Kansas State University


K-State Turfgrass

Category: Diseases

Paying Attention to Pine Diseases

Now is a really good time to check for Dothistroma Needle Blight on Austrian, Ponderosa and Mugo pine trees. Several pine samples from northeast Kansas have the K-State Plant Disease Diagnostic Lab with classic symptoms. This disease tends to show up in crowded, mature pine plantings. The key is crowded plantings that lead to poor air circulation. Wet weather and poor air circulation lead to increased disease severity.


If you are trying to sort out winter damage from Dothistroma needle blight, the first thing to do is to look into the bottom of the tree. Dothistroma causes needle shedding and tends to be more severe in the bottom of the tree. Essentially when you look into the bottom of the tree, the interior needles are gone and all of the lower limbs tend to be bare. Needle loss tends to be particularly severe in crowded windbreaks where air circulation is poor.

Next take a look at the foliage. The needles will have scattered spotting and a half needle scorch. The outer needle tip will be brown and the inner portion of the needle will be green. Each needle will be affected in a different location.

You can contrast this with winter burn which can also produce a half needle scorch but will always burn all of the needles back in exactly the same location. Plus the damage tends to be in the outermost foliage.

The last thing to look for is raised black fruiting bodies (acervuli) on the affected needles. This is diagnostic sign for the disease. You may need a magnifying glass or 10X hand lens to see them, although when they are fully mature they are visible with the naked eye. The fungal fruiting bodies don’t start developing until late December or January, but now is a good time to look for them. If you don’t initially see them you can put the suspect needles in a Ziploc bag with a wet paper towel for couple of days. The high humidity will help the fruiting bodies pop out.

Dothistroma needle blight and winter damage can look very similar. If you are going to spend money to treat for the Dothistroma needle blight disease then it is a good idea to confirm that the disease is present. Samples can also be sent to the K-State Plant Disease Diagnostic Lab at the address listed at the bottom of this post. Dothistroma needle blight can be managed with fungicides.

For more information on managing this problem see the pine disease factsheet at the following web link (O’Mara):


K-State Plant Disease Diagnostic Lab
4032 Throckmorton, PCS
1712 Claflin Rd
Manhattan, KS 66503
Send Questions to: jomara@ksu.edu
Testing for Needle Blight: $10 Extension/$13.50 Non-Extension

Cut and destroy those pine wilt infected trees ASAP

(Megan Kennelly, KSU Plant Pathology)

Pine wilt has been killing our pines for decades. It is caused by a nematode (microscopic worm) that is spread by a beetle. The nematodes and beetles spend the winter in dead and dying trees. The beetles, loaded up with nematodes, start emerging in late April or early May and spread to new trees. Got pine wilt? Get that tree outta there! Chop it down, and burn or chip the wood, making sure not to leave stumps. Get this done in early April to stop disease spread.

If you have a dead pine in the eastern 2/3 of Kansas it could very well be pine wilt. Sure, it could be something else, like drought, but if it’s dead anyway you might as well assume it is pine wilt, and get it out and destroyed. You can send a sample in to KSU for testing if you want to know.

And, if you suspect pine wilt in the western part of the state, contact your local county K-State Research and Extension agent for help. Not only do we want it destroyed, we want to know where it is so we can understand where disease is spreading. (Find your agent here: https://www.ksre.k-state.edu/about/stateandareamaps.html)


Entirely dead tree? Cut it down and destroy the wood by chipping or burning.




Pines have multiple problems though, such as tip blight and Dothistroma needle blight. If you have any doubt you can work with your KSRE Extension agent to ship a sample up to KSU. For more information on pine diseases, and how to tell them apart, check out our publication about Pine Diseases in Kansas

Weekend Warrior Turfgrass Lawn Care

(By Jared Hoyle, KSU Turfgrass Research and Extension)

Finally I think we have turned the corner into Spring.  With that, I see more and more of my neighbors, and myself, working in the yard.  I get excited when the turf starts to turn green.  But before I get too carried away I want to get out on the right foot and planning is everything.  To help help you plan out your lawncare program below are monthly calendars for tall fescue, Kentucky bluegrass, buffalograss, bermudagrass and zoysiagrass.

Bermudagrass and Zoysiagrass Lawns


Buffalograss Lawns


Tall Fescue and Kentucky Bluegrass Lawns


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” – Home Lawn Winterkill

(By Jared Hoyle, KSU Turfgrass Research and Extension)

HOME LAWN WINTERKILL– It was a fairly harsh winter in this region.  And that has homeowners wondering if their lawn grasses were adversely affected by the extended cold and wet conditions. K-State turfgrass specialist Jared Hoyle says while the likelihood of outright turfgrass winterkill is relatively low, some limited damage may have occurred.

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

Control of Turfgrass Diseases

“Turfgrasses under intensive management are often subject to outbreaks of infectious diseases. Diseases usually are most damaging when weather or cultural conditions favor the disease-causing agent but not plant growth and vigor.”


This quote from the “Chemical Control  of Turfgrass Diseases 2017” publication at University of Kentucky and Rutgers University, really sums up why we have diseases in our turfgrass systems.  Many times we have no control over weather or the cultural conditions that favor disease-casuing agents and those same conditions do not favor turfgrass growth.  To prepare for 2019 download this publication from Drs. Vincelli, Clark and Munshaw and keep it around as a great reference.  I keep a copy of this publication along with my weed control manual (https://blogs.k-state.edu/turf/new-turfgrass-weed-control-for-professionals-2019/) at all times.

  • Jared Hoyle

First 2019 Disease Report from Mizzou

Only of our good friends to the east, Dr. Lee Miller, posted his first disease report of 2019.  In this update he covers what we have been through over the past winter and what to look for in the weather to come.  Check it out!  This is some great information, especially if you are on the east side of Kansas.


(Figured I would add a picture in here that shows some green turf! – Jared Hoyle)

Large patch in research plots

Before the snow hit I was able to view some large patch symptoms in our breeding plots with our PhD student Manoj Chhetri.

Strong large patch symptoms:

Not much symptoms here:

Definitely some differences in % green after the recent cold snaps, but before the snow and this weeks extreme cold temps:

Odd weather patterns lead to odd disease patterns


I saw some brown patch recently – in late September/early October!

In the meantime, our warm-season grasses are slowing down, and all the cool, cloudy, rainy weather this week may trigger some large patch in zoysiagrass.

Pathogens will take advantage of conducive conditions whenever they occur. Here are some great updates from my excellent turf pathology colleague Dr. Lee Miller, next door in Missouri:



Flower garden sanitation to improve plant health next spring

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:

So what can we do? Here are some tips from the Horticulture News (http://www.ksuhortnewsletter.org/):

Iris are known for a couple of common problems: a fungus disease known as iris leaf spot and an insect named iris borer. Though both cause problems in the spring, now is the time to start control measures. Both the fungus and eggs of the borer overwinter on old, dead leaves. Remove dead leaves and cut back healthy leaves by ½ this fall to reduce populations of these pests. Also remove other garden debris from the iris bed.  This can significantly cut down on problems next spring. (Ward Upham)

Another disease that lurks over the winter is peony leaf blotch (also known as red spot or measles) and you can find info on that disease here on the Common Plant Problems website.



(Photos by Megan Kennelly)

Cool-season Turfgrass Lawn Care Reminders!

(By Jared Hoyle, KSU Turfgrass Research and Extension)

It is that time of year again to start working on your cool-season lawn.  To try and cover it all, I have listed a couple posts from the past that can help you get that lawn into shape.  I also have added a list of publications. Enjoy!

Time to fertilize cool-season turfgrass


Monthly calendar for cool-season lawns for the rest of the year


Power raking or core aeration – That is the question!


The art of knowing your seed label


For seeding success, pay attention to other crop on the seed label



Lawn Fertilizing Guide – https://www.bookstore.ksre.ksu.edu/Item.aspx?catId=545&pubId=10639

Recycling your grass clippings  – https://www.bookstore.ksre.ksu.edu/Item.aspx?catId=545&pubId=701

Mowing your lawn – https://www.bookstore.ksre.ksu.edu/Item.aspx?catId=545&pubId=615

Tall Fescue Lawns – https://www.bookstore.ksre.ksu.edu/Item.aspx?catId=545&pubId=1460

Watering New Lawns – https://www.bookstore.ksre.ksu.edu/Item.aspx?catId=545&pubId=1337

Planting a Home Lawn – https://www.bookstore.ksre.ksu.edu/Item.aspx?catId=545&pubId=595

Aerating Your Lawn – https://www.bookstore.ksre.ksu.edu/Item.aspx?catId=545&pubId=713

Kentucky Bluegrass Lawns – https://www.bookstore.ksre.ksu.edu/Item.aspx?catId=545&pubId=713


Check out the KSRE Bookstore for more publications – https://www.bookstore.ksre.ksu.edu/Category.aspx?id=528&catId=545