Rain and Pesticide Storage Concerns
By Steve Tomasko, UW PAT Program

With the heavy amount of rain Wisconsin has been seeing this year, it might be a good time to evaluate whether your pesticide storage area is safe from flooding. Improperly stored pesticides can pose significant threats to people, livestock and the environment. We outline and discuss characteristics of proper pesticide storage in our pesticide safety training manuals, but let’s review some of that information here.

Remember, it’s always best to have a plan for flooding (or any other potential disaster) before it happens. If you do store pesticides in an area prone to flooding, it’s critical that that you take preventative measures to minimize any chance for flood waters to damage and spread pesticides.

Prevention and Planning

Store products in a safe location. Store all hazardous products in an area that will not flood or is protected from flooding. For obvious reasons, don’t locate your pesticide storage area in a flood zone. Work with local zoning and building code professionals to determine how best to protect the environment if high water were to enter the storage facility.

You should store pesticides on raised pallets or on shelves to prevent water and condensation from damaging pesticide containers. Water or excess moisture can cause metal containers to rust, paper and cardboard containers to split or crumble, pesticide labeling to peel, smear, or otherwise become unreadable and otherwise degrade the products themselves.

Keep pesticide inventory to a minimum, after all, the less product you have on site, the less you have to worry about. Want to clean out existing inventory? If you have products that are no longer registered or you just want to dispose of because you don’t use them anymore, consult Wisconsin’s Clean Sweep program (see link at end of article).

Develop an emergency response plan in case of a flood, leak, spill or fire. Depending on what kind and how much hazardous material you store, you may be required to develop a contingency plan for commercial pesticide storage.

After a Flood has Occurred

If, despite precautions, you do have a flood of your storage area use caution in investigating because the floodwaters might be contaminated with pesticides. Wear appropriate PPE to avoid exposure, especially safety boots and gloves.

If pesticides were released by floodwaters, call the Wisconsin Spill Hotline (800-943-0003) to report it. The hotline is staffed 24 hours a day. Trained staff can provide information to help you in a pesticide emergency.

If possible, take steps to prevent further release of the pesticides. Place leaking containers into sealed, larger containers. Again, wear proper PPE to protect yourself before attempting any control or clean up.

During clean-up, watch for signs of pesticide poisoning. Acute (sudden in onset) symptoms frequently include headache, nausea, diarrhea, blurred vision, excessive salivation or sweating, difficulty breathing, weakness, tremors, or convulsions. These symptoms will usually appear immediately or within a few hours of exposure. See a doctor immediately or contact the National Poison Control Center at 1-800-222-1222 if you think you may have symptoms of pesticide poisoning. If possible, write down brand names or active ingredients of pesticides you have handled.

Hopefully you will never have to deal with a flooded pesticide storage area, but again, remember that planning ahead is key to both preventing damage from a flood, and to responding safely and appropriately if one does occur.

For more information on the storage of pesticides, the “Storage” module of the Pesticide Environmental Stewardship website has information about storage plans and ideas:

Pesticide Environmental Stewardship: Storage

DATCP’s website on chemical storage and containment

Wisconsin Clean Sweep program

Audio (MP3)


New Genetic Tool for Corn Rootworm Control One Step Closer to Use
By Steve Tomasko, UW PAT Program

In the November 2016 edition of this newsletter, Glenn Nice wrote about a coming genetic technology for controlling pests—RNA Inhibition, or RNAi. RNAi is useful because it can be highly specific in the pests it targets. This technology is one step closer to being in the field with the Environmental Protection Agency’s recent registration of SmartStax Pro. The U.S. Food and Drug Administration and Department of Agriculture have both already approved the technology.

The SmartStax Pro (a collaboration by Monsanto and Dow) is an example of a “plant-incorporated protectant” (PIP). Scientists create PIPs by inserting genes into a crop so that the plant itself then produces a pesticide or other beneficial trait inside its own tissues. When plants are genetically modified to produce pesticides in this manner they are regulated by the EPA.

This particular PIP is aimed at controlling western corn rootworm. Corn rootworm is a major pest of corn in the U.S. and has developed resistance to several other pesticides. Some refer to corn rootworm the “billion-dollar pest” because of the damage it does and the money used to try and control it. With the approval, Monsanto expects corn seed with RNAi to be on the market by the end of this decade.

SmartStax Pro is a line of genetically modified corn seeds made in. When a corn rootworm starts eating the corn, the plant’s self-made pesticide disrupts a critical gene in the rootworm and kills it. In theory, this product is so specific that it only affects the corn rootworm. See Glenn’s earlier article for a more in-depth explanation of RNAi technology in general below.

The EPA says the new corn has the potential to help combat corn rootworm’s resistance to Bt in Bt corn. SmartStax Pro corn will contain both the RNAi genes along with Bt-producing genes. However, some people caution that just like any technology or new pesticide growers should use caution and not rely on a single tool. Rotating crops and planting refuges of non-modified corn are still important tools so that the bugs don’t simply develop resistance to the new technology.

For more information see links below.

New Pesticide Mode of Action Being Investigated - RNA inhibition

EPA Registers Innovative Tool to Control Corn Rootworm

Audio (MP3)


Dicamba: in Wisconsin.
By Glenn Nice, UW PAT Program

If you are in agriculture you've probably heard of the herbicide active ingredient dicamba, more so than you may wish as of late. Dicamba is a broad-spectrum herbicide that acts as a growth regulator. Some brand names for formulations of this herbicide include Banvel™, Diablo™, Oracle™ and Vanquish™. Right off the bat, it should be noted that these are not labeled for dicamba-tolerant soybean or cotton.

Last year, several states reported dicamba injury to crops. Some of these reports were the result of non-labeled products used on dicamba-tolerant soybean and cotton. Last year, there were no dicamba products labeled for use over the top of these dicamba-tolerant crops, therefore any use of a dicamba product over these specialized crops was illegal.

In 2017 three products were registered for use over the top of soybean and cotton with the dicamba-tolerant trait: Engenia™ from BASF, FeXapan™ Herbicide Plus VaporGrip™ Technology from Dupont and XtendiMax™ with VaporGrip™ from Monsanto. 2017 is the first year that both the seed and herbicide technology are available together.

Still, there are reports of dicamba damage in several states. As of June 13, the state of Arkansas was investigating 686 alleged drift complaints; Indiana, a suspected 50 complaints that might be due to growth regulators; Missouri is investigating 176 complaints; and Minnesota and Illinois have also reported complaints. Wisconsin presently has not seen an increase in complaints from historical norms (knock on wood), however one of our UW researchers did see some growth regulator injury earlier in the year on his variety trial plots.

In July, the EPA released an advisory statement highlighting some important compliance issues. The EPA says there should be no applications by air or when the wind speed is over 15 MPH. Also, applications can only be made with the approved nozzles at very specific pressures. Finally, regulations require buffer strips in certain situations.


Drift of a pesticide can occur two different ways. The first can be as particle drift. This is a situation very fine droplets can be moved by wind currents off-site. In this case, the pesticide does not reach the target. The second kind of drift is vapor drift. In this case, the pesticide reaches the target, but then evaporates into a gas and moves off-site as vapor.

There are several things that can be done to reduce drift potential, and all of these can be found on the labels.


Formulation can have a large impact on its potential to volatilize (turn into a gas or vapor). The new products labeled for dicamba-tolerant soybean are formulated to decrease volatility. Several dicamba products available on the market are not formulated in this way and they are typically more volatile. These more volatile products are not labeled for use in dicamba-tolerant soybean.

Using non-labeled products in these crops, as is in any, is against the law and not wise, increasing the potential for damage.

Temperature and Relative Humidity

Both temperature and relative humidity can affect volitility, but it can also effect particle drift. Low humidity and/or high temperature can increase evaporation, which increases the potential for the liquid to turn into a vapor. It also increases evaporation of the liquid carrier of the herbicide in the droplet form. When water evaporates that means the droplets are shrinking. As the droplets get smaller their potential to move off-site increases. Having less surface area, smaller droplets are more susceptible to this, becoming smaller faster.

Pesticide labels warn of low humidity and high temperatures. The Engenia™ and FeXipan™ with VaporGrip™ label warns to “avoid spraying” in these conditions or to configure equipment to produce larger droplets if you do. The XtendiMax™ with VaporGrip™ label provides a specific temperature of 91 degrees F° to where you should configure your equipment to produce larger droplets.

Configuring your equipment might include running at the lower end of the pressure range for the nozzle you are using. See the section on nozzles below.

Temperature Inversions

Temperature inversions increase drift potential. This is a situation where the air above the application site is layered. Having a cooler layer near the ground and a warmer layer above. Although there might be little movement of air, there can be movement above and a striking difference in temperature. Pesticide particles or vapors that enter this upper layer can accumulate and travel large unpredictable distances before settling back into the lower layer and falling to the ground and on sensitive plants.

Inversion layers often form in the late afternoon or evening caused by the cooling of ground after a hot day. They are characterized by low winds (less than 3 MPH) when the sun is low, in Wisconsin, essentially those pleasant nights when the mosquitoes are at their worst. They can often be identified by fogs or smokes rising in a strait column then abruptly changing direction and moving off.

Nozzle Selection

The dicamba products have very specific requirements on the nozzles that you use. As would be expected, you are required to use nozzles that are engineered to produce a higher number of large droplets at pressures that would also have this result. Larger droplets fall faster and evaporate slower, so an application that has a higher percentage of these will have less potential for drifting. However, keep in mind that due to shear force it is impossible to completely eliminate the creation of small droplets. So we still have to be aware of other factors. See product web pages for approved nozzles.

Conventional flat fan nozzles that produce a large percentage of fine droplets are not allowed.

Tank Mixing

NO AMS! AMS (ammonium sulfate) can change the chemistry leading to higher volatility, decreasing the benefits of formulation of the active ingredient dicamba. As for other mixtures, tanks mixes have to be specifically stated and approved by the label. All three of the dicamba products we've been discussing have web pages that provide information on approved tank mixes.

Boom Height

Do not set boom height over 24 inches. If you can go lower and still be effective, even better. The higher the boom, the farther droplets have to travel to reach the target and the greater air flow tends to be.

Travel Speed

All three products have limited travel speed to a maximum of 15 MPH. It is recommended that speed be less than that.

Wind Speed and Directions

Be aware of what is around you. If there is a million-dollar vineyard next door, prudence would suggest not using these products. These labels limit applications to wind speeds between 3 and 15 MPH. Be aware of wind direction. Essentially be cautious and aware of your surroundings (as you should be when applying any pesticide).

Buffer Zones

All three products require buffer zones between applications and sensitive plants. FeXapan™ and XtendiMax™ require a 110-foot buffer if using 22 fl.oz. and 220 if using the 44 fl.oz rates. Enginia™ requires a 110-foot buffer. Roads, and non-crop areas can sometimes be incorporated in the buffer zone, reducing the amount of area needed to take out of actual production.

Tank Cleaning

Although this is a little bit of a deviation from drift factors, tank contamination can take a toll on susceptible crops. All three labels have very specific tank cleaning procedures. All three require the use of a chemical detergent or ammonia and specific time durations for flushing and rinsing. There are 10- or 11-step cleaning procedures. If you are in a situation where you use more than one spray rig, designating spray rigs for specific applications is a great idea. Not everyone has this luxury though.

In Conclusion

Pesticide resistance is a reality for many producers. In some states weeds such as Palmer amaranth and waterhemp threaten production. At the very least they increase the costs of production substantially. Growth regulator tolerant crops just add another valuable tool to the tool box. However, like any tool, if used incorrectly or an over-dependence on this one tool occurs, it will lead to trouble and the erosion of its value in the future. It takes more than a hammer to build something and it will take more than this one tool to control pests.

XtendiMax™ with VaporGrip™ Technology

Fexapan™ with VaproGrip™ Technology


The Dicamba Dilemma in Illinois: Facts and Speculations

Audio (MP3)


Weathering the Emerald Storm: EAB in Wisconsin
By PJ Liesch, Insect Diagnostics Lab, origonally posted May 22, 2017.

Like a kid watching a summer thunderstorm slowly rolling in and wondering how long until the rumbles would be directly overhead, I’ve had a morbid fascination with watching the progression of the emerald ash borer in the Midwest for over a decade. Although emerald ash borer wasn’t found in Wisconsin until 2008, my connection with EAB precedes that by a few years. It turns out my first job as a budding entomologist was as a summer intern for UW-Extension looking for signs of the insect in the state during the summers of 2005 and 2006. Fast forward twelve years and that storm is finally overhead, at least in my neck of the woods. I knew such a time would come, but it really hits close to home when the sounds of chainsaws mark the final days of your neighborhood’s ash trees—at least the ones that aren’t being treated.


Map of Emerald Ash Bore distrabution in Wisconsin
EAB Detection and Quarantines as of May 19, 2017. Click for larger version. Image source: WI-DATCP.


At the time of writing, 42 counties in Wisconsin have been quarantined for EAB. While the southeastern part of the state has already been hit hard (green on the map above), a large chunk of the state has not yet seen the emerald ash borer or has only seen light pressure (click the map above to see more details on this topic). Unfortunately, this means that the emerald storm will only be getting worse over the coming years. Along these lines, when EAB first arrived in Wisconsin, spread was slow and the annual number of new community-level detections was small. However, as the populations of this insect have built up in the state, the number of new detections has increased dramatically as illustrated below:


Map of Emerald Ash Bore distrabution in Wisconsin
Chart created using data from WI-DATCP on May 22, 2017.


Unfortunately, the outlook for the Midwest’s ash trees doesn’t look good and we’ll still be dealing with this insect for years to come. Ironically, this isn’t the first time that we’ve watched a scenario like this play out. As the baby boomer generation grew up, they watched as elms were devastated by the likes of Dutch elm disease. As with emerald ash borer, Dutch elm disease had significant impacts on forested and urban areas and led to irreversible changes in the landscape around us.

With all this Doom-and-Gloom, is there a light at the end of the tunnel? Possibly—but it may be a ways off. For the time being, there are insecticide treatments available that can maintain the health of ash trees, although treatments are costly and are only feasible for relatively small numbers of trees. Biological control is being explored as a potential way to control EAB populations, although results have been limited thus far. However, with any biological control program, it can take years to work the kinks out of the system and see results.

A long-term plan may be to develop varieties of ash trees that are resistant to attack by the emerald ash borer. In several locations in Ohio and Michigan, scientists have found a small percentage of “lingering” ash trees that have survived the initial onslaught of EAB and are monitoring those trees over time for continued survival and genetic traits that may help stave off infestations. Interestingly, one particular species of ash (blue ash, Fraxinus quadrangulata) may hold important clues for long-term ash survival. In some spots in Michigan, > 60% of blue ash trees have survived in areas attacked by emerald ash borer. While tree breeding programs may ultimately develop a resistant ash variety, this is likely years away and for the time being we’ll have to face the emerald storm.


Map of Emerald Ash Bore distrabution in Wisconsin
Larval tunnels of the emerald ash borer beneath the bark of an ash tree. This damage disrupts the flow of water and nutrients and ultimately kills the tree. Image source: PJ Liesch, UW Entomology.


Audio (MP3)


Brown Marmorated Stink Bug
By Bryan Jensen, UW Extension and IPM Program

The brown marmorated stink bug (BMSB) is a new stink bug species which was first detected in North America in 2001 and Wisconsin during 2010. BMSB has a wide host range and overwinter as adults. Likely, there will be a single generation per year in our state. Nymphs were recently observed by PJ Liesch, UW Insect Diagnostic Lab, and I thought it would be a good time to give you a quick heads-up.

After initial detection within an area/state, the normal progression of events is that BMSB first becomes established as a household nuisance before they become an economic agricultural pest. In some areas of the state we are past that first stage and now is the time to start looking for them in the field. Likely, we are a few years away from significant problems, however, it is better to become familiar with them prior to a serious infestation.

We do have several native stink bug species that can be found in agricultural setting but there are subtle differences. Most native adult stink bugs are slightly smaller (1/2 inch) compared to BMSB (5/8 inch). All species, including BMSB, will have a very distinct “shield-shape”. The most identifiable characteristics of the adult BMSB are 1) alternating light to brown spots on the outer edge of their abdomen 2) antennae have alternating brown and light bands and 3) the eyes of fresh specimens are dark red. Please see PJ’s ID picture below. BMSB do have brown/white mottling; however, this characteristic does not separate BMSB from native stink bugs. The immature BMSB is smaller than the adults and range in size from a pin head to ½ inch in length. Nymphs are oval and have dark red eyes similar to adults. Nymphs vary in color and appearance with age. Initially, they range in color from a yellowish red to a creamy white with reddish spots just prior to turning into adults.

BMSB have piercing sucking mouth parts and damage to corn and soybean is commonly found along field edges. In soybean, economic damage is from pod and/or seed feeding which results in absent, discolored or shriveled seed. Furthermore, foliage may stay green longer. In corn BMSB feed through the husk and individual kernels may become shriveled and discolored.

Economic thresholds specific to BMSB have not been established. Until more information is known, consider treating soybean if 40 stink bugs are found/100 sweeps. In corn, economic thresholds are not well developed especially for the reproductive stages. Again, economic damage is not expected at this point in time.


spined soldier bug
Spined soldier bug. Note pronounced “shoulder spines” Photo credit: Kansas Department of Agriculture , Bugwood.org


brown stink bug
Brown stink bug. Note: although similar in color/shape it does not have the brown/white banded antennae Photo credit: David Stephens, Bugwood.org


Audio (MP3)


Reminder of No Atrazine Use after July 31
By Steve Tomasko, UW PAT Program

Wisconsin puts restrictions on the herbicide atrazine that go beyond the label. One of those restrictions is that no one can apply atrazine between July 31 and March 30 of the following year. There are other restrictions on rates, and areas where the herbicide is never allowed to be applied (prohibition zones). The restrictions are due to atrazine and its metabolites being found to enter Wisconsin's groundwater. Remember that many products contain atrazine as an active ingredient, even if it is not part of their brand name.

DATCP website on atrazine rules

List of Products Containing Atrazine

Audio (MP3)


CREP Deadline Approaching; Flooded Lands Good Candidates
By WDATCP Press Release.

Although this is not pesticide application related, this information crossed my desk and I thought it might be good to pass along to those of you who might be interested.

Landowners whose CREP contracts are expiring this year have until Aug. 31 to re-enroll in the program, an option that might look more and more attractive in light of this summer's floods in Wisconsin. Enrolling for the first time is also an option that non-participating landowners should consider if they have fields or pastures that frequently flood. CREP is the Conservation Reserve Enhancement Program, a component of the federal Conservation Reserve Program, or CRP.

The CREP program offers both state and federal financial incentives to landowners who install conservation practices along waterways or return continually flooded fields or pastures to wetlands. Adjacent land can remain in agricultural production. There is no minimum acreage, and landowners may enroll land under either a 15-year agreement or a perpetual easement.

Landowners who enrolled acreage in CREP in 2002-03 must complete the re-enrollment process by Sept. 30, or lose annual and incentive payments. They may also add or remove lands. To re-enroll or enroll lands for the first time, they should call or visit their local USDA Farm Service Agency office. Lands in 50 Wisconsin counties are eligible for CREP.

Full Press Release

DATCP CREP program information

Audio (MP3)


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