from products held in three separate tanks. The rinse system, number of tanks, pumps and the point of injection (main pump suction or pressure side) are system-specific.
In the 1980’s, Mid-Tech first offered the TASC peristaltic pump injection system. The bulk of this market was (and still is) right-of-way applications (e.g. railways, highways). Unlike a field application, which covers an area, these sprayers cover a linear distance that makes reloading challenging. When the chemistry is carried onboard, water can be easily accessed along the way.
Boomless roadside spraying using an injection system (Photo courtesy of TeeJet).
In the 1990’s, field sprayer operators tried using direct injection and encountered problems:
Spray concentrations would fluctuate because product was injected based on travel speed while the carrier rate was a constant.
Latency (aka lag) issues were commonplace. Imagine spraying 10 gpa using a boom that holds 15 gallons. A change in speed would prompt a change in injection rate that would not reach the outermost nozzles until half the acre was sprayed.
And, changes in temperature affected the accuracy of the injection systems, so rates changed as cold mornings gave way to warm afternoons.
But the technology has evolved. Today’s injection systems are more consistent and accurate. Here are a few niche usage scenarios to consider:
Usage scenarios
1. Anhydrous ammonia applications require nitrogen stabilizers. The stabilizers are intended to treat the soil, not the ammonia. An injection system can introduce nitrogen at a rate that matches a field’s soil type, while the ammonia is applied on a per-area rate.
2. *Small plot work, such as seed production, consists of many sub-acre plots requiring a range of doses. Injection systems improve work rate by reducing refills or cleanouts between applications.
3. Where appropriate, border sprays of insecticide can be introduced during herbicide post applications.
4. Applicators can adjust herbicide mixtures and glyphosate rates between fields depending on weed pressure.
5. Custom applicators can adjust glyphosate rates when terminating cover crops. For example, alfalfa is a perennial planted for feed before corn. When it gets hardy and begins dormancy late-season, it requires more glyphosate. Oats are used as a cover following winter wheat, and both oats and volunteer wheat require a much lower dose.
6. Clients of custom application may or may not want foliar fertilizer (e.g. zinc) amendments. This service is only feasible using direct injections systems.
*This scenario was communicated to the author by a company selling the equipment, but subsequently there has been some question as to how this might work. The amount of time and water required to clear lines between applications would depend on the nature of the chemistry and whether it is a rate or wholesale chemistry change. As such, there are situations that would make this an impractical use of the technology.
Today’s injection systems
Mid-Tech/TeeJet
In early 2000, TeeJet acquired Mid-Tech and offers two injection systems that can control up to six 28 L (7.5 gal.) or 95 L (25 gal.) tanks on a single sprayer. The tanks have an optional agitation feature.
The MT-500 peristaltic pump (still predominantly for roadway applications) injects into the suction side of the main pump to facilitate mixing. It delivers 6-10 ml/min. (0.2-350 oz/min.) but flow rate can be changed by changing hoses. Peristaltic hoses lose accuracy as they wear with time, but hose is cheaper to replace than seats on a piston pump. It can run in reverse to pull product back from the lines. It works with the TASC controller.
The MT-600 is a piston-pump with a mixing chamber option that injects the pressure side of the main pump leaving more clean line and increasing response time at the nozzle (i.e. less lag). It must have backflow prevention (typically a seated ball valve). Depending on the rate required, high and low-volume product pumps can be added in pairs to extend the range: 15-1,500 ml/min. (0.5-50 oz/min.), 30-3,000 ml/min. (1-100 gal./min.), 45-4,500 ml/min. (1.5-150 oz/min.) or 60-600 ml/min. (2-200 oz/min.). High and low-volume product pumps can be added in pairs to extend the range. This pump works with TASC controllers and the ISOBUS Legacy 6600 and Aeros 9040.
Raven
The Raven Sidekick Pro replaced their original Sidekick in 2011. It is ISOBUS compatible with many sprayers and their controllers (e.g. Deere’s Greenstar 3, Raven RCM). It controls up to five 90 L (24 gal.) or 190 L (50 gal.) tanks with optional agitation that can be removed like totes. Depending on the rate required, low [0.03-1.2 L/min. (1-40 oz/min.)] and high-volume [0.15-6 L/min. (5-200 oz/min.)] positive displacement product pumps can be used alone or in pairs to extend the range. Product is injected into a length of latticed pipe in-line on the pressure side of the main pump to create a mixing action prior to the boom.
Other entries
In North America, SurePoint sells the Spartan, which claims to support the direct injection of liquid chemical, fertilizer, biological, or other product into the carrier flow stream. It may be intended for towed implements rather than on a self-propelled sprayer. There are also European entries from Danfoil (theMultidose) and Diimotion (prototype PiiXdi), but information is sparse and the last update we found on either was c.2017.
In 2025, the UK’s Knight Sprayers won gold at LAMMA 2025 for their Smart-Inject chemical system. Details are light at this point, but it’s described as a third-party retro fit for spot sprayers. Slightly diluted product in held in a second, smaller tank and circulates separately and in parallel with the sprayer’s existing lines. Chemistry is injected on demand (e.g. when a weed is detected) directly into the nozzle body between the shut-off valve and the nozzle cap.
Pump and tank selection
Quite often, direct injection users regret limiting their pump capacity and the number of tanks installed. This limits travel speed and encourages risky practices such as mixing multiple products in a single injection tank.
Direct injection systems should be capable of staying within your target rate and travel speed. You can calculate your pump requirement in oz/min. using the following formula:
So, if you are considering a direct chemical injection system, give some thought to the following pros and cons.
Pros
Cleanout is faster when the main tank is reserved for water (Although some operators continue to mix in the main tank and use the product tanks to amend the mix).
Product tanks are filled from bulk, so there are fewer jugs to handle. That reduces waste and operator exposure during loading.
Work rate is improved by altering tank mixes between fields without cleaning and reloading.
There is no spray math required during loading and no excess or deficiency at the end of a field.
There is no concern about a tank mix sitting for long periods during delays.
There is reduced potential for spills due to accident or malfunction.
Tracibility is improved; Instead of recording tank mix per acre, record tank mix by field.
Cons
Expense.
Rinsing systems, if available, do not clean lines between injection pumps and tanks. Cleaning requires pulling them apart manually.
Product tank loading can be slow (up to ½ hr to load 50 US gallons with certain loading assemblies).
Some products are harder to clean out than others and can plug the injection pump if left full of chemical.
The number and volume of product tanks may not hold a day’s worth of chemicals.
Viscous or clay-based products prone to settling or separation (e.g. PrimExtra on corn or Boundry on beans) should not be used.
Thanks to Rob Warwick and Markus Redmond (John Deere), Dennis Frey and Jordan Diefenbacher (Clean Field Services), Brian Satorius and Andy Graber (TeeJet Technologies), Nick Michael and Gary Esselink (Raven Applied Technology), Jan Langenakens (AAMS) and Mark Ledebuhr (Application Insight LLC) for informing this article.
We’ve identified and discussed shortcomings in the content and design of today’s pesticide labels in an earlier article. From the perspective of the spray applicator, the information needed most often can be difficult to locate, anachronistic, contradictory, subjective or even missing from the label altogether. To truly encourage an applicator to read and follow the label we need a consistent, concise and clear format that summarizes critical content.
To that end, we have worked with growers, university/government extension and industry to develop a prototype we’re calling the “Label Summary Sheet”, or LSS for short. We presented the concept in a series of public presentations in western Canada as part of the RealAgriculture TechTour Live event in 2018. You can watch a recording of part of that event at the end of this article.
The LSS does not replace or interpret the current label, which is a legal document. It is a summary intended to accompany it. At this stage the LSS is simply a proposal. These documents are not intended for use right now; we hope they will grow and change for the better as they stimulate discussion.
Consider this metaphor: You have just purchased a laptop. When you unbox it, you get an in-depth instruction guide that covers everything from operation to trouble shooting and includes all the legal riders. It’s a daunting technical document that you likely won’t read unless something goes wrong. Knowing that, manufacturers include a graphic and accessible quick start-up guide that summarizes the most common and critical issues. It doesn’t replace the instruction manual, it just augments it. If you can’t find what you need in the quick start-up guide, you are referred to the more fulsome description in the instruction manual. Think of the pesticide label as the instruction manual and the LSS as the quick start-up guide.
Some agrichemcial companies recognize this need and have developed short documents to summarize key aspects of the label, but they are inconsistent and brand-specific marketing documents that do not always contain the information we are proposing. Here, for example, is the technology sheet for Integrity herbicide.
We tested the versatility of our LSS format by summarizing four diverse pesticide labels. Our selections are not intended to imply that these labels are particularly deficient. Only that they are commonly used, somewhat complicated and represent the spectrum of pesticide categories and application methods.
Download and look at the variety of labels we have summarized as examples. They are available here:
Note that each LSS features the same section headings and a relatively consistent layout, no matter the manufacturer. Generic icons are used to illustrate content and make it easier for users to navigate without language barriers. The LSS are black and white to facilitate reproduction and refer back to their respective pesticide labels (i.e. the online PDF, not the booklets that come with the pesticides).
LSS Sections
Here is the Pristine LSS broken down by section to highlight the key features.
1. Banner Section
The banner is at the top of every LSS. It gives the commercial product name and the date to ensure the LSS reflects the current pesticide label. Four icons represent the most common application technologies: Horizontal boom sprayer, airblast, aerial and handheld. If an application method is prohibited, a banned symbol appears (such as aerial in this case). Note we have left room for RPAAS (UAV’s) anticipating the day we have products registered for that technology. The table notes the type of pesticide (e.g. fungicide, insecticide, adjuvant, etc.). The mode of action and active ingredient(s) are noted, as well as the formulation and the Pest Control Product number.
2. Resistance Management / Planting Restrictions
Intended to provide key information on managing pesticide resistance, this section reflects label content about carry over and the rotation of active ingredients. Further, to aid in application decisions, it reflects any restrictions around maximum number of applications, sequential applications or plant back issues following use.
3. Environmental Conditions
Any restrictions regarding weather conditions during or after application are noted here. This includes set-backs or buffer zones that reflect method of application and the nature of the adjacent or downwind area in question.
4. Sprayer Settings
This section includes the six most commonly asked questions an applicator has when calibrating or adjusting their sprayer prior to use. It is organized by target crop and method of application. When the label provides a high level of detail, the user is referred to the correct page. Note the use of graphics to quickly direct the reader to the information they need. Any additional qualifications found in the label relating to sprayer settings are indicated in the notes beneath the table.
5. Handling Safety (PPE)
The concept for this simple and graphic table originated in France, and was communicated to us by Dr. Carol Black of Washington State University. This unambiguous format encourages the use of PPE while ensuring the handler uses the appropriate level of protection for each activity.
6. Mixing
As operators tank mix more products to curtail resistance, improve efficacy or improve productivity, there is a greater chance of chemical or physical incompatibility. This section summarizes any restrictions noted in the label. Learn more by downloading Purdue Universities’ publication “Avoid Tank Mixing Errors“.
7. Rates and Restricted Entry Intervals
This table can be quite complicated depending on the pesticide label. It summarizes the rates, volumes and restricted entry intervals by crop. It reflects the broadest range of product rates listed in the label. Restricted entry duration is affected by the post application activity, and this is captured in the REI column. If more detail is required, the user is referred to the appropriate page(s) of the label. Any additional qualifications found in the label relating to rates, volumes or REI are indicated in the notes beneath the table.
8. Equipment Cleanout
Finally, equipment cleanout is summarized (where possible) in a sequence of steps. When the pesticide label is silent on the cleanout procedure, the user is provided with the triple rinse protocol, which is generally held to be the industry best-practice.
Adoption
To date, this proposal has been made to Croplife Canada, the American Society of Agricultural and Biological Engineers (ASABE), an International Organization for Standardization (ISO) mirror committee (Equipment for crop protection) and more than 1,400 growers and stakeholders across Canada.
Our suggestion for adoption of the LSS (in its current form or something similar) is that regulatory agencies commission a working group comprised of representatives from grower groups, industry and government to oversee the process. The working group would support registrants as they populate (or update) the LSS template when a new product is submitted for registration, or as part of the natural review cycle.
Should the registrant encounter duplicate, missing or contradictory information while completing the LSS, it should be considered an opportunity to remedy the problem on the pesticide label. This will clarify the safest and most effective use of the pesticide for the applicator, who is currently forced to selectively ignore or interpret such errors. To our minds, this was the intent of the original labelling system, and the inclusion of the LSS is a simple and effective way to achieve that goal.
The Confusicol Sketch
In 2018 we participated in Real Agriculture’s TechTour Live event that toured four major cities in Western Canada in four days. We presented the “Confusicol sketch” as a light-hearted way to open a discussion with the audience on the strengths and weaknesses of Canadian pesticide labels and how the Label Summary Sheet might be a viable supplement. Here’s one of the live takes, warts and all. Turns out live sketch comedy is tricky…
