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Month: May 2019

What’s What on Juniper Shrubs?

By: Judy O’Mara

You can drive to any grocery store, fast food restaurant or mall in Kansas and see a spreading juniper shrub planting. They are pretty well adapted to Kansas but a few problems show up.

Winter damage is common following cold temperatures and desiccating winter winds. Die back tends to show up on the ends of the branches during December through February. If the damage isn’t too bad, it can be pruned out and with some added care, the shrubs may recover.

Snowy and Salty

In addition to cold temps last winter, there was lots of snow. According to Assistant State Climatologist, Mary Knapp, Manhattan Kansas received 27.8” of snow during the recent winter, which is 11.1” over the normal 16.7” snowfall. So what does this have to do with junipers? Well, with snow comes slippery sidewalks and driveways, which in turn can lead to the use of salt or de-icing products. They work pretty well to keep people safe slipping and breaking a hip, but sometimes the products can damage nearby shrubs.

It is not uncommon to see salt damage or browning on the side of juniper shrubs closest to the sidewalk in the spring. In this case, salt leached from the sidewalk and burned the roots closest to the edge. There is a nice article on which ice melts are appropriate to use at the K-State Johnson County Extension web site. Something to keep in mind for next winter.

Pictured above on the left, the juniper shrubs are experiencing salt burn from the sidewalk. Pictured above on the right is a heavy concentration of salt crystals.

Wet and More Wet

I got caught in a down pour on a recent trip to Hiawatha, KS.  The area creeks were flooded and topped the roads in a few places. It was an awesome sight, plus a little bit scary. It’s been a fairly common phenomenon this spring and there are a number of articles out there on the impact of flooding on landscape plants. I thought I would throw in my two cents, as well.

One of the more serious challenges for junipers plantings is damage due to ‘wet feet’. It is not uncommon during heavy spring storms to see shrubs floating in a pool of water. Aggravating factors may be locations with heavy clay soils that drain poorly or even locations that have a compaction layer not far from the soil surface. In either case, prolonged expose to wet soils will damage the roots and cause a collapse of the planting. I tend to think of this as center decline. Sometimes the entire plant will die, and sometimes just a portion (frequently the center). So, if a large section of the planting is going out, it may be a root health issue. Juniper shrubs never recover from this type of damage. It is really important to select a well-drained site for juniper plantings.

Branch Tip Die Back

I know this juniper shrub looks bad but, it’s actually okay. The damage here is caused by a fungal disease called Kabatina tip blight. It causes a die back of the branch tips, usually 2-8” with symptoms showing up between February and mid-June. It can cause a scattered branch die back or it can hit every single tip, making the shrub look like it is going to die. But no, like magic the planting recovers. By late June, the dead tips dry up and fall, slowly improving the appearance of the shrub. Some creeping junipers are particularly susceptible.

As always, there is the question ‘What can I spray?’. There are two reasons why that is not a practical option. One, the infection period is in the fall, so by the time you see the symptoms it  is too late to spray. Two, the disease is basically a cosmetic issue. In most years, it shows up as scattered dead tips (barely noticeable). In years with a prolonged cool, wet spring Kabatina tip blight symptoms can be dramatic. But…summer eventually arrives and with warmer temps and drier conditions disease activity halts. At that point, the dead tips start dropping off and the planting starts to look better. So best management option? Do nothing, or maybe rip it out and plant something less susceptible.

Pictured above, you can see daffodils, so you know it is early spring and conditions are favorable for Kabatina tip blight. Pictured on the right is the same planting later in the season. As you can see, all of the dead tips have dropped off of the plant.

 

Spring Leaf Drop – Sycamore Anthracnose

by Judy O’Mara

I walk past a big beautiful Sycamore tree on my way into work every day. I recently noticed leaves dropping to the ground. A close look at the defoliated leaves showed the characteristic symptoms for a fungal disease called sycamore anthracnose – brown lesions along the veins and on the petiole. Once the water conducting tissue in the veins is damaged, the leaf gets knocked off the tree. Also visible in the tree were also small, blighted shoots.

Sycamore anthracnose is a spring disease, meaning it is favored by cool (60-73F), wet conditions. With a prolonged spring weather pattern, the disease can sometimes look dramatic. In Kansas, chemical control of this disease isn’t necessary. With the move into warmer summer weather, sycamore anthracnose ceases activity and the tree pushes out a new flush of growth.

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.***

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

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

 

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.***

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

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

 

K-State Radio Network “Plantorama” – Oversoaked Homelawn Management

(By Jared Hoyle, KSU Turfgrass Research and Extension)

Home lawns have been soaked to the point of oversaturation.  Even if it’s not outright flooding, K-State turfgrass specialist Jared Hoyle says these conditions can be detrimental to that lawn grass, so a little extra care in lawn management may be in order.

Click the link below for K-State Research and Extension Agriculture Today Radio Program “Plantorama” hosted by Eric Atkinson.

Check out the KSRE bookstore more more information on all things turf! – https://www.bookstore.ksre.ksu.edu/Category.aspx?id=528&catId=545

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

Yellow Nutsedge Reported Across KS

(By Jared Hoyle, KSU Turfgrass Research and Extension)

 

With all the rain across the state we tend to forget about how that can influence our weed population.  One weed that loves flooded and wet soils is yellow nutsedge. It has been reported in many different locations across KS and now is the time to do something about it.  The earlier the better!

One 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
  • 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! Also make sure you check for turfgrass tolerances.

For more information on yellow nutsedge 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.***

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

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

Tree and shrub update: managing impact of floods, and why is there heavy seed set in some trees this spring?

Flooding and Trees by Ward Upham

Trees differ markedly in their ability to withstand flooding. Some trees have mechanisms in place to provide oxygen to the roots of plants with water saturated soils and others do no. However, most trees will maintain health if flood waters recede in 7 days or less. It also helps if water is flowing rather than stagnant. If the roots of sensitive trees are flooded for long periods of time, damage will occur including leaf drop, iron chlorosis, leaf curl, branch dieback, and in some cases, tree death. Another danger of flooding is the deposition of sediment. An additional layer of silt 3 inches or more can also restrict oxygen to
the roots. If possible, remove deep layers of sediment as soon as conditions permit. This is especially important for small or recently transplanted trees.
Try to avoid any additional stress to the trees this growing season. Ironically, one of the most important practices is to water trees if the weather turns dry. Flooding damages roots and therefore the root system is less efficient in making use of available soil water. Timely waterings are vital to a tree’s recovery. Also be diligent in removing dead or dying branches that may serve as an entry point for
disease organisms or insect pests. The following information came from the US forest Service.

Trees Tolerant of Flooding: Can survive one growing season under flooded conditions. Red maple, silver maple, pecan, hackberry, persimmon, white ash, green ash, sweetgum, sycamore, eastern cottonwood, pin oak and bald cypress.

Trees Moderately Tolerant of Flooding: Can survive 30 consecutive days under flooded conditions. River birch, downy hawthorn, honeylocust, swamp white oak, southern red oak, bur oak, willow oak and American elm.

Trees Sensitive to Flooding: Unable to survive more than a few days of flooding during the growing season.  Redbud, flowering dogwood, black walnut, red mulberry, most pines, white oak, blackjack oak, red oak and black oak.

 

Lots of Flowers, Lots of Seeds by Ward Upham

I have never seen lilacs bloom like they did this year.  Also, elms and maples have produced enormous amounts of seed in some areas.  In certain cases, this has delayed leaf emergence, especially in the upper portions of the tree. Why did this happen?  What triggered it?
We know that stress can cause trees and shrubs to put more energy into seed production.   The strategy seems to produce lots of seed in case the “mother” plant dies.  This large expenditure of energy means that there was less energy left over to push out leaves in the spring resulting in delayed leaf emergence. So, let’s look at the likely cause. Remember the flowers and seeds that were produced this year came from buds that were produced last year during the growing season. Therefore, it was a stress that came last year that caused the problem.  Actually, I think it was a stress from the Fall of 2017 through much of the Spring of 2018 that triggered the plants. In the Manhattan area, we had adequate rainfall through October of 2017, but then virtually nothing until May of 2018.  This drought was
severe enough that root systems were likely damaged so that even when rainfall returned, the plant was under moisture stress, especially in the upper portions of the tree.  This stress, then, stimulated the plant to set an abnormally high number of fruit buds resulting in tremendous flowering and seed production this year.
What do we do about this?  First, don’t assume a tree is dead if leaves don’t appear immediately.  Also, don’t assume the top portion of the tree is dead if it is slower to leaf out than the lower portions of the tree.  Give the tree a few more weeks and see what happens. Next, these trees and shrubs don’t have a lot of energy reserves left so they need to be given extra care.  Primarily this means watering as needed.  Keep in mind that too much water is as bad as too little.
Roots need to breathe; they need oxygen.  With the excessive rains much of Kansas has received recently, it may be a while before watering needs to be done.  Just don’t wait too long as the damaged root system will not be as efficient in taking up the water the plant needs.
So when do you start watering? Use a screwdriver to try to penetrate the soil
under the tree.  If it is difficult to push the tang of the screwdriver into the soil, it is time to water.  Water enough so that the soil is moist to a depth of one foot. Use a long-tanged screwdriver, a wooden dowel or a metal rod such as a section of rebar or electric fence pos to test. It will stop when it hits dry soil.

Why is that Redbud tree blooming along the trunk?

Cauliflory on Redbuds

by: Judy O’Mara

It was a beautiful year for flowering redbud trees this spring. The pink flowers seemed to go on and on. As in past years, the question arises as to why redbud trees flower on the trunk or on large branches. The question just popped into my email inbox this morning: Is it a disease? Like everyone else, I’ve always meant to look up this interesting phenomena.

 

According to Michael Dirr (Manual of Woody Landscape Plants) and the Virginia Native Plant Society (https://vnps.org/wildflowers-of-the-year/2013-woty-redbud/), it turns out that flowering on the trunk or limbs aka ‘cauliflory’ is a normal growth characteristic for redbud trees. Flowers are produced in pink nodal clusters that can develop on any part of the tree, from twigs to branches, as well as the main trunk (particularly on old trees).

So now we know.

Spring turf diseases

(Megan Kennelly, KSU Plant Pathology)

As we move through spring and launch towards summer, don’t forget some key disease resources.

Fungicide info is available here:

https://entomology.ca.uky.edu/files/catmanualpdfs/ppa1.pdf

and here in a searchable online database:

https://turfpests.wisc.edu/filter.aspx?id=8-fungi

 

Large patch in zoysiagrass

Large patch has definitely been active lately with the cool, wet weather.

This is an area that was previously inoculated for a study, so it’s a high-pressure location:

In the photo below, the clear area was treated with a fungicide (tebuconazole) in early September and again in early October:

Some light N may help the turf recover. Some prior KSU work with U of Missouri (click here for info) and additional follow-up work by U of Missouri demonstrated that light N (think 0.25-0.5 lb/1000) in spring will not enhance this disease.

 

Dollar spot

 

 

The photo above is a worst-case scenario of the heaviest disease anywhere at Rocky Ford. It is an untreated area of a Cato-Crenshaw stand, which is highly susceptible. Untreated areas of less-susceptible cultivars are looking clean for now. KSU is part of a recently-published study that looked at disease susceptibility of various cultivars across several states. You can find a short preview/summary here.

What are you seeing? Let us know.

 

Root rot

We have not received samples here of Pythium root rot, but there are reports from nearby. You can read about findings of Pythium root rot in Missouri from our colleague Dr. Miller here:

https://turfpath.missouri.edu/reports/2019/05_14_19/

Spring Zoysia News

By: Dr. Jack Fry

Meyer Winter Injury

Significant winter injury has occurred on Meyer zoysia throughout the Kansas City area on golf courses – some have suffered more than others. The injury is most pronounced in the following areas:

  • Turf exposed to tree shade (even moderate levels from trees casting shadows from the rough)
  • High traffic areas
  • Areas that don’t drain well

We often try to compare differences among courses and determine why one course had better winter zoysia survival than other.  Ultimately, it seems that cultural practices have less of an impact on the freezing injury observed than the environment in which the zoysia is growing.   The above stresses can be matched directly with plant metabolism:

1) Shade – more light allows higher levels of photosynthesis and carbohydrate production, which is critical to winter survival;

2) Traffic – less compaction allows more oxygen in the soil and more root respiration and growth – high traffic reduces soil oxygen;

3) Drainage – areas that collect water also have lower soil oxygen levels and poor root growth.  In addition, plants growing in saturated areas are subject to crown hydration freezing injury – crowns fully hydrated don’t tolerate low temperatures well. Methods for correcting the above are straight forward, but implementing the changes can be difficult – politically and financially:  removing or thinning trees, redirecting traffic, correcting drainage issues.  If nothing else, the zoysia injury is indicating to turf managers where the problem areas are on the golf course.

 

Pictured above: Zoysia grown in high traffic areas in more prone to winter injury, such as this area surrounding a putting green where golfers enter and exit.

 

Innovation Zoysia is on the Market

Innovation zoysia, the new cultivar developed cooperatively by K-State and Texas A&M is on the market. Ted Wilbur, owner of Sod Shop in Wichita, recently cut and sold the first Innovation sod in the U.S..  He currently has about 25 acres in production – some is available now, some will be available later this summer.

Compared to Meyer zoysia, Innovation has:

  • Darker green color
  • Higher density
  • Finer texture
  • Fewer and smaller seedheads
  • Better billbug resistance
  • Freezing tolerance that is equivalent

Find more about Innovation here: https://sodsolutions.com/industry/innovation-zoysia/

Interested in ‘Innovation’?  Reach out to Sod Shop in Wichita: (316) 838-5888

 

Pictured above on left: Ted Wilbur (left) and Travis Achilles (right) with Sod Shops in Wichita, KS have cooperated with K-State in the production of  ‘Innovation’ zoysiagrass. Pictured above on right: The first ‘Innovation’ sod was cut and delivered to Hesston, KS for use at a local water park.