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winter injury, one more resource

Well, I've finally calmed down from the Packer victory against the Bears on Sunday. Whoa!

I do have to admit, I'm excited mainly because I know everyone back in my home state of Wisconsin is excited, not because I am a major follower of football. Poor little Jimmy Kerns, Chicago boy, is drowning in a sea of green-and-gold.

Lane (Pittsburgh native) and I have discussed some type of wager... keep posted. You might be seeing Lane in a cheesehead, dancing a B.J Raji style dance. I'm sure John can link us up with video...

A man who has embraced his body-type. Shake it, Raji, shake it!

Winter Injury

Anyway, with the chatter this week about cold injury I thought I'd pass on another link from Ohio State. It's kind of a virtual magazine where you can flip through the pages. Click HERE


Finally, I'm looking forward to the upcoming GIS in Orlando. Frank and I are teaching a course on diseases of warm-season turf on Monday along with Phil Harmon. Then, on Tuesday, I'll be one of the helpers in the microscope class. If any of you blog followers are in those classes, or you just see me in the hallway, I'd love to meet you in person so feel free to pull me aside and say hi. I'll be dressed in my tyvek superhero suit (just kidding)..

Cold throughout the Northeast

I just returned from a trip to the British International Golf Greenkeepers Association (BIGGA) meeting in Harrogate, England and can say that I was unpleasantly surprised by the extreme cold temperatures upon my return. I never thought that I would have to go all the way to the UK in the winter for better weather.

Back in the Northeastern United States, snow fell throughout much of the area while I was gone and now we are in the midst of another potential major snow storm starting this week and lasting for a few days. Not that anyone puts any faith in the weather reporters, but it looks as though we are getting more significant accumulation.

Ice forming on annual bluegrass putting greens and lasting for an extended period of time can spell "death" to the Poa. (Photo courtesy of Iestyn Jones of Norway)

One of the things that is a concern for golf course superintendents is the survival of their annual bluegrass under the snow when cover is expected for a extended period of time. While this snow cover is probably looked at as a great thing considered the extremely low temperatures throughout the region, the presence of ice under the accumulated snow may be a big problem for some. Over in England, I gave a talk on preparing for and recovering from winter damage (a topic that I am first to admit not an expert in AND thanks to Michelle DaCosta of UMASS for sending some slides of her own). However, during my preparation I pulled a lot of useful information about winter damage. In some of the literature, it appeared clear that fewer days of ice cover were needed to cause winter injury to annual bluegrass relative to other common species such as creeping bentgrass. Some of the data suggested 45-60 days of ice cover was a problem, while others reported damage in as few as 15 days of cover.

Part of the problem with giving a definitive length of time required for death to occur has to do with the conditions prior to the ice cover. If plants were given sufficient time to harden off during the progressively colder temperatures in the fall, the plants seemed to hold up better for a longer period of time. Having said that, in my experience in the Northeast and dealing with superintendents in other areas, much of the damage to the Poa actually occurs in the spring when snow melts, forms puddles and then refreezes on ground that not frozen. In these instances, temperatures can quickly decrease and plants can die quickly.

The bottom line for those of you concerned about the potential damage, it is important to monitor your snow cover to make sure that ice has not formed underneath. If ice has formed, you should track the time period that it covers the turf and potentially be prepared to remove ice that has been in place for several weeks. In most cases in the Northeast, this is not a problem. For those who are concerned in the spring, it is important to pull samples early and conduct a glasshouse test to see if your turf is actually going to grow once the weather improves. Simply pulling a sample and putting on your windowsill is often sufficient to determine plant health. Additionally, getting water off of the surface in the spring via squegeeing or pumping (if severe) will be another important component of preventing additional damage.

We are a long way from the end of winter, but it's never too late to start forming your plan for dealing with potential problems.

Potassium, Hokkaido, and Snow Mold

I'm at snow-covered Hokkaido for some seminars this week and one of the things I have mentioned in the seminars is the possible increase in snow mold damage that can occur with high rates of potassium application in the fall season. Dr. Kerns mentioned the research being done at Cornell now to investigate this phenomenon.

We came across this observation on an L-93 field trial that we had designed to study soil testing methods, not snow mold. What we found, as you see below, is that plots treated with potassium in the previous year (and to which no fungicides were applied to prevent snow mold) had an increase in snow mold damage compared with plots to which no potassium had been applied in the previous year.

In both 2003 and 2004, when the snow had melted from the research green, we observed a linear increase in gray snow mold damage with increasing rates of potassium application.

Hokkaido has heavy snow mold pressure. Many of the golf courses are under snow for four months. The photo below shows the effect of fungicide application in the fall (at right) vs. no fungicide (at left) in the snow mold damage to a golf course rough at Obihiro in mid-May. Clearly, one would not want to exacerbate the disease intensity by unwarranted application of potassium.

Arkansas turf conference

I spent a couple of days in Hot Springs (see photo), Arkansas, this week as a guest speaker at the Arkansas Turf Conference. I'd like to thank the Arkansas group for inviting me down. It was fun to meet the turf managers. 2010 was a rough year for turf in Arkansas where they faced many of the same decline issues we all did. Several guys pulled me aside and said that they follow this blog and that it helped them communicate issues to their golfers, etc. I think we are all still traumatized by 2010!

I talked about moss in one of my sessions and shared the survey results from Kansas moss surveys:

I handed out the same survey there, and the Arkansas crowd had a similar mix of responses. One guy said he used to have a few greens that were about 80% moss!

On this disease side, large patch in zoysia definitely sounds like a major problem in that part of the world, especially since spring and fall are prime seasons for play. One guy said that the majority of his golfers come down from places like Wisconsin. I guess they can't quite wait for spring in Wisconsin, so they head down to AR in April/May which is when large patch is most active. Then, by the time the disease goes away it is too hot for the Cheeseheads who go back north to golf up there.

Finally, it was also good to get to know my U of Arkansas colleagues a little better and I would like to thank Doug Karcher and Mike Richardson for their hospitality. And, Joey Young, great to see you again too!

Flying back in to Manhattan yesterday I got a nice view of a snowy Stagg Hill Golf Course next to the icy Kansas River as we were landing:

Flint Hills from the sky:

Go Pack, Go!

Is Emerald a Poor Curative for Dollar Spot?

Over the years, I've heard a number of people say that Emerald is a slow or poor fungicide for curative control of dollar spot. I must confess that I've never understood what everyone is talking about.

Given that boscalid, the active ingredient in Emerald, controls fungi by depleting their energy reserves, it makes sense that it might be a little slow to work on a curative basis. However, in reality, I've always been impressed with it's activity on both a preventive and curative basis.

Let's look at a couple of examples. In this first curative dollar spot control study, we had an average of 40 to 45 dollar spot infection centers in each plot before initiation of treatments. That's not a huge amount of dollar spot on a 20 square foot plot, but certainly enough to warrant a curative fungicide application in a golf course setting.

On July 20, just 5 days after applying the low rate of Emerald, we reduced the number of infection centers down to 2 per plot, whereas the number in untreated plots held constant. So, the low rate of Emerald reduced dollar spot incidence by 95% in 5 days. I'd consider that to be pretty good curative activity! If you're expecting more than this out of a curative application, then you are probably expecting too much.

Looking at some older data, in 2006 we evaluated Emerald, Daconil + Emerald, and Daconil + Banner for curative dollar spot control. In this case, the dollar spot pressure was much more intense, with 150 to 200 dollar spot infection centers per plot before the initiation of treatments. After the first application on 19 Jun, dollar spot incidence declined in all of the treatments at a similar rate and none of the treatments were disease free until three weeks later on 10 Jul. And this is even though dollar spot disease pressure was much lower during late June and early July, as evidenced by the decline in the amount of disease in untreated plots.

Curative control of any disease is more dependent on the level of disease pressure, the amount of turf injury present, and the growth rate of the turf after the application. Which fungicide is applied probably isn't that important in most cases. In order for the disease symptoms to go away, the turf has to grow out of the symptoms and spread into the damaged areas. This, of course, takes time. There aren't any fungicides that will make dollar spot go away over night.

For a lot of reasons, we don't recommend controlling dollar spot on a curative basis. Perhaps the most important reason is that curative applications increase the risk for fungicide resistance to develop. If you find yourself in a situation where you need to make a curative application for dollar spot control, be sure that you are tank-mixing with chlorothalonil to reduce the potential for resistance to develop. This is especially important for products with a high resistance risk like Emerald.

Fungicide resources

Hello everyone,

Happy New Year! Do you have any New Year's Resolutions related to turfgrass management to share? Your comments are welcome here or on the Facebook page.

After weeks, or actually, more like MONTHS with no significant precipitation, much of Kansas was blanketed by several inches of snow a few days ago. Until moving to Kansas, I spent my life in Wisconsin, New York, and Michigan, so I'm happy to see some "real winter." I think I have a physiological need for snow.

I did have some snow adventures over the holidays, too, in Wisconsin (see the line of mini-snow-people at my parents house, above) and Pennsylvania, while luckily not getting caught up in the travel nightmares of the big nor-easter that shut down the East Coast.

Overall, though, we have been hurting for moisture. Several superintendents mentioned firing their irrigation systems back up last week after blowing them out for the season since the turf was getting crispy.

Fungicide resources

There are two fungicide references that I thought I'd let y'all know about. First, the 2011 turfgrass fungicide guide is available from U of Kentucky, by Paul Vincelli and David Williams. If you've never checked it out, CHECK IT OUT!

The next one is a new book published by APS Press. It's called A Practical Guide to Turfgrass Fungicides, by Rick Latin from Purdue. It's comprehensive and written in a style for the educated turfgrass manager. Ie, it's not a bunch of scientific jibber-jabber suitable only for fungicide geeks (I'm looking at you, Frank and Lane).

Here's the link


One last recap of 2010

For those of you that have come to know me on this site, you probably also know that I am nuts. This is the kind of crap that keeps me busy during my insomnia in the middle of the night. Although this information is probably useful for web developers to make sure that the site shows up similarly across different platforms, I don't really have that much interest in the information. BUT, I do like the way that Google Analytics allows us to visualize the information. Without further adieu, here are the top browsers used to surf the Turf Disease Blog!

#7-10 Blackberry Phones
#6 Opera
#5 Mozilla Compatible Agent
#4 Chrome
#3 Safari
#2 Firefox (my personal choice)
#1 Internet Explorer

Check out the use during the year in this video!

Top 10 Visits by Country

As mentioned earlier in the week, we had visitors from 130 different countries or territories. While the majority by a long shot are from the United States, here is a round up of the top 10 visits by country in 2010:

#1 United States
#2 Canada 
#3 United Kingdom
#4 Thailand 
#5 Australia
#6 Japan
#7 Turkey
#8 Ireland
#9 Germany 
#10 South Korea

2010 Wrap Up from the West - Top 10 Diseases

Happy New Year to Everyone!!!
2010 was a mixed year, many California superintendents said that it was one of the best years for growing grass (we had some good rainfall this winter and a mild start to the summer), while I heard from a number of superintendents in the Pacific Northwest that the year was somewhere between sh*tty and really sh*tty because of the hard freezes that came in late 2009 and put them behind the 8-Ball from the start of 2010. In any case, last year was really hard financially on our industry and I really hope that 2011 brings us some better fortunes!

Just a quick round up of 2010 based on what we saw in the diagnostic lab here at UC Riverside. It was a busy year here in the lab with over 90% of our samples coming from California, with the rest coming in from our neighbors in Washington, Oregon, Nevada and Arizona.

We received 310 packages this year with a total of 536 samples (plugs). Disease activity in the west was fairly constant with the majority of our samples coming in July and October, reflecting increased disease pressure in the early summer and then an odd spike of activity in the fall.

No surprises as far as what turf species we encountered the most....

Poa dominated the samples sent into the lab with 69% of our samples being annual bluegrass and almost all of these being from putting greens. Bermudagrass and perennial ryegrass came in 11 and 10% of the time, almost all from fairways and roughs. Surprisingly, it was a good year for creeping bentgrass with only 5% of our samples coming from bentgrass greens.

Pathogens were present in the samples about 81% of the time, and the diseases we saw reflected the high prevalence of annual bluegrass samples we received.

Leading the pack was anthracnose, which was diagnosed in 14% of 536 samples. This continues to be the number one problem for golf courses in the west on annual bluegrass.

Coming in at #2, algae was present in 6% of our samples; although algae is often not a "disease" per se, its presence often indicates poor growing conditions on putting greens, and it can slow down turf recovery and cause some significant yellowing of the turf.

Rapid blight was our #3 disease of the year. Although the rain we had early in the year seemed to slow down rapid blight development, it seemed that prolonged cloudy, mild conditions in the early summer and then again in the fall promoted the development of this disease on annual bluegrass putting greens.

Bipolaris leaf spot (#4) was commonly found as a disease on drought stressed turf, mainly from perennial ryegrass or other cool season species in fairways and roughs.

Summer Patch came in at #5, again affecting primarily annual bluegrass putting grens; one observation we made from this year was that summer fungicide programs that focused on foliar applications for anthracnose control and didn't use QoI or thiophanate-methyl applications monthly tended to get this disease. Just a reminder that we need to control both of these diseases at the same time, which may require different fungicide strategies.

Large patch on kikuyugrass and bermudagrass was our #6 problem. Not surprising with all of the rain we got this last winter.

At #7 was Pythium Root Rot. This is still a little bit of a controversy - many of the locations where we diagnosed this were annual bluegrass putting greens also affected by freeze damage or had cold wet conditions. So what came first? Was the Pythium a weak pathogen attacking weak plants or did Pythium root rot make the plants weak?

Fairy ring came in at #8 on just about all turf types, with many of the diagnoses coming in the early spring. Lane's work at NCSU on preventive applications with DMIs when soil temps are 55 makes a lot of sense when controlling this disease.

Although foliar Pythium was our #9 disease, many of these diagnoses also came during periods of extended cold or warm wet weather and not necessarily during those hot hot 100 during the day, 70 at night type of situations where you'd expect Pythium to fire. We even picked up Pythium on bermudagrass this fall, how weird is that? My take away lesson from 2010 regarding Pythium was that as long as it's wet, you can get foliar Pythium.

Finally at #10 was brown ring patch. Since we saw it only 20 or so times this year on annual bluegrass putting greens, I hope that means that most superintendents are recognizing it early and controlling it fairly easily with fungicides and increasing nitrogen fertility.

OK - I hope this quick round up of 2010 diseases helps for 2011 disease management planning in the West. Until then, keep an eye out for those diseases!

Signing off from the Left Coast....

Top 5 Blog Posts of 2010

There's no doubt about it, 2010 was a tough year for golf course superintendents. Here's a look back and what was most important or relevant to you from our site last year.

#1 Bacterial wilt of bentgrass...
This was the posting of a letter from Dr. Mitkowski of the University of Rhode Island in which he talks about his recent finding of bacterial wilt in bentgrass. Definitely a hot (and controversial) topic in 2010.

#2 Summer fungicide programs for cool-season putting greens
There is no doubt that those growing bentgrass in the Southeast United States had their hands full this summer. In this post, Dr. Tredway shares some early (June) information about planning your summer fungicide programs with special mention to specific diseases including: Pythium blight, Pythium root rot, Pythium root dysfunction, anthracnose, fairy ring, nematodes and brown patch.

#3 Bacterial Wilt, no not? That is the question.
Dr. Wong posts a September blog about recent reports of dying annual bluegrass and creeping bentgrass greens. He links to a few other posts and suggests that although bacterial wilt may be the cause, getting conditions required for the disease in Southern California would be "like coordinating a trainwreck."

#4 Beware of the DMI fungicides
 In another post by Dr. Tredway, he warns of the potential issues with using the DMI fungicides during the summer months. This post was on June 16, so hopefully you heeded his warning and backed off of these products during the intense summer we had. If you didn't then you likely played right into the hands of Pat O'Brien and went through or are planning a bermudagrass conversion!

#5 The Turf Diseases Image Gallery
Did you even know that the Turf Diseases blog had an image gallery for the various common diseases that you may see at your golf course. Hosted on flickr and utilizing images from Dr. Tredway and me, the gallery serves as a visual tool to help diagnose your turf diseases problems or even as a photo collection for you to build powerpoint presentations for your club (giving full credit to the photographers of course).

Top 10 Referrers of 2010

While we would love to think that all of you have us booked marked or saved as your browser's homepage, we definitely understand and appreciate the fact that many of you find us by clicking on links from referring sites. We want to recognize those sites for providing content or links that got your to us. So to steal the thunder from David Letterman, here is our:

 Why they drove visitors to our site-list.

No. 10: It was either you or Voodoo Donuts.

No. 9: Wait, we did what?

No. 8: สิ่งที่เราควรทำอย่างไร

No. 7: I guess the words "disease" and "porn" are closely related.
(Google images)

No. 6: Because we don't update during our insomnia.
(Golf Course Industry) 

No. 5: Even we're tired of listening to Kaminski.

No. 4: @turfdiseases needed more followers.

No. 3: We ran out of money to produce more Frank Rossi videos.

No. 2: This is what we do, dumbass.

...and the number 1 reason our referrers said they drove traffic to our site...

No. 1: Because we're trying to drive the old people from our own site.

Turf Diseases 2011 Recap

Now that 2010 season is finally over, it is time for us here at Turf Diseases to recap some of the highlights from the past year. This week I will bring you some "Top Lists" for the website. I am happy to say that we have branched out beyond just what happens here in the United States. To the right you can see that although our focus audience is here in the states, we are reached 130 countries/territories in 2010.

Over 57,000 visitors (over 24,000 unique visitors) frequented the site last year (figure below). It was clear that there were a few hot spots in terms of times to visit. Needless to say it is obvious that things were tough in July and August and this caused many of you to I assume check out what was happening around your region and with other golf course superintendents as well.

The 2010 Top 10 List...
Some other things of note coming up this week include my version of Letterman's Top 10 for the following categories:

Top referrers to the website in 2010 (some of you made the list!)
Top Posts of 2010 (based on your visits)
Top Visits by Country (see how your country stacks up)

Special Turf Nerd Post (you could probably do without seeing this one)

What the future holds...

The 2010 season marked the first full year of our existence and we couldn't be more happy with the results. In fact, the success of this little blog site has inspired me to expand in 2011 with the hopes of something big by 2012 (sponsors beware). If you have any ideas on how we can improve the site (big or small), please feel free to share it with us in the comments below!
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