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Category: Weeds

Developing a Weed Control Program

(By Jared Hoyle, KSU Turfgrass Research and Extension)

There are many important factors to consider when you are developing a weed control program.  Here is a list of information you should have to help you develop your program.

  1. Turfgrass species
  2. Area needing to be treated.
  3. Correct identification of the problematic weeds.
  4. The time of year the weeds are present.
  5. Determine why the weeds are invading and correct the conditions or cultural practice that are leading to the weed invasion.
  6. Select a chemical that is effective and label for control of the weeds you are treating.
  7. Follow all label instructions!!!!!!!
  8. Apply at the correct time and rate.
  9. Apply herbicides evenly.
  10. Follow up with repeat applications if recommended on the label.

This is also great information to have if you can’t figure out why a weed control method didn’t work.  For more information on diagnosing why a weed control method didn’t work, click here – https://blogs.k-state.edu/turf/i-sprayed-but-i-didnt-kill-the-weed/

Information in this article is from Turfgrass Weed Control for Professionals.

Patton, A.J., M. Elmore, J. Hoyle, J. Kao-Kniffin, B. Branham, T. Voigt, N. Christians, A. Thoms, G. Munshaw, A. Hathaway, T. Nikolai, B. Horgan, L. Miller, X. Xiong, W. Kreuser, R. Gaussoin, D. Gardner, Z. Raudenbush, D. Li, P. Landschoot, D. Soldat, and P. Koch. 2019 Turfgrass Weed Control for Professionals. Purdue University Extension Publication. TURF-100. pp. 128.

Get your copy here – https://www.bookstore.ksre.ksu.edu/Item.aspx?catId=545&pubId=20239

***Mention of trade names or commercial products in this article is solely for identification purposes and does not imply recommendation or endorsement, nor is criticism implied of similar products not mentioned by Kansas State University.***

Don’t forget to follow me on twitter @KSUTurf.

Also, visit our facebook page www.facebook.com/KSUTurf

Bermudagrass Control Options for Reseeding

(By Jared Hoyle, KSU Turfgrass Research and Extension)

Last week Ward Upham wrote an article on bermudagrass control in the KSU Horticulture Newsletter.  In the article below he explains the difficulty of controlling bermudgrass, the process and the multiple applications of a non-selective herbicide.

Bermudagrass Control by Ward Upham

Bermudagrass can make a nice lawn if you don’t mind its
invasiveness and short growing season. But many people dislike both
these characteristics. Warm-season grasses, such as bermudagrass,
zoysiagrass and buffalograss, green up later than cool-season grasses
such as tall fescue and Kentucky bluegrass. They also go dormant earlier
in the fall, which can make a lawn unattractive. Bermuda that invades a cool-season lawn will be brown during much of the spring and fall while the tall fescue portion of the lawn is green. Bermuda is much more drought and heat resistant than cool-season grasses, so it will take over a cool-season lawn during the summer months if it is in full sun.

So, how do you control bermudagrass that has invaded a cool-season
lawn? Research conducted in 1996 showed that glyphosate is the best herbicide for the job. Glyphosate is a nonselective herbicide and will kill everything—
including tall fescue or Kentucky bluegrass. Therefore, you will need to
reseed treated areas. In our study, we applied a 2% solution of
glyphosate on July 15 and again on August 15 on a bermudagrass plot that
was more than 15 years old. More than one year later, we saw no
regrowth. Glyphosate works best if bermuda is growing well. The better
the bermudagrass is growing, the more chemical is taken up and pushed
into the roots. Water and fertilize if needed to get it going.
Spray about the middle of July (or when the bermuda is growing
well). Use glyphosate (2% solution). Wait two weeks and scalp the lawn
(mow as low as possible and remove clippings.) This will prevent dead
grass from covering any bermuda that starts to recover. Wait another two
weeks and spray again with glyphosate if there is any green. Wait two
more weeks and reseed. (Ward Upham)

(For the KSU Horticulture Newsletter click here – https://hnr.k-state.edu/extension/info-center/newsletters/index.html)

But during this time areas are dead, may not be acceptable and re-seeding must be done in the fall.  What if you are wanting to seed in the spring (Especially if you ware wanting to convert to buffalograss)? This process might not work due to the timeline. Therefore, a couple years ago we looked into some other options and combinations for bermudagrass control. Here is a brief overview of the project.

Multiple summer applications of glyphosate are commonly recommended for bermudagrass (Cynodon spp.) control. However, this regime results in an extended period of displeasing and nonfunctional turfgrass, and is not ideal for spring establishment. An autumn glyphosate application prior to winter dormancy can control bermudagrass and may benefit spring  establishment projects. However, research is needed to more precisely define the parameters of efficacious late-season herbicide applications for bermudagrass control as it transitions into dormancy. Therefore, our objective was to examine late-season bermudagrass removal using combinations of glyphosate, fluazifop, and mesotrione. Experiments were initiated in October 2013 at the Rocky Ford Turfgrass Research Center in Manhattan, KS, on mature ‘Midlawn’ hybrid bermudagrass, and at Stagg Hill Golf Course in Manhattan, KS, on mature common bermudagrass. Seven herbicide treatments containing combinations of glyphosate, fluazifop, and mesotrione were evaluated. Green bermudagrass cover (0–100%) was visually estimated when treatments were applied and every 14 d after application. Only treatments containing glyphosate reduced the green cover of bermudagrass at each site the following year. Across all ratings dates and locations, adding mesotrione, fluazifop, or both to glyphosate did not further reduce green bermudagrass cover. Overall, results indicate that a single autumn application of glyphosate prior to bermudagrass dormancy reduces bermudagrass cover the following spring. The significant reduction at spring green-up may allow turf managers to make additional applications in the spring for increased control before spring establishment.

For the full article;

Hoyle, J.A.,C. Braun, C.S. Thompson and J.A. Reeves. 2018. Late-Season Bermudagrass Control with Glyphosate, Fluazifop, and Mesotrione Combinations. Agrosystems, Geosciences & Environ. 1:180014 (2018) doi:10.2134/age2018.06.0014

https://dl.sciencesocieties.org/publications/age/pdfs/1/1/180014

***Mention of trade names or commercial products in this article is solely for identification purposes and does not imply recommendation or endorsement, nor is criticism implied of similar products not mentioned by Kansas State University.***

Don’t forget to follow me on twitter @KSUTurf.

Also, visit our facebook page www.facebook.com/KSUTurf

I sprayed but I didn’t kill the weed!

(By Jared Hoyle, KSU Turfgrass Research and Extension)

“I sprayed but I didn’t kill the weed!” I get this comment many times throughout the year and there could be may possible reasons why, other than saying that herbicide doesn’t work. What I have found is that the most common reason is human error. So, here are a couple questions you should ask yourself to help determine what went wrong.

  1. Did you correctly identify the weed?
  2. Was the weed listed on the label?
  3. Did you use the correct rate?
  4. Did you have uniform spray coverage?
  5. Did you apply it at the appropriate growth stage?
  6. What was the temperature when you applied? Was it within the label recommendation?
  7. Was there adequate soil moisture for weed growth?
  8. Did you tank-mix?  Could have an antagonistic effect!
  9. Where you suppose to make two applications (according to the label)?
  10. Did it rain or did the irrigation run soon after application?
  11. Did you add an adjuvant or surfactant that was recommended on the label?
  12. If you applied a PRE, did you water it in, within the next few days? or has the weed already germinated or emerged?

These are just a couple questions used to help figured out what happened if you sprayed and didn’t kill the weed.

Always remember to READ THE LABEL for the correct rate, turfgrass tolerance, and specific instructions before application!!!

***Mention of trade names or commercial products in this article is solely for identification purposes and does not imply recommendation or endorsement, nor is criticism implied of similar products not mentioned by Kansas State University.***

Don’t forget to follow me on twitter @KSUTurf.

Also, visit our facebook page www.facebook.com/KSUTurf

Postemergent Crabgrass Control

(By Jared Hoyle, KSU Turfgrass Research and Extension)

Today I was walking around the Rocky Ford Turfgrass Research Center in Manhattan, KS looking for an area to put out a postemergent crabgrass study and notice that the crabgrass on the research farm is all different stages.  It is important to know what stage the crabgrass is in to help with control.  That could determine your success in controlling it with postemergent herbicides

There are postemergent herbicide options out there for crabgrass control.  But depending on how big or how many tillers the crabgrass has will help you determine what product to use.  First, determine the size or stage of crabgrass you have present.

Here is a picture to show the tillering stages of crabgrass.

The smaller the crabgrass the easier it is to kill it.  The tillered crabgrass may take more than one application and higher rates so make sure you check the label for correct application rates and intervals.

  • dithopyr – Can provide control to crabgrass up to one tiller stage.  This product also has preemergence activity.
  • quinclorac – Can be applied on most cool- and warm-season turfgrass species.  This product controls crabgrass when it is one tiller or smaller or when it has four or more tillers.
  • mesotrione – Can be effective for crabgrass control but in most cases will take two applications at two week intervals. The label also states that applications must be made before the four tiller crabgrass stage.
  • topramazone – Similar to mesotrione, this product will require two applications at three week intervals. Use at higher rates on crabgrass that have greater than one tiller.
  • fenoxaprop – Are very effective in controlling crabgrass.  Label states that this product can be applied to annual grasses up to the five tiller stage. Remember not to tank mix with products that contain 2,4-D, antagonism can occur.

As one last reminder, do not apply post emergent herbicides outside the recommended temperature on the label.  This will increase the risk of turfgrass injury.

Always remember to READ THE LABEL for the correct rate, turfgrass tolerance, and specific instructions before application!!!

***Mention of trade names or commercial products in this article is solely for identification purposes and does not imply recommendation or endorsement, nor is criticism implied of similar products not mentioned by Kansas State University.***

Don’t forget to follow me on twitter @KSUTurf.

Also, visit our facebook page www.facebook.com/KSUTurf

Research UPDATE – Influence of Herbicide Combinations and Sequential Applications on Windmillgrass (Chloris verticillata) Control

(By Nic Mitchell and Jared Hoyle, KSU Turfgrass Research and Extension)

Windmillgrass (Chloris verticillata Nutt.) populations commonly infest turfgrass systems in the mid-west, which result in aesthetically unacceptable turfgrass stands. Windmillgrass is a perennial monocot bunch-type grass. It often spreads by stolons and by its panicle shape seed which acts much like tumble weed.

Prior research found that Pylex (topramezone) and Acclaim Extra (fenoxaprop) result in fair to minimal control of windmillgrass with a single application. Tenacity (mesotrione) which, labeled for two applications for best control of windmillgrass, recommends the second application should be three weeks after initial application. Additionally, studies have shown the addition of triclopyr to HPPD inhibitor herbicides increases windmillgrass control in a controlled environment.

The goal of this research was to determine the effect of a sequential postemergent herbicide applications and the addition of triclopyr to HPPD inhibitors herbicides on windmillgrass control.

Research trials were initiated in 2018 at Rocky Ford Turfgrass Research Center in Manhattan, Kansas. Windmillgrass was infested in a low maintenance tall fescue (Schedonorus arundinaceus) system. Seven herbicide combinations were applied as a single application or with a sequential application and non-treated control was included for comparison for a total of 15 individual treatments. All herbicide treatments were applied on August 16, 2018 and treatments that received a sequential application were applied on September 9, 2018. Herbicide treatments consisted of Pylex (topramezone) at 2 fl oz/a, Tenacity (mesotrione) at 8 fl oz/a, Acclaim (fenoxaprop) at 39 fl oz/a, Alligare Triclopyr 4 (triclopyr) at 32 fl oz/a, Pylex (topramezone) at 2 fl oz/a + Alligare Triclopyr 4 (triclopyr) at 32 fl oz/a, Tenacity (mesotrione) at 8 fl oz/a + Alligare Triclopyr 4 (triclopyr) at 32 fl oz/a, Acclaim (fenoxaprop) at 39 fl oz/a + Alligare Triclopyr 4 (triclopyr) at 32 fl oz/a, and a nontreated control. Data collection consisted of visual percent windmillgrass cover (0-100%) and were transformed to percent windmillgrass control for presentation purposes. Analysis of variance (ANOVA) was performed in SAS 9.4 (SAS Institute Inc., Cary, NC) and means were separated according to Fisher’s protected least significant difference (LSD) level at 0.05.

We found that Pylex (topramezone) applied at 2 fl oz/a resulted in 87% windmillgrass control at 8 weeks after treatment. A single application of Pylex (topramezone) at 2 fl oz/a + Alligare Triclopyr 4 (triclopyr) at 32 fl oz/a and Tenacity (mesotrione) at 8 fl oz/a + Alligare Triclopyr 4 (triclopyr) at 32 fl oz/a resulted in 96% and 97% windmillgrass control 8 weeks after initial treatment, respectively. All treatments that received a sequential application on September 9, 2018 excluding the non-treated control and Acclaim (fenoxaprop) at 39 fl oz/a provided 100% windmillgrass control at 8 WAT. Acclaim (fenoxaprop) at 39 fl oz/a applied on August 16, 2018 followed by an application at 39 fl oz/a on September 9, 2018 resulted in 88% windmillgrass control.

Table 1. Windmillgrass (Chloris verticillata Nutt.) control 8 weeks after initial application from single and sequential applications at Rocky Ford Turfgrass Research Center in Manhattan, KS; 2018.

Treatment Herbicide Rate Application Date Controla
___%___
1 non-treatedb 4 Cc
2 Pylex + MSOd 2 fl oz/a + 1% v/v Aug. 16, 2018 87 A
3 Tenacity + NISd 8 fl oz/a + 0.25% v/v Aug. 16, 2018 9 C
4 Acclaim Extra + NIS 39 fl oz/a + 32 fl oz/100 gal Aug. 16, 2018 16 C
5 Triclopyr 32 fl oz/a Aug. 16, 2018 64 B
6 Pylex + Triclopyr + MSO 2 fl oz/a + 32 fl oz/a + 1% v/v Aug. 16, 2018 96 A
7 Tenacity + Triclopyr +NIS 8 fl oz/a + 32 fl oz/a + 0.25% v/v Aug. 16, 2018 97 A
8 Acclaim Extra + Triclopyr +NIS 39 fl oz/a + 32 fl oz/a + 32 fl oz/100 gal Aug. 16, 2018 63 B
9 Pylex + MSO 2 fl oz/a + 1% v/v Aug. 16, 2018 fbe Sept. 9, 2018 100 A
10 Tenacity + NIS 8 fl oz/a + 0.25% v/v Aug. 16, 2018 fb Sept. 9, 2018 100 A
11 Acclaim Extra + NIS 39 fl oz/a + 32 fl oz/100 gal Aug. 16, 2018 fb Sept. 9, 2018 88 A
12 Triclopyr 32 fl oz/a Aug. 16, 2018 fb Sept. 9, 2018 100 A
13 Pylex + Triclopyr + MSO 2 fl oz/a + 32 fl oz/a + 1% v/v Aug. 16, 2018 fb Sept. 9, 2018 100 A
14 Tenacity + Triclopyr +NIS 8 fl oz/a + 32 fl oz/a + 0.25% v/v Aug. 16, 2018 fb Sept. 9, 2018 100 A
15 Acclaim Extra + Triclopyr +NIS 39 fl oz/a + 32 fl oz/a + 32 fl oz/100 gal Aug. 16, 2018 fb Sept. 9, 2018 100 A

a Ratings were conducted 8 weeks after initial application; October 11, 2018.

b Non-treated control contained approximately 65% windmillgrass cover throughout the research trial. 4% control was observed due natural declining of windmillgrass populations to environmental considerations on October 11, 2018.

c Treatment means followed by a common capital letter are not significantly different according to Fisher’s protected LSD (α= 0.05).

d MSO, methylated seed oil and NIS, non-ionic surfactant were added to treatments according to herbicide manufacture recommendations.

e fb, followed by.


Always remember to READ THE LABEL for the correct rate, turfgrass tolerance, and specific instructions before application!!!

***Mention of trade names or commercial products in this article is solely for identification purposes and does not imply recommendation or endorsement, nor is criticism implied of similar products not mentioned by Kansas State University.***

Don’t forget to follow me on twitter @KSUTurf.

Also, visit our facebook page www.facebook.com/KSUTurf

Warm-season Turfgrass Lawn Care Reminders

(By Jared Hoyle, KSU Turfgrass Research and Extension)

Now that the summer weather is finally here it is time to start thinking about maintenance on warm-season turfgrass.  Below are some monthly reminders for everyone that has warm-season turf.


Bermudagrass and Zoysiagrass

May – August 15
Fertilize with 1 lb. of nitrogen per 1,000 square feet per application. Follow the recommendations on the bag. More applications will give a deeper green color, but will increase mowing and may lead to thatch buildup with zoysiagrass. Bermudagrass can also have problems with thatch buildup but thatch is less likely with Bermuda than zoysia. Bermudagrass – Use two to four applications. Zoysiagrass – Use one to two applications. Too much nitrogen leads to thatch buildup.

One Application: Apply in June.
Two Applications: Apply May and July.
Three Applications: Apply May, June, and early August.
Four Applications: Apply May, June, July, and early August.

Remember to look and see if you are using a quick release nitrogen source or a slow release nitrogen source.  If you use a quick release source then it is immediately available but only lasts a couple weeks.  Thats why you would have to make a couple of applications like it is listed above.  If you are going to use a slow release source it will tell you on the bag how long the product will last.  Therefore, you might not have to make as many applications.

So generally you want to use a total of 2 to 4lb. of nitrogen per 1,000 square feet per year for bermudagrass and 1 to 2 lb. of nitrogen per 1,000 square feet per year for zoysiagrass.

June
If grubs have been a problem in the past, apply a product containing imidacloprid by mid July. Imidacloprid can be applied as early as mid May if there are problems with billbugs or May beetle grubs. These products kill the grubs before they cause damage. They are effective and safe but must be watered in before they become active. June is a good time to core aerate a warm-season lawn. Core aeration will help alleviate compaction, increase the rate of water infiltration, improve soil air exchange and help control thatch.

Late-July through August
If you see grub damage, apply a grub killer. If Imidacloprid has been applied, this should not be necessary. Grub killers must be watered in immediately.

For more information check out the Zoyisagrass Lawns Publication at the KSRE Bookstore – https://www.bookstore.ksre.ksu.edu/Item.aspx?catId=545&pubId=1451

For more information check out the Bermudagrass Lawns Publication at the KSRE Bookstore – https://www.bookstore.ksre.ksu.edu/Item.aspx?catId=545&pubId=586


Buffalograss

June

Fertilize with 1 lb. of nitrogen per 1,000 square feet during June. More applications will give a deeper green color, but can encourage weeds. If it is felt that a second application is needed, apply in July.

If grubs have been a problem in the past, apply a product containing imidacloprid by mid July. Imidacloprid can be applied as early as mid May if there are problems with billbugs or May beetle grubs. These products kill the grubs before they cause damage. They are effective and safe but must be watered in before they become active. Again, I would only treat if grubs have been a problem in the past. Note that the whole area may not need to be treated. The beetles that lay the eggs for the grubs are attracted to lights and moist soil and those areas are most likely to be infested.

Late-July through August

If you see grub damage, apply a grub killer. If imidacloprid has been applied or if grubs have not been a problem in the past, this should not be necessary. Grub killers must be watered in immediately.

For more information check out the Buffalograss Lawns Publication at the KSRE Bookstore – https://www.bookstore.ksre.ksu.edu/Item.aspx?catId=545&pubId=1447


Always remember to READ THE LABEL for the correct rate, turfgrass tolerance, and specific instructions before application!!!

***Mention of trade names or commercial products in this article is solely for identification purposes and does not imply recommendation or endorsement, nor is criticism implied of similar products not mentioned by Kansas State University.***

Don’t forget to follow me on twitter @KSUTurf.

Also, visit our facebook page www.facebook.com/KSUTurf

Bentgrass Putting Green Fertility – Helping or hurting silvery-thread moss?

(By Jared Hoyle, KSU Turfgrass Research and Extension)

At Rocky Ford Turfgrass Research Center in Manhattan, KS we have two bentgrass putting greens.  On one of them we “try” to maintain as a common putting green with typical disease, weed and fertility programs.  On the other one we don’t apply any fungicides at all to see what disease we can grow.  On that same putting green we are growing a nice crop of silvery-thread moss as we aren’t doing anything to help suppress or control it.

When I came on board here at KSU in 2013, the KSU Turfgrass Faculty and graduate students were really diving into figuring out programs to help control or suppress silvery-thread moss in bentgrass putting greens.  Quick to find out, controlling moss is not just an application but a program and part of that program is fertility.

I quickly went through some of the past research reports on the KSU Turfgrass Website (https://www.k-state.edu/turf/research/index.html) and came across a short report on the influence of nitrogen source and spray volume on the establishment of silvery-thread moss.  Establishment! Establishment!  Why are we studying the establishment?  Well, knowing what helps establishment also tells you what is going to promote growth of silvery-thread moss.

As Drs. Raudenbush and Keeley explain in the research report, “the practice of spraying small quantities of soluble nitrogen at a relatively high frequency my promote silvery-thread moss growth because the moss lacks a vascular system of removing water and nutrients from the soil.”  Apply small quantities of soluble nitrogen at relative high frequencies is a common practice for managing bentgrass putting greens, so we maybe making the problem worse.

To summarize the project that was conducted in the greenhouse, spraying soluble nitrogen increased moss cover compared with the untreated control and ammonium sulfate has the highest moss cover at all the ratings dates.  Comparing ammonium sulfate to urea, ammonium sulfate caused more than a threefold increase in moss dry weight (At 7 weeks after the initial treatment the moss was harvested, dried and weighed.) and there was no difference between urea and the water only control.

There are many other factors to consider when looking at suppressing or controlling silvery-thread moss including but not limited to; watering, herbicide applications, topdressing and promoting healthy bentgrass. But remember fertility, as it does play a roll in silvery-thread moss management.

For the full report check out Page 12 of the 2014 Kansas State University Turfgrass Research Report – https://krex.k-state.edu/dspace/bitstream/handle/2097/20427/Turfgrass2014.pdf?sequence=1&isAllowed=y

Should we be hitting the panic button on goosegrass control?

(By Jared Hoyle, KSU Turfgrass Research and Extension)

Not too long ago I received a text from a friend of mine with a picture of goosegrass and the caption, “goosegrass emergence reported in Salina, KS in areas w/o PRE.”  With the mild temperatures and just now seeing crabgrass germinate in some thin areas where no preemergence has been applied, I thought to my self, “Oh no.”  I then posted the picture on Twitter to let everyone know what was going on in the area.

One of my good friends, Scott, down in Georgia commented “Should we hit the panic button?”

To answer that question honestly… I’m not sure.  Then I went back and looked at the picture.  There was a set of keys in the picture to help show the relative size of the goosegrass and on the key was a “panic” button that is commonly on keyless entry vehicles. Ironic?

So should we hit the panic button?  I am not sure but I do think that means we need to keep an eye out and know that goosegrass is on its way if not already germinated and especially in areas that haven’t been applied with a preemergent herbicde.

Goosegrass (Eleusine indica) is a summer annual weed that typically germinates after crabgrass in the spring.  That is about when the soil temperatures consistently reach approximately 60° F.  Like crabgrass, goosegrass is best controlled with a preemergence herbicide.   Herbicides that contain the active ingredient oxadiazon work very well.  Other preemergence herbicide efficacy can vary.

But as it seems like everyone has already put down preemergence herbicide so, you have nothing to worry about.  Well what if you didn’t, or there is break through?  There are some POST application control options.

First, Know you turfgrass species.  Your herbicide selection is going to vary greatly depending on species.

If you have cool-season turfgrass then you can use fenoxaprop (Acclaim Extra), fluazifop (Fusilade II), tropramizone (Pylex), or MSMA (golf courses and sod farms only!).  You will probably have to do more than one application if the goosegrass is tillered out.  Sulfentrazone (Dismiss) is also effective on goosegrass if it has not tillered out yet.

Bleaching of goosegrass from topramazone application

Creeping Bentgrass

For all you golf courses out there that have creeping bentgrass fairways it is going to be a little bit more difficult because the herbicides that work best tend to injure  the turf.  1-Tiller or smaller can be controlled with fenoxaprop (Acclaim Extra) at 3.5 fl oz/A but you will need to re-apply every two weeks to make sure you are applying to small plants.

As crazy as it sounds a herbicide that has commonly been used for broadleaf weeds has shown control on goosegrass.  SpeedZone (2,4-D +dicamba + MCPP) has shown control but a follow up[ application is going to be needed 30 days after initial application.

Tropramizone (Pylex) can be used on bentgrass at lower rates (0.25 fl oz/A) but definitely might need a repeat application at 21 days

Bermudagrass and Zoysiagrass

Now if you have bermudagrass or zoysiagrass then you can use Tribute TOTAL (thiencarbazone + foramsulfuron + halosulfuron).  Fusilade II and Acclaim Extra that works in cool-season grass can also be used on zoysiagrass.  If you mix these products with triclopyr (Turflon Ester Ultra or Triclopyr 4) then you will get better results.

Always remember to READ THE LABEL for the correct rate, turfgrass tolerance, and specific instructions before application!!!

***Mention of trade names or commercial products in this article is solely for identification purposes and does not imply recommendation or endorsement, nor is criticism implied of similar products not mentioned by Kansas State University.***

Don’t forget to follow me on twitter @KSUTurf.

Also, visit our facebook page www.facebook.com/KSUTurf

Sandbur Control for Turfgrass Professionals

Photo credit – https://hnr.k-state.edu/extension/info-center/common-pest-problems/common-pest-problem-new/Grassy%20Sandbur.pdf

(By Jared Hoyle, KSU Turfgrass Research and Extension)

It is that time of year where we are going to start seeing more and more summer annual grassy weeds emerge, especially if you didn’t get a preemergent herbicide down.  One of that problematic summer annual weeds is sandbur (Longspine sandbar – Cenchrus longispinus; field sandbar – Cenchrus incertus).  These sandbur species are often found in sandy soils but can grow in a wide range of soil conditions.  They can appear to look like crabgrass and foxtail but the seedheads are spike-like racemes with bur-like fruit.  This is the major problem.  These seedheads can cause physical injury to a person, animals and equipment.

There is good news.  Like many of the other summer annual weeds you can control sandbar with preemerge herbicides if you follow the recommendations for preemergent crabgrass control.

But if you have an escape or didn’t treat with a preemerge herbicide this year you have a couple of options;

  • Herbicides that contain fenoxaprop (Acclaim Extra, Last Call), MSMA or topramazone (Pylex) are most effective (≥ 90% control).
  • To achieve 75-90% control use; asulam (Asulox), fluazifop (Fusillade II, Ornamec), imazapic (Plateau), sethoxydim (Segment II) and sulfentrazone + imazethapyr (Dismiss South).
  • Atrazine (AAtrex) and simazine (Princep) provide fair control (50-75%)
  • The flowing herbicides have resutled in some activitly but ≤50% control.
    • 2,4-D+quinclorac+dicamba (Momentum Q, Quincept)
    • carfentrazone+2,4-D+MCPP+dicamba (Speedzone)
    • ethofumesate (Prograss)
    • foramsulfuron (Revolver)
    • imazaquin (Image 70DG)
    • mesotrione (Tenacity)
    • metsulfuron (Manor, Mansion)
    • metsulfuron + rimsulfuron (Negate 37WG)
    • pronamide + quinclorac (Cavalcade PQ)
    • pronamide (Kerb)
    • quinclorac (Drive XLR8)
    • quinclorac + sulfentrazone +2,4-D + dicamba (Q4 Plus)
    • sulfentrazone (Dismiss)
    • sulfentrazone + quinclorac (Solitare)
    • trifloxysulfuron (Monument)

For more information on sandbur and many other weeds, check out Turfgrass Weed Control for Professionals 2019 Edition – https://www.bookstore.ksre.ksu.edu/Item.aspx?catId=545&pubId=20239

****Always remember to READ THE LABEL for the correct rate, turfgrass tolerance, and specific instructions before application.****

***Mention of trade names or commercial products in this article is solely for identification purposes and does not imply recommendation or endorsement, nor is criticism implied of similar products not mentioned by Kansas State University.***

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Little Barley Control Options (or Option)

(By Jared Hoyle, KSU Turfgrass Research and Extension)

I was walking through some of our research plots (with waders on due to all the rain) and I came to a nice patch of little barley.  It was lush!  I thought to myself, “How did this get so bad?” but, then I noticed there wasn’t any turf in the area at all.  Little barley (Hordeum pusillum) is a winter annual that is many times confused with foxtails because the seedbed look similar. To see the differences in seedbeds click here –  https://blogs.k-state.edu/turf/tag/little-barley/

But the problem is I have lots of little barley and what do I do;

1.Promote healthy dense stand of turfgrass. Maybe overseed this spring/early summer if you have to depending on your situation and turfgrass species. Definitely overseed in the fall if you have cool-season turfgrass.

2. Use a preemergence in the fall.

3. Can use Certainty (sulfosulfuron) in warm season turfgrass but typically don’t.

4. Do nothing….  Seems like a trick question but this species will thin and die as temperature increase in the summer.

So there are a couple of options but if you do have little barley it is probably because the turfgrass isn’t doing well.

For more information on little barley and many other weeds, check out Turfgrass Weed Control for Professionals 2019 Edition – https://www.bookstore.ksre.ksu.edu/Item.aspx?catId=545&pubId=20239

****Always remember to READ THE LABEL for the correct rate, turfgrass tolerance, and specific instructions before application.****

***Mention of trade names or commercial products in this article is solely for identification purposes and does not imply recommendation or endorsement, nor is criticism implied of similar products not mentioned by Kansas State University.***

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