The Kansas Forest Service is hosting a tree event at the Overland Park Arboretum on Friday, June 2. It’s the Walnut Council Field Day, and usually the focus is more on rural trees. But, with the unique Overland Park location, some of the topics are right in line with urban trees, including tree identification and tree problems
Here is the registration form and full schedule:
http://www.kansasforests.org/events/news_docs/calendar/WCFD2017.pdf
I think we all know that plants and nature are good for people. However, to read more about the social side of the green industry you can check out this interesting article about “Trees, jobs, health, and equity in the urban forest.”
As the article says, “Even the smallest bits of nature in the city can make a positive difference in people’s daily lives.”
Here is the link:
https://tcia.org/TCI-publications/tci-magazine/2017/05/index.html#?page=62
Here is a quick update from Ward Upham and the Horticulture News:
We are starting to see anthracnose on sycamore. Anthracnose is a fungal disease favored by cool, wet weather. Young leaves may wither and turn black. On older leaves, look for brown areas that follow the major veins of the leaves. In some cases, the petiole (leaf stem) is infected, which causes leaf drop. The leaf may look perfectly fine, so look for browned areas on the petiole.
In severe cases, the tree drops heavily infected leaves and may be completely defoliated. Healthy trees will leaf out again in a few weeks. Defoliation this early in the year does not affect overall tree health. Trees have plenty of time to produce new leaves and make the energy reserves needed to survive the winter.
Other types of trees that are affected by anthracnose include birch, elm, walnut, oak and especially ash. Anthracnose seldom causes significant damage to trees in Kansas, so chemical controls are usually unnecessary. Also, fungicides do not cure infected leaves. Applying fungicides now will not help.
For a detailed overview of anthracnose diseases of shade trees, you can check out the free online pdf version of Diseases of Trees in the Great Plains. I’ve mentioned this book before – it is a great resource! Here is the link, and the anthracnose part is the section section, on p. 22 of the pdf.
Anthracnose is also covered in our Tree and Shrub Problems of Kansas book.
Wet, cool weather is favoring continued activity of large patch and other spring diseases. If you have not downloaded it yet, be sure to check out the 2017 fungicide guide from Vincelli et al.
For a superb update on large patch, dollar spot, spring dead spot, and root problems, you can roll on over to the Missouri Turf Pathology Report .
Here is some large patch in our research plots:
Just for fun, here is some fairy ring activity. I walk past this spot a lot, and those mushrooms popped out after a recent rain.
And also just for fun here are two panoramas of Rocky Ford! You can click to zoom and imagine birds chirping and a soft spring breeze in the air… ahhhh….
Got holes in your elm leaves? Could be the European elm flea weevil. For more pointers, here is an article by Dr. Cloyd on the Entomology blog:
This insect and many more are covered in our comprehensive book Tree and Shrub Problems in Kansas: Diseases, Insects, and Environmental Stresses.
(Information from Ward Upham, K-State Horticulture and Natural Resources)
Many areas of western Kansas suffered tree damage from the winter storm. There is an article in our January 17 Hort Newsletter on how to prune damaged trees. See http://hnr.k-state.edu/extension/info-center/newsletters/2017/January_17_2017_3.pdf .
Here is a brief tour of our zoysiagrass progeny evaluation plots. The study is in collaboration with Texas A&M, Purdue, and several other universities across the region. It is funded by the US Golf Association. PhD student Mingying Xiang is working on this as part of her dissertation research.
Here is the link to a brief video on YouTube.
Sorry about the wind noise! I tried on Monday, and it was even worse, so this is at least better than my first attempt. We can’t be too picky about the wind here in Kansas, right?
Here is a link to a post from last fall where we talk about the inoculation method.
And here is a checkerboard of inoculation points in Meyer zoysia, from a few years back:
I came across a nicely-written article from U of Kentucky about gloves and pesticide safety. It’s pretty short, and worth 2 minutes of your time as a quick review.
For example, did you know this? “Research has shown that workers mixing pesticides received 85% of the total exposure on their hands and 13% on their forearms. The same study showed that wearing protective gloves reduced exposure by 99%.”
Read the full article by clicking HERE
(Photo from Entomology News)
What’s that thing chewing up my pine needles? Dr. Raymond Cloyd provides some answers about the European pine sawfly:
We recently posted about pine wilt and pine tip blight. To round out the big three pine diseases, below are a few quick notes about Dothistroma needle blight. For a review of all three of these diseases, plus natural needle drop, you can check out Pine Diseases of Kansas. (Click that link to download a free pdf with lots of photos and management information.)
Dothistroma needle blight is common in Austrian and Ponderosa pine. It can occur on Mugo pine, too.
Dothistroma spends the winter in infected needles. During wet conditions in late spring/early summer the fungus infects new needles.
Here is a photo of the fungal fruiting structure – the little black lump peeking out from under a flap of needle tissue:
We have been seeing those in the past couple of months on needles that were infected last year. December through April is when those fruiting bodies start to pop, allowing us to make a diagnosis.
Those fruiting structures produce spores that spread in rain to infect new needles. This often occurs during wet, mild weather in late spring, early summer (but can occur all summer). Those needles eventually show a partial needle scorch, with the base staying green. Each needle is a little different, depending on where the fungus got in there. The photo below shows some needle spots and banding and then the browning (necrosis) from the infection point outward.
On a tree, this shows up as partial browning, then complete browning, of the needles one year back on the branch:
The older, needles eventually drop off, leaving just a one-year tuft of the newest needles. The branch looks like a broomstick or a lion’s tail:
The damage tends to start in the lower part of the tree and work its way up. The disease is more likely in older trees. Mature, overcrowded windbreak trees are susceptible. Normally, pines keep several years of needles. If all those inner needles drop the tree has less capacity to do photosynthesis and it can weaken. Each little needle is like a solar panel, and fewer solar panels means less energy.
What do you think about this tree?
It is a young tree, and the damage is more top-down, not bottom up. So the overall pattern does not seem right for Dothistroma. Remember – with Dothistroma the disease usually starts at the lower part and works up, with older trees more prone to the disease.
Let’s take a closer look. What do you see? Or NOT see?
The damage is pretty uniform, with each needle looking quite similar. Compare it to that photo farther up where each needle is a little different. Plus, there is no spotting/banding. My guess is this is environmental stress. Pines can definitely get the moisture sucked right out of them during dry winter winds.
To know for sure, samples can be submitted to our Plant Disease Clinic either directly or (even better) through your local K-State Research and Extension Office.
Need more details? Remember our publication about Pine Diseases in Kansas where you can find more information about diagnosing and managing Dothistroma and the other pine diseases.
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