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K-State Turfgrass

Month: July 2018

Postemergent Crabgrass Control

(By Jared Hoyle, KSU Turfgrass Research and Extension)

Did you apply a preemergent herbicide this year and still have crabgrass? There are many different reasons you may have break through from a preemergent herbicide application.  If the turf is stressed and thin, along with over use of the turf and misapplications are some reasons you may be seeing crabgrass pop-up across many turfgrass areas.

Good news! There are some postemergent herbicide options out there for crabgrass control.  But depending on how big or how many tillers the crabgrass has will help you determine what product to use.  First, determine the size or stage of crabgrass you have present.

Here is a picture to show the tillering stages of crabgrass.

The smaller the crabgrass the easier it is to kill it.  The tillered crabgrass may take more than one application and higher rates so make sure you check the label for correct application rates and intervals.

  • dithopyr – Can provide control to crabgrass up to one tiller stage.  This product also has preemergence activity.
  • quinclorac – Can be applied on most cool- and warm-season turfgrass species.  This product controls crabgrass when it is one tiller or smaller or when it has four or more tillers.
  • mesotrione – Can be effective for crabgrass control but in most cases will take two applications at two week intervals. The label also states that applications must be made before the four tiller crabgrass stage.
  • topramazone – Similar to mesotrione, this product will require two applications at three week intervals. Use at higher rates on crabgrass that have greater than one tiller.
  • fenoxaprop – Are very effective in controlling crabgrass.  Label states that this product can be applied to annual grasses up to the five tiller stage. Remember not to tank mix with products that contain 2,4-D, antagonism can occur.

As one last reminder, do not apply post emergent herbicides when temperatures are greater than 85 deg F.  This will increase the risk of turfgrass injury.

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

Bentgrass Declining? It’s from Western Europe, You live in Kansas

(By Jared Hoyle, KSU Turfgrass Research and Extension)

The past couple weeks have been a struggle to grow bentgrass.  Some areas in Kansas are getting rain but others are not.  The rains have been localized and here at the Rocky Ford Turfgrass Research Center in Manhattan we keep missing the isolated showers.

I know some other golf course are in the same place as we are and it has been a struggle to keep bentgrass alive.  Well, I dug through the blog and found a post from Dr. Jack Fry about bentgrass management in the summer.  Dr. Fry leads of the article with..

“In the midst of a summer with 100+ F temperatures, it’s worthwhile to consider some of creeping bentgrass’s preferences and management strategies that might be helpful to reduce its stress, and yours.  See, the thing about creeping bentgrass on putting greens is….”

Click below to find out more about bentgrass management in the summer.

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

Don’t miss the Kansas Turfgrass Field Day August 2nd in Manhattan!

(By Jared Hoyle, KSU Turfgrass Research and Extension)

The Kansas Turfgrass Field Day will be held Thursday, August 2 at the Rocky Ford Turf Research Center in Manhattan.

You can register online at https://2018turfday.eventbrite.com

The field day program is designed for all segments of the turf industry – lawn care, athletic fields, golf courses, and grounds maintenance. Included on the program are research presentations, problem diagnosis, commercial exhibitors, and equipment displays. There will be time to see current research, talk to the experts and get answers to your questions.

Pesticide recertification credits in 3A and 3B are available, as well as GCSAA education points.

Would you like to be a vendor at field day?

For more information check out The Kansas Turfgrass Foundation Website – http://www.kansasturfgrassfoundation.com/annual-ktf-field-day.html

A Hard Winter on Bermuda

By Dr. Jack Fry and Mingying Xiang, (KSU Turfgrass Teaching, Research and Extension)

It was a hard winter for bermudagrass, and we saw extensive winter injury in Kansas – even to cultivars that we usually consider winter hardy. There is a trial at the Rocky Ford Turfgrass Research Center in Manhattan in which we’re evaluating experimental bermudagrasses from the breeding program at Oklahoma State University lead by Dr. Yanqi Wu (Fig. 1). Here are averages (of three replicated plots) of winter injury for standard cultivars included in the trial when we rated them on May 25: Tifway (100%); Latitude 36 (80%); Northbridge (75%); and Patriot (70%). The total loss of Tifway isn’t unusual, as it has poor cold hardiness. However, the severity of this winter caused severe damage to cultivars we previously thought were relatively hardy, including Latitude 36 and Northbridge. There is some good news. Several experimental grasses included in this trial experienced almost no winter injury, which bodes well for release of grasses with good cold hardiness in the future.

Fig. 1. Dr. Yanqi Qu and Mingying Xiang evaluate Oklahoma State’s experimental bermudas growing in 5 by 5 ft plots at Rocky Ford on May 25. Notice that many have extensive winter injury, while others are showing good recovery.

We heard from turf professionals in the state who indicated that injury was severe in some cases, and minimal in others – microclimates and differences in exposure likely had a lot to do with that.   Yukon bermudagrass, a seeded cultivar, had almost no winter injury at Wildcat Creek Golf and Fitness in Manhattan (Fig 2). This was impressive considering it was seeded in 2017.

Fig. 2. Yukon Bermuda, seeded in the summer of 2017 by Kevin Fateley at Wildcat Creek Golf and Fitness in Manhattan, KS showed very good recovery in May and almost no winter injury.

Fortunately, it has been a great summer for recovery. High temperatures above 100 F and lows in the mid 70s speed the growth and spread of bermuda. Unfortunately, it’s been another one of those hard summers for cool-season grasses. Here we are in Kansas trying to cope with the wrath of extreme winter and summer temperatures – been here, done this.

 

K-State resources to help you take care of trees during drought

(Megan Kennelly, KSU Plant Pathology)

Large swaths of Kansas are under drought conditions, and this week it’s only going to get worse.

We’ve talked a bit on the blog about irrigating turf, but what about our landscape trees? How can we keep them going under stressful conditions?

K-State has a set of resources to help you irrigate wisely and efficiently.

With water restrictions, it can be hard to know what to take care of first. Ward Upham provides some tips on how to prioritize watering in this week’s Horticulture News, in “Plant Triage and Watering.” 

Young trees are very susceptible to drought. They are also susceptible to overwatering! How can you get it right? Check out Watering Newly Planted Trees and Shrubs.

Older trees have more mature roots, but they can still succumb to drought.  For tips, check out: Watering Established Trees and Shrubs

Are you looking ahead to planting new trees? Keep drought in mind as a factor to consider.

 

Anthracnose crown rot in putting greens, and the turf stress behind it

(Megan Kennelly, KSU Plant Pathology)

We had a sample come in with soggy roots, algae, and a lot of thinning.

Here is the root zone. Lots of organic matter holds water, which holds heat. Hot, wet roots can decline quickly.

 

 

Hot, soggy roots can’t support growth.

(I did not find Pythium root rot structures in this sample, but these same conditions can lead to that disease, too.)

Looking closely, there was algae present. The dark green stringy stuff in the circled area is algae growing on the turf, viewed in the dissecting microscope. Algae is another indicator of wet conditions.

At closer inspection, in the compound microscope, spiny black structures were visible near the base of many declining plants that were just starting to fade from green to yellow or tan.

These structures are called setae, from the anthracnose pathogen, which is a fungus.

The publication Chemical Control of Turfgrass Diseases has a very detailed section about anthracnose, outlining many agronomic practices to reduce turf stress and reduce the threat of disease. You can find those tips at this link:

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

The anthracnose section starts on page 8.

As you glance through, you may notice that many of the practices to reduce anthracnose are similar to practices to reduce overall summertime stress in putting greens, such as providing enough but not too much water, raising mowing height (even a tiny bit can make a difference), skipping mowing and rolling instead, and maintaining adequate N. You can find the whole list starting on page 6 of Chemical Control of Turfgrass Diseases which, in short, includes information about mowing height, watering, fertility, foot traffic, dew, phytoxicity warnings, and more. We highlighted those a few weeks back in another post.