Category: Nozzles & Droplets

Articles helping with field sprayer nozzle selection

  • Angled Spray Nozzles in Wheat

    Angled Spray Nozzles in Wheat

    When T3 wheat rears its head, the first rainy day brings questions about spray angles. Let’s begin with a graphic that illustrates how angled sprays cover a vertical target like a wheat head. Assuming moderate wind and sufficiently large droplets, this is a simplified depiction of what we would expect to see.

    But is this how the nozzles actually perform? Are dual angles really better than a single fan with an aggressive angle? We hoped to answer these questions when we demonstrated a selection of dual fan nozzles at Canada’s Outdoor Farm Show in 2013. But it was a very windy few days and what we saw was that regardless of the nozzle, most of the spray tended to deposit with the wind.

    A 10 km/h wind will easily deflect Medium-and-smaller droplets and at 20 km/h all but the coarsest spray is deflected. This leads to non-uniform deposits and unacceptable levels of drift (yes, even through it’s a fungicide and you have lots of acreage.) To learn more, we turned to the literature to review studies performed in Ontario and Saskatchewan.

    Wolf and Caldwell

    In 2002, Dr. Tom Wolf and Brian Caldwell experimented with fan angles. They evaluated the impact of nozzle angle, travel speed, and droplet size on the “front” (facing the sprayer’s advance) and “back” (sprayer’s retreat) of vertical targets. They ran three laboratory experiments: spray configuration (single vs. double fan), travel speed (7.6 and 15.2 km/h) and spray quality (conventional versus air-induced droplets) using TeeJet XR’s and Billericay air bubbles at a rate of 175 L/ha. Here’s what they observed:

    • Larger, air-induced droplets produced higher average deposits than smaller, conventional droplets.
    • Twin fans improved overall average deposit compared to single fans.
    • Building on the first two points, twin air-induction fans improved overall average deposit versus conventional twin fans, and also improved deposit uniformity (i.e. coverage on the front versus the back of the vertical targets).
    • Higher travel speeds improved overall average deposit, but at the cost of reduced uniformity as the rear-facing target received reduced coverage (particularly in the case of conventional droplets).
    • Spray angle did not impact coverage from conventional tips, but increasing from 30 to 60 degrees improved coverage for AI tips.

    While the coverage data was compelling, growers were not reporting improved efficacy with the improved coverage. The authors felt there were confounding variables like crop susceptibility, disease pressure and product effectiveness. Their conclusion was that applicators should strive for improved coverage, but only after integrated pest management (IPM) criteria such as product choice, crop staging and application timing are satisfied.

    Hooker and Spieser

    In 2004, Dr. David Hooker (University of Guelph) and Helmut Spieser (OMAFRA) started exploring nozzle configuration and sprayer set-ups to optimize Folicur applications in wheat. For several years they ran field trials exploring panoramic wheat head coverage. That is, not only the front and back of the wheat head, but the sides as well. Ten different nozzle configurations were used:

    • TurboTeeJets mounted in dual swivel bodies (backwards and forwards)
    • AirMix air induction nozzles mounted in dual swivel bodies
    • Air induced Turbo TeeJets mounted in dual swivel bodies
    • Single Turbo TeeJets angled forward or angled backwards
    • Single Turbo FloodJets angled forward or angled backwards
    • TwinJets
    • Single Hollow cones
    • Turbo TeeJet’s mounted in Twincaps
    • Turbo TeeJet Duos
    • Single Turbo FloodJets alternating forward and backwards

    They explored boom height (0.5 m and 0.8 m above the crop), travel speed (10 km/h and 20 km/h) and application volume (93.5 L/ha and 187 L/ha). Here is a summary of their findings:

    • Travel speed did not appear to impact overall coverage.
    • Spraying higher volumes improved coverage.
    • Lowering the boom improved coverage.
    • Coverage from conventional flat fans and TwinJets gave ~15-18% coverage and 22-26 mg of copper was deposited per m2, but alternating Turbo FloodJets gave ~29% coverage and deposited ~37 mg copper per m2.
    • The highest percent coverage was obtained using Turbo TeeJets or the AirMix tips mounted in dual swivels (~26% coverage), or single Turbo Floodjets alternating forward and backwards (34% coverage) as long as the spray was not obstructed by the boom structure itself.

    Hooker and Schaafsma

    A few years later, Dr. Hooker and Dr. Art Schaafsma worked with OMAFRA to explore efficacy. DON is a mycotoxin that may be produced in wheat infected by Fusarium Head Blight (FHB) or scab. There is an indirect relationship between wheat head coverage of fungicide and the reduction of FHB and DON: The higher and more uniform the coverage (with the right timing) the lower FHB and DON.

    In two field experiments they performed in 2008, DON values in the untreated checks were around four parts per million. DON was reduced by an average of 22.5% using a single flat fan, 23.0% using a TwinJet and 41.5% using alternating Turbo FloodJets when averaged across two fields, two fungicides and four reps (n=16). They all reduced DON significantly. There was no statistical difference between singles and twins, but control from the alternating Turbo FloodJets was significantly better.

    The Return of Wolf and Caldwell

    Then, in 2012, Tom and Brian evaluated the new asymmetrical twin fan nozzles from TeeJet. The marketing claimed they could improve overall coverage at higher travel speeds because they decrease the contribution of the front-facing fan and increased the angle of the back. Tom and Brian’s lab-based experiments determined that:

    • Asymmetricals increased overall deposit amounts and uniformity versus single fan and symmetrical twin fans.
    • Nozzle orientation (alternating or not) seemed unimportant.
    • As suggested earlier, boom height was a big factor in coverage. Nozzle angle didn’t improve coverage when the boom was too high, but spray deposit increased significantly when the boom was lowered.
    • Coarser spray droplets have more momentum, so they can travel greater distances on their original vector. A coarser spray quality is the best choice for any angled fan.

    Water volumes and FHB

    Let’s address the notion that high water volumes might increase Fusarium Head Blight (FHB). This is a hypothesis that seems to have resonated with growers. Dr. David Hooker ran trials where he tried to favour FHB by spraying 40-50 gpa of water multiple times per day (even up to 100 gpa). There was no pathological impact (personal communication).

    Consider that 1″ of rain is the equivalent of 2,715 gpa of water. Raising your carrier volume from 15 gpa to 20 gpa is the equivalent of 0.000184″ of rain. Admittedly, it’s all aimed at the wheat head, but it’s still a tremendously small volume. While studies have shown a diminishing return in coverage at 30 or 40 gpa, spraying with 20 gpa appears to be a safe way to improve coverage significantly.

    Learn more about early morning spraying here, and a more in depth discussion of spraying when there is dew here.

    PWM

    What if you’re running a PWM system? Sizing for PWM requires the tip be sized about 20-40% more than if you were running a conventional sprayer. In other words, at expected travel speeds, the pulsing duty cycle should be approximately 60-80%. Nozzles that are permitted on PWM sprayers are limited and the angled fan selection for PWM is, at the time of writing, more so. It requires some experimenting. The following list uses the JD Exact Apply as an example system, and it is not exhaustive. We’re always looking for new ideas.

    1. 3D90 (the original 3D is arguably too misty) in the A or B positions, alternating front and back <or> in both A and B positions. This tip may not be readily available in North America.
    2. LDT (Low Drift Twin) which is two LD tips installed in a Twincap (twin 30° angles) in position A or B.
    3. LDM (Low Drift Max) which is two LDM installed in a Twincap in position A or B. This tip only goes down to an 03.
    4. The Deere 40 degree angled adaptor (developed for See and Spray) can be used to convert any PWM-compatible nozzle into an angled spray.
    5. GAT (GuardianAir Twin) is an air-induced tip, running in conventional “A” mode or in Auto Mode but sized for “B”. Avoid operating in A and B to prevent pattern interference.
    6. Wilger Wye Adaptor with SR nozzles. This does cause tips to drop below the boom frame but is a versatile option.
    7. Wilger Dual Angle Max. More compact than the wye adaptor, this asymmetrical assembly (30° fore and 50° aft) prioritizes Coarse spray.
    8. TeeJet Accupulse TwinJet.
    9. Greenleaf Blended Pulse Dual Fan Assembly.

    Summary

    So here’s what we can say based on all this research:

    • Higher volumes improve coverage (significantly up to ~200 L/ha or 20 gpa). Can you go to 30 gpa? Yes, and it will likely improve coverage, but it’s a diminishing return and at some point you will incur run-off.
    • When using angled sprays, coarser droplets improve vertical coverage. Compared to finer droplets, they move faster, survive longer (i.e. resist evaporation) and are less likely to be deflected by wind.
    • Maintaining the lowest operable boom height improves coverage from angled sprays. We want 100% overlap at target height, and with angled sprays that means getting pretty close. Aim for the highest wheat heads and not the tillers. If you’re 2′ away, you’re likely too high.
    • Symmetrical fans with shallow angles (e.g. 30°) improve coverage uniformity on vertical targets versus single fans, and a steeper backward-facing angle (e.g. 70°) improves coverage even more on the sprayer-retreat side.
    • Travel speed may or may not affect coverage, but slower speeds do facilitate lower booms, which do improve coverage.
    • Timing, weather and product choice are likely the most critical factors.

    Angled sprays may offer some advantage in other situations, but they are primarily intended for panoramic coverage of vertical targets.

    Short videos about dual fans

  • Circulating Spray Mix Through a Tank-Rinse Nozzle Maintains Nematode Concentration

    Circulating Spray Mix Through a Tank-Rinse Nozzle Maintains Nematode Concentration

    This article was co-written with Jennifer Llewellyn, former OMAFA Nursery Crop Specialist

    With more and more bio-rational products on the market, crop protection methods may require reassessment. Certain products require exacting water quality, cannot tolerate residues, and have half-lives that are both time- and temperature-critical. We’ve been getting questions about sprayer compatibility with some of these new products, so it seemed like a good opportunity to recycle this article from 2013.

    Many horticultural commodities, such as turfgrass and nursery crops, include the application of live nematodes as part of their annual IPM program. We performed preliminary research into the claim that a grower’s nematode applications were becoming less effective. In the course of the investigation it was discovered that the nematode concentration (i.e. dose) sampled from the spray nozzle was diminishing over the course of the application.

    (A) Tank-rinse assembly mounted through tank lid with a flow-regulating valve. (B) Close up of tank-rinse nozzle.
    (A) Tank-rinse assembly mounted through tank lid with a flow-regulating valve. (B) Close up of tank-rinse nozzle.

    After eliminating potential sinks in the sprayer’s plumbing (e.g. filters, strainers, etc.) it was hypothesized that the nematodes were adhering to the interior of the poly tank. If this was the case, the concentration would drop as the level of spray mix dropped. To test the hypothesis, we installed a tank-rinse nozzle to sparge the inner walls of the tank throughout the application and to re-suspend any stranded nematodes.

    A high capacity roller pump (Pentair series 1700C) was installed to operate the tank-rinse nozzle (Pentair Proclean Tankwash) during spraying. It was installed through a bulkhead fitting in the tank fill lid. During testing it was discovered that the tank-rinse nozzle shunted too much flow and pressure to maintain flow to the spray gun. A valve was installed behind the tank-rinse nozzle to restrict flow to the point where it gently rinsed the inner walls of the tank, restoring flow and pressure to the spray gun.

    (A) Installing a high-capacity roller pump. (B) Tank-rinse nozzle, with valve, installed through tank lid. (C) Control manifold installed to plumb the return, the tank-rinse nozzle, spray gun and boom. (D) The entire installed system.
    (A) Installing a high-capacity roller pump. (B) Tank-rinse nozzle, with valve, installed through tank lid. (C) Control manifold installed to plumb the return, the tank-rinse nozzle, spray gun and boom. (D) The entire installed system.
    (A) Nematodes, as-shipped, in a sponge. (B) Suspending nematodes for tank mixing. (C) Counting nematodes. (D) Undiluted, healthy nematodes in a stock solution via microscope ocular.
    (A) Nematodes, as-shipped, in a sponge. (B) Suspending nematodes for tank mixing.
    (C) Counting nematodes. (D) Undiluted, healthy nematodes in a stock solution via microscope ocular.

    The 200 L tank was inoculated with a stock solution containing 25 million nematodes (125 nematodes / ml). 20 L of the spray solution was sprayed into a bucket every 10 minutes, whereupon 1 L of spray solution was immediately removed and 1 ml volumes were sub-sampled for counting.

    In the first trial, nematode counts continued over a period of 2 hours and viability dropped by ~40%. It was assumed the damage was caused by prolonged circulation through the roller pump. In subsequent trials, the sampling duration reduced to 10 minutes (more realistically reflecting the time it took the grower to apply 200 L in the field). The tank was rinsed and re-inoculated for each trial. 1 ml samples were drawn from the spray gun, which operated continuously, with and without the tank rinse nozzle in operation.

    Univariate analysis confirmed data normality and a GLM procedure was conducted for analysis of variance. Results indicate that nematode concentration dropped by ~15% without tank-rinse with minimal nematode damage observed. With the tank-rinse nozzle engaged, the concentration still declined slightly, but significantly less (<5%) (see graph below).

    Nematode concentration over time for each condition.
    Nematode concentration over time for each condition.

    The results suggest that a tank-rinse system that sparges the tank walls preserves nematode concentration throughout an application and may lead to more efficacious applications.

    Horticultural Crops Ontario, Ground Covers Unlimited, Pentair (Hypro) and Nemapro are gratefully acknowledged for making this research possible.

  • Nozzle Choice in Vegetable Crops – an Australian Perspective

    Nozzle Choice in Vegetable Crops – an Australian Perspective

    Editor’s Note: Any brand-specific references or recommendations in this article are based on the author’s experience. Sprayers101 endeavours to preserve brand independence and impartiality to best serve our readers. This article was originally posted in 2018.

    During my many years of work in the Australian vegetable and horticultural industry, I am continually asked:

    Q. What is the best spray unit to use?

    My answer is simple:

    A. The one that has been correctly set up and matched to the crop you are spraying.

    That can be hard to achieve, especially in vegetable crops where the target can vary enormously from bare ground to upright leaf crops (e.g. onions), to horizontal leaf crops (e.g. potatoes and brassica).

    Generally, I have found that air-assist booms offer the best starting point for achieving good spray coverage of vegetable crops. However, like any spray boom, they must be set up correctly. Air-assist booms are more expensive and require a few more horses to operate, which is why most Australian vegetable growers prefer to make do with a non air-assist boom.

    So, if air-assist isn’t an option, it then becomes imperative to determine the most suitable nozzles for their particular requirements. I have worked in many vegetable crops over the years. I’ve held my share of “fluorescent dye nights” and checked spray coverage and canopy penetration with many grower groups. Based on my experience, there are three types of nozzles I recommend for most vegetable crops:

    Nozzle #1: Air Induction Flat Fan

    Here’s what I say when the grower (inevitably) asks which nozzle is the best for every task:

    Using only one nozzle will compromise some aspect of a series of applications. However, the Syngenta 110 025 air induction nozzle generally performs well. Manufactured by Hypro it creates more droplets per liter than other air induction nozzles of the same size (as of 2018). (Editor’s note: as of 2025, a likely North American equivalent is alternating-direction Syngenta 3D 90’s. They produce a high-velocity Extremely Coarse-Ultra Coarse spray quality and the manufacturer claims they improve the penetration of broad leaf canopies over conventionally-angled sprays. However, when drift potential is low, travel speed is reasonable, and boom height is low, alternating-direction Defy 3Ds produce a Medium-Coarse Spray quality which may be more conducive to retention on hard-to-wet vertical targets).

    As long as the crop isn’t too large (e.g. later season), I recommend this nozzle with lower water volumes. This is because I tend to see more application issues arising from excessive water rates that wash product off the plant. Unless you are after soil borne diseases, avoid run-off and wastage by using the SAI 110 -25 with volumes of about 200 L/ha. The following graph shows the results of application volume on brussels sprout coverage (per Syngenta UK).

    Nozzle #2: Narrow Spray-Angle Flat Fan

    When I am trying to increase canopy penetration, I like the Syngenta Vegetable Nozzle (SV65-04 flat fan). I feel the narrow spray fan angle delivers a directed spray pattern into the crop canopy which can significantly improve penetration. This is a good fit for late-season insecticide and fungicide sprays in brassica crops, where pests and diseases can be hidden deep in the crop canopy.

    I worked with a vegetable grower who was having trouble controlling sclerotinia in his mature fennel crop. The target was the base of the stem, deep in the canopy. In the following image you can see the water sensitive paper taken from ground-level in the canopy. The nozzles used from left to right are; Hardi Twin AI 110-05, Syngenta 65-06 vegetable nozzle and Syngenta AI 110-05. Coverage was estimated using the SnapCard app (freely available for iPhone and Android platforms). (Editor’s note: as of 2025, Syngenta’s silver 06 and gold 08 vegetable nozzles are not available in North America. They produce high volume, slow-moving, Coarse-Very Coarse sprays. TeeJet’s Visiflo is a 65 degree tip, but produces too fine a spray quality to be serviceable. As spot-spraying is increasingly adopted, the development of narrow-angled nozzles is anticipated and may offer a reasonable alternative.).

    So, I know pyrethrum is a flower and not a vegetable crop (think chrysanthemum), but it can be hard to penetrate, so this is a good example. We compared five nozzles and estimated coverage using SnapCard. The Veg 65-04, AI 110-035, and Twin AI 110-04 seemed to improve coverage over the Defy 3D 85-04 and conventional AI 110-04.

    For broadacre farmers (i.e. field or cereal crops) the SV65 flat fan nozzle has also proven to be extremely successful at penetrating thick standing stubble residue when using pre-emergent herbicides. Likewise, it performs well when targeting lower leaves during fungicide applications. Again, I believe that this is due to the narrow fan angle of the spray giving a more direct spray down through both the stubble and the current season’s foliage. Be attentive to nozzle spacing and boom height when using narrow fan angles to ensure correct overlap and complete coverage.

    Nozzle #3: Angled Flat Fan

    For onions and broadleaf crops (e.g. potatoes and beans), I feel the nozzles that have their spray fans angled forwards and backwards along the (non air-assist) boom are best suited.

    The following image shows coverage from angled sprays on simulated upright targets in the field using water sensitive paper.

    The Syngenta angled nozzles are designed with a 30° incline intended to improve foliar coverage down to the lower leaves on some vegetable crops. Although originally designed for use in potato crops, I have also had success in other vegetable crops such as onions and leeks. (Editor’s note: as of 2025, the Gold 04 and Orange 05 potato nozzles do not appear to be commercially available, although possibly in Ireland. They produced a ~Medium spray quality at an angle similar to that of the vegetable nozzles).

    Summary

    No matter the nozzle choice, or how good the application technique may be, the priority should be to manage disease and insect pests early in crop development. If you are trying to control heavy pressure from disease or insects and it’s deep within the crop canopy, often, you’re going to come off second best. Prevention is always better than cure, no matter what crop protection product you are spraying.

    With that caveat, I’ll leave you with my suggested nozzle choices. Preferably, I would suggest installing (at least) a triplet nozzle selector to quickly change between three nozzles for each crop.

    CropGrowth StageWater Volume (L/ha)Suggested NozzleNotes
    CabbageSmall, open100-200Air InductionRun-off is the enemy of small plants.
    Hearted300-80065 ° Fan Angle NozzleAngled spray important to get spray under top leaves. Use twin cap option for volumes greater than 300 L/ha.
    CarrotsSmall100-200Air InductionCarrots are good at catching spray. Angling nozzles e.g. Twin Cap will give best results.
    Large200-40065 ° Fan Angle Nozzle65º fan the best for penetrating to crown. Apply volume of 200 L/ha, increasing to 400 L/ha in denser crops. Avoid air induction (aka bubble jet) and hollow cone nozzles for later application timings.
    Brussels SproutsSmall, open100-200Syngenta AI 110025Run-off is the enemy of small plants.
    Large200-300Syngenta 3D nozzle 85 04 or 85 05
    LeeksSmall100Syngenta 3D Nozzle 85 03, 85 035 and 85 04 cover both sides of the plant.Coverage, run-off and missing the target are the problems likely in Leeks. Angled spray forward and backwards is important. High Volumes = Run-off.
    Large200-300Syngenta 3D nozzle 85 04 or 85 05Angled spray forward and backward. High Volumes = Run-off.
    LettuceSmall, open100-200Air Induction Run-off is the enemy of small plants.
    Hearted300-80065 ° Fan Angle Nozzle
    OnionsSmall100Syngenta 3D Nozzle 85 03, 85 035 and 85 04 cover both sides of the plant.Coverage, run-off and missing the target are the problems likely in onions. Angled spray forward and backwards is important. High volumes = run-off.
    Large200Syngenta 3D Nozzle 85 04 or 85 05Angled spray forward and backward to cover both sides of the plant.
    PotatoesPrior to row closure100Syngenta Pre-em 03 nozzleAngled spray forward and backward.
    After row closureSyngenta 3D Nozzle 85 03, 85 035 and 85 04
    Pre harvest (desiccation)200-400Syngenta 3D Nozzle 85 04 or 85 05The desiccation of very large canopies may require up to 400 L/ha of water on the 1st application.
    Peas and Edible BeansSmall100Syngenta 3D Nozzle 85 04 for 7–9 km/hr. Syngenta 3D Nozzle 85 05 for 10–12 km/hr.Medium spray quality and use higher water volumes in dense crops. All nozzles 0.4-0.5 m above top of crop.
    Large200
  • Beluga Drop Hoses in Corn: Utility and Return on Investment

    Beluga Drop Hoses in Corn: Utility and Return on Investment

    In 2019 we evaluated the spray coverage from nine application methods on corn silks. The results showed that a directed application from drop hoses (aka drop pipes, drop legs) suspended in between the rows gave significantly higher deposits. The results led us to wonder if the superior coverage from a directed application translated to improved yield.

    Around this time we started considering the Beluga Drop Hose developed by Agrotop (Germany) and distributed by Greenleaf Technologies (USA). Originally designed to apply neonicotinoids in canola, we found that the stiff-but-flexible hose did not tend to deflect or sway during an application. Further, their unique low-profile nozzle body had less potential to cause mechanical damage or otherwise snag in dense canopies. Unlike homemade drop pipes or other commercial solutions such as the Y-Drop with 360 Undercover, the Belugas were lightweight, simple to install/remove, and did not need a break-away section to prevent damage.

    Three examples of directed application systems. Left: Homemade drop pipes and a TeeJet QJ90-2-NYR split nozzle body (inset). Centre: Beluga drop hose with streamlined nozzle body (inset). Right: Y-Drop side-dress drop pipes with Yield 360 Undercover option (inset).

    In 2021 we initiated a four-year trial with the Beluga drop hose system in Port Rowan, Ontario. Our objective was to evaluate return-on-investment based on yield using two pesticide regimes. Treatments were established for conventional overhead technology, directed applications (i.e. the Beluga) and unsprayed checks.

    Construction and Installation

    We ordered 150 cm (60″) drop hoses with two nozzle bodies each so we could customize them. The instructions were in German, but after running them through translation software we were confident in how to proceed (download the translated copy here). We started by determining the hose length.

    Hose Length and Boom Spacing

    We started by temporarily fixing the mounting plates to the boom using quick ties because we wanted to ensure they did not interfere with boom folding. The drop hose quickly and easily “keys” into the plate allowing it to swing freely and find plumb. The corn was planted on 76 cm (30″) spacing so we aligned the plates with the alleys to permit the drop hoses to move between the planted rows. Each hose is plumbed to the nearest nozzle body via a quarter-turn quick-connect coupler.

    Temporarily attaching mounting plates every 30 inches to correspond with corn alleys. The Beluga keys into the mounting plate and is then plumbed into the sprayer via a quarter-turn quick-connect coupler that attaches to the nearest nozzle body.

    The drop hose had to clear the ground but still be long enough permit nozzle bodies to span the target region in the canopy. We later learned to cut the excess hose closer to the lowest nozzle body. This eliminated a source of pesticide collection (like a boom end) and prevented them touching the ground and “walking” as occasional contact would cause them them to flex and leap forward.

    Target Zone and Nozzle Body Spacing

    Before we could permanently install the nozzle bodies on the drop hoses, we had to decide what our target was. This required us to establish a primary coverage zone within the corn. Dr. David Hooker (University of Guelph) experimented with directed sprays (triazoles) and leaf disease control in the 2010’s. Dr. Hooker noted that leaf diseases were controlled above the ear to the flag leaf, and postulated it may be due to xylem mobility (i.e. acropetal movement) of the fungicides used at the time. This concept warrants further investigation with modern fungicides, especially with the need to control tarspot and reduce DON risk in SW Ontario.

    Tarspot in corn – Southwest Ontario, 2023

    Given that the nozzles would be about 38 cm (15″) from the stalk, we elected to use 110° flat fan nozzles on two nozzle bodies spaced 50 cm (20″) apart to increase the swath. Our objective was to protect against foliar disease, so the bottom nozzle was aimed approximately at the ear (for silk coverage) and the upper nozzle covered the higher foliage without being so high as to spray out of the canopy. Between gravity, the wake of the drop hose, and the initial angle of the spray, all surfaces received some degree of spray coverage no matter their orientation or depth. This was later confirmed using fluorescent dye.

    It has been suggested that this target zone may not be ideal for all hybrids, and that an overhead component should be included. However, we felt this was the most efficient distribution of the spray given Dr. Hooker’s observations and the results from the 2019 spray coverage work referenced earlier.

    Each drop hose was suspended on 76 cm (30″) spacing to correspond with the centre of each alley. Nozzle bodies were spaced 50 cm (20″) apart to cover the primary target zone within the canopy. The outer two drop hoses only had inward-facing nozzles to contain the treatment. We later cut the excess hose closer to the lowest nozzle body.

    Using the jig provided, we drilled holes for the two nozzle bodies. Then we blew-out the hoses to clear them of any plastic shavings that could plug nozzles. The hoses were cut to length and the end plug was installed with a hex key. Once we found a rhythm, the assembly went quickly and easily. Expect assembly and mounting to take a day.

    Customizing the hose length and nozzle spacing. We built our own clamping jig to hold the pipes steady.

    Plot Design, Sprayer Set-up and Chemistry

    The study took place on 11.3 ha (28 acres) spanning two fields. The corn variety was Pioneer P0720AM, which has a Gibberella Ear Rot rating of 4. Four overhead treatments, four directed treatments and four unsprayed checks were arranged in a random block design for each of two fungicide regimes (n=8 for each treatment per year). Each treatment area was between 1.05 and 1.10 acres..

    The sprayer was a self-propelled John Deere R4038 with a rear-mounted 36.5 meter (120′) boom. Treatments were eight corn rows wide, so the boom was nozzled to permit all three treatments in a single pass. Travel speed was between 8.85 – 11.25 km/h (5.5 – 7 mph) and the application volume was 225 L/ha (20 gpa).

    Nozzle choice is indicated in the following table. Note that after the first year, we elected to use a smaller droplet size on the Belugas; This gave the advantage of higher deposit density with little or no risk of drift from inside the canopy.

    YearBroadcast (Overhead)Directed (Beluga)Unsprayed Check
    1TeeJet AIC11005’s on 15″ centres4 Airmix 110015’s per drop on 30″ centresNozzles blocked
    2,3,4TeeJet AIC11005’s on 15″ centres4 Spray Max 110015’s per drop on 30″ centresNozzles blocked
    Treatment nozzles by year

    Two tank mix regimes were applied each year, as indicated in the following table. Tank Mix 1 was used each year. Tank mix 2 changed based on pesticide availability and the farmer cooperator’s preference. The insecticide “Delegate” (50 g/ac) was also included in each tank mix. However, there was very little evidence of the target pest (Western Bean Cutworm), so the impact of Delegate will not be discussed. Further, to keeps matters simple, we will not be discussing the relative efficacy of each tank mix in this article. Instead, the results are combined and only the application method and total cost of fungicides will be compared in this study.

    Tank Mix (Year)ProductRate (/ac )
    Tank Mix 1 (all)Miravis Neo405 ml
    Tank Mix 2 (2021)Headline AMP + Caramba303 ml + 405 ml
    Tank Mix 2 (2022)Veltyma + Proline202 ml + 170 ml
    Tank Mix 2 (2023)Veltyma DLX202 ml + 405 ml
    Tank Mix 2 (2024)Veltyma DLX202 ml + 405 ml
    Tank mix treatment rates by year.

    Qualitative Results

    Leaves

    In all four years, a qualitative comparison of randomly-selected ear leaves showed less evidence of disease in the fungicide treatments compared with the unsprayed check. Generally, there was also less evidence of disease in the Directed application treatments versus the Overhead broadcast application treatments.

    A typical random sampling of ear leaves were selected from multiple locations in the treatments. Leaves appeared cleaner in the fungicide treatments versus the unsprayed checks. Leaves from the Directed applications seemed cleaner than the Overhead broadcast applications.

    Cob Size / Quality

    In all four years, preliminary samples showed evidence of disease and tapered-ends in both fungicide treatments and the unsprayed checks, but trends indicated improved size and quality of the cobs from fungicide treatments. It was difficult to discern any difference between Overhead and Directed application at this stage.

    Typically, preliminary sampling showed less incidence of disease in the fungicide treatments but no obvious difference between methods of application.

    Quantitative Results

    Net Revenue

    Each treatment yielded corn with different moisture levels, so we chose not to compare bushels per acre harvested. Instead, we calculated net revenue for each year based on the current market values in the Port Rowan area. We normalized the treatment yields by moisture level and calculated their relative drying costs. Then we accounted for the other inputs (see list below) using the following formula:

    Net Revenue (CDN) = Seed Yield × Corn Sale Price – Drying Cost – Treatment Cost

    Item2021 ($)2022 ($)2023 ($)2024 ($)
    Corn Sale Price (/bu)6.008.006.506.00
    Custom Spray Cost (/ac)12.0012.0015.0015.00
    Drying Cost based on Moisture Levels (/bu)0.58-0.640.60-0.690.49-0.560.47-0.54
    Tank Mix 1 (/ac)16.6618.2418.5018.86
    Tank Mix 2 (/ac)15.7528.5222.0922.49
    Net revenue input costs and prices by year in Port Rowan, Ontario

    Averages were calculated for the eight replications for each treatment. These average yields (bu/ac), moistures and ROIs ($/ac) are presented for each treatment, for each year, in the table below. The average values of all four years are also presented in this table. With few exceptions, it always paid to spray, and the directed application produced a higher yield than the conventional overhead treatment.

    YearTreatmentYield (bu/ac)Moisture (%)Average ROI ($/ac)
    1Broadcast vs. Check-2.26+0.58-0.49
    1Directed vs. Check+3.48+0.60+20.93
    1Directed vs. Broadcast+5.74+0.01+21.42
    2Broadcast vs. Check+9.79+0.22+52.48
    2Directed vs. Check+14.56-0.04+89.14
    2Directed vs. Broadcast+4.77-0.26+36.66
    3Broadcast vs. Check+8.40-0.20+23.70
    3Directed vs. Check+22.7+0.20+117.10
    3Directed vs. Broadcast+14.4+0.40+93.40
    4Broadcast vs. Check+45.7+1.00+244.37
    4Directed vs. Check+43.7+0.80+232.09
    4Directed vs. Broadcast-2.10-0.20-12.28
    AllBroadcast vs. Check+13.40+0.40+69.07
    AllDirected vs. Check+19.60+0.40+107.00
    AllDirected vs. Broadcast+6.200.00+37.93
    Final accounting. Bold indicates a desirable outcome, while italics signify an undesirable outcome (n=8 per year).

    Return on Investment

    Given that costs changed each year, it’s not ideal to average the final costs. However, doing so gives a relative indication of the value of spraying versus spraying with overhead systems versus spraying with directed systems.

    • Directed (Belugas) vs. Unsprayed check: Profit of $107.00/ac CAD
    • Directed (Belugas) vs. Broadcast (Overhead): Profit of $37.93/ac CAD
    • Broadcast (Overhead) vs. Unsprayed check: Profit of $69.07/ac CAD

    Perhaps a more realistic review of the ROI is to calculate how many acres were required to pay for the Beluga system each year. In other words, how many acres would a grower have to spray for the profit to offset the cost of purchase? This value was different each year due to changes in costs and relative disease pressure.

    In 2021, 48 Belugas on (30″ centres) and 192 110 degree flat fans was $8,400.00 CDN. 2022: $8,600.00. 2023: $8,800.00. 2024: $8,890.00. Perhaps it was demand, or a change in dealers, or perhaps it was tariffs (or both) but in 2025: $13,500.00. Note that the break even point spanned from roughly 40 to 400 acres, but on average was less than 100 acres.

    Corn acres required to offset start up costs of the Beluga system from 2021-2024. A broad description of growing conditions and disease pressure in the test fields is noted for context. n=8 each year.

    While now a little out of date, the following video filmed by Real Agriculture discusses the return on investment based on 2021 and 2022 data.

    Mycotoxin Assays

    We submitted samples for lab analysis of mycotoxins for each treatment, annually. However there are many factors that influence ear mould pathogens, and we did not see any clear correlations between the fungicide, application method, or even the unsprayed check with the level of Deoxynivalenol (DON aka vomitoxin) or zearalenone detected.

    The Drop Hose Experience

    While cost and efficacy are key considerations, we felt it was also important to describe the utility and user-experience. This study focusses on the Port Rowan trials, but over the years several other Ontario farmers have adopted the Beluga system and reported on their experience. We have included their observations:

    • Installing and uninstalling the drops took roughly 90 seconds apiece, including moving the ladder.
    • Deflection was minimal, even when they were dragged perpendicular to the rows through headlands.
    • The factory mounting bracket permits the drop to be “keyed in” from either side, however this may have led to drop hoses occasionally detaching in shorter corn stands and on sharp turns. The weak point may be the plastic hose barb, which can be damaged if the drops detach from the mounting plates. Rather than the current slot positions of “9:30 and 2:30”, “11:00 and 1:00” may prevent detachment. One dealer, however, has redesigned the mounting plate and linkage to compensate.
    • Initially, it was a little unnerving not being able to see the spray but the operator quickly got used to it (see video below).
    • There was no issue folding the boom or driving between fields with the drops installed. They did note that the lugs on the front tires did contact the drops on tight turns, but adjustments were made.
    • There were issues with other sprayer types (e.g. New Holland Guardian) when folding the booms. Drops did not hang plumb during transport. One dealer developed new linkages to account for differences in boom design.
    • The drop hoses rinsed as easily as any nozzle. One dealer developed new hose-end plugs to facilitate rinsing.
    • There were initial concerns that using 015’s nozzles to maintain the target 20 gpa might cause plugging issues, but none occurred.
    • The drops were resilient. The operator bent the hoses by lowering the boom and then dragged them along the ground. They returned to plumb and appeared undamaged. One operator elected to use a NutraBoss Y-Drop mount to stiffen the top few inches of the Belugas (image below) but no other user found this necessary.
    • Once removed, the drops stored compactly and easily on a utility shelf, repacked in their original box or hung on the shed wall.

    Beluga drop hoses mounted on a NutraBoss frame

    Custom Operators

    Some custom operators have also begun to use the Beluga system and have reviewed it positively, but others question the fit. The latter feel this technology makes more sense for a home farm operation where the drops can be cut to a size that aligns the nozzles for a specific combination of boom height and corn variety. The concern is that a custom operator would have to adjust boom height (if not already maxed) or swap drop hoses to configurations that align correctly with the client’s crop. However, four years in, early adopters have collectively sprayed more than 20 different corn varieties with multiple sprayers and have had no issues reaching the target zone.

    Additionally, our study has focused on 20 gpa where some custom operators would prefer 15 gpa. Reducing volume necessitates a change in travel speed (may not be practical) or a reduction in operating pressure (may increase average droplet size). It would be inadvisable to drop from 015’s to 01’s (think plugs and misty spray).

    Both limitations translate to additional cost (currently about $2.00 CDN per acre) to a client. The value proposition becomes the added cost for an efficacious application versus the potential losses should conventional application methods fail to control devastating diseases such as Tar Spot and Northern Corn Leaf Blight.

    Adoption in North America

    Beluga drop hoses are distributed by Greenleaf Technologies in Covington, Louisiana and resold through dealers in the USA and in Ontario. It is not possible to determine how many sets have been sold, but if a boom is 100′ to 120′ and drops are placed every 30”, then a set would be 40-48 hoses. We started reporting on their value in corn protection in 2021. The following sales figures are annual sales (i.e. not cumulative) from Greenleaf Tech. This includes the 36″ hoses, which may or may not be used in corn. These figures will be updated annually:

    Conclusion

    With the exception of 2024, which was essentially parity between Overhead and Directed methods, we saw an annual increase in mean net revenue from corn sprayed using a directed application. The low price point, ease of use, and high rate of return make this an attractive proposition in corn production.

    Thanks to Petker Farm Ltd. and other early adopters for participating in the study. Thanks to Corteva and Syngenta for contributing the pesticides used.

  • Nitrogen Application Technology in Winter Wheat

    Nitrogen Application Technology in Winter Wheat

    With an ever growing selection of options for nozzles and streamer bars, many growers are asking the question, what should I outfit my sprayer with for winter wheat liquid fertilizer applications? Well, it depends on what are you trying to accomplish.

    If the goal is to push your winter wheat management and improve yields, then the accurate and uniform application of liquid nitrogen is key. Selecting the appropriate sprayer technology can have a huge impact. Using a twitter poll, we learned that growers use many methods:

    • 3, 5, 6 or 7 hole streamer nozzles
    • Flood nozzles
    • 3 or 5 hole streamer bars

    Let’s look at some of the options and consider why you might choose one technology over another.

    Floods on a Terra-Gator. Photo courtesy of Kyle DeCorte.

    Air Induction, Conventional Flat Fan or Flood Nozzles

    Let’s get this one out of the way first. Air induction (AI), conventional flat fan and flood nozzles are a no-go when it comes to applying 28% UAN in winter wheat. Dr. Peter Sikkema (University of Guelph) demonstrated that when 28% UAN was applied with an AI nozzle there was an increase in visual crop injury (Table 1).

    He also showed that injury increased substantially when tank-mixed with herbicides and when nitrogen applications were delayed (Table 2). So, while AI nozzles are great for herbicide applications, they are not suitable for 28%. Growers should consider fall weed control to avoid the need for spring herbicide applications.

    Table 1. Potential yield loss associated with applying UAN 28% as overall broadcast treatment using FloodJet or TeeJet nozzles. 11 gallon (Imperial) = 1.2 U.S gal. Source: P. Sikkema, University of Guelph (RCAT), 2008–2013 (OMAFRA Pub 811: Agronomy Guide).

    Application CombinationVisual InjuryYield
    200 L/ha water (18 1g/ac water)0%6.4 t/ha (95 bu/ac)
    150 L/ha water + 50L/ha UAN (13.4 g/ac water +4.5 gal/acre UAN)3%6.4 t/ha (95 bu/ac)
    100 L/ha water + 100L/ha UAN (9 g/ac water +9 g/ac UAN)5%6.1 t/ha (91 bu/ac)
    50 L/ha water + 150L/ha UAN (4.5 g/ac water +13.4 g/ac UAN)7%6.1 t/ha (91 bu/ac)
    200 L/ha UAN (18 g/ac UAN)9%6.0 t/ha (89 bu/ac)

    Table 2. Crop injury (%) and yield (bu/ac) of winter wheat following an application of 28% UAN (400 L/ha) alone with air induction nozzles and with various herbicides compared to an untreated control that received the same amount of nitrogen. Source: Dr. P.H. Sikkema, 3 trials from 2008-2010, University of Guelph (Ridgetown Campus) – Additional information on tank-mixing with herbicides can be found here.

    TreatmentHerbicide rate/acInjury (%)Yield (bu/ac)
    control (unsprayed)——0105
    28% UAN alone——6105
    28% UAN + Infinity0.33 L9104
    28% UAN + Buctril M0.4 L8103
    28% UAN + Estaprop XT0.48 L9102
    28% UAN + Refine M12 g + 0.36 L1799

    Streamer Nozzles

    Streamers significantly reduce crop injury when applying UAN 28% in winter wheat. Growers in Ontario are using a range of 3, 5, 6 and 7 hole nozzles. These nozzles provide even coverage and minimize burn compared to flat-fan or flood nozzles; however, boom height can have an impact on crop injury. This is particularly important with 3 and 6 hole streamer nozzles. If there are significant variations in boom height (e.g. uneven emergence, uneven land, or a boom with excessive sway and yaw), significant crop injury can occur. This is exacerbated by hot and dry conditions.

    The damage is the result of non-uniform coverage. Streamers deliver spray in a triangular shape. If the boom is too low gaps in the spray pattern reduce coverage. If the boom is too high the crop may receive increased overlap, resulting in crop injury. Therefore, these nozzles are an excellent option for apply UAN 28% to winter wheat crop (see image below) as long as boom height can be managed effectively.

    Pro tip: 28-0-0 often has crystals so strainers are important.

    UAN 28% being applied uniformly to winter wheat using 3 hole streamer nozzles. Photo courtesy of: Jim Patton.

    Streamer Bars

    Streamer bars (see image below) may be the best choice. Streamer bars deliver liquid nitrogen to the crop vertically. This allows for even distribution across the winter wheat crop at various boom heights, often permitting great speed. Some even have a sliding orifice to permit an easy transition between rates. Research performed in Kentucky showed that streamer bars produced a 2.8 bu/ac yield advantage compared to 3 hole streamer nozzles, and a 4.9 bu/ac yield advantage over 7 hole streamer nozzles.

    Some may argue those aren’t significant yield advantages, but most Ontario growers would argue differently. Streamer bars provide uniform coverage no matter the state of emergence, boom height, topography or even wind conditions. Streamer bars can be adapted to most sprayers and are available in 15″ or 20″ spacing. The only caveat is that they can be fragile and can make folding the boom difficult.

    Chafer streamer bar. Photo courtesy of Alex Zelem.

    Other Ways to Reduce Burn

    In addition to proper nozzle selection there are a few things you can do to reduce the risk of crop injury from N applications.

    • Avoid applications of 28% when the crop is stressed or during hot and dry conditions.
    • If conditions are more conducive for crop injury, increasing water volumes or applying less N can also help reduce burn significantly.

    At the end of the day it is important to remember the end goal – maximize yield potential. If we can deliver UAN 28% as uniformly as possible to a standing winter wheat crop while minimizing crop injury, the 100+ bu/ac wheat crop will be well worth the effort.

    Here’s Peter Johnson (@WheatPete) to tell you more in this RealAgriculture Wheat School episode: