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K-State Turfgrass

Month: October 2019

Temperature fluctuations and turf diseases

(Megan Kennelly, KSU Plant Pathology)

As I write this on Thursday we are looking into a weekend with forecast lows deep down into the 30’s. This comes after a September with multiple days in the 90’s and even more in the upper 80’s. Depending on how the weather shakes out after this weekend our warm-season turf may start showing signs of dormancy. Right now it is all still quite green.

In our cool season turf I’ve not seen much dollar spot lately, and it should be simmering down. I have heard a few reports of rust,

and my first suggestion in those cases is to review the fertility regime and make sure it’s not too low on N.

We are seeing and hearing reports of large patch across the region. Here is one example from today at our research facility in Manhattan:

Spring dead spot happens in … spring. But fall is a time to think about it. I’ll point you to an excellent summary of fall disease info from Dr. Miller next door in Missouri, with details about large patch, spring dead spot and other diseases:

https://turfpath.missouri.edu/reports/2019/10_09_19/

 

Green June beetle larvae crawling around

KSU Entomology has been getting reports of Green June beetle larvae being noticed crawling around right now.

You can read more about it here:

http://blogs.k-state.edu/kansasbugs/2019/10/10/green-june-beetle-larvae/

June beetles are described in more detail in this publication:

https://www.bookstore.ksre.ksu.edu/pubs/mf2901.pdf

As stated in that publication, “Although Phyllophaga grubs can be recovered from most turf venues, populations rarely are sufficient to cause visible damage.”

New publication on oak leaf itch mite

(Megan Kennelly, KSU Plant Pathology)

In my neighborhood, and many communities across Kansas, we had an outbreak of oak leaf itch mites with a peak a couple of years ago. If you have itch mites in your area this year, you’ve had them before, or you simply have oak trees around, here is a new information sheet from KSU Entomology about this topic:

https://www.bookstore.ksre.ksu.edu/pubs/MF2806.pdf

With raking season upon us, take extra care if you do have them active in your area this year.

Curled leaf symptoms:

Unhappy person with itch mite bites during windy raking season a few years ago:

Recent Release: Free Soil Moisture Mapping Protocol

Dr. Chase Straw, Turfgrass Scientist at the University of Minnesota, informed us of the recent release of a free soil moisture mapping protocol that can be utilized by golf course superintendents to assist them with fairway irrigation decisions. The protocol explains how to collect GPS soil moisture data with a commercially available device (FieldScout TDR 350), which are then used to generate fairway soil moisture maps with free software. The maps could be used as a tool to program an irrigation system to irrigate based on the soil moisture variability across a golf course, among possibly many other things.

More information about the protocol, in addition to details regarding how the Minnesota Golf Course Superintendents Association of America chapter is utilizing it as a service to their members, can be read from a recent blog post on the UMN turfgrass website.

The protocol can be downloaded here.

The protocol requires a $0 licensing agreement. FREE!!! Should you have any questions, don’t hesitate to reach out to Dr. Chase Straw (cstraw@umn.edu) and his team at the University of Minnesota.

 

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

 

 

The (ob)noxious weed: Field Bindweed

By: Brooke Garcia

Perhaps you don’t recognize the name, but you may recognize the white flowers of this perennial weed called Field Bindweed. If you can’t recall the flower, you have probably still had an interaction with this weed in your garden or landscape. Don’t be fooled by the flower, as this is an (ob)noxious weed in the field and landscape.

Better Kansas Blog features a post that highlights this weed, as well as valuable links to additional information. For more information, click here.

Here is the link from Extension Agronomy: Fall Control of Bindweed

Here is a link from KSRE Johnson Country: Bindweed: a noxious weed

***Photo provided by Better Kansas Blog.

Zoysia breeding line evaluation work continues

(Megan Kennelly, KSU Plant Pathology)

KSU continues its work with the turf breeding team at Texas A&M and colleagues at Purdue. We recently inoculated some breeding lines with the large patch pathogen. We grow the fungus on sterilized oats then bury it just under the thatch layer. Sometimes we see symptoms in fall, but often we do not see them until spring. Scientific research takes a lot of patience :). In the meantime, we are keeping the plots moist to foster fungal growth.

In the meantime, large patch is active especially in wet areas:

Take note of these areas. It’s too late to fertilize zoysia now, but when spring comes around a bump of slow-release N may prompt recovery. In the meantime there may be actions you can take to improve drainage.

Breaking disease life cycles with good sanitation

(Megan Kennelly, KSU Plant Pathology)

Many plant pathogens like to survive the winter in infected crop debris. One example is iris leaf spot.

 

Here is a zoom – the black spots are structures where the fungus produces spores:

Here are some other flower diseases that carry over on debris:

Rose black spot lesions, close-up of lesions, and microscopic view showing abundant spores:

Cercospora leaf spot on hosta:

For many of these common flower-garden leaf spots, removing diseases and dead leaves can help reduce the amount of the fungi lurking over winter to cause disease next year. If composting, don’t put the compost back in the spot where you took the leaves.

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