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K-State Turfgrass

Month: August 2016

Turf health problems, above and below ground. And why your putting green soil should not look like tiramisu.

(Megan Kennelly, KSU Plant Pathology)

The soggy weather continues, and diseases are in full swing. Dewy, wet mornings lead to mycelial growth of the pathogens that cause dollar spot or foliar Pythium. These are mainly golf course concerns, but the diseases can occur at other sites.

Here is a sample that came into the lab, loaded with foliar Pythium:

IMG_3151

It is from a golf course fairway at a site that has received a lot of rain and some foggy mornings where everything is wet-wet-wet.

For management info on foliar Pythium, you can check these links:

http://www2.ca.uky.edu/agcomm/pubs/ppa/ppa1/ppa1.pdf

(scroll through to the Pythium part on p.17)

http://extension.missouri.edu/p/IPM1029-17#Pythiumfoliarblight

 

Root health continues to be a problem, especially on putting greens. We’ve posted a lot of information this year about wet soils leading to physiological decline and triggering Pythium root rot in some cases (see links at bottom of this post). Putting greens with poor drainage, less-than-ideal construction, or a build-up of organic matter are particularly susceptible. Here are some putting green rootzones with a lot of organic matter build-up, visible as dark layers:

layers FullSizeRender

All those layers kind of look like tiramisu…mmm… yummy… getting distracted.

tiramisu

Unlike delicate layers of a tiramisu, layering in a putting green rootzone is NOT a delectable delight. Another complication of poor drainage is that it can make the turf more prone to anthracnose. I received a couple of samples in recent days with crown rot anthracnose. Both also had layering problems and root decline.

There is some information about anthracnose here:

http://www.bookstore.ksre.ksu.edu/pubs/EP147.pdf

and here is an excellent list of best management practices:

http://turf.rutgers.edu/research/bmpsanthracnose2015.pdf

Many of the practices to reduce anthracnose also promote overall turf health. That is, when you implement agronomic practices to promote good rooting you also reduce the risk of anthracnose and other problems. You may not be able to do ALL of the beneficial agronomic practices you would like, due to budgetary limits or lack of equipment or golfers’/greens committee opinions, but the more you can fit in, the better.

We posted on these topics earlier this year. If you want to go back and review, here are some links:

https://blogs.k-state.edu/turf/season-long-agronomic-practices-to-reduce-anthracnose-risk-in-putting-greens/

https://blogs.k-state.edu/turf/root-decline-it-aint-benign/

https://blogs.k-state.edu/turf/best-management-practices-for-turfgrass-anthracnose/

https://blogs.k-state.edu/turf/your-turf-is-trying-to-bike-up-a-mountain/

https://blogs.k-state.edu/turf/bentgrass-declining-its-from-western-europe-you-live-in-kansas-by-dr-fry/

 

 

The plight of urban trees (and you thought YOU were having a bad day!)

(Megan Kennelly, KSU Plant Pathology)

Ideally, trees should be protected during construction. For some tips, you can check out this website:

Protecting Trees During Construction – 7.420

However, sometimes, the project just has to go where it needs to go and the budget does not allow time, personnel, or resources to consider tree preservation.

This corner went through some major construction in 2010. At that time, a big section of the tree’s root section was basically destroyed, with a sidewalk set in close to the trunk.

Fig 30a Fig 30bIMG_6583

Despite having half its root system lobbed off, with broken roots as potential infection sites by wood decay fungi, the tree hung in there.

Over the past year, that area has had even more construction at that site, and the tree finally said, “Enough – I can’t take this anymore!”

IMG_3142 IMG_3145 IMG_3148

IMG_3141 IMG_3147

The tree is scheduled to be taken down next week. RIP, big old friend!

 

It’s Finally September – That Means Football and Fescue

(By Ward Upham and Jared Hoyle, KSU Research and Extension)

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September is almost here and that means it is prime time for football and to fertilize your tall fescue or Kentucky bluegrass lawns. If you could only fertilize your cool-season grasses once per year, this would be the best time to do it.

These grasses are entering their fall growth cycle as days shorten and temperatures moderate (especially at night). Cool-season grasses naturally thicken up in the fall by tillering (forming new shoots at the base of existing plants) and, for bluegrass, spreading by underground stems called rhizomes. Consequently, September is the most important time to fertilize these grasses.

Apply 1 to 1.5 pounds of actual nitrogen per 1,000 square feet. The settings recommended on lawn fertilizer bags usually result in about 1 pound of nitrogen per 1,000 square feet. We recommend a quick-release source of nitrogen at this time. Most fertilizers sold in garden centers and department stores contain either quick-release nitrogen or a mixture of quick- and slow-release.

The second most important fertilization of cool-season grasses also occurs during the fall. A November fertilizer application will help the grass green up earlier next spring and provide the nutrients needed until summer. It also should be quick-release applied at the rate of 1-pound actual nitrogen per 1,000 square feet.

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Low Water Use Turfgrass Event – Hays, KS

Tuesday evening, Sept. 20 is set for the annual Horticulture Night at the Kansas State University Agricultural Research Center in Hays. This year the emphasis is on low water use turfgrass demonstration plots, tomato and pepper varietal trials, and the Prairie Star flower performance trials.  The event is scheduled later in the summer this year than usual so attendees can better view the results of the complete season.

Dr. Jared Hoyle will be there to answer any turfgrass questions you might have!

http://www.ksre.k-state.edu/news/news-stories/2016-news-releases/august/horticulturenight-hays.html

 

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Golf Tournament to Support K-State Turfgrass Students

(By Jared Hoyle, KSU Turfgrass Research and Extension)

Need something to do on October 1st?  Come out to Colbert Hills Golf Course, play a round of golf and support the Kansas State University Golf Course Superintendents Student Chapter.

The money raised in this tournament pays for the students travel to attend the Golf Industry Show (By GCSAA) in Orlando, FL in 2017 and participate in the National College Turf Bowl Championship.

Come out and support the students!  Hope to see you there. Information about registration is below!

Golf tournament

Broadleaf Weed Control and PRE Crabgrass Control – VIDEO

(By Jared Hoyle and Jake Reeves, KSU Turfgrass Research and Extension)

Just a couple weeks ago the turfgrass team held the Annual Kansas Turfgrass Field day in Manhattan, KS at the Rocky Ford Turfgrass Research Center.  At one of the stops Dr. Jared Hoyle talked about new products that are on the marked for post-emergent broadleaf weed control and pre-emergent crabgrass control.  If you couldn’t make it out to field day here is a short little video about what you missed.

Converting Tall Fescue to Buffalograss – VIDEO

(By Jake Reeves and Jared Hoyle, KSU Turfgrass Research and Extension)

Are you thinking about converting your tall fescue lawn into buffalograss?  If you are, new research is currently being conducted at Rocky Ford Turfgrass Research Center in Manhattan, KS to pin down the best herbicide application timing to reduce the amount of time that you don’t have turf in your lawn.

Check out the video here of KSU Turfgrass Research Technician, Jake Reeves, discuss this research and how it will impact turfgrass areas across Kansas.

Twig girdlers

This post is from Ward Upham, originally on the KSU Hort News.

twig-girdlers

We are starting to see damage from twig girdlers as evidenced by fallen twigs up to 3 feet long. The beetle Oncideres cingulata is most likely the culprit. Host trees include elm, oak, linden, hackberry, apple, pecan, persimmon, poplar, sour gum, honey locust, dogwood, and some flowering fruit trees. This insect is distributed throughout the eastern United States from New England to Florida and as far west as Kansas and Arizona. Adults are long-horned beetles with a grayish-brown bodies that are stout and cylindrical. The larvae are also cylindrical with small heads and shiny exteriors. Larvae can be up to an inch long and are light brown to brownish-gray.

Girdled twigs often remain on the tree until a strong wind blows them down. Large infestations can result in a high percentage of girdled twigs. Though this may reduce the vigor and appearance of the tree, the overall effect on the tree’s health is not severe. Twigs are unsightlyand do not fall all at once, so clean up is a drawn out process.

This beetle has a one-year life cycle. Late in the growing season, the female deposits eggs in small scars chewed through the bark and then chews a continuous notch around the twig, girdling it. The notch is cut below the site of egg deposition apparently because the larva is unable to complete development in the presence of large amounts of sap. Girdled twigs die and fall to the ground where the eggs hatch.

Girdled twigs look like a beaver has chewed on them, only in miniature. The outside of the twig is smoothly cut, but the center of the twig appears broken. The larvae begin feeding on dead wood inside the twigs the following spring and continue through most of the summer. Pupation takes place inside the feeding cavity. Development is completed during August when the adult emerges to repeat the cycle.

Though adults feed on the bark of host twigs, damage is minimal until the female starts girdling. Chemical control is impractical, so gather and dispose of fallen twigs in the fall or spring to destroy the larvae inside. Often, natural mortality is high because fallen twigs are excessively dry or carry too many larvae per twig.

Peonies may be cut back

This post is from Ward Upham, originally on the K-State Horticulture Newsletter

peonies-browing_orig

Peonies often look a little bedraggled by this time of year and gardeners may want to cut them back. That will not be a problem with this perennial. Peonies are essentially dormant by this time of the year, even though leaves may still be green. Cut leaves off close to the ground and compost or discard. (Ward Upham)

Gray leaf spot in perennial ryegrass

(Megan Kennelly, KSU Plant Pathology)

If you manage perennial ryegrass you are probably well aware of the risks of gray leaf spot.I have not seen it, but I just got my first question about it for the year.

In this region the most common time for GLS symptoms to first appear is early to late August. In some years, epidemics can be severe. In other years, there is little to no GLS. The fungus is picky, with 82-90 degrees as its favorite temperature range. The fungus needs wet conditions as well. The fungus requires certain durations of leaf wetness at different temperatures. At that prime window of 82-90 degrees the infection can occur quickly.

Damage in a rye fairway, a few years ago.

gls-cropped

GLS spores in the microscope, a few years back.

spores

For more details and photos you can check out this page for general information:

http://extension.missouri.edu/p/IPM1029-11#Grayleafspot

And, here is some detailed fungicide information (scroll to page 13):

http://www2.ca.uky.edu/agcomm/pubs/ppa/ppa1/ppa1.pdf