Illinois Pesticide Review
July / August 2014
In This Issue
University of Illinois Spray App Now Available
University of Illinois Extension has released a new smartphone app for making sprayer-related calculations. Pesticide Spray Calculator, or Spray Calc, is available for both Apple and Android smartphone platforms. It contains multiple functions related to calibrating a sprayer.
The opening screen (Figure 1) allows the user to select from one of four main options:
1. Calibration: allows user to calibrate four different sprayers types.
2. PSI for GPM: allows user to calculate required pressure in order to provide a specific flow rate, or do the opposite.
3. Nozzle Speed: determine minimum and maximum speeds for a specific nozzle.
4. Convert Value: various pesticide application related unit conversions.
Throughout the app, help menus are available to provide guidance as to the function of various app components, as well as definitions for many of the variables listed. For most variables, touching the name of the variable brings up a definition of what the variable is and how it is measured.
Selecting "Calibration" leads to a screen with four options: Aircraft, Ground Rig, Turf Boom, and Boomless. Within each section, calibration scenarios can be saved for future reference and for values to be loaded into some of the other functions available on the app. Each option will be discussed separately.
The aircraft option has two different screens. The first screen (figure 2) allows the user to enter their speed in miles per hour, desired swath width in feet, the GPA (gallons per acre) of spray to be applied, and the total number of nozzles on the boom. The required flow rate for the boom is calculated, as well as the required flow rate for each individual nozzle. The user can save the entered values with a name of their choice, and, if so desired, slide to the second aircraft calibration screen for more calibration options.
The second aircraft calibration screen (figure 3) allows the user to fine-tune number of nozzles, orifice size, and operating pressure in order to achieve the required boom GPM flow rate. It also allows the user to use up to two different orifice sizes on the boom in order to achieve the required boom GPM. The needed boom GPM from the first screen is carried over from the first screen.
Users can the select how many different orifice sizes they want on the boom (one or two) and the operating pressure (psi or pounds per square inch) they want to operate at. For each orifice size, they need to enter the flow rate provided by that orifice size at 40 psi (example: a 4010 flat fan nozzle provides 1.0 GPM at 40 psi) and the number of nozzles with that orifice size. The app will calculate the total GPM for all nozzles of that size, as well as the total for the entire boom. If only one orifice size is used, the total for nozzles and boom total will be the same. The user can change any of the variables until the boom total at the bottom matches the needed boom GPM at the top.
Ground Rig Calibration
This function consists of a single screen and can be used to calibrate a ground rig sprayer. The user enters the speed at which the application will be made in miles per hour, the nozzle spacing in inches, and the targeted GPA. The app calculates the required nozzle flow rate in gallons per minute. Similar to the aerial function, each application scenario can be saved with a user-determined name for future reference and use in other app functions.
Turf Boom Calibration
The turf boom function is identical to the ground rig function except that the spray application rate is entered as gallons of spray per 1,000 square feet instead of gallons per acre. This function can be used to calibrate boom sprayers used to make broadcast applications to turf with products labeled using spray application rates in gallons per 1,000 square feet. Each application scenario can be saved with a user-determined name for future reference and use in other app functions.
The boomless function is identical to the ground rig function except that swath width in feet is entered instead of nozzle spacing in inches. This function can be used to calibrate sprayers set up with off-center type nozzles that are typically used to make applications to rights-of-way areas and pastures. Each application scenario can be saved with a user-determined name for future reference and use in other app functions.
PSI for GPM
This function allows the user to do one of two things. The first is to calculate the required pressure at which to operate a nozzle in order to achieve a specific flow rate. This can occur when the required flow rate for an application is not specifically listed in a nozzle manufacturer's flow rate table. To make this calculation, the user needs to know a flow rate and associated psi. This is easily determined by the name of the nozzle. For example, an XR11004 is an extended-range nozzle (XR) with a 110-degree spray angle. The last two digits provide the flow rate for the nozzle at 40 psi by placing a decimal point between them: 0.4 GPM. So if you wanted to use a XR11004 nozzle to provide a 0.36 GPM flow rate, you would need to operate it at 32.4 psi (figure 4).
Another way to use the PSI for GPM function would be if an applicator wanted to operate a nozzle at a specific pressure. This might occur in order to create a droplet spectrum required by a label. As with the previous usage, users must enter a known flow rate and pressure for the nozzle. They then enter the psi at which they wish to operate the nozzle and the app will calculate the GPM generated by the nozzle at that pressure.
This function can be used to determine the maximum and minimum speeds at which a nozzle should be operated. It should be used when an applicator has a sprayer equipped with a flow control system. Flow control systems automatically maintain an applicator-selected spray application rate. They do so, however, by adjusting pressure. As a sprayer is operated faster, nozzle flow rate must be increased in order to maintain the set GPA. Unless the sprayer is outfitted with a pulse width modulation control system, the flow controller has to increase pressure in order to increase flow rate. A similar thing happens when the sprayer slows down – pressure is reduced to reduce nozzle flow rate so that the GPA is maintained.
The factor limiting the speed range of the sprayer, therefore, is the operating pressure range for the nozzle. The nozzle speed function is used to calculate the sprayer speeds that correspond with the upper and lower pressure limits of the nozzle. The applicator enters the nozzle spacing and the targeted GPA (figure 5). Next, the applicator refers to the flow rate table for the nozzle that will be used; GPM min operating pressure is the nozzle flow rate in GPM when the nozzle is operated at its lowest pressure; GPM max operating pressure is the nozzle flow rate in GPM when the nozzle is operated at its highest pressure.
For an XR110004, the minimum pressure is 15 PSI and the maximum pressure is 60 PSI (figure 6). At 15 PSI, the flow rate is 0.24 GPM; at 60 PSI the flow is 0.49 GPM. When these values are entered into the nozzle speed function, the app calculates the minimum operating speed as 7.13 MPH and the maximum operating speed is 14.55 MPH. Keeping the sprayer within this speed range will ensure the nozzle is operated within its pressure operating range. It will not, however, prevent the droplet spectrum from changing. As can be noted in figure 6, an XR110004 will produce a medium (M) droplet spectrum at 15 PSI, but it will change to a fine (F) droplet spectrum at 60 PSI.
The convert value function allows the user to convert various values commonly associated with pesticide applications. The list of values that can be converted is by no means exhaustive and will likely be expanded as the app is updated. The top section of the convert value screen allows the user to select the type of values to be converted. These include flow rates, spray rates, rate conversions for volume per unit area, weight per unit area, and weight per volume.
Once the user has selected the type of value they wish to convert, they select the unit they wish to convert from and the unit the wish to convert to. For example, figure 7 shows the function being used to convert a gallons-per-minute nozzle flow rate into a fluid-ounces-per-minute nozzle flow rate.
Spray Calc was created to assist applicators
with many of the calculations used to calibrate and set up a sprayer. In the
future, functions to assist with tank mix calculations will be added along with
other possible functions. If you have any questions or suggestions about Spray
Calc, please contact Scott Bretthauer at email@example.com. Spray Calc is available at these links: https://itunes.apple.com/us/app/sprayer-calibration-calculator/id899216316?mt=8
US-EPA Releases New Label Review Manual
The US-EPA has released a new Label Review Manual (LRM) in May 2014. According to the manual, "the goal of the LRM is to improve the quality and consistency of labels" and helping state label reviews, registration and others in producing readable and unambiguous labels.
Additionally, "[p]esticide product labels provide critical information about how to safely handle and legally apply pesticide products. Unlike most other types of product labels, pesticide labels are enforceable, and all of them carry the statement: 'It is a violation of Federal law to use this product in a manner inconsistent with its labeling.'"
As we constantly state in trainings, the "label is the law."
According to the US-EPA website, they consider the document to be an instructional aid that does not establish new guidance, but instead compiles existing interpretations of statutory and regulatory provisions and reiterates existing Agency policies.
The LRM is divided into some interesting and easy-to-read chapters that tend to follow those sections on current labels: General Label Requirements, Ingredient Statement, Use Classification, Precautionary Statement, Environmental Hazards, Worker Protection Labeling, Directions for Use, and Storage and Disposal. There are also chapters on less common topics, such as Labelling claims, Graphics and Symbols, and Physical and Chemical Hazards.
One of the largest chapters is Worker Protection Labeling. While the purpose of the LRM is for labels, this chapter (like many of the others) is a great reference on what is required for worker protection.
The Worker Protection Labeling chapter puts in one place the requirements for minimum clothing, as well as standards for gloves and respirators. Some of this is new language approved by NIOSH (National Institute for Occupational Safety and Health). For example, new labels that follow the new language in the LRM will now conform to current standards for descriptions of respirators and filters to use for each type of pesticide. The same would apply for gloves.
The charts in this section would be GREAT for posting as reference if you use products requiring special respirators or gloves.
So what does this mean for you?
Well, generally most people reading this aren't producing a label for a product, but ultimately you will be reading a label. In the future, hopefully labels are going to be easier to read and follow. You won't be referenced to a product that might have been registered years ago. False and spurious claims won't be allowed. Confusing wordings hopefully will be a thing of the past.
There should be less confusion in the future in the selection of the correct gloves and respirator and filters and when purchasing gloves and respirators. Until now, there has been multiple ways labels have identified the same glove or respirator with some labels retaining outdated designations.
Of course, this won't happen overnight. As long as a product isn't changed, the old label will still apply, and of course, you MUST follow that label.
But as companies create different products and formulations, the new guidelines will apply. Labels will slowly change. And hopefully for the better.
For more information, click on the link below to access the new LRM.
Are You Using the Right Type of Gloves?
Many pesticide labels state gloves should be worn when using the product. While it is a recommended practice to ALWAYS wear gloves when using pesticides, it is completely label-driven. If the label doesn't state the need to wear gloves (in the mixing and loading, application, or clean-up), then technically you don't have to.
But what types of gloves are acceptable?
The new Label Review Manual (see article in this issue) should help companies to state more accurately which gloves should be used. While current labels may state what types are acceptable, they only provide "the type." Most labels don't go that next step and provide details about those gloves including thickness.
Fortunately, most pesticide applicators know cotton and leather gloves are NOT acceptable. But did you know food handler gloves (polyethylene) were acceptable for some products?
A recent study found some interesting facts regarding glove use when applying agricultural products.
First, 92% of the respondents use gloves, even if the label doesn't say they are needed. But 8% never used gloves.
Reusable nitrile gloves (washable) were used by 38% with disposable nitrile used by 28%; thus, 66% use nitrile gloves. Other types used include rubber/latex, reusable neoprene, and polyvinyl chloride. In one part of the study, 9% didn't know what type of gloves they were using.
The surprising part of the study showed that 73% of the applicators indicated that they wear the same glove for multiple products. This is okay if the same glove meets the requirements for the different pesticide products used. That's where the label comes in.
On the other hand, this finding could also suggest the same glove is used for convenience without meeting the label requirement.
It is important to keep in mind that the glove type is based on solvent category, not type of pesticide or task, whether it's mixing and loading, or application of the product.
Based on an analysis of 1,552 pesticide product labels, there are 193 different pesticide products where nitrile gloves are not acceptable (Shaw and Harned, 2013). In fact, there are several herbicides that require either barrier laminate or Viton® gloves. Some of these herbicides can be used by highway departments.
Some other interesting statistics:
• Chemical resistance (49%) followed by fit (15%) and dexterity (13%) were the reasons specific gloves were chosen.
• 37% wear the gloves provided by the employers, though if you are an operator or applicator, it is up to you to follow the label.
While the vast majority of pesticide operators and applicators use gloves, the study concluded that there is a need for additional training on reading and interpreting glove statements on the pesticide label regarding the type(s) of gloves that should be used (particularly regarding the glove requirement for different formulations of the same active ingredient), especially for required tasks such as mixing and loading, and application.
One final thought: The US-EPA suggests a minimum thickness of 14 mils for gloves, especially for non-water solvent products. The thickness is stated on the package. Are your gloves at least that thick???
Change Is in the Air Now That Palmer Amaranth Seeds Are Here
Palmer amaranth growing tall in a soybean field in northern Illinois.
Changes are needed for weed control management practices in corn and soybeans across the Midwest. Palmer amaranth (Amaranthus palmeri) has established itself across the state. Sure, we've battled fellow pigweed species for years, but this new one with its rapid growth is a game changer.
Recently, I had the pleasure of attending a field research tour sponsored by Bayer CropScience. I've attended similar field day events in the past and had no reason to think this one would be much different. My expectations of joining no more than 30 others were exceeded when between 400 and 450 showed up! In fact, the hosts were caught a bit off guard by the record attendance. One representative commented that about 250 had preregistered. That many unexpected participants were a bit of a problem with catering….but overall, it was a GOOD problem because it was abundantly clear that producers have realized this new weed is in their area and they came to learn what this is going to mean for current management practices on their farms.
The tour featured four presentations by weed scientists from the University of Illinois and the University of Tennessee as well as a representative of Bayer CropScience. They gave tips on identification of Palmer amaranth. They discussed herbicide resistance among waterhemp and Palmer amaranth populations. They told stories of how this weed had devastated crops in southern states. Not only crops, but farms have been lost to this extremely competitive weed. Lastly, they gave recommendations on management.
This last part really resonated with me. I was reminded that nothing is constant but change. Now some practices will be the same. There is a big emphasis on scouting with this new weed. Fields were scouted before, but now the practice will be amped up considerably where populations are suspected or known. Weed size was always important but now it is critical. Post-emergent applications must be made to small plants. Soil residual herbicides must now be used. They used to be common, but glyphosate alone did such a fabulous job. It was easy and the price was right. We rode that train as long as we could. However, using multiple modes of action and rotating chemistries are of extreme importance in keeping Palmer amaranth controlled. In fact, one speaker noted that using a single chemistry was just stupid. Yet, that was the common practice for years.
Two thoughts came to mind with that comment. One was the time in grad school when I asked if we'd ever see weed resistance occur with glyphosate and I was laughed at and told, "No, we would have seen it by now." That was roughly 16-17 years ago. We know better now. The other thought that occurred to me is, "What practices are we using now that in 16-17 years will no longer be recommended?" We will continue to conduct research and learn and amend recommendations and practices as needed. That's what humans do no matter the topic or area of concern.
Many in the crowd yesterday had questions and concerns such as, "Will I spread the seed from here to my farm? Would it get stuck on my boots or clothing, or fall into the information bags we were given?" There were jokes of setting fire to clothing and boots before returning home. How many left the tour and went directly out to take a closer look at the suspiciously fast growing pigweed patches in their own fields?
The comment was made by one bystander that producers will need to sit down and make a multi-year plan of their management strategies. He thought four years would be good. His recommendation made sense, but how many will do this and do so right away? Producers want to use products that are effective, easy, and inexpensive.
It's not as simple as rotating between corn and soybeans from year to year. There are herbicide tolerant crops on the market and coming to the market within a few years that offer improved flexibility for growers. But they must be used wisely and planning will be needed so that the herbicide mode of action is rotated. The use of tank mixes with multiple modes of action will be vital in controlling Palmer amaranth. Weed control costs are expected to rise to $100 per acre for soybeans and $60-70 for corn. Ouch!
Other less commonly used methods of control were discussed as being effective options for this weed. Many have sold their field cultivators with the reduced need for them in past years, but cultivators may be making a comeback, as is hand removal in the form of "walkin' beans." Speaking from much personal experience, the latter is an unpleasant job – even if you are working for only one night out that involves pizza and a trip to the movie theater once all of your dad's fields are weed free. I do hope most kids get paid better these days. For more information on what "walkin' beans" involves, check out this article: http://www.farmtalknewspaper.com/local/x197375941/Walkin-Beans
The field day presenters had maps showing the Illinois counties where Palmer amaranth has been documented. They noted, too, that they have no reason to believe that this plant is not already in every county. How long it will take for this weed to spread beyond the agricultural fields into natural areas and other landscapes where it will completely take over in a short amount of time? My recent Home, Yard, and Garden article raised some of these concerns: http://hyg.ipm.illinois.edu/article.php?id=609. Currently, Palmer amaranth is not listed as a Noxious Weed in Illinois, but other states have listed it as such.
It was noted by one speaker that seeds are spread by wind, but birds also assist in spreading Palmer amaranth seed. The site of the tour is that of an old landfill and has no shortage of birds; sea gulls are common visitors. Just south of the research plots is a landscape waste compost facility. All morning, trucks entered and left via the rock road bordering the research farm. I can't help but wonder how much Palmer amaranth seed was in that compost and were it will eventually end up.
In other good news, neighbor disputes are bound to happen when one is accused of not controlling this weed and allowing the seed to spread to neighboring property. Lawsuits will likely follow. Stories were shared of landlords that took away land from renters who were not managing this weed. Questions were raised by potential renters. Should they even consider renting ground with a known infestation?
Again, we know now that Palmer amaranth IS manageable with at least 3 herbicide application passes across the field. Watch the Bulletin (http://bulletin.ipm.illinois.edu/ ) for recommended control strategies and more information. Certainly, the game has changed a bit in how we keep yield-robbing weeds at bay and what it will cost.