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K-State Turf and Landscape Blog

Tag: postemergent

Crabgrass Has Emerged

Posted on by Brooke Garcia

By Dr. Jack Fry

Crabgrass emergence was evident last weekend – at least in Olathe, KS (picture below).

Crabgrass seedlings (inside white border) emerging on April 19, 2020 in Olathe, KS.

 

This was on bare soil next to a paved sidewalk. It can take a few weeks longer for crabgrass to emerge within areas of thin turf due to cooler soil temperatures (see article on timing herbicide applications here: Flowering Ornamentals and Crabgrass Emergence). So, on a lawn of acceptable quality (and no bare areas), you should still have time to get a preemergence herbicide out. Once you see crabgrass such as this emerging within a lawn, consider using a preemergence herbicide that has postemergence activity, such as dithiopyr (Dimension) or mesotrione (Tenacity). Of course, there are also a number of postemergence herbicides that can be used for crabgrass control as well.

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.***

Postemergent Crabgrass Control

Posted on by jahoyle

(By Jared Hoyle, KSU Turfgrass Research and Extension)

Did you apply a preemergent herbicide this year and still have crabgrass? There are many different reasons you may have break through from a preemergent herbicide application.  If the turf is stressed and thin, along with over use of the turf and misapplications are some reasons you may be seeing crabgrass pop-up across many turfgrass areas.

Good news! There are some 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 when temperatures are greater than 85 deg F.  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.***

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

Whats new at #ksuturf farms in Manhattan and Olathe?

Posted on by jahoyle

(By Jared Hoyle; KSU Turfgrass Research and Extension)

This summer has been a crazy one.  We have been getting ready for field day in Olathe on August 6th (Hope to see everyone out there! – Register here – http://www.eventbrite.com/e/kansas-turf-ornamentals-field-day-tickets-16109376579) but there are a lot of new projects that graduate students, faculty and staff are up to.  Here is just a list of what is going on and we will be talking more about it at field day and at Annual Turfgrass Conference in December!

We have a new GPS navigated robot mower being tested out at Rocky Ford in Manhattan.

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Pre- and Post-emergent herbicide trials at Olathe and and Manhattan. (Photo form Olathe).

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Influence of tall fescue mowing height on crabgrass populations demonstration at Olathe.

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I have been traveling everywhere. (Had to throw that in there)

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New zoysaigrass variety trials at Rocky Ford in Manhattan.

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Ross Braun (KSU Turfgrass PhD Graduate Student) has been evaluating multiple turfgrass species, mowing height and traffic in drought conditions.

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Evan Alderman (KSU Turfgrass MS Graduate Student) installed a new fairway (5/8″) of ‘Cody’ buffalograss at Rocky Ford.

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There is a new ornamental herbicide testing facility installed at the forest research center in Manhattan to evaluate potential turfgrass herbicides to ornamental plants.

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The use of adjuvants with Pylex  and triclopyr combination demonstration trial at Olathe. Brown patch control research trial was installed at Olathe this summer. New granular products for broadleaf weed control (Olathe – Photos not shown).

Dr. Bremer and Ross Braun (KSU Turfgrass PhD Graduate Student) has been studying greenhouse gas emissions under drought conditions at Rocky Ford.

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More traveling…

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Lastly, I would like to congratulate Dr. Zane Raudembush for completing his PhD this past spring.  Good luck in all your do Zane.

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This is not all of what have been going on but just wanted to share some of the pictures of some of the new things that are going on here in the KSU Turfgrass Program.

Don’t forget to come out to field day August 6th and see some of the research that we have been conducting.  Thanks and have a great rest of the week!

Jared