Tag: label

  • Don’t try this tempting shortcut

    Don’t try this tempting shortcut

    There’s a call that I’ve been getting for 20 years now. It came again this week. Someone has a twincap with two small air-induced tips, and they’re applying herbicides and fungicides with low water volumes, often 5 gpa, sometimes less. They call because they want to know how much wind they can spray in. Is 30 km/h OK? They want my blessing.

    I don’t need to hear much more. Some nozzles are sold entirely on the premise that they provide superior coverage – more droplets per square inch – and that this improved coverage permits the reduction of water volumes. Furthermore, the claim goes, when water is reduced, the spray concentration increases and the whole darn package just works a lot faster and better.

    This line of thinking is as old as spraying itself. Applicators seek pesticide performance as well as productivity, and this approach gives them both. The proponents are well aware of their customers’ desires, and sell into it. “Use these tips and cut back on water. Any more than this just runs off anyways. You’ll get better coverage and better performance, get more spraying done.” It’s a convincing argument. Get an edge on your neighbour, the person who’s not in on the secret and is wasting time and water.

    Why don’t I embrace it? There are a few reasons.

    First, it doesn’t tell the whole story. Invariably it involves a twin nozzle setup. Use two nozzles, get more droplets, right? If that were true, believe me, I’d be advocating for quintuples.

    Fact is that the only factors that change droplet numbers are droplet size (spray quality) and water volume. Want more droplets at the same water volume? Make the spray finer. Want to keep spray quality and add droplets? Add water (not nozzles).

    The easiest way to improve coverage at the same volume is to use a finer nozzle, or to increase spray pressure. Depending on how far you go, you could make the spray finer and cut water, and still have more droplets per square inch.

    The hardest way to improve coverage is to purchase a twincap and buy two nozzles, each of them half the size. True, within any given nozzle type, smaller sized tips usually generate finer sprays. But why bother with two tips? They’re more expensive and plug more.

    If someone asks me how to improve coverage without changing water volume, I usually tell them to speed up a few mph. The rate controller will increase pressure and the spray gets finer. If speeding up is not possible, get one size smaller nozzle and run at higher pressure, same speed. Or keep nozzle and speed, and add some gpa, pressure will go up. It’s that easy. No twins necessary.

    Second, the twin nozzle/low volume approach exaggerates the value of the twin nozzle for herbicides. With small plants and relatively open canopies in the early season, plus our high booms and travel speeds, the twin tips are not adding a lot, if anything at all, to coverage. It remains a sum of droplet size and water volume, the angle is not important at this stage. Deposit is by turbulence and wind, most of the time.

    Third, low volume believers ignore a few potential problems. Drift is a big one. Low volume, fine spray operators are surrounded by nervous neighbours. They have fewer hours per day during which drift is acceptably low. And they definitely should not be on the field when wind is at 30 km/h. Basically, they’re a bit uncomfortable (at least they should be) and get less done per day.

    Another potential problem is evaporation. Most sprays, even when applied at lower volumes, are still 90% or more water. The same volume of water evaporates much quicker when atomized into smaller droplets. This has two main downsides: On their way to the canopy, small droplets evaporate and become even more drift prone, and may not impact at all. Those that impact evaporate shortly thereafter. Research has shown that pesticide uptake is better from wet than dry deposits.

    When Delta T (dry bulb minus wet bulb temperature) is high, evaporation can be so strong that it reduces pesticide performance or causes solvent burn. Fine sprays make it worse.

    I also hear about the use of oily adjuvants to control evaporation from small droplets. This could be even more dangerous. Small droplets drift, and evaporation to dryness is actually helpful in reducing the impact of that drift. How? It makes the small droplets disappear, with their remnants dispersing into the turbulent atmosphere. With oily adjuvants, the small droplets stick around and stay potent and their drift damage is much worse.

    Lastly, the practice is possibly off label. Water volume and spray quality label statements are designed to offer good performance and acceptable drift risk. While that part of the label is often a bit dated, it does provide better support from the manufacturer should something go wrong.

    If you’re spraying under hot, dry and windy conditions, the low volume, fine spray approach is irresponsible. Use sufficient water (7 to 12 gpa) to allow low-drift sprays, at least Coarse to Very Coarse, in some case, even coarser.

    Agronomists provide the best possible information for their clients, based on scientific evidence and experience and in accordance with their professional code of ethics. Sometimes the news we deliver aren’t what the customer wants to hear. But we have to represent the interests of all of us, collectively. I find that pretty important.

  • Pesticide Safety for Student Workers

    Pesticide Safety for Student Workers

    This article is based on a presentation by Dr. Melanie Filotas, who delivered it as part of the 2019 agriculture summer student orientation day.

    Most crops are sprayed with organic or synthetic pesticides at some point during the growing season. Use caution before entering any area where crops are grown (e.g. corn field, nursery, greenhouse, orchard etc.). Always confirm that it is safe to enter.

    Most crops receive some form of chemical input during growth. Be aware of what has been applied.
    Even organic operations apply controlled products that may make it unsafe to enter for a period of time.

    You can be exposed to pesticides if you enter a treated area before pesticide residues break down and vapours dissipate. The minimal time that must elapse before being permitted to enter is called the Restricted Entry or Re-entry Interval (REI).

    REIs are data-driven and established by the federal government. They are defined as: “The period of time that agricultural workers, or anyone else, must not do hand labour in treated areas after a pesticide has been applied.” Hand labour can be any task involving substantial contact with treated plants, plant parts or soil, including planting, harvesting, pruning, and scouting.

    Things you should know about REIs:

    • REIs can range from one hour to several days
    • If a pesticide label does not indicate a REI, the default is 12 hours
    • REIs can vary with the product, crop and type of activity (e.g., scouting, harvesting, etc.)
    • REIs can change over time so always refer to the most recent label
    • If a tank mix (multiple products) was applied, observe the most restrictive REI

    Before visiting an operation to work in the field:

    • Tell your supervisor where you will be that day
    • Ask the grower or spray applicator what was sprayed. Records may be posted, but verbal confirmation is preferred
    • Look up the REI for the product on the crop you will be entering
    • Check with your supervisor on any products with special instructions beyond the REI

    Do not enter the field until the REI has ended. Pesticide REIs can be found in local production guides, or on pesticide labels.

    Local production guides summarize REIs.
    Local production guides list REIs by crop, by product applied, and by activity.

    If local production guides are not available, registered pesticide labels can be found using Health Canada’s Pesticide Label Search service online. In the United States, most labels can be found on the EPA’s Pesticide Product and Label System website.

    Health Canada’s online pesticide label search.

    Miscommunication can sometimes happen. Learn to recognize the signs of spraying. When in doubt, leave the planted area and call the grower to confirm or call your supervisor.

    • In some cases you can look for fresh tracks in the operation, but be aware they may not have been made by a sprayer
    • Some products have a distinctive odour
    • It can be difficult to see a sprayer operating, particularly in orchards, but they can be heard. Do not wear earbuds or headsets while in a production area
    • Look for foliar residue. This is an indicator, but does not always mean it is unsafe to enter
    Fresh wheel tracks may indicate recent spraying.
    Some products have a distinctive odour.
    It may be difficult to see a sprayer operating in the vicinity, such as in this orchard. However, they can often be heard. Do not wear a headset or earbuds in a production area.
    Residue on leaves may indicate a recent application, as in the left photo. However, it could also be unrelated. On the right is calcium magnesium precipitation from irrigation water. (Photo credit [right]: Jennifer Llewellyn)

    There are many potential symptoms of pesticide exposure: headache, fatigue, irritation of the skin, eyes, nose or throat, loss of appetite, dizziness, nausea or vomiting, diarrhea, decreased muscle coordination, and blurred vision. Each product has a Material Safety Data Sheet (MSDS) that will provide details on exposure symptoms and treatments.

    While sometimes confused with symptoms arising from sun stroke or dehydration, if you suspect pesticide exposure it is always best to be prudent and get medical help immediately. Contact your local poison centre or 911.

    Summer work in crop production can be rewarding and enjoyable, but always use caution and be safe.

  • Rainfastness of Insecticides and Fungicides on Fruit

    Rainfastness of Insecticides and Fungicides on Fruit

    This article was co-authored by Kristy Grigg-McGuffin, OMAFA Horticulture IPM Specialist

    In view of the frequent heavy rains in many regions this season, understanding rainfastness, or the ability of a pesticide to withstand rainfall, is important to ensure proper efficacy. All pesticides require a certain amount of drying time between application and a rain event. Typically, residue loss by wash-off is greatest when rain occurs within 24 hours of spraying. After this point, the rainfastness of a product will depend on formulation, adjuvants and length of time since application.

    Rainfastness of Insecticides

    John Wise, Michigan State University has studied rainfastness of common tree fruit insecticide groups and his findings are summarized below. For the complete article, refer here. Note that some products listed in this article may not be registered for use in Canada. Check with your local supplier or in Ontario, refer to OMAFA Publication 360 for a complete list of registered products.

    According to Wise, the impact of rain on an insecticide’s performance can be influenced by the following:

    1- Penetration

    Penetration into plant tissue is generally expected to enhance rainfastness.

    • Organophosphates have limited penetrative
      potential, and thus considered primarily surface materials.
    • Carbamates and pyrethroids penetrate the cuticle,
      providing some resistance to wash-off.
    • Spinosyns, diamides, avermectins and some insect
      growth regulators (IGR) readily penetrate the cuticle and move translaminar (top
      to bottom) in the leaf tissue.
    • Neonicotinoids are considered systemic or
      locally systemic, moving translaminar as
      well as through the vascular system to the growing tips of leaves (acropetal
      movement).
    • For products that are systemic or translaminar,
      portions of the active ingredient move into and within the plant tissue, but
      there is always a portion remaining on the surface or bound to the waxy cuticle
      that is susceptible to wash-off.

    2- Environmental persistence and inherent toxicity

    Environmental persistence and inherent toxicity to the target pest can compensate for wash-off and delay the need for immediate re-application.

    • Organophosphates are highly susceptible to
      wash-off, but are highly toxic to most target pests, which means re-application
      can be delayed.
    • Carbamates and IGRs are moderately susceptible
      to wash-off, and vary widely in toxicity to target pests.
    • Neonicotinoids are moderately susceptible to
      wash-off, with residues that have moved systemically into tissue being highly
      rainfast, and surface residues less so.
    • Spinosyns, diamides, avermectins and pyrethroids
      are moderate to highly rainfast.

    3- Drying time

    Drying time can significantly influence rainfastness, especially when plant penetration is important. For instance, while 2 to 6 hours is sufficient drying time for many insecticides, neonicotinoids require up to 24 hours for optimal penetration prior to a rain event.

    4- Adjuvants

    Spray adjuvants that aid in the retention, penetration or spread will enhance the performance of an insecticide.

    The following tables can serve as a guide for general rainfastness to compliment a comprehensive pest management decision-making process. They are adapted from “Rainfast characteristics of insecticides on fruit” by John Wise, Michigan State University Extension.

    Based on simulated rainfall studies to combine rainfastness with residual performance after field-aging of various insecticides, including carbamates (Lannate), organophosphates (Imidan, Malathion), pyrethroids (Capture), neonicotinoids (Assail, Actara, Admire), IGRs (Rimon, Intrepid), spinosyns (Delegate) and diamides (Altacor), Wise recommends the following re-application decisions for apples. Additional work was done on grapes and blueberries; see Wise’s article for this information. Among the crops, variation in rainfastness of a specific insecticide occurs since the fruit and leaves of each crop have unique attributes that influence the binding affinity and penetrative potential.

    • ½ inch (1.25
      cm) rainfall:       All products with 1-day old residues could withstand ½ inch
      of rain. However, if the residues have aged 7 days, immediate re-application
      would be needed for all products but Assail, Rimon, Delegate or Altacor on
      apples.
    • 1-inch (2.5
      cm) rainfall:       In general, most products would need re-application following
      a 1-inch rainfall with 7-day old residues, whereas Delegate and Altacor could
      withstand this amount of rain on apples and would not need to be immediately
      re-applied. Some products such as Imidan on apples could withstand 1 inch of
      rain with 1-day old residues.
    • 2-inch (5
      cm) rainfall      : For all products, 2 inches of rain will remove enough
      insecticide to make immediate re-application necessary.

    It is important to note, not all products registered for the selected pests were included in this study. Refer to Publication 360 for a complete list of management options.

    Rainfastness of Fungicides

    There is no comparable research on rainfastness of fungicides and few labels provide this kind of information. A general rule of thumb often used is that 1 inch (2.5 cm) of rain removes approximately 50% of protectant fungicide residue and over 2 inches (5 cm) of rain will remove most of the residue. However, many newer formulations or with the addition of spreader-stickers, some products may be more resistant to wash-off. Avoid putting on fungicides within several hours before a rainstorm as much can be lost to wash-off regardless of formulation. As well, there are exceptions to the general rule in regard to truly systemic fungicides such as Aliette and Phostrol.

    The effectiveness of sticker-spreaders with fungicides is variable and product/crop specific. Penetrating agents don’t help strobilurins; in fact, some fungicide/crop combinations have been associated with minor phytotoxicity due to excessive uptake. Captan, which is intended to stay on the surface, is notorious for causing injury when mixed with oils or some penetrating surfactants that cause them to penetrate the waxy cuticle.  Consult labels for minimum drying times for individual products and recommendations for using surfactants. 

    Annemiek Schilder, Michigan State University suggests the following to improve fungicide efficacy during wet weather:

    • During rainy periods, systemic fungicides tend
      to perform better than protectant (or contact) fungicides since they are less prone
      to wash-off.
    • Applying a higher labelled rate can extend the
      residual period.
    • Apply protectant fungicides such as captan
      (Supra Captan, Maestro), mancozeb (Manzate, Dithane, Penncozeb) and metiram
      (Polyram) during sunny, dry conditions to allow for quick drying on the leaves.
      These types of fungicides are better absorbed and become rainfast over several
      days after application.
    • Apply systemic fungicides such as sterol
      inhibitors (Nova, Fullback, Inspire Super), SDHI (Fontelis, Sercadis, Kenja, Aprovia
      Top, Luna Tranquility) and strobilurins (Flint, Sovran, Pristine) under humid,
      cloudy conditions. The leaf cuticle will be swollen, allowing quicker
      absorption. In dry, hot conditions, the cuticle can become flattened and less
      permeable, so product can breakdown in sunlight, heat or microbial activity or
      be washed off by rain.

    Click here to refer to the complete article.

  • Do Labels Help us Apply Pesticides Properly?

    Do Labels Help us Apply Pesticides Properly?

    It happened three times this spring.  As is often the case, I was contacted by growers who wanted help with herbicide application.  In most of these calls, the discussion revolves around the proper choice of nozzles for a specific task, perhaps some questions on spray pressure, water volume and travel speed.

    But these three were different.  Instead of being seasoned applicators, all three were new to the business.  And more importantly, they had done their homework by looking at product labels before calling.

    Labels give us important information on product rates, crop and weed staging, mixing order, sprayer cleaning, and personal and environmental protection.  They’re very valuable there.  But they also provide application information, and that’s where the problems begin.

    Perseverance Required

    I have to commend my three clients:  they showed great tenacity by actually finding application information on a pesticide label in the first place.  This document is so mired in legalese protectionist language at the front that it discourages all but the most persistent.

    And often, the application information comes in several parts, interspersed among other information.  Mixing instructions.  A little later, application. Somewhere nearby, buffer zones.  Another paragraph for cleaning.  Rainfastness?  Keep looking.

    It forces the reader to skim through the document, hunting for relevant information.

    But once my clients found application instructions, they obviously questioned if they should believe it, or else they wouldn’t have called.  The application statements on many labels, simply put, are from long ago, and it’s obvious.

    Consider the following two label excerpts, the first from a product initially registered in the mid 1980s and still available, the second from one registered about 30 years later:

    1980s:

    Application should be made using a minimum of 55-110 litres of water per hectare, at a pressure of 275 kPa, or 310 kPa if using check valves, and at a ground speed of 6-8 kph.

    The use of 80° or 110° flat fan nozzles is recommended for optimum spray coverage.

    Do not use flood jet nozzles, controlled droplet application equipment or Sprafoil® equipment.

    Application of the spray at a 45° angle forward and higher water volumes will result in better spray coverage and penetration of the crop canopy.

    Uniform, thorough coverage is important to obtain consistent weed control. Higher water volumes should be used under dense crop and weed canopies to ensure thorough coverage of the target weeds.

    2010s:

    Apply in a spray volume of 46.8 – 93.5 L/ha unless otherwise specified in tankmix partner section of this label – at 207-345 kPa (30-50 PSI) pressure to ensure proper weed coverage.

    Flat fan nozzles of 80° or 110° are recommended for optimum coverage.

    Do not use floodjet or controlled droplet application equipment or Sprafoil® equipment.

    Nozzles may be oriented 45° forward to enhance crop penetration and to give better weed coverage.

    Uniform, thorough coverage is important to obtain consistent weed control. Higher water volumes should be used under dense crop and weed canopies to ensure thorough coverage of the target weeds.

    Thirty years apart, but remarkably similar.

    Crop protection companies spend about 10 yrs. and $250 million to produce a new pesticide and register it for use.  Having made this commitment, it would be most useful to see a small further investment to provide current application information that is relevant to applicators.

    After all, these applicators purchase the active ingredient to provide a return on this multi-million dollar investment, to the tune of about 2 billion dollars per year in Canada alone. They deserve good application information.

    Imagine this scene:

    “Doctor, thank you for this new high tech pharmaceutical engineered to help me with my serious illness.  How should I take it?”

    “Not sure.  Here, read this cough syrup label I found in my drawer.  Should be pretty close.”

    It’s clearly ridiculous

    Let’s dissect these labels to see how they could be improved.

    Flat fan nozzles of 80° or 110° are recommended for optimum coverage…

    Our sample labels refer to what we assume are conventional flat fan nozzles.  While popular in the 80s, these have all but disappeared from sprayers over the course of the past 20 years or so.  We haven’t recommended them since then because they drift too much. They’ve been replaced by low-drift nozzles, either pre-orifice, or air-induction.

    Nozzle fan angles are now generally 110 degrees or more, and frankly, the difference between 80 and 110 degrees is not that important.  What’s important is proper overlap, achievable with a visual assessment followed by boom height and pressure adjustments.  Unfortunately the label is silent on that.

    Application should be made … at a pressure of 275 kPa, or 310 kPa if using check valves…

    A nozzle’s recommended operating pressure depends on the specific nozzle model and on the spray quality (average droplet size) required. With literally many dozens of nozzles now available to each applicator, general pressure suggestions are likely to be wrong, and are more of a liability than a help. And they force label non-compliance when over-ruled by a nozzle manufacturer’s recommendations.

    Speaking of spray quality, growers crave to know at what spray quality a product should be applied for best performance and lowest drift. Some labels refer to spray quality (e.g. “apply with a Coarse spray”), but this is with reference to spray drift and buffer zone distances, not efficacy, and that distinction is not made.  Knowing the right quality for efficacy would help applicators choose the right nozzle and pressure to meet that criteria.

    Higher pressures if using check valves?  Nobody has brass screens with check valves anymore.  Sprayers have had modern diaphragm check valves for a generation, and those don’t produce pressure losses.

    And we all know that six to eight km/h is hardly a common speed these days.

    Do not use floodjet or controlled droplet application equipment or Sprafoil® equipment

    Sprafoil nozzles have not been produced in Canada for about 25 years, in fact their manufacturer is no longer in business.  Controlled droplet atomizers, while becoming more popular again on aircraft, were last seen on ground sprayers in the 1980s. Even then, total installed numbers were probably in the single digits.

    As for FloodJet nozzles, those went out of style for herbicides in the late 70s, and were replaced by the very successful TurboTeeJet nozzles shortly after.

    Nozzles may be oriented 45° forward…

    Nozzles are rarely tilted 45 degrees forward for herbicide application anymore.  Maybe that’s because spray booms aren’t built that way today, or because modern booms on self-propelled sprayers are now about 30” (75 cm) above ground, and we travel at about 15 mph (22 km/h).  So the forward tilting, though shown to be effective for grassy weeds at 5 mph (8 km/h) and 20” (50 cm) boom heights, as researched in the 1970s, isn’t relevant for herbicides with higher booms.

    Uniform, thorough coverage is important to obtain consistent weed control.

    Statements advocating for good coverage are nice, but they aren’t useful.  Everybody knows we want good coverage.  What applicators need to know is how they should measure coverage, and what good coverage actually is.  Can we use water-sensitive paper?  How much of the target should be covered?  How many droplets should be in each square centimetre?  How can we measure that in the field, right now? How does it depend on the crop canopy, on weed stage, and on spray quality? The more information an applicator gets, the higher the chance of success.

    Apply in a spray volume of 46.8 – 93.5 L/ha…

    The only statement that survives our little examination is about water volume. Water volume is important.  But even there we have a problem.  The volume is in L/ha.  This is useful in some parts of Canada, but not in the west, where producers communicate primarily in US gallons per acre.  And in the west, provincial guidelines have generated this odd hybrid of L/acre, which few people use for spray volume.  But 46.8 to 93.5 L/ha?  How is that level of precision justified? (I know that this is a conversion from 5 and 10 US gpa…so why not just say so?)

    A Solution

    The problem with having outdated or impractical information on labels is that it creates disrespect.  Since labels are documents enforceable by federal law, applicators want to comply. At this time, they can’t, and probably shouldn’t, if they want to do the job right.

    A vision for a good label should be one that respects the needs of the applicator.  Such a label:

    • places the information that applicators need at the top;
    • is updated regularly to reflect modern practice and useful advice;
    • helps a new applicator work out how to apply the product with any equipment;
    • identifies a spray quality that offers good coverage and low drift;
    • makes reference to research that supports variations in the application guidelines;
    • is available electronically, readable on a mobile device, i.e., not pdf.

    This label would protect the environment and bystanders, and would foster better pesticide performance.

    This label is easy to generate.

    This label would be read by applicators.

    What’s it going to take?

    Additional:

    This article created a great deal of discussion. We decided that if we were going to point out issues with the current labelling system, we should also propose a way forward. Read about our Label Summary Sheet proposal.

  • Biopesticides: Holy Grail or Giant Pain?

    Biopesticides: Holy Grail or Giant Pain?

    Biopesticides are a rapidly growing segment in horticultural pest control. While they are often billed as green “miracle cures”, applicators should be aware that they require unique considerations. Issues with lifespan, target specificity, and application technology can all impact their efficacy. However, like any pesticide application, careful planning can minimize wasted time and money.

    Typically defined as pesticides derived from “natural” sources, biopesticides contain active ingredients extracted from plants, microorganisms, animals, and/or certain minerals. Given their origin, and the fact that many biopesticides are living organisms (as is the case with most of the microbial-based pesticides), they are often photo-sensitive and quickly break down. This generally means that they need to be re-applied often.

    Mixing and handling

    Pre-suspending nematodes before inoculating the spray tank.
    Pre-suspending nematodes before inoculating the spray tank.

    Consideration should also be given to the lifespan of these products during the application. Many have an optimum pH for both the carrier water and the soil, and a limited temperature range outside of which they may not be active. As already mentioned, direct sunlight can quickly degrade many biopesticides, which means they should be applied either early or late in the day. Timeliness is also a factor: efficacy can be greatly reduced if the product is not used quickly – many biopesticide organisms begin to break down as soon as they are tank mixed. Also, be aware that it can be difficult (or impossible) to find suitable tank-mix partners. For example, a fungal biopesticide obviously shouldn’t be mixed with a fungicide. That also leads the applicator to consider their spray program carefully and clean their sprayers thoroughly between applications.

    Efficacy

    Applicators should understand how each biopesticide is supposed to control (or more likely, supress) pests. Many biopesticides have to be ingested or physically contact the pest. As such, they often need high application volumes to ensure sufficient coverage of all target surfaces. Many are slow to control the pest, so the applicator may mistakenly think the product is not working, and reapply unnecessarily.

    Application equipment

    Cleaning a strainer - image courtesy of M. Lanthier.
    Cleaning a strainer – image courtesy of M. Lanthier.

    Applicators may need to reconsider their current equipment when using biopesticides. If the product has to contact the pest, high droplet density is preferred. This can be accomplished with high volumes, but also with higher droplet counts, and that means smaller droplets. Drift issues aside, many biopesticides are actually living organisms (e.g. nematodes) which might be negatively affected by the small nozzle orifice.

    The “Spray Guy”, Dr. Jason Deveau, (Application Technology Specialist with the Ontario Ministry of Agriculture, Food and Rural Affairs) suggests using a nozzle with a larger exit orifice and no pre-orifice to minimize clogging or any potential damage to the microorganisms. Clogging can be further reduced by using a minimum of three levels of filtration on a sprayer. With proper agitation, a tank basket, suction filter at the pump and slotted strainers behind each tip should catch any “chunks”. In-line filters at the boom are also potentially helpful. Each filter, from tank to nozzle, should be filter smaller particles than the last. Cleaning screens diligently and inspecting the effectiveness of the agitation system, should be part of every spray day.

    Applicators can account for many of these issues by understanding what the biopesticide is and how it is intended to work. Consider these questions:

    • When is the pest active/vulnerable?
    • Under what conditions does the product need to be used to be most effective?
    • Are there special handling or mixing considerations?
    • What do I need to have in place to minimize the time between mixing and applying the product?

    Ultimately, an effective application of biopesticides relies on integrated pest management (IPM). Biopesticides can work as advertised when used thoughtfully and appropriately. Understanding the products benefits and limitations will ensure applicators reap the full benefits of these new and evolving methods of control.