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K-State Turf and Landscape Blog

Category: Cultural Practices

Root decline, Pythium root rot, and anthracnose in recent samples

(Megan Kennelly, KSU Plant Pathology)

Here is a sample that came into the lab recently:

You can see turf decline, and if you look closely you can see some dark green algae in the brown area. Algae often indicates poor drainage. This site is in a low area with poor airflow. The site has a lot of underlying stress.

Here is a view of the washed-off roots sitting on the dissecting microscope. They should be a creamy white but instead they are more of a brown color. They were mushy in texture as well.

 

Finally below is a closer view in the compound microscope. You can see how the roots are dark. Healthy roots are much more clear/transparent. These are also lacking fine root hairs, and the outer tissues have sloughed off.

These symptoms occur frequently in sites with poor drainage. The roots sit wet, and oxygen flow is disrupted. The wet soil holds heat overnight as well.

The environmental stress alone can cause major root decline and turf damage.

In addition, these conditions can trigger Pythium root rot. (This particular sample did have some Pythium as well, I just had a hard time getting a clear photo). And, these stress conditions can also lead to crown anthracnose. I’ve seen a couple of samples with that disease lately as well. Anthracnose is more likely to chow down on turf that is already stressed.

Here is a link to a publication I’ve mentioned countless times on this blog:

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

There are excellent sections on individual diseases, but there is also a detailed section about summer stress on page 6. Many of the stress-reducing practices listed there will also reduce susceptibility to diseases.

That publication does not discuss Pythium root rot (PRR). (It does discuss Pythium root dysfunction (PRD) which is related but different.) Here is a great resources on PRR:

https://www.turffiles.ncsu.edu/diseases-in-turf/pythium-root-rot-in-turf/

Each year, we say, “I hope this August isn’t a bad one”. This coming week there will be some lower highs (low to mid 80’s) and “lower lows” (mid-60’s overnight, and even some upper 50’s! Woohoo!). Cool temps will be a blessing. However, continued rain may exacerbate drainage problems.

Managing the diseases is important, but it’s critical to address the physiological/environmental stresses as well or the turf can still suffer major decline this time of year.

 

 

Euonymus Scale

By Brooke Garcia

This is the time during the summer season when Euonymus Scale may be extra noticeable on evergreen euonymus. The scale insect will appear as small, white dots covering the planting. If you are wearing darker clothing and come into contact with the shrub, you may notice the white “debris” coming off of the plant. The plant can quickly become infested and covered with this insect. Euonymus Scale is capable of killing the plant if left untreated. Keep a watchful eye on plantings during this time. There are cultural strategies that can be incorporated into the garden to reduce the likelihood of this insect becoming a problem, but it is extremely prevalent and may require chemical treatment.

Euonymus Scale Infestation On Euonymus Plants Located Near Building (Auth-Raymond Cloyd, KSU)

For more information about the biological characteristics of this insects, as well as cultural and chemical practices that can aid in prevention and/or treatment, visit the K-State Extension Entomology post here: https://blogs.k-state.edu/kansasbugs/2020/07/02/euonymus-scale-4/

Seeding Tall Fescue in January? Sure!

By Dr. Jack Fry

Identifying seeding windows for cool-season grasses,  like tall fescue, in our region is often difficult because weather is so different year to year.  For example, for autumn seeding, October 15 is often suggested as the deadline for seeding in northeast Kansas.  Seeding after that date doesn’t mean that there won’t be success – some years there may be, others year not.  The concern is that germination and emergence may still occur after mid-October.  However, the seedling that emerges may not mature to a point where it can survive the cold, dry conditions common during Midwest winters.

Following the mid October deadline, the next window for seeding opens around Thanksgiving and continues into March.  We call it “dormant” seeding.  Dormant seeding means that the grasses out in the lawn now are dormant and not growing.  In addition, the seed you scatter in mid-winter will also remain “dormant” until warmer conditions and moisture return in the spring.  Unfortunately, some of us remain dormant until spring as well – outdoor work in midwinter may not sound attractive.  Tall fescue germination is optimized between soil temperatures of 59 and 72 F, so seed applied in winter will remain inactive in the soil until it warms to near 60 F, and it will then begin to germinate.  Other grasses are also candidates for dormant seeding as well, including other species of cool-season grasses, buffalograss, and bermudagrass.

Seed-to-soil contact is critical.  If conditions are dry, vertical mowing or slit seeding may be possible.  In addition, a light topdressing of soil applied over seed can also maximize seed-to-soil contact.  Seeding on frozen soil is also possible, and seed-to-soil contact is improved as the soil thaws and freezes, which creates cracks in the surface in which seed can lie.  Covering or mixing seed with the soil, where it will likely remain for a number of weeks before germination, also prevents it from being a source of food for birds and rodents.

Twenty years ago, Ward Upham, Extension Associate in Horticulture and Natural Resources, did a study to evaluate dormant seeding month effects on tall fescue cover in May.  He seeded plots on the 15th of each month from December through March onto bare soil that had been tilled and raked.  On May 18, plots seeded in February and March each had an average of 80% coverage.  December and January seedings were each at about 60% coverage.  Ward suspected that having seed out in the environmental longer made in subject to erosion and consumption by animals.

Advantages to Dormant Seeding:

  • Sometimes it is drier in mid-winter than early spring, which allows outside work to be done. Seeding in April and May can be difficult months for seeding during frequent rainfall.
  • Spring emergence will occur at the earliest possible date.
  • There may be more time and labor available now that’s not available in the spring.

Disadvantages to Dormant Seeding:

  • Weather doesn’t always cooperate, and midwinter may be too wet to get it done. However, if just small areas are needing seed, that can be done by hand.
  • Stand establishment may not be as successful as seen with autumn seeding, the preferred time. And, just like spring seeding, weed competition will be greater as the stand matures.
  • Preemergence herbicides applied in late fall or in spring may inhibit germination and growth of the seedlings. Preemergence herbicides that can be used in the tall fescue seedbed include siduron (Tupersan) and mesotrione (Tenacity).

Research in progress: zoysia seedhead suppression

(Megan Kennelly, KSU Plant Pathology)

I was out looking at our zoysiagrass breeding plots the other day and in a couple of plots I saw some seedhead development:

 

This was unusual, as we typically see this in spring, and it’s probably just a unique physiology of these couple of breeding lines. Anyway, this observation prompted me to mention that we are continuing KSU’s work on zoysiagrass seedhead suppression. You may have seen the articles about the prior excellent work by Dr. Hoyle and colleagues which you can view here:

Suppressing Meyer zoysiagrass seedheads

and here (academic peer-reviewed version)

https://dl.sciencesocieties.org/publications/cftm/abstracts/4/1/180012?access=0&view=pdf

We are following up on this work with additional trials to hone in on the biology and management of seedheads, fine-tuning application timings of ethephon. Stay tuned for results in the coming 1-2 years as we collect data. The project team members are PhD student Manoj Chhetri, Jack Fry, Jared Hoyle, me, and Aaron Patton (Purdue). The project is funded by the GCSAA, Heart of America Golf Course Superintendents Association, and Kansas Turfgrass Foundation.

Fall Fertilization and Turf Tips

(By Jared Hoyle, KSU Turfgrass Research and Extension)

Dr. Bill Kreuser, Assistant Professor and Extension Turfgrass Specialist, at the University of Nebraska – Lincoln posted some great information on fall turfgrass fertility and some other fall turfgrass tips.

Dr. Kreuser quoted, “Fall is arguably the most import season for turfgrass managers. While we’re busy preparing for a new growing season in spring and trying to survive stressful conditions in the summer, fall is the time to recover from summer, renovate, and prepare for winter. It’s a season of seeding, cultivation, weed control, and fertilization. While fall is still widely considered the most important time to fertilize turfgrass, the fertilization recommendations have evolved over the past decade.”

I couldn’t agree with him more.  There has been lots of recommendations evolve over the years and just because “this” is way it has always been done doesn’t mean it is right.  See what Dr. Kreuser has to say and check out the links below.

 

  1. Rethinking Fall Fertilization
  2. Mid-Fall Turf Tips 

 

Tips and tricks on planting trees before you trick-or-treat

(Megan Kennelly, KSU Plant Pathology)

My family did a campfire and cooked our first pot of chili in awhile – it’s really feeling like fall! We have a few weeks remaining in October, and between now and Halloween is still a great time to plant trees and shrubs. Here are some articles with tricks of the trade before you trick-or-treat:

Nice summary from Johnson County:

https://www.johnson.k-state.edu/lawn-garden/agent-articles/trees-shrubs/planting-trees-shrubs-in-fall.html

Excellent nuts and bolts of tree planting:

https://www.bookstore.ksre.ksu.edu/pubs/MF3313.pdf

A few more details on methods:

https://www.bookstore.ksre.ksu.edu/pubs/mf402.pdf

Watering new trees and shrubs:

https://www.bookstore.ksre.ksu.edu/pubs/MF2800.pdf

Now, with all that, truly your most important FIRST step is deciding on what to plant. If you have not yet done your research on that question, here are some more resources on tree and shrub selection.

Trees and shrubs for difficult sites:

https://www.bookstore.ksre.ksu.edu/pubs/MF2205.PDF

Trees for Northeast Kansas:

https://www.kansasforests.org/community_forestry/community_docs/NE%20Kansas%20Preferred%20Trees.pdf

Trees for Northwest Kansas:

https://www.kansasforests.org/community_forestry/community_docs/NW%20Preferred%20Trees122016.pdf

Trees for Southwest Kansas:

https://www.kansasforests.org/community_forestry/community_docs/Pref%20Trees%20SW.pdf

Water-wise plants for south central Kansas:

https://www.sedgwick.k-state.edu/gardening-lawn-care/documents/Water%20Wise%20Plants%202015.pdf

 

 

Fall Soil Testing

By Jared Hoyle, KSU Turfgrass Research and Extension

Fall is an important time for cool season turfgrass species because air and soil temperatures are optimal for carbohydrate accumulation and root growth. However, adequate plant nutrition is essential for these processes to operate at maximum efficiency. The importance of using soil test reports to guide fertilization programs cannot be emphasized enough.  The Kansas State Soil Testing Lab (https://www.agronomy.k-state.edu/services/soiltesting/) provides a variety of high quality testing services for turfgrass managers. Testing for pH, phosphorus (P), and potassium (K). A good sampling method is necessary to ensure the soil test results are accurately representing the sampled area. To sample, use a soil probe an extract a 4” to 6” core. The leaf and thatch material should be discarded from the core (see picture). Eight to ten individual cores should be extracted and combined into a single sample for testing. Results are typically sent back within a week of the lab receiving the sample.  Fertilizer recommendations will also be provided by a county agent or K-State horticulturalist.

Of all the possible nutrients, potassium is of particular interest as temperatures continue to decline, because it helps the plant acclimate to cold temperatures. Some soils, especially golf greens, throughout Kansas are low in potassium, leaving turfgrass more susceptible to winter injury. Deficiencies can be addressed by applying K containing fertilizers, such as, potassium chloride (KCl), potassium sulfate (K2SO4), and potassium nitrate (KNO3). Remember, soil tests are a relatively inexpensive tool, but provide a wealth of knowledge.

For more information pertaining to soil testing check out the article below by Dorivar Ruiz Diaz, Nutrient Management Specialist.

Fall Soil Testing: Sample Collection and Submission to the K-State Soil Testing Lab

By: Dorivar Ruiz Diaz

Soil testing provides producers and homeowners important information concerning the fertility status of the soil. This information can help produce better crops and reduce costs by guiding management decisions like the type and amount of fertilizers to apply. If you plan to do your own soil sampling and use the K-State Soil Testing Laboratory, the following outline provides specific information on methods for collecting soil samples and mailing instructions.

  • To take a sample, you will need a probe, auger or spade, and a clean pail. (If you’re also having the soil analyzed for zinc, be sure to use a plastic container to avoid contamination from galvanized buckets or material made of rubber.) You will also need soil sample containers and a soil information sheet from your local Extension office or fertilizer dealer. You can also order soil sample bags online from K-State Research and Extension by clicking here.

  • Draw a map of the sample area on the information sheet and divide your fields into uniform areas. Each area should have the same soil texture, color, slope, and fertilization and cropping history.
  • From each area, take a sample of 20-30 cores or slices for best results. At the very minimum, 12-15 cores should be taken per sample. Mix the cores thoroughly in a clean container and fill your soil sample container. For available nitrogen, chloride, or sulfur tests, a subsoil sample to 24 inches is necessary.
  • Avoid sampling in old fencerows, dead furrows, low spots, feeding areas, or other areas that might give unusual results. If information is desired on these unusual areas, obtain a separate sample from the area.
  • Be sure to label the soil container clearly and record the numbers on the soil container and the information sheet.
  • Air-dry the samples as soon as possible for the available nitrogen test. (Air drying before shipment is recommended, but not essential, for all other tests.) Do not use heat for drying.
  • Fill out the information sheet obtained from your Extension office, or download a sheet.
  • Take the samples to your local Research and Extension office for shipping. Samples may also be sent directly to the lab by placing them in a shipping container. Information sheets should be included with the package. Shipping labels can be printed from the Soil Testing Lab website listed below. Mail the package to:

Soil Testing Laboratory
2308 Throckmorton PSC
1712 Claflin Road
Manhattan, KS 66506-5503

A listing of the types of soil analysis offered, and the costs is available on the Soil Testing Lab web site, http://www.agronomy.k-state.edu/services/soiltesting . You can also contact the lab by email at soiltesting@ksu.edu and by phone at 785-532-7897.

For more information on the proper procedures for the Soil Testing Laboratory, see K-State publication MF-734 at: https://www.bookstore.ksre.k-state.edu/pubs/MF734.pdf. Detailed information on soil sample collection can be found in the accompanying article “The challenge of collecting a representative soil sample” in this eUpdate issue.

Dorivar Ruiz Diaz, Nutrient Management Specialist
ruizdiaz@ksu.edu

K-State turfgrass specialist urges mid-summer checkup on lawns

Many Kansas landscapes include warm-season grasses, which require a little care in order to stay healthy during the hot summer months.

Hoyle says warm-season grasses may need fertilizer to remain healthy

MANHATTAN, Kan. – Kansas State University Associate Professor and Extension Turfgrass Specialist, Dr. Jared Hoyle says homeowners ought to be thinking about a mid-summer checkup on their lawns, which likely includes applying fertilizer and weed killer.

Many Kansas summer landscapes include warm-season grasses, namely bermudagrass, zoysiagrass and buffalograss. Each of those requires a little care in order to stay healthy through the hot weeks ahead.

“Those three grasses are not all created equal and some grow faster than others, which means we need to feed them a little bit different,” said Hoyle, an associate professor in the Department of Horticulture and Natural Resources.

For bermudagrass and zoysiagrass, Hoyle suggests applying a total of 1-3 pounds of nitrogen per 1000 square feet during a typical growing season, which is the beginning of May through the middle of August.

“You can split that up into multiple applications of a quick release fertilizer, or you could do fewer applications of a slower release,” he said. “But the main goal is 1-3 pounds of nitrogen per 1000 square feet regardless of what number or percentage product you’re using.”

Buffalograss does not require as much nitrogen. Studies at Kansas State University indicate that “about 1 pound of nitrogen per year for 1000 square feet is good,” according to Hoyle.

“It’s hard to split up a pound over multiple applications, so that’s one where you might want to look at a slow release to put that pound of nitrogen per 1000 square feet throughout the year,” he said. “You can do that right now and that will get you through the rest of the year with a slow release fertilizer.”

In addition to fertilizing warm-season grasses, Hoyle said homeowners should be looking at ways to control thatch and weeds in the lawn.

“We really like to preach that if you are going to do something with the lawn — whether it is fertilizing or watering — do it when it’s actively growing,” Hoyle said. “Right now, with warm-season grasses, if you have a thatch problem, you can tear that area up (with a verti-cutter or slicer), fertilize the lawn, and it will grow right back in. If you try to do that during the fall or spring months, there will be periods of time when the lawn isn’t growing, or delayed growth, and it could lead to more problems.”

Among weeds, crabgrass and yellow nutsedge are two of the most troublesome this time of year.

““I’m seeing a lot of crabgrass and yellow nutsedge and I blame it on the weather,” Hoyle said. “Yellow nutsedge loves flooded, compacted soils and because of periodic flooding around the state, I have seen a lot of areas that typically never have yellow nutsedge. It’s a weed to keep an eye out with the weather conditions as they have been.”

To control yellow nutsedge, look for products with the active ingredients halosulfuron or sulfrentrazone, he said.

Crabgrass that has already emerged can be treated with products that include the active ingredient quinclorac.

Hoyle noted that homeowners should be patient when applying herbicides to yellow nutsedge and crabgrass; it might take more than one application to control those weeds.

K-State’s Department of Horticulture and Natural Resources publishes a weekly horticulture newsletter with updated information on lawn care and other turfgrass issues. Residents may also contact their local extension agent.

Watering Your Lawn – Resources

(By Jared Hoyle, KSU Turfgrass Research and Extension)

I’m going to say it because everyone else is thinking of it. As soon as we started to complain about all the rain, it stops and now its hot and dry.  So to help out here are two recently updated publications with information on watering your lawn.

Did you know that about half of the water applied to lawns is wasted? This fact sheet offers tips on turfgrass selection, soil preparation, and maintenance practices to increase watering efficiency.

https://www.bookstore.ksre.ksu.edu/Item.aspx?catId=545&pubId=670

Suggestions for homeowners on maintaining a healthy, attractive lawn while conserving water.

https://www.bookstore.ksre.ksu.edu/Item.aspx?catId=363&pubId=663

**** Picture looks blurry doesn’t it!  Thats because this picture was taken when the irrigation was running while it was raining outside. Make sure you take control of your irrigation otherwise it will take control of your lawn…****