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K-State Turf and Landscape Blog

Month: April 2017

Stinkgrass

(By Jared Hoyle, KSU Turfgrass Research and Extension)

Many people like the smell of freshly cut grass but there is a weed out there that is common in many lawns in KS called stinkgrass and it stinks.  It stinks cause it is a weed and it also literally stinks.

Stinkgrass sometimes referred to as stinking lovegrass or candy grass is a summer annual grassy weed that was introduced from Europe. This weed is most noticeable when the grayish-green triangular shaped panicle type seedhead is present. The seedhead closely resembles that of the bluegrass family and may cause confusion in identification. Individual spikelets, however, possess a grayish-silver, sometimes purple color and at times may appear waxy.

The leaves are smooth, glossy below and rough on top typically ranging from ¼ to ½ inch wide. The stem of the plant is jointed with slightly swollen nodes, occasionally with a 45 degree bend near the stem base.To vegetatively identify stinkgrass, look at the ligule, the sheath and back of the leaf blade where it attaches to the collar. The ligule is a short fringe of hairs, with several long hairs at the outer edge.

Another distinctive characteristic of stinkgrass is that it produces a bitter pungent odor, most noticeable when the tissue is crushed or mowed, hence the name stinkgrass. It is said to be poisonous to livestock, particularly horses, but most animals avoid grazing it because of the odor. Stinkgrass normally spreads by seed dispersal which emerges in late spring a few weeks after crabgrass or at a similar time to goosegrass. Maximum germination occurs when soil temperatures remain above 65°F for several weeks. Mature this plant will grow from 1 to 2 feet tall and it can temporarily survive mowing heights typical for home-lawns.

Occurrence

In general, stinkgrass is not a persistent problem in lawns but commonly occurs in newly established or poorly maintained lawns and low maintenance areas like roadsides that were once cultivated as agricultural land. It can also be a problem in newly planted sod fields. It has a shallow fibrous root system and is normally not a problem in properly maintained turf the second year after planting.

Non-Chemical Control

Stinkgrass can be very easily removed by hand. In newly established lawns, however, practices to promote maximum density of the desirable turf species like adequate fertility, proper mowing and irrigation will eventually crowd out this weed. Stinkgrass will die after the first killing autumn frost allowing a vigorous desirable turf species to fill the voids.

Chemical Control

No specific pre-emergence herbicides are labeled for turf use, though most common pre-emergent herbicides suitable for crabgrass and goosegrass should also be effective on stinkgrass without injury to the desired turf species. The only compounds labeled for post-emergent control are glufosinate (Finale) or glyphosate (Round-up). Both of these herbicides are non-selective herbicides which kill all green plants and should not be applied to desirable turfgrasses. Once the stinkgrass has been controlled, however, these areas can then be reseeded or sodded.

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

#ksuturf Undergraduate Students Compete in Research Symposium

(By Jared Hoyle, KSU Turfgrass Research and Extension)

Last Friday, three undergraduate turfgrass science students completed in the Gamma Sigma Delta Undergraduate Research Poster Competition; Dani McFadden, Peyton South and Gage Knudson.  Peyton South received 1st place and a 100 dollar monetary prize.  Congrats to Peyton and a job well done to Dani and Gage!

Below you can read about the research that they conducted over the past two semesters.

Titles included;

  1. Effect of Dormant ‘MidIron’ Bermduagrass Colorant Applications on Clothing Blemishing
  2. Influence of Tall Fescue Baseball Infield Mowing Height on Ground Ball Speed
  3. The Effect of Human Insect Repellents on Perennial Ryegrass Growth and Recovery

Effect of Dormant ‘MidIron’ Bermduagrass Colorant Applications on Clothing Blemishing

L. McFadden* and J. A. Hoyle*

*Department of Horticulture and Natural Resources, Kansas State University, 2021 Throckmorton Plant Sciences Center, Manhattan, KS; Corresponding author’s email; dmcfadden@ksu.edu

Bermudagrass (Cynodon dactylon) is a warm-season turfgrass used on athletic fields in the midwest. Although a desirable turfgrass species for athletic fields it fails to maintain acceptable green color during winter. Turfgrass colorants have been utilized to maintain acceptable green turf color through dormancy periods. Athletes of all ages play on sports fields where colorants have been applied. Extensive research has explored turfgrass colorants on turfgrass quality but minimal research exists on potential clothing blemishing when athletes contact turfgrass applied with colorants. The objective of this research was to determine if turfgrass pigments and paints blemish athletic clothing after the recommended dry time. Researcher’s hypothesis paints would result in greater blemishing and pigments would have no effect due to coloring occurring from inside the plant. Field research trials were initiated Feb. 16, 2017 at Rocky Ford Turfgrass Research Center in Manhattan, KS on dormant ‘MidIron’ bermudagrass maintained at 3.8 cm. Treatments were applied to 1.5 by 1.5 m plots arranged in a randomized complete block design with four replications. Treatments consisted of three paints (Wintergreen Plus, Green Lawnger, Endurant Premium), one pigment (Envy) and a non-treated control for comparison. All colorant treatments were applied at 1:6 (v:v) dilution in 1,234 L ha-1 spray volume. After recommended drying time (4 hrs), a white cotton t-shirt was pulled 1.5 m across the plot weighted down with 11.4 kg. Digital image analysis was used to determine percent blemishing of t-shirt area. Data was subjected to ANOVA in SAS and means were separated according to Fisher’s Protected LSD at 0.05 significance level. Envy (turfgrass pigment) resulted in the highest blemished clothing percentage (60%). All other treatments were no different than the non-treated. Results demonstrate that the tested turfgrass paints safely adhere to the turfgrass canopy and do not blemish athletic clothing.

Influence of Tall Fescue Baseball Infield Mowing Height on Ground Ball Speed

Gage M. Knudson* and Jared A. Hoyle*

*Department of Horticulture and Natural Resources, Kansas State University, 2021 Throckmorton Plant Sciences Center, Manhattan, KS; Corresponding author’s email; knudson.gage@gmail.com

Tall fescue [Schedonorus arundinaceus (Schreb.)] is a drought tolerant turfgrass species commonly used as a baseball infield playing surface. Cultural management practice studies on athletic surfaces have shown direct influences on playability. Minimal information exists on the influence of infield mowing height and ball-roll speed. Results of ball-roll speed studies can be used to predict success of infield hits. Research trials were initiated on November 21, 2016 at the Rocky Ford Research Center (RF) in Manhattan, KS to determine the influence of tall fescue baseball infield mowing height on ground ball speed and batter on-base success. Research trials were conducted on 30.5 m long simulated tall fescue infield. Two experimental runs were conducted on three different infield mowing height treatments; 2.5, 5, and 7.6 cm. Six individual replications of a simulated ground ball were applied to each infield condition and experimental run. Ground balls were applied with a pitching machine set to 112.6 kph. Simulated ground balls were timed in seconds (s) from simulated pitched ball and bat contact (insertion into machine) to baseball fielder location (30.5 m distance). Successful infield hits were calculated using constant athletic ability data and infield ball-roll data. Data was subjected to ANOVA in SAS and means were separated according to Fisher’s protected LSD at 0.05 significance level. Mowing heights of 2.5, 5, and 7.6 cm resulted in 1.77, 2.08 and 1.88 s ground ball times, respectively. Utilizing ground ball speed results, researchers were able to predict that a simulated batter, if a ground ball was hit to the shortstop position (30.5 m distance), would result in a unsuccessful at bat if a tall fescue infield was mown at 2.5 cm and successful if mown at 5 and 7.6 cm, utilizing consistent player athletic ability data.

The Effect of Human Insect Repellents on Perennial Ryegrass Growth and Recovery

 Peyton E. South* and Jared A. Hoyle*

*Department of Horticulture and Natural Resources, Kansas State University, 2021 Throckmorton Plant Sciences Center, Manhattan, KS; Corresponding author’s email; southpeyton@ksu.edu

Human insect repellents containing diethyltoluamide (DEET) commonly damage turfgrass due to non-target application. Common visual damage results in two areas of healthy growing turfgrass in the shape of footprints with necrotic and chlorotic turfgrass surrounding. Damage results in unacceptable turfgrass quality and playability. Minimal research has been conducted to explore the influence of human insect repellents on turfgrass injury and recovery. Research trials were initiated in November of 2016 at the Throckmorton Plant Sciences Center Greenhouses in Manhattan, KS to determine the influence of human insect repellents on perennial ryegrass (Lolium perenne) growth and recovery. Perennial ryegrass was established in 10 by 10 cm pots at 387 kg ha-1, maintained at 4.4 cm and were irrigated to prevent drought stress. Greenhouse environment was a 12 hr photoperiod at 15.5°C/ 22.2°C (night/day). Insect repellent treatments were applied to perennial ryegrass plants arranged in a randomized complete block design with 4 replications. Treatments included 9 insect repellents and a non-treated control for comparison. Five treatments contained the active ingredient DEET. Other commonly used insect repellents were also included for comparison. Collected data included visual percent injury on a 0%- 100% scale, where 10% represented maximum acceptable injury. Data was subjected to ANOVA in SAS and means were separated according to Fisher’s protected LSD at 0.05 significance level. All treatments except the control resulted in at least 6% turfgrass injury 1 day after application (DAA). Repel Max (40% DEET) and Off Active (15% DEET) resulted in 68% and 30% injury, respectively 21 DAA. At 21 DAA all other treatments resulted in turfgrass injury similar to the non-treated. Results demonstrate that permanent non-target turfgrass injury will occur if Off Active and Repel Max are applied as a human insect repellent.

Roundup for Lawns – UPDATE – K-State Radio Network

(By Jared Hoyle, KSU Turfgrass Research and Extension)

This past weekend I was at a lawn and garden store and saw the Roundup for Lawns display.  Customers were walking by and picking up a bottle.  Some would get Roundup MAXX, Roundup for Lawns and some bought just straight Roundup. I thought to myself, “I hope they know the different between those products.”

Here is some information on the products and a link to Agriculture Today, daily radio program, with Eric Atkinson and Dr. Jared Hoyle.  He explains the difference between the products and even what the bottles look like and why it is important to make sure you pick up the correct product.

Article – https://blogs.k-state.edu/turf/every-homeowner-needs-to-know-the-difference-between-roundup-roundup-for-lawns/

Radio Program – https://www.ksre.k-state.edu/news/radio-network/agtoday-mp3/042017-hoyle.mp3 

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

To bag… or not to bag? Whether ’tis nobler to recycle clippings.

(By Jared Hoyle, Turfgrass Research and Extension)


A week or two ago I posted on mowing and introduced two new publications for homeowners and professionals about correct mowing practices.  Well since we are all out mowing I tend to get the question about bagging lawn clippings.  Do I bag clippings?  Doses it cause thatch? Can I use it as mulch in my garden? Etc…

Well I just updated the Recycling Grass Clipping Extension Publication at the KSRE Bookstore.

http://www.bookstore.ksre.ksu.edu/Item.aspx?catId=545&pubId=701

Check it out for more information and to answer the question….

To bag… or not to bag? Whether ’tis nobler to recycle clippings.

***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

Dothistroma needle blight in pines … or not?

We recently posted about pine wilt and pine tip blight. To round out the big three pine diseases, below are a few quick notes about Dothistroma needle blight. For a review of all three of these diseases, plus natural needle drop, you can check out Pine Diseases of Kansas. (Click that link to download a free pdf with lots of photos and management information.)

Dothistroma needle blight is common in Austrian and Ponderosa pine. It can occur on Mugo pine, too.

Dothistroma spends the winter in infected needles. During wet conditions in late spring/early summer the fungus infects new needles.

Here is a photo of the fungal fruiting structure – the little black lump peeking out from under a flap of needle tissue:

We have been seeing those in the past couple of months on needles that were infected last year. December through April is when those fruiting bodies start to pop, allowing us to make a diagnosis.

Those fruiting structures produce spores that spread in rain to infect new needles. This often occurs during wet, mild weather in late spring, early summer (but can occur all summer). Those needles eventually show a partial needle scorch, with the base staying green. Each needle is a little different, depending on where the fungus got in there. The photo below shows some needle spots and banding and then the browning (necrosis) from the infection point outward.

 

On a tree, this shows up as partial browning, then complete browning, of the needles one year back on the branch:

The older, needles eventually drop off, leaving just a one-year tuft of the newest needles. The branch looks like a broomstick or a lion’s tail:

The damage tends to start in the lower part of the tree and work its way up. The disease is more likely in older trees. Mature, overcrowded windbreak trees are susceptible. Normally, pines keep several years of needles. If all those inner needles drop the tree has less capacity to do photosynthesis and it can weaken. Each little needle is like a solar panel, and fewer solar panels means less energy.

What do you think about this tree?

It is a young tree, and the damage is more top-down, not bottom up. So the overall pattern does not seem right for Dothistroma. Remember – with Dothistroma the disease usually starts at the lower part and works up, with older trees more prone to the disease.

Let’s take a closer look. What do you see? Or NOT see?

The damage is pretty uniform, with each needle looking quite similar. Compare it to that photo farther up where each needle is a little different. Plus, there is no spotting/banding. My guess is this is environmental stress. Pines can definitely get the moisture sucked right out of them during dry winter winds.

To know for sure, samples can be submitted to our Plant Disease Clinic either directly or (even better) through your local K-State Research and Extension Office.

Need more details? Remember our publication about Pine Diseases in Kansas where you can find more information about diagnosing and managing Dothistroma and the other pine diseases.

Ash/Lilac Borer: Don’t Get “Bored-Down” By This Caterpillar Borer

The time of year has come to be thinking about dealing with the ash/lilac borer (Podosesia syringae). First, you need to understand that this is not the same insect pest as the Emerald ash borer (Agrilius planipennis), which was recently discovered (March 31, 2017) in Doniphan County (Kansas now has 7 counties under quarantine). Emerald ash borer is a wood-boring beetle whereas the ash/lilac borer is a wood-boring caterpillar.

Read more on the Entomology Blog!

 

Impatiens downy mildew – it’s still “out there.” K-State’s Prairie Star program can help you diversify your shade beds

It is April, and everybody has spring fever. As you plan your ornamental beds for the year, consider using a diverse array of species. Specifically, I’m talking about avoiding a monoculture of impatiens.

You might remember a few years ago when a disease called impatiens downy mildew (IDM) hit the scene. Here in Kansas we did not see the vast losses that occurred in states farther east, but a few sites got hit. IDM has not received as much attention recently, but it is still out there. I’m not saying don’t use impatiens at all, I’m saying you should consider some diversity in the landscape. Don’t put all your eggs in one basket.

Filling every shady nook and cranny with impatiens now may seem easy, but that easy may turn into “disease-y”, and you might look back and wish you had included more diversity.

The standard, typical impatiens, Impatiens walleriana, is highly susceptible to downy mildew. If the weather is conducive to disease (moderate temps, wet, humid), a bed of I. walleriana can get wiped out quickly. The plants lose all their leaves, with only a stand of stems left behind. The pathogen can survive year-to-year as a survival structure called an oospore. So, if you know you had IDM history last year you should definitely avoid impatiens in the same bed this year.

The two photos below show dense, white sporulation on the undersides of leaves. The leaves drop, and entire plants can lose their leaves quickly.

 

Other related species, such as I. balsamina and certain hybrids, exhibit good tolerance, and those are options. Breeders are working to develop more resistance. Stay tuned!

What else can we use in shade, besides impatiens? K-State’s Prairie Star and Prairie Bloom program highlights species and varieties that thrive here. You can scan through to see which species flourish in shade, and click on photos to check out the blooms and other traits. Begonias are one option, but there are other shade-tolerant plants to explore. At the Prairie Star website you can opt to print a pdf version of the list to carry with you to the garden center for easy shopping. Here is a link to some of the new additions for 2017.

If you want to read some more details about impatiens downy mildew you can check out this article by Margery Daughtrey in the online version of Grower Talks.

Turfgrass Care for Homeowners (K-State Radio Network) – April Broadcast

(By Jared Hoyle, KSU Turfgrass Research and Extension)

About a week ago I was invited back again to speak with Eric Atkinson, host of Agriculture Today a daily program distributed to radio stations throughout the state. It features K-State agricultural specialists and other experts examining agricultural issues facing Kansas and the nation.

This week we covered the following;

  • fertilization of cool-season lawns
  • fertilization of warm-season lawns
  • weed control
  • preemergent herbicide control
  • spring mowing heights

Check out the radio program below!

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