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K-State Turfgrass

Month: June 2017

Help us help you – Submitting a sample to the KSU Plant Disease Diagnostic Lab

You think you have a plant problem, and you want some help. So, now what? You’ve heard of the diagnostic lab, but you aren’t sure what to do.

Here are some tips on submitting a turf sample

Here are some tips on submitting a tree/shrub sample

Two nice-sized turf plugs, at the transition of healthy and damaged? YES! That is great:

Tiny branch, smaller than my pinky? NOT! This is not ideal:

So, check out those links above for the guidelines on what to send.

If you have more questions feel free to email me at kennelly@ksu.edu

“Soil Evolution Par for the Golf Course”

Soil water management is a big topic on this blog. Are you curious about some of the science behind it?

How does water infiltration rate change as putting greens age? Big hint – it sure does not get BETTER over time.

This topic was featured in the recent edition of the news magazine of the CSA News (from the American Society of Agronomy/Crop Science Society of America/Soil Science Society of America). Here is the link to the article.

The article also talks about a weird iron layer that can build up over time.

Here is a key figure from the article, sourced from the USGA. Read the whole article to get the story. As you can see, older greens = slower infiltration:

Beware localized dry spot in putting greens – exacerbated by hot, dry winds

Summer is really here now, with fireflies, trips to the swimming pool, and … hot south winds to suck the moisture out of the ground. In sand-based putting greens, localized dry spot can pop up FAST, causing major damage in a short period of time.

Here is what localized dry spot can look like:

Keep an eye on your soil profile so you can stop this damage before it starts. When you get damage to the extent shown in those two photos above it is a long road to recovery.

To check for localized dry spot, pull up some cores and use the “droplet test” by putting drops of water on the plug. If the drops just sit there, not wicking in, you have a problem. The soil is water-repellent.

Sometimes there is a defined hydrophobic layer with normal soil above and/or below, so check at different depths, all the way down the rootzone:

You might also notice water beading up on the surface and not wicking in.

You don’t want this to sneak up on you. Keep an eye on your soil profile, especially locations with a history of problems. Aerification and use of wetting agents can help get moisture where it needs to go.

This example below shows how a slight change in the rootzone can cause problems. The round spots are all locations where the soil was altered for research, with little mini-plots inside tubes sunk into the ground. These spots are prone to LDS. We all know that putting greens are pretty sensitive, so be careful if you are changing up your sand topdressing or other soil-related factors.

Wet and humid = slime mold weather

Hey, what’s that stuff? Slime molds! They can look pretty alarming, and they can pop up seemingly overnight. They are pretty harmless, and you can read more HERE and if you would like a fascinating glimpse into how these organisms work there is a short video clip HERE called “Are you smarter than a slime mold?”

 

Some other shapes and colors of slime mold:

 

Emerald ash borer confirmed in Shawnee County (Topeka)

The Kansas Department of Agriculture, along with the U.S. Department of Agriculture, has confirmed the presence of emerald ash borer (EAB) in Shawnee County, Kansas.

Read on for more details:

http://agriculture.ks.gov/AllNewsItems/2017/06/09/emerald-ash-borer-confirmed-in-shawnee-county

 

(Photo credit:

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Brown Patch Resources

(By Jared Hoyle, KSU Turfgrass Research and Extension)

Tall fescue [Festuca arundinacea Schreb.] is one of the most predominantly used cool-season turfgrass species in the transition zone. Its deep root system and coarse textured leafs lend to its ability to withstand drought, heat, and wear stress. Although it is well adapted to survive the summer months in Kansas, it can be susceptible to injury from disease. Brown patch [Rhizoctonia solani] is a disease that can damage leaf tissue, shoots, and the crown of tall fescue during the summer months. This disease is most prevalent during periods of high humidity, high temperature (above 80°F), and high nitrogen levels. During the mornings mycelia can be seen forming a “smoke ring” around the affected area. Applications of preventative fungicides have proven to be a successful management strategy in reducing the occurrence of brown patch incidences in tall fescue stands.

Here are some resources from the past about brown patch!

Last year Dr. Fry was seeing brown patch in May.  With moisture and warm nights brown patch can start to develop.  http://blogs.k-state.edu/turf/im-not-ready-to-be-thinking-about-brown-patch-jack/

There are many products out there for brown patch control in turfgrass.  Which one is right for you.  Here is a quick update on research that was conducted at Olathe on some brown patch products. http://blogs.k-state.edu/turf/best-way-to-get-your-turf-noticed-brown-patch/ 

Do you know what brown patch looks like?  Do you know how to tell the difference between turfgrass stress and the disease.  Dr. Kennelly can show you the difference. http://blogs.k-state.edu/turf/is-this-brown-patch/

K-State Publications

Commercial Management of Brown Patch – https://www.bookstore.ksre.ksu.edu/pubs/EP146.pdf

Homeowner Management of Brown Patch – http://www.plantpath.k-state.edu/extension/documents/turf/Brown%20patch%20%20homeowners%202016.pdf

Homeowner Do-It-Yourself Lawn Calendar Reminders!

(By Jared Hoyle, KSU Turfgrass Research and Extension)

Earlier this year I wrote two blog posts that listed out both a cool- and warm-season lawn calendar for homeowners.  If you are anything like me then I have already forgot what I was suppose to do so sometimes it is good to have a reminder.

Cool-season Lawn Calendar Reminder 

June through Mid-July
Apply second round of crabgrass preventer by June 15 – unless you have used Dimension (dithiopyr) or Barricade (prodiamine) for the April application. These two products normally provide season-long control with a single application. Remember to water it in. If grubs have been a problem in the past, apply a product containing imidacloprid during the first half of July. This works to prevent grub damage. It must be watered in before it becomes active.

Warm-season Lawn Calendar Reminder

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.

Buffalograss – Fertilize with 1 lb. of nitrogen per 1,000 square feet during June. More applications will give a deeper green color. If it is felt that a second application is needed, apply in July. Do not exceed more than 2 lbs of nitrogen per 1,000 square feet per YEAR for a home lawn.

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 also 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.

For the full Do-It-yourself Lawn Calendars click the links below

Warm-Season – http://blogs.k-state.edu/turf/homeowner-do-it-yourself-lawn-calendar-for-warm-season-grass/ 

Cool-Season – http://blogs.k-state.edu/turf/homeowner-do-it-yourself-lawn-calendar-for-cool-season-grasses/

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

Attack of the 1 inch C-shaped Grub

(By Jared Hoyle, KSU Turfgrass Research and Extension)

In the summer time we typically see dead spots in turf due to many factors but one of those could be annual white grubs.  The annual white grub is one of the most common grub pests in Kansas.  Masked chafers emerge from the soil around mid June in Kansas then after mating they deposit eggs back into the soil.  They then grow and develop in the soil and mature around September.  This is when we typically see damage in turf, once the grubs are large.  But if we can get them before they get big the easier it is to control.

For control measures, you can apply it preventatively or as a rescue treatment (after you have already seen damage.

Preventative controls should be applied during that time when the grubs are mating and laying eggs.  This is typically in June/July time frame. Using a preventative insecticide gives you greater flexibility.  Products for preventative applications contain the systemic active ingredients; imidacloprid, chlorantraniliprole, clothianidin, thiamethoxam and halofenozide.  For a complete list of chemicals go here;

https://www.bookstore.ksre.ksu.edu/pubs/mf2635.pdf

Rescue treatments are “wait-and-see” if you have grubs type of application. If you have grubs you can easily pull up the turf like carpet because all the roots are gone and you also might see skunk, raccoon and bird damage where they have tried to eat the grubs.  Rescue treatments consist of carbaryl and trichlorfon.

For more information check out the link above!

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

The 70 MPH weed – Yellow nutsedge

(By Jared Hoyle, KSU Turfgrass Research and Extension)

The 70 MPH weed….  That is what I call yellow nutsedge.  Why?  It’s because you can be driving 70 MPH down the highway, look over, and see yellow nutsedge growing in a lawn.  The erect light green linear leaves tend to grow faster than the turf so it sticks up above the canopy.

Yellow nutsedge can not only grow in wet soils but also extremely dry soils as well.

Yellow nutsedge is not a new weed but it sure is a persistent weed.  In Kansas, typically we don’t see it until about June.

Once of the easiest ways to identify yellow nutsedge is by a couple special features;

  • erect
  • persistant
  • yellow inflorescence
  • gradually tapering leaves to a sharp point
  • tubers not in chains
  • triangular stem

To control yellow nutsedge, if you can get applications out before tuber production then you will see increased control.  But beware, yellow nutsedge will continue to grow as long as the environment is favorable for growth, so more than one application maybe necessary.

If using a herbicide application timing is critical.  During mid summer yellow nutsedge starts making tubers and if you apply herbicides before tuber production you will get better control.  If you wait until the yellow nutsedge is big and starting to make tubers then you will be playing catch-up all year. So sooner is better.  Don’t wait for it to get too big.

Here are some options for yellow nutsedge control for turfgrass professionals;

  • sulfentrazone
  • halosulfuron
  • iodosulfuron
  • mesotrione
  • bentazon
  • triflozysulfuron
  • flazasulfuron
  • sulfosulfuron

There are many different products out there that contain these active ingredients so just make sure you have an active ingredient that has yellow nutsedge control!

For homeowners – Here is some more information to help with yellow nutsedge control in a home lawn.

http://blogs.k-state.edu/turf/revisiting-yellow-nutsedge-control-in-home-lawns/

****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

 

 

Don’t miss the 2017 KSU Turfgrass Field Day – August 3rd

The next Turfgrass Field Day will be held on Thursday, August 3, 2017 at the John C. Pair Horticultural Research Center, Wichita.
The KTF Turf Field Days are a great way to see and learn about the turfgrass research at K-State first hand. The events are held annually in the summer at the turfgrass research locations of Kansas State University.

The Field Day qualifies for recertification credit hr for commercial pesticide applicators.

You can now Register and Pay Online at  https://2017turffieldday.eventbrite.com
or you can register by downloading, printing, and mailing go to the 2017 Field Day brochure.

Exhibitors can get more information from the Exhibitor Registration Form.

Schedule of the 2017 Field Day 
8:00 a.m. Registration (coffee, tea, donuts)
Visit Exhibitors
8:45         Welcome
9:00        Tour Highlights:

*Turfgrass Weed Control Update
*Turf & Ornamental Diseases
*Bermudagrass & Zoysiagrass Cultivar Selection
*Using Kansas Mesonet to Imrpove Accuracy in Landscape Irrigation
*Right Plant, FROM the Right Place
* Prairie Star Flowers
*Tall Fescue NTEP
*Turf & Ornamental Insect Control
11:30       Lunch

After Lunch

  • Equipment Demonstrations

If you have any questions, please contact,
    Christy Dipman 
    1712 Claflin, 2021 Throckmorton Hall
Manhattan, Kansas 66506
Phone: (785) 532-6173
Fax: (785) 532-6949
Email: 
Christy