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K-State Turf and Landscape Blog

Author: kennelly

Hot and sticky summer weather = brown patch and Pythium

Posted on by kennelly

(Megan Kennelly, KSU Plant Pathology)

 

Is this brown patch in a tall fescue home lawn? Look for lesions to be sure! See below!

It’s that time of year when you go outside in the morning and immediately start to sweat. Ugh.

High humidity means that the temperatures stays high even overnight. Sticky, humid nights = conditions ripe for brown patch and foliar Pythium.

Brown patch is common in tall fescue lawns, perennial ryegrass athletic fields and fairways, and bentgrass putting greens. I’ve been hearing reports of brown patch popping up in the past few days.

Foliar Pythium is common in bentgrass and rye fairways, and we occasionally see it in lawns that are very lush and wet. Foliar Pythium is very rare on greens. I haven’t seen any yet, but with humidity and nighttime lows in the 70s it’s a possibility.

Fungicides and cultural practices for both diseases are spelled out in detail in the publication Chemical Control of Turfgrass Diseases.

 

In tall fescue, brown patch symptoms can resemble drought or other injury. If in doubt, check around for the characteristic lesions:

Both diseases can produce mycelium in the turf during wet, humid, dewy mornings. With Pythium, usually the turf looks matted down and greasy.

Brown patch:

Pythium – grass is matted down and greasy/mushy:

Not sure? You can always send a sample to the KSU Plant Diagnostic Lab.

Declining turf? Look below the surface

Posted on by kennelly

Each year we get samples into the lab where there is turf decline and people think there is a disease problem, but the culprit is thatch. The photo above is from a sample that came in this week.

Any time you have a turf problem, take a soil probe, pocket knife, or trowel, and take a look underground. I’m saying 100% of the time. Not 90%. E-V-E-R-Y time. You never know what you might find down there.

We see a lot of decline from thatch-related desiccation in the heat of summer, but we also see it in spring after thatchy turf gets the moisture sucked out of it by dry winter winds.

Here are a few others from prior years:

 

 

In this one, the turf had thick thatch and got very desiccated over winter and was not able to green up in spring:

 

At this site, they also had grub problems. They had applied an insecticide, but as you probably know, pesticides can get pretty tied up in thatch which makes it hard for them to do their jobs.

For more details:

https://www.bookstore.ksre.ksu.edu/Item.aspx?catId=545&pubId=714

 

 

Nozzles! More interesting and important than you think

Posted on by kennelly

We are getting into summer crazy-time, and during crazy-time it’s easy to forget about things like calibrating and replacing worn nozzles.

Here are a couple of reminders about nozzles, re-posting a short note from last year:

 

nozzle1

Spray nozzles might seem like a boring topic, but as stated in an article by Shepard, Agnew, Fidanza, Kaminski, and Dant in 2006 in Golf Course Management, nozzles are “The last piece of equipment through which sprays pass before contact with the turf.”

Think about the cost of all that stuff going through the sprayer, the time of the person applying those materials, and the fuel to power that sprayer Nozzles are small, and they don’t cost much, but they can really contribute to the success of an application and help maximize the bang for your buck on all those OTHER costs.

Anyway – as noted in the article cited above, nozzles determine the amount of chemical applied, the uniformity of the application, the coverage, and they can influence the risk of drift. Make sure you calibrate your equipment, replace worn nozzles, and follow all label instructions about application equipment for the materials you are spraying. A worn-out nozzle could easily be allowing 10% or more excess material to be applied, which = 10% more money. Equipment that is not calibrated right might be applying LESS than you need to get adequate control.

Weather – you can’t control it, but you can maximize your knowledge of it

Posted on by kennelly

We’ve had a taste of every season here in Kansas these past few weeks.

With that, here’s a reminder on an excellent source for weather details – the KSU Mesonet.

If you have ever been to Rocky Ford, you have seen our weather station:

This station is linked up to Mesonet: http://mesonet.k-state.edu/

You might have your own on-site weather station. At minimum, you might have a soil temperature probe.

To supplement those, you can visit the Mesonet website and check for a station near you. Just click on a site, and some info will pop up.

For historical weather, click on the menu on the upper left, then go to WEATHER and then HISTORICAL WEATHER and you can select the days you want to consider. There are various options for soil temperatures and many other features. Soil temperatures can be important indicators for different management practices. Again, I highly encourage you to measure your own conditions on site, since there are lots of different microclimates in the world of turf and landscape. But it does not hurt to compare to a nearby weather station.

If you have never used Mesonet, check it out!

 

Conifer Trees for Kansas – new resource hot off the press!

Posted on by kennelly

Are you interested in planting conifers, but you are not sure what to choose? The new Conifer Trees for Kansas publication provides details.

You can download a copy for free. There are color photos on nearly every page. The publication describes landscape evergreens suitable for specific regions in Kansas. Includes botanical and common names, photos, growth rates and dimensions, significant pests, with comments from the authors based on personal observations.

 

 

Remembering our pine diseases

Posted on by kennelly

(Megan Kennelly, KSU Plant Pathology)

Everything is late-late-late this year, but soon our pine shoots (candles) will be expanding. Pine tip blight is most likely to infect newly-emerging shoots. Dothistroma comes a little later and infects needles. With pine wilt, what we see now is pines that were infected last year and are dead by now. (We need to get those chopped down and chipped/burned ASAP).

Here’s the link to some pine tip blight info  in last year’s summary

Here’s the link for Dothistroma needle blight .

And, of course, don’t forget about PINE WILT. Get those pine wilt trees cut down by May 1 at the latest.

For a summary of all the major pine diseases in one convenient spot, you can download our publication Pine Disease in Kansas.

 

“The grass is always greener” – national media story about sports turf

Posted on by kennelly

Green industry professionals often work behind the scenes without much publicity. However, there was a great story this weekend about what goes on behind the scenes at Nationals Park on NPR.

You read the text and see photos here, or click to listen to the recorded interview.

https://www.npr.org/2018/04/07/600482865/the-grass-is-always-greener-at-the-baseball-field

 

 

Cut down and destroy dead pines to help prevent spread of pine wilt

Posted on by kennelly

Now you see it:

call-hall-2012-10-09_17-20-05_109

Now you don’t:

Call-Hall-now-gone-2012-10-25_17-20-32_596

This tree had pine wilt disease, and it was cut down and chipped or burned to reduce the risk of spread to other trees.

Pines have several disease and insect problems. One of them is pine wilt disease. It kills the entire tree quickly.

Pine wilt is caused by the pinewood nematode, a microscopic worm. The nematode is spread by the pine sawyer beetle. The nematode feeds and multiplies in the tree’s resin canals, causing wilting and death in several weeks to several months. The nematode and beetles spend the winter in the infected tree. In spring, the beetles emerge starting around May 1, carrying nematodes to new trees and continuing the cycle of infection.

The disease is common in the eastern half of the state and has gradually spread west. There have been pockets of infection in the western part of the state, but we’d like to keep it out. Also, sanitation efforts will help reduce spread even in the east where the disease is common. Here is a map of pine wilt from our Kansas Department of Agriculture colleagues based on recent survey data:

 

 In Kansas, new pine wilt infections are most visible from August to December. Trees wilt and die in a short period of time, from several weeks to a few months. In the first stages, the needles turn grey or green, then yellow and brown. The discoloration sometimes occurs branch by branch, sometimes all at once. With pine wilt, eventually the whole tree dies, within a few months. The brown needles stay on the tree for up to a year after the tree has died. Another key symptom is reduced resin. On a healthy tree, sticky resin bleeds from the site of a wound. In contrast, if a tree has pine wilt the resin is often reduced or absent, and branches become dry or brittle.

There is a website with color photos and descriptions at the following link:

http://muextension.missouri.edu/explorepdf/miscpubs/mx0858.pdf

There are images to compare and contrast pine wilt with other pine diseases here:

http://www.ksre.ksu.edu/bookstore/pubs/l722.pdf

With the other diseases (tip blight, needle blight) only parts of the tree turn brown. With pine wilt, the whole tree is brown and dead.

If you aren’t sure if your tree has pine wilt or something else, contact your local K-State Research and Extension Office or the K-State Diagnostic Lab (clinic@ksu.edu).

If a tree has pine wilt,  the tree should be cut down by  April 1  to make sure there is time to destroy the wood by May 1, when the beetles start to some out. Cut the tree to the ground—don’t leave a stump. Chip or burn the wood immediately to destroy the beetles and nematodes. Don’t keep pine wood around for firewood.