Another Way to Stick it to Weeds

Tony Koski, Extension Turf Specialist

Since it was first introduced in 1974, Roundup (glyphosate) has always been sprayed on weeds. Because it is largely non-selective (will kill or harm any plant that is sprayed) in what it controls, using Roundup and its generic counterparts near desirable plants has to be done carefully to avoid unintended injury. The introduction of Roundup Precision Gel Weed and Grass Killer potentially makes it easier to apply glyphosate to individual weeds – without the concern of overspray, wind drift, and other application errors that could harm desirable plants. But a question we have, as with all new technology, is: does it work?

The application process reminds one of using a gel deodorant stick. A button on the bottom of the stick is clicked until the gel (containing a 1% concentration of glyphosate) is extruded through holes on the top of the stick. You then apply the gel by wiping the leaves of the weed. Sounds easy, right? What I

found, however, was that – to get a decent application of herbicide to a weed’s leaf surface – you have to support the leaf with your other hand while applying the gel. Of course, a rubber glove should be worn to avoid wiping your hand with the gel in the process. (Gloves should ALWAYS be worn when using any pesticides, whether natural/organic or synthetic types).

Because glyphosate is a systemic herbicide, complete leaf coverage isn’t essential to get good weed control. With the gel, you get streaks of gel on the leaf surface – which should be sufficient to control the weed. I tried this on some plantain growing in a groundcover bed outside of my office. The series of photos

shows the progressive death of the plantain. While plantain is admittedly one of the easiest landscape weeds to kill, the Roundup Gel worked well on this weed. For those of you expecting “instant gratification” weed control, you will have to be patient with this product. In the case of this plantain, it took about 16 days from application to death. I will next test this on quackgrass growing in juniper beds and perennial beds, which could be an excellent use for this product.

Roundup Gel applied on 23 June

Injury appears the next day thanks to the pelargonic acid that is also in the
gel stick; complete leaf coverage (I did try!) would have burned the leaves
down more quickly.

Complete death is achieved after about 2 weeks

Fall is Coming!

Rudbeckia triloba, Tri River Gardens, Photo by SL Carter

To some people, fall might be a four letter but to me it’s one of my favorite times of the year.  Those tomato plants are finally producing, mornings are cool and crisp, Grand Junction is rarely hitting 90 degrees and lots of yellow and purple late blooming plants are blooming.  This is also a time when a lot is going on under the ground.  Cool season turf has perked up, trees are starting to grow more roots and all perennial plants (trees included) are being like chipmunks and storing up food to make it through the winter.  Here is a wonderful handout called healthy roots, healthy trees: http://extension.colostate.edu/docs/pubs/garden/02926.pdf

So what can you do to help your plants make it through winter?  Well, for one, since the nights are getting longer and the days cooler, hopefully you have adjusted how much you are watering.  We need to help slow down plants so they can harden off for winter.  If you keep giving frequent water, they will continue to grow.  So slowly start reducing the times you water but you may need to increase the length of time you are watering.  The best way to check is to use a screwdriver from the drip edge out on trees to see if it easily slides into the soil to a depth of 6-8”.  If it only gets a couple of inches down, you definitely need to water deeper.  If it comes out all muddy, you have over-watered.  Ideally, you should be checking your lawn and garden this way thru and season and adjusting the irrigation; once a month is a good rule to follow.

Lawn at Mesa County Fairgrounds, Photo by SL Carter

As the weather cools, cool season grasses (Kentucky bluegrass, tall fescue and perennial ryegrass) will begin to grow faster.  Mowing will be needed more often to ensure that the grass is not stressed.  No more than one-third of the grass blade should be removed at each mowing. Continue to maintain the grass at the same cutting height as during the summer.  Even though lawns grow faster in the fall they will need less water than during the summer.  Adjust your lawn watering accordingly.   Here is a handout on watering established lawns:

http://extension.colostate.edu/topic-areas/yard-garden/watering-established-lawns-7-199/

This is a good time to install sod.  Preparing the soil properly is critical to success. Contact your local extension office for suggestions.  Do not apply weed killers to newly seeded lawns; wait until the new grass has been mowed at least twice before spraying for weeds.  Sodded lawns can be treated for weeds as soon as the weeds are noticed. And speaking of herbicides, one of our agents did some work the last two falls spraying bindweed with glyphosate, and does it work well.  Targeting certain perennial weeds in fall with the appropriate chemical allows the chemical to be pulled into the roots as the weed is trying to store energy.  Always read the label and follow the instructions.  It is best to make sure what you are using is appropriate for what you are controlling.  If you only have to do it once, it will save you money too.

At lower/warmer elevations, now is a good time to plant some cool season greens to get a last batch before winter gets here.  I will say, I hate when winter gets here and there is no more fresh veggies.  So for now I’ll enjoy the cool morning that still brings abundance. Enjoy!

By Susan L Carter, Horticulture Agent, CSU Extension, Tri River Area

Is Academia in Bed with Monsanto?

Tony Koski, Extension Turf Specialist

Source: Discover Magazine

Those of us who work at universities (especially if we work in agriculture or horticulture) are sometimes accused of being bought and owned by the big chemical and fertilizer companies - the Monsantos and Scotts of the world. Those who look unfavorably upon the use of synthetic pesticides and fertilizers suggest that those of us in academia are unable to conduct independent research, teach in the classroom in an unbiased fashion, or present public education without somehow endorsing the slathering of landscapes with pesticides. Heck, if you believe some people, you would think we run in the same circles as politicians or FIFA officials? Anyway..........

The reason I bring this up is because of a question I answered today that was submitted to the national eXtension Ask an Expert (AaE) system. In AaE, you can ask a question about pretty much anything - and some expert (associated with Land Grant universities across the U.S.) will provide an objective, research-based answer. Those of us who volunteer (yep, no extra pay...) to answer these questions receive an email notice that a question is awaiting our attention. We log in to the system, read the question, provide an answer - and the client receives our response to their question. Clients can submit photos of sick plants, insects, weeds, etc. for identification and diagnosis. When necessary, we can engage in some back-and-forth dialogue with the client. Now that the kinks have been worked out, it's a pretty good way for citizens to get questions on just about any topic answered without someone trying to sell you something.

Here is the question, exactly as received (from an Anonymous person), along with my response...and quickly followed by their response. I have yet to respond...

Legitimate Glyphosate education

Hello, I recently ran into a 'master gardener' representing CSU at a local hardware store. This person was about 15 feet away from 2,000 pounds of RoundUp. Why is it that CSU still condones the use of glyphosate when all the research points to cancer in humans, and detrimental effects both directly and indirectly of our pollinators?
http://www.beyondpesticides.org/infoservices/pesticidefactsheets/toxic/glyphosate.php

My response:

 A couple of comments regarding the presence of a CO Master Gardener (CMG) at a hardware store where glyphosate/Roundup was being sold.

First, the mere presence of a CMG at this store (in proximity to bottles of Roundup herbicide) doesn't imply that CSU "condones" glyphosate use any more than does their presence condone or endorse any of the 1000s of other products sold at that store (like Toro mowers or Makita power tools). The CMGs are present at Q & A booths to answer home gardener questions - not to sell any products. CMGs provide advice that is based on the best-available research. For example, weed management advice for a home garden or lawn might include (as appropriate) the use of pulling weeds, cultivating soil, mulching, mowing/fertilizing/watering adequately - and even the use of herbicides (including glyphosate, where appropriate). We realize that some people prefer NOT to use herbicides on their personal landscapes, so provide options for weed management that utilize cultural practices. When people are open to the use of herbicides as a weed management option, we provide information on how to use those products safely.

We recognize that people will disagree on whether or not pesticides are "safe" for the environment, for wildlife, for pets, and for humans. We base any suggested/recommended uses of pesticides on research-based information regarding environmental and health safety (EPA and other Federal guidelines).

The recent news story about the World Health Organization's WHO’s International Agency for Research on Cancer (IARC) determination that glyphosate is "probably" (their use of the word) a carcinogen has generated a great deal of conversation about potential health concerns of glyphosate. It is important to note that the IARC does not conduct their own research; rather, the IARC reviews published research. Numerous scientists and government agencies around the world have suggested that IARC's interpretation of some of the research (which lead to their declaration that glyphosate is a probable carcinogen) was flawed - or that some of the research they reviewed was perhaps flawed, biased, or even discredited by other scientists. For example, one of the studies that the IARC relied heavily upon has been so discredited (referred to as the Seralini study) by other scientists that the author was forced to retract it from the journal in which it was published.

For some other scientific opinions on the IARC's proclamation on the potential for glyphosate to be carcinogenic, I would suggest this website:
http://academicsreview.org/2015/03/iarc-glyphosate-cancer-review-fails-on-multiple-fronts/

CSU Extension can not (and will not) use information from groups like Beyond Pesticides because they do not present information in an unbiased fashion. They are openly unapologetic in their opposition to the use of all pesticides - even if the preponderance of research suggests that there are safe ways to use those pesticides for agriculture or in your own backyard. We base our landscape management recommendations on research that has been conducted at universities and by independent agencies - the results of which are then peer-reviewed for publication. While the peer review process does not work perfectly - and some biased or poorly performed research occasionally makes its way to publication - the overwhelming majority of peer-reviewed, published research can be viewed with confidence.

I would suggest that you read (and compare the wording and citation format) of this document to the one you read from Beyond Pesticides - and hope that you will see the difference.
http://npic.orst.edu/factsheets/glyphotech.pdf

In our CMG program we teach using research-based information. We teach the CMGs, in their interactions with the home gardener, to offer a range of options for managing landscapes and controlling pest problems in those landscapes. And we encourage the CMGs to be sensitive to the preferences of individuals when it comes to the use of pesticides in their home landscapes - whether those individuals prefer NOT to use pesticides, or prefer TO use them. Our goal in sharing knowledge on landscape and pest management options is simply to be as unbiased as possible.

Thank you. Let me know if you have further questions.

Tony

And they responded...quickly...

Thank you very much. You answered my question. It's obvious to anyone paying attention that glyphosate and other pesticides, neonics for instance, play a huge role in the fact that we have enormous amounts of these products in our water systems, all the way out through the North American terra firma (and then some). The EPA has been clear in it's cooperation with private research, sure, funded by those that produce the chemicals in the first place. Some believe that CSU is 'educating' the public, when in fact, they aren't. Endless research, both in and out of this country points to the fact these pesticides, which are allowable from the EPA, are killing any pollinator with an exoskeleton, which includes them all I believe, and giving humans cancer. I can appreciate Beyond Pesticides as being bias, but I challenge CSU as an institution to perform the necessary research regarding neonics and glyphosate--but it won't happen. Because just like the EPA, grant funding from agribusiness keeps 'the lights on' so to speak. I'm a beekeeper, and when anyone within 3 miles of my home uses pesticides, it affects the bees. I hope that universities and states get on board one day with true education about our food supply. People spray RoundUp like it's water. Here's some interesting data from the EPA, nowhere in the world are these numbers OK. ""RoundUp use: from 85-90 million pounds in 2001 to 180-185 million pounds in 2007. Pesticide use: from 948 million pounds in 2000 to 877 million pounds in 2007 . . . still close to a billion pounds of toxic chemicals intentionally introduced into the environment and our food supply each year."" I appreciate your time here, and the well thought-out response. I never assumed that CSU endorses anything, other than education.

"Anonymous"

The response wasn't surprising. And while there is so much that I COULD respond to here, would it be a productive use of my time?  I'll consider responding...after I ponder the writer's revelation that the "obvious" has somehow escaped my attention throughout all of my years in academia, and that perhaps all of these past 20+ years of teaching really can't be considered "true education"? I'm sure (?) that these words weren't directed at me personally? Were they? Nahhh...couldn't be....not me! :) And as I write this, I realize with some horror that I never addressed this person's question of glyphosate and pollinators... a much less controversial topic, right?

Roundup-Resistant Turf: Coming to a Lawn Near You?

Tony Koski, Extension Turf Specialist

 

Lately, it seems, the acronym “GMO” (genetically modified organism) can be heard or read daily in the news we receive. I did a Google search of “GMO” and got 85.6 million hits. That’s a lot to wade through – especially if you are looking for unbiased information. A great deal of the debate revolves around potential health effects that GM plants and animals may have when they in some way become part of the food we eat and the labeling of that food. How the growing of GM crops and animals affects the environment, and the economic implications of GMOs, also pose concerns for many people. Unfortunately for those seeking valid information on GMOs, the facts and science often become lost among ideological debates, conspiracy theories, and distrust that both sides have for each other. Well, my purpose here is not to provide the answers for which you might be searching. Heck, this might cause even more confusion – and debate.

In the past week, kind of “under the radar”, a few articles have appeared about field testing the Scotts Company will begin of a glyphosate/Roundup-resistant (RR) tall fescue (as far as I can tell, there has been no official press release about this grass from Scotts). Almost more newsworthy than the grass itself is the fact that the USDA determined in January 2014 that it had no authority to regulate the testing or introduction of this GM tall fescue. They concluded (read the USDA’s letter to Scotts here), that the USDA and APHIS (Animal and Plant Health Inspection Service) have no authority to regulate the testing of the Scotts RR tall fescue because: a) the tall fescue was not transformed (i.e., made glyphosate/Roundup resistant) using plant pests, unknown organisms, or regulated organisms, .

b) that tall fescue is not a federal noxious weed, and c) that there is no reason to believe that the glyphosate-resistance transformation is likely to “increase the weediness of tall fescue”. The USDA and APHIS similarly ruled in 2011 that they would not regulate the development or release of glyphosate-resistant Kentucky bluegrass by Scotts – a ruling which paved the way for the testing of GM bluegrass in the yards of some Scotts employees in 2014 and limited commercialization in 2015

For many years Roundup-tolerant (not resistance to glyphosate, but tolerance of lower rates of the herbicide) tall fescues and perennial ryegrasses have been commercially available. But if Scotts begins selling their GM bluegrasses and tall fescue, they would be the first RR turfgrasses (and genetically modified ones, in the GMO sense) to become commercialized. Scotts’ first attempt at releasing a Roundup-resistant turfgrass (a creeping bentgrass) was nothing short of disastrous and was discontinued when the Roundup-resistance gene escaped (via pollen) from Oregon test seed production fields and was found in native bentgrass plants 12 miles away. As recently as 2010, populations of glyphosate-resistant bentgrass were still being discovered in eastern Oregon after the gene escaped from western Idaho seed fields that were destroyed by Scotts in 2006.

So why the interest by Scotts in the development of RR tall fescue and Kentucky bluegrass – or any turfgrass, for that matter? Because it makes weed control simpler: there would be (theoretically) only one herbicide needed to kill weeds in lawns planted with RR grasses – Roundup (glyphosate). This is the basis for the development of the many “Roundup-Ready” agricultural crops (soybeans, corn, cotton, alfalfa, others) being grown worldwide.

Are there valid reasons to be concerned about the commercialization of RR tall fescue and bluegrass? Certainly.  Because these species also produce pollen, the potential exists for the gene to move – as happened with the GM bentgrass 10 years ago. And the development of glyphosate-tolerant/resistant weed populations, as has happened with some Roundup-Ready cropping systems, is a legitimate concern. Proponents of the Scotts RR turfgrasses might suggest that these grasses would provide simplified weed management for the end user, allow the use of an environmentally benign herbicide for weed control when needed, and that by employing integrated weed management principles the potential for resistant weeds would be minimized. And it has been suggested that tall fescue pollen is much less likely to cause the problems experienced with the RR creeping bentgrass.

The concerns of those opposed to the commercialization of these grasses are valid ones. Hopefully the research will be done properly, care will be taken in the commercialization and production process, and the debate will be based on science and not like what I just read on this blog – which suggests that rolling on a lawn of “poisonous” RR tall fescue or Kentucky bluegrass might be hazardous to your health. (I hesitated to link to this blog, but am confident that our readers are intelligent enough to filter out the more ridiculous rantings of the writer).

To finish on a lighter note…I did a Google search of “golf” and found – to my delight – an impressive 1.38 BILLION hits. This proves that golf is 60% more important…and fun…and popular to read and write about… than GMOs. 

Finally, my prediction for the national football championship tonight: Ohio State defeats Oregon 41-38. Go Buckeyes!!!

Roundup is Roundup…Right?

Tony Koski, Extension Turf Specialist

Which one do I use? They both say  Roundup!

If you are reading this in hopes that the turf specialist has seen the light and jumped on the Occupy Monsanto bandwagon, well…you can stop reading now. Glyphosate/Roundup is still, in my opinion, one of the most effective, inexpensive, easy-to-use and safest herbicides available to the home gardener – and to professional weed managers as well. But a stroll through the pesticide aisle of any hardware store or big box garden center can present to even the sharpest of gardeners a somewhat bewildering selection of Roundup products from which to choose…Roundup Concentrate…Roundup Concentrate Plus…Roundup Extended Control. The various Roundups entice you with promises like “Results in 12 hours” (faster is always better…right?) or “Controls weeds for up to 4 months” (longer is always better…right?). And then there is yet another glyphosate-containing product, ominously named GroundClear, which provides one year or more of weed control (REALLY longer is BEST…right?). It’s easy to understand the confusion when asking oneself “Which one do I buy?”. And I suppose it’s somewhat easy to understand when consumers (professional applicators don’t get a break here) misuse these products in the landscape – although a thorough reading of the label would, in most cases, prevent some damn dumb mistakes. (What? Read a label? Ain’t nobody got time for that!). Sooo….how different are these Roundup products? Can they be used interchangeably? Is one better than the others? Are all of them “safe” for home landscapes?

First, the traditional verbiage – to protect my you know what – whenever we Extension types write about pesticides: READ THE LABEL before purchasing, much less using, any of these products! A reading of the ingredients section of the various Roundup products demonstrates that they aren’t the same. And while the "where to use/not to use" instructions aren’t always the most clearly written, a close reading (ok, maybe 2 or 3 times…) of the label will help prevent misuse of these products. 

Roundup Super Concentrate (white bottle…purple cap) is your good ol’ pure and simple glyphosate.  Use it wherever (wherever the label allows, that is…yes, READ THE LABEL!) you need non-selective control of weeds in your landscape. It is taken up only by leaves and other above-ground green plant tissue. No soil residual. No root uptake. No extended control.  This Roundup can be safely used: on your driveway or sidewalk or patio…on mulch circles around trees (but don’t spray the trunk, or surface roots, or suckers)…to renovate your lawn…or to kill a section of your lawn and replace it with a flowerbed or veggie garden. This is the slowest acting Roundup product, taking anywhere from 5-10 days before you begin seeing symptoms that the weeds are dying. But because we are so impatient (we “need” FASTER internet… FAST food…RAPID transit…INSTANT mashed potatoes), a couple of other Roundup products were developed to satisfy consumer demand for more rapid weed kill. Enter Roundup Plus…

Faster Roundup is better....isn't it?

Roundup Concentrate Plus (white bottle…red cap) contains glyphosate and another herbicide called diquat dibromide. The diquat is added to give a more rapid burndown of weeds that have been sprayed. Other than providing the more rapid (within about 12 hours during hot weather) visual symptoms that the weeds have been sprayed, this Roundup product works the same way as the basic concentrate. All foliar absorption, no root uptake or soil residual. No extended control. 

Roundup Ready-to-Use Plus (blue and white bottle) contains glyphosate and pelargonic acid. The pelargonic acid makes this Roundup product work even more quickly than the Roundup Concentrate Plus – you may see wilting within 3 hours on a hot, sunny day. So, for the VERY impatient, this Roundup product works even more quickly than the Concentrate Plus product – but is otherwise the same: all foliar uptake, no root uptake, no soil residual, no extended control. Use it the same way you would the above two Roundup products.

Roundup Extended Control (gray bottle) contains pelargonic acid (for rapid burn down) and a herbicide called imazapic. Imazapic is added to provide the “extended control”. It works as a preemergence herbicide to provide 3-4 months of weed control by killing germinating seeds/seedling weeds. However, imazapic also is somewhat root active and can provide postemergence control of some weeds as well. This is where things get tricky. Imazapic is fairly water soluble, so it can move in soil. This means it can move to parts of the landscape where you haven’t sprayed it (down slopes, for example…or when sprayed on gravel-covered plastic). And because of the long soil residual, don’t use this product where you may want to plant something in the near future (so this one is a no-no for lawn renovation, nor should it be used where you plan to plant a veggie or flower garden in the future…or trees or shrubs).  The label does allow use over the root zone of trees and shrubs (established ones…not newly planted), including on mulch circles around trees. However, imazapic has been shown to cause injury to a

few tree species which are sensitive to it: lindens, green ash, and cherry trees. Soooo….while it is generally safe to use in those parts of the landscape where you need control of existing weeds AND desire some long term weed control/prevention, you have to recognize the potential for this stuff to “move” in the landscape. Use the same precautions that you would with any Roundup product…and maybe consider if you REALLY need to use this over the root zone of your trees? 

And then there is GroundClear….While it doesn’t have Roundup prominently displayed on the label, this is another Roundup product. It is aggressively marketed on the radio and in the aisles of big box stores. Who wouldn’t want weed control for a year - or longer? This is the one where the “Keep out of reach of children” line on the label maybe should read “Keep out of reach of adults who don’t read a label”. This Roundup product contains imazapyr (a close relative of imazapic…see above), which is a VERY long-lasting, soil/root-active herbicide. Imazapyr can last a year or longer in soil, depending on soil type and how much moisture the soil receives. It is non-selective, can move with water in soil, and is easily taken up by roots of trees (yours or your neighbor’s), shrubs, vines, flowers, veggie plants, turf….you get the idea. As the name would imply, this product really does “clear the ground” on which it is applied. In my opinion, there are few places in a home landscape where this product could be safely used. I doubt that there is a driveway, patio, or fence line in any urban landscape that doesn’t have a tree or shrub root growing under it. Unfortunately, the promise of long-term weed control is so irresistible, it is bought and used in places where there is significant potential for damage to trees and other desirable landscape plants. This is one that you want to avoid using in your landscape, unless you REALLY, REALLY know what you are doing – and even then I would be hesitant to use it.  I have visited landscapes where professional applicators (who should know better…and who violated the label by using it where they shouldn’t have) have killed or injured dozens of trees using this and similar products for mulch circle weed control.

Trees killed by improper use of herbicide
containing imazapyr.

Like most things in life - when preventible, bad things happen - you can only blame yourself for not reading (or following) instructions and heeding warnings.  When you purchase any pesticide, you enter into a legal agreement that you will use it as the label instructs. Your trees and turf can’t read the label…they trust that you will.