Illinois Pesticide Review
May / June 2013
In This Issue
- Washing Pesticide-Contaminated Clothing
- Honey Bee Health Report by USDA and EPA
- European Union Restricts Neonicotinoid Insecticides
- Registered Herbicides Recommended Over Non-Conventional Weed-Killing Mixes Touted Online
- Supreme Court Ruling – Bowman v. Monsanto
- A Different Perspective on a Common Drift Reduction Strategy
Washing Pesticide-Contaminated Clothing
The spray season is upon us. Without a doubt, unless you're covered head to toe with a protective suit, your clothing is bound to become contaminated with pesticides.
If you don't launder the clothing, you can keep contaminating yourself over and over again by putting the shirts, slacks, shoes, and hat back on. This slow, chronic poisoning can actually be worse than a one-time pesticide spill since that is so blatant you notice it and take action. With bit-by-bit, you don't think much about it.
Those handling pesticides should get in the habit of washing clothing daily, never wearing anything two days or more in a row. Also, realize that leather absorbs pesticides and removing that potential poisoning can be difficult.
Of course, the first line of defense is proper clothing. Even though it may be 85 degrees outside with a similar humidity, employees handling pesticides should be wearing long pants and long-sleeved shirts, coupled with socks, shoes, hat/cap, and gloves.
And the second line of defense is showering daily. If using toxic products, consider showering twice daily – once at noon and once at the end of the day. Of course, change clothing after showering.
Below are some tips from NPIC (National Pesticide Information Center: http://npic.orst.edu/)
• First, talk to the person doing the laundry. Let them know that clothing could be contaminated. Give them tongs or plastic gloves to handle the clothing.
• Store and wash contaminated clothing separately from the family laundry. Why would you want to potentially contaminate your families clothing?
• Have a separate hamper or basket specifically for contaminated clothing. Keep the hamper away from children.
• Clothes that are soaked with pesticides, pesticide concentrations, or those labeled Danger/Poison should be thrown away rather than washed. This is a must! This is also a great reason for having disposable coveralls.
• Wash work clothing DAILY to maximize removal of chemicals. Clothing can keep pesticides away from the skin during work hours; however, that same clothing can become a source of contamination if pesticides aren't laundered after each use.
• Pre-rinse contaminated clothing by hosing them down outdoors, soaking in a separate tub or agitating in the washing machine for a few minutes, draining the tub and refilling.
• Wash only a few items at a time.
• Use hot water - the hotter the better. While this is ideal, remember that hot water can shrink cotton and wool.
• Use heavy duty laundry detergent.
• Laundry additives such as chlorine bleach or ammonia do not improve removal of pesticide residues.
• Line dry, if possible. Sunlight breaks down many pesticides and it can prevent residues from collecting in the dryer. If you are drying, use a cool setting.
• Remove any leftover pesticides from the washer by running an "empty load" through the complete cycle with hot water and the heavy duty laundry detergent.
• Businesses might want to consider having a laundry system, especially if uniforms are required by workers. This is just one more way to provide a pesticide safety system for employees.
• Personal Protection Equipment such as boots, aprons, goggles, and gloves should be washed thoroughly daily and allowed to dry.
• There isn't much research on the new low-water washers and their ability to remove pesticides. So, until there is, use the old fashioned washers that fill the washtub with water.
Honey Bee Health Report by USDA and EPA
The U.S. Department of Agriculture (USDA) and the U.S. Environmental Protection Agency (EPA) released a comprehensive scientific report on honey bee health on May 2, 2013. The report states that there are multiple factors playing a role in honey bee colony declines, including parasites and disease, genetics, poor nutrition, and pesticide exposure.
The two agencies jointly released the report by a National Stakeholders Conference on Honey Bee Health that convened in October, 2012. The conference was developed by federal researchers and managers, along with Pennsylvania State University. It was convened to synthesize the current state of knowledge regarding the primary factors that scientists believe have the greatest impact on managed bee health.
Key findings include:
Parasites and Disease Risks:
The parasitic Varroa mite is recognized as the major factor underlying honey bee colony loss in the U.S. and other countries. There is widespread resistance to the chemicals beekeepers use to control mites within the hive. New virus species have been found in the U.S. and several of these have been associated with Colony Collapse Disorder (CCD).
Increased Genetic Diversity Needed:
U.S. honeybee colonies need increased genetic diversity. Genetic variation improves bees' thermoregulation (the ability to keep body temperature steady even if the surrounding environment is different), disease resistance, and worker productivity. Honey bee breeding should emphasize traits such as hygienic behavior that confer improved resistance to Varroa mites and diseases (such as American foulbrood).
Nutrition has a major impact on individual bee and colony longevity. A nutrition-poor diet can make bees more susceptible to harm from disease and parasites. Bees need better forage and a variety of plants to support colony health. Federal and state partners should consider actions affecting land management to maximize available nutritional forage to promote and enhance good bee health and to protect bees by keeping them away from pesticide-treated fields.
Improved Collaboration and Information Sharing:
Best Management Practices associated with bees and pesticide use exist but are not widely or systematically followed by members of the crop-producing industry. There is a need for informed and coordinated communication between growers and beekeepers and effective collaboration between stakeholders on practices to protect bees from pesticides. Beekeepers emphasized the need for accurate and timely bee kill incident reporting, monitoring, and enforcement.
Additional Research on Pesticide Risks:
The most pressing pesticide research questions relate to determining actual pesticide exposures and effects of pesticides to bees in the field, and the potential for impacts on bee health and productivity of whole honey bee colonies.
The report will provide important input to the Colony Collapse Disorder Steering Committee led by the USDA, EPA, and the National Agricultural Statistics Service (NASS). The Colony Collapse Steering Committee was formed in response to a sudden and widespread disappearance of adult honey bees from beehives, which first occurred in 2006. The Committee will consider the report's recommendations and update the CCD Action Plan which will outline major priorities to be addressed in the next 5-10 years. This will serve as a reference document for policy makers, legislators, and the public, and it will help coordinate the federal strategy in response to honey bee losses.
To view the report, which represents the consensus of the scientific community studying honey bees, visit: http://www.usda.gov/documents/ReportHoneyBeeHealth.pdf.
Modified by Phil Nixon from an EPA and USDA Press Release
European Union Restricts Neonicotinoid Insecticides
The European Commission of the European Union adopted a restriction on the use of clothianidin, imidacloprid, and thiamethoxam due to their being determined to being harmful to Europe's honey bee population. All three are classified as neonicotinoid insecticides.
The restriction starts on December 1, 2013 and will be reviewed within two years. Uses restricted are seed treatment, soil application of granules, and foliar treatment on plants and cereals that are attractive to bees. Winter grains are exempt from the restrictions. Exceptions include the treatment of bee-attractive crops in greenhouses and outdoor fields after flowering. Many applications to ornamental plants including turfgrass will continue to be allowed. These applications can only be made by professionals.
This is part of a strategy to try to reverse the decline of Europe's bee population. Other actions that have been taken or are underway include an EU laboratory for bee health, increased funds for national apiculture programs, funds to carry out surveys in 17 voluntary EU member states, and EU research programs such as BeeDoc and STEP studying the multiple causes of Europe's bee decline.
In an Appeal Committee vote on April 29, 2013, 15 member states supported the proposal, 4 abstained, and 8 voted against. Because a qualified majority was not obtained in the committee, the decision lay with the European Commission, which chose to adopt the proposal. The proposal was in response to the European Food Safety Authority's scientific report that identified "high acute risks" for bee exposure to dust in several crops including maize (corn), cereals, and sunflower, to residue in pollen and nectar in crops such as oilseed rape and sunflower, and to guttation in maize.
The press releases by the European Commission on the restriction of neonicotinoids is at http://europa.eu/rapid/press-release_IP-13-457_en.htm?locale=en and on the Appeal Committee is at http://ec.europa.eu/food/animal/liveanimals/bees/neonicotinoids_en.htm.
Registered Herbicides Recommended Over Non-Conventional Weed-Killing Mixes Touted Online
Weed control can be expensive. Times are tough and folks are always looking for ways to save money. Weeds continue to grow, not seeming to care about your wallet or your budget. Learning to live with them and spending nothing on weed control may not be an option. Couple the need for money savings with the fear or mistrust of herbicides and pesticides in general and the result is that people are willing to put just about anything they can find around the house or workshop on their weeds.
And let's not forget the individuals who are wary of chemicals produced by large chemical companies. This is an actual quote from a message board online: "I prefer this recipe to the harsh Roundup formula put out by Monsanto." That's to be debated, but that's another article for another day. Regardless, there are many reasons why do-it-yourself weed killers are so popular. As with anything though, you often get what you pay for.
Recipes for weed killers abound on the internet. It's important to keep in mind that anyone can post anything and make it look believable. All that is needed is a recipe using any of the ingredients listed below, an adjective like AMAZING or BEST, and a pretty picture to draw attention to it. These little gems spread like wildfire on social media. Facebook and Pinterest aren't the only places you can find recipes for alternative weed killers; chat boards are full of passionate discussions on this topic. Popular mixes seem to include one or more of these main ingredients: vinegar, boiling water, bleach, baking soda, alcohol, salt, dish soap, molasses, citrus oil, borax, gasoline, diesel fuel, and even motor oil. There is a certain comfort level associated with these products. They can be found around the home after all. Some of them are even edible!
Unfortunately, the disadvantages of these home remedies often outweigh the advantages. These products don't contain labels with safety or rate information and yet they can still be hazardous to your health. Vinegar can be effective for weed control but only if it is a strong enough grade, which the bottle in your kitchen likely isn't. Vinegar contains acetic acid, and acetic acid concentrations over 11% can cause burns upon skin contact.
In fact, eye contact can result in severe burns and permanent corneal injury. This is why reading and following the label is so important. There are now registered herbicidal vinegar products you can buy, which have use and safety information printed on the label. I wrote about using vinegar as a herbicide a few years ago. You can read my article here: http://hyg.ipm.illinois.edu/pastpest/200714f.html .
Although borax may sound like a "natural" weed-control method, it is important to remember that it may still be harmful to children and pets. Mixtures should be kept out of their reach. Registered pesticides have been studied extensively and come with labels that tell you how to protect yourself and others. The borax box tells you how to wash your clothes.
One other important disadvantage is that weed control often is only temporary or partial with only the top growth being affected. Boiling water would certainly be death on green leaves. The roots, however, are protected. If your weed is a perennial or if it has a deep taproot, you can bet it will grow back. Plus, how safe is it to carry big pans of boiling water out the door to your garden? Everything has a risk and furthermore everything can be toxic…even water. Remember, the dose makes the poison.
Some homemade weed killer ingredients can have a lasting effect on the soil, making it barren so nothing will grow there for a long time. Depending on the area, that may not be too bad, you think. Conventional herbicides are made to break down or dissipate in a timely fashion. Unfortunately, the result is new weed growth but at least the soil is healthy and can promote growth.
A problem with using borax is that the boron it contains does not break down or dissipate like conventional weed killers do, so repeated or excessive applications can result in bare areas where no vegetation can grow. Similarly, salt can be used for long-term weed control. But it destroys the soil structure; furthermore, it is mobile, which means that it can move to nearby areas in your garden, resulting in unwanted plant damage.
I knew that diesel is sometimes used for weed control but I had no idea just how common the practice is until a recent phone call led me to do a little search online. The chat board discussions go on and on about it. There is even an eHow.com article on how to use diesel to control grass. For what it's worth, the author has a degree in philosophy and gives no mention of training or experience in weed control. You be the judge. The internet is a powerful and dangerous tool, kids.
Some claim that their recipes or methods are more effective or longer lasting than registered herbicides. What about their environmental impact? Are these products mobile in the soil? Will they end up in the groundwater? Have they been tested for this use? Would EPA approve of these weed control methods or would they insist that the contaminated soil must be removed? Gas and diesel are flammable and the smell of diesel can linger for days, which neighbors may not appreciate.
I would be remiss if I didn't mention, however, that there are some herbicide labels that call for the addition of diesel to speed up top kill or increase penetration. These are often used for brush and stump control. The use is legal when label directions are followed. The use of gasoline and diesel fuel alone (without a herbicide) is not recommended. In addition, many herbicides provide residual control that can last much longer than diesel or gas.
Finally, money savings is often what drives the use of these mixtures. But how much are you really saving? When calculating this, be sure to factor in your personal safety, any potential environmental damage, and the expected length of control. Corners should not be cut when it comes to these important factors…even if the recipe does sound AMAZING.
Supreme Court Ruling – Bowman v. Monsanto
Vernon Bowman is a 75-year old farmer from southern Indiana who had a unique way around paying Monsanto for Roundup Ready® soybeans: he'd go to the elevator at the end of the season and buy some of the harvested soybeans to plant for the following year, using those beans for his second crop. (However, he always bought Roundup Ready seed for his first crop and signed the appropriate legal documents.) Then, since the Roundup Ready gene was in the elevator-bought seed, he would control his weeds with glyphosate and harvest the crop. He thought by doing this he wouldn't have to pay Monsanto any fee for the crop. He got away with it for about 10 years.
Well, the US Supreme Court thought otherwise in an unanimous opinion favoring Monsanto and affirming an Appeals Court decision.
Bowman's contention was that Monsanto retained control over their seeds for the first generation, but not subsequent generations. Monsanto, of course, thought it contained control over all future generations forever.
Of course, there are always arguments on both side, including stifling innovation or the reliance on one product that produces changes in nature such as resistance. The Supreme Court looked only at the legalities of the case before them.
Bowman's lawyers used the Doctrine of Patent Exhaustion, which essentially said that you can do what you want with a patented product after you purchased it. For example, if you bought a CD or book, you could sell that book or CD to anyone else you want without giving the publisher anything.
Justice Kagan, writing for the Court, stated that the Doctrine does give the purchaser that right; however, the right does not allow the purchaser to make new copies of the patented invention. She stated that Monsanto's seed is "self-replicating technology" and that Bowman was producing more product, similar to printing more copies of the book or CD and selling those. In other words, you can sell what you have; you can't make more of it and sell.
Still to come is the case involving Myriad vs. the Association of Molecular Pathology, et al, over whether a company can patent a human gene, turning on the issue "Can someone patent something that occurs in nature?" That decision will arrive before the end of the Court's term in June.
The entire Bowman v. Monsanto opinion can be found at: http://www.supremecourt.gov/opinions/12pdf/11-796_c07d.pdf.
A Different Perspective on a Common Drift Reduction Strategy
It's that time of year again: pesticide applications are being made, and among all of the considerations applicators have, drift is always in the front of the list. Recently I've read several articles reminding applicators about strategies to reduce drift.
I use the word remind because none of these strategies are new. For that matter, the reasons drift occurs aren't new either. Small spray droplets move off-target in the wind. I would like to take this opportunity to reexamine one of these common suggestions for reducing drift and offer a somewhat different perspective on it.
First, I'll offer my thoughts on why drift incidents continue to occur. As I just stated, we've not invented new ways to drift. The strategies for reducing drift haven't really changed either and have been discussed for many years. Why, then, does drift continue to be an issue? If we know how it occurs, and we've been talking about reducing it for so long, shouldn't we have this issue pretty much solved?
In my opinion, many drift incidents occur because of this: a large number of acres needing to be sprayed in a short period of time. This translates into applications being made under less than ideal conditions. I do not believe this occurs because applicators don't know any better. They do. It occurs because of the pressure to get the job done. Applicators aren't paid to reduce drift. They're paid to control pests. Drift is their problem; it's not a priority of their customers.
Weather is always covered as part of any drift reduction training. One of the standard recommendations is to not spray when wind speeds are greater than 10 miles per hour (mph). I often get the sense that members of the audience do not consider this recommendation to be practical all of the time.
Am I saying I'm wrong and that wind speeds above 10 mph don't increase drift? No, I'm right. Spraying when the wind speed is between 3 and 10 mph is optimal for drift reduction. However, it's impractical because of the many acres that need to be sprayed in a certain amount of time. Waiting for the ideal weather conditions isn't always an option. Applications occur in less than ideal weather conditions because applicators are under intense pressure to get the acres sprayed.
With this in mind, let's reexamine one of the most commonly stated drift reduction strategies - increase the gallons per acre used in the application. This recommendation has become one of my pet peeves for a number of reasons. First, it is often given without an explanation of the underlying principle, which is to recalibrate with a larger nozzle orifice size.
The gallons per acre (GPA) of a sprayer is based on three things: sprayer speed, nozzle spacing, and nozzle flow rate. When this recommendation is given it is implied that the applicator will increase the GPA by increasing the nozzle flow rate, using a nozzle with a larger orifice. A larger orifice size typically means a larger droplet size in addition to the higher flow rate. Larger droplet size equates to a reduction in the risk of drift.
But what about the use of pressure to change the nozzle flow rate? Another way to increase flow from a nozzle is to increase the pressure. Higher pressure means a smaller droplet size, which increases the risk of drift, the opposite of the desired goal.
Second, let's go back to my thought on the primary reason drift occurs: there are many acres to spray in a short period of time. What does increasing the GPA lead to? Reduced productivity. If you go from 10 GPA to 20 GPA in order to reduce drift, what have you done? You've cut the acres you can spray with a single tank load in half.
A higher GPA means more water needed at the job site and more time refilling the sprayer. The result? Same number of acres, but now you need even more time to get those acres sprayed. This compounds the drift problem because there is now a greater likelihood the application will occur under less than ideal weather conditions.
And does using that larger orifice to make the higher GPA application really gain you that much drift reduction with today's modern drift reduction nozzles, such as air-induction and pre-orifice designs? Let's do some math and examine this further. We'll run the calibration math for a 10 GPA application with nozzles spaced at 20 inches and a speed of 6 mph.
Yes, I realize 6 mph is much lower then what most applications are made at with self-propelled sprayers, but I needed to use this speed to make the math work for the droplet size data I have available to use. This application scenario means we need a nozzle flow rate of 0.2 gallons per minute (GPM). If we chose a 02 sized nozzle and operate it at 40 psi, we will achieve that flow rate.
Now let's talk about spray droplet size. One way we describe the droplet size for a nozzle is by the percentage of spray volume contained in droplets smaller than 100 microns in diameter (%V<100µm). As a reference, human hair is about 100 microns in diameter. This is considered the driftable portion of the spray volume produced by the nozzle, as it is the droplets that are 100 microns in diameter or less that are most at risk of moving off-target. So the higher the %V<100µm, the higher the risk of drift.
For our nozzle selection to make this application, we are going to look at two options. One is an extended-range nozzle, and the other is an air-induction nozzle. The droplet sizes for these two nozzles were measured for a research project in a laboratory and are available in a published paper.
If we chose the 02 extended range nozzle operated at 43 psi (slightly higher than what we need to make our 10 GPA application, but this is the pressure at which the study was conducted), the %V<100µm is 9.2%. If we chose the air-induction nozzle, the %V<100µm is 0.7%. The air-induction nozzle is obviously a much better nozzle selection in terms of reducing our risk of drift for this application.
However, we have decided that because we want to reduce our risk of drift we are going to increase to 20 GPA. For this application a 0.4 GPM flow rate is required. For the 20 GPA application, a 04 orifice operated at 40 psi will provide that flow rate. The %V<100µm for the 04 extended range nozzle at 43 psi is 4.2%, meaning we've reduced the volume of our spray at risk for drift by 5% by going from a 10 GPA application with a 02 orifice to a 20 GPA application with a 04 orifice. The %V<100µm for the 04 air-induction nozzle at 40 psi is 0.5%, meaning we've reduced the volume of our spray at risk of drift by only 0.2% by going from the 10 GPA to the 20 GPA application.
If we use extended-range nozzles, increasing the GPA to reduce drift by using a larger orifice makes sense. With the air-induction nozzle, however, does a 0.2 decrease in volume of fine droplets warrant the increase in GPA and the subsequent decrease in productivity? What if we go to a larger orifice size for an even higher GPA?
For the 06 air-induction nozzle, the %V<100µm was also 0.5%, meaning that there was no reduction in drift potential when increasing the nozzle orifice size further. For extended-range nozzles, there is an increase in spray droplet size as the orifice size increases. Droplet size typically still increases with orifice size for air-induction nozzles. This rate of increase, however, is much lower than with extended-range nozzles.
Since many applicators use air-induction nozzles, particularly for herbicide applications, I think it is important to ask ourselves if increasing the GPA as a means of reducing the risk of drift is a practical recommendation with these nozzle types. In the above example, twice as much water would be needed, there would be twice as many refills of the sprayer, and the gain would be only a 0.2% reduction in driftable fines.
Because the 20 GPA rate will require more time, there is a greater likelihood spraying will be done under unfavorable weather conditions. In my opinion, given the time crunch to get acres sprayed, it is better to stick with the 10 GPA application and get the acres sprayed quicker. This reduces the time pressure and means an applicator will be more likely to not push spraying when weather conditions become unfavorable.