Mites, Weather, Australia, and Dollar Spot

I'm posting this from Australia where the winter is just beginning. At the Redlands Research Station near Brisbane today I saw plenty of dollar spot on seashore paspalum. Pictured is a plot of Sea Isle Supreme. These are the typical symptoms of dollar spot that occur when the growth of seashore paspalum is slow.

I also saw some interesting mite damage yesterday on bermudagrass (or green couch as it is called here). From a distance the area pictured below looked as if it were suffering from drought stress, but upon closer inspection these severely stunted shoots, so typical of mite damage, were found. Last year I saw mite damage at Bangladesh and wrote about it in this post.

At Thailand last week I visited four golf courses. There were two with zoysia greens and two with TifEagle greens. One had seashore paspalum fairways, one had zoysia fairways, another had bermudagrass fairways, and another had native grass fairways. I'm fascinated by the types of warm-season grasses that grow in different parts of the world, and clearly the weather has a lot to do with that. Some grasses thrive in one area, while others struggle. I put together a series of bubble charts that plot world cities by their climatological normals, the average weather data over a number of years.

I'll be updating these charts monthly on www.blog.asianturfgrass.com. As the northern hemisphere summer progresses, we will see that transition zone cities such as Atlanta, Osaka, Shanghai, and Tokyo move very close on this bubble chart to places where only warm-season grasses are grown such as Miami, Singapore, and Tahiti. The difficulty of managing cool-season grass during the summer is shown clearly when the average weather conditions are the same as in tropical cities.

From thaw to freeze, and back again, then back AGAIN again!

I don't really have any turf or disease info today, just thought I'd share our interesting recent weather.



You might remember my last post about thawing out... but I also mentioned upcoming weather fluctuations. It is one of those times of year when anything can happen here in the mid-continent. Arctic masses from the north, warm Gulf air from the south. Our record lows can be below zero, and record highs near 80, or even higher.

The graph above (click on it to zoom) shows our ACTUAL daily highs and lows here in Manhattan KS. Yup, that lowest line shows a minimum of -2.8F on Feb 10, and a max of 71.8 a few days later.

On Sunday, I went for a comfortable walk in sandals, shorts, and t-shirt. Two hours later, I was out on another walk with some friends and their dog. The wind had shifted, and though I had put on a sweatshirt, I was soon freezing.

On Wednesday it was a balmy 60 degrees again. I had the windows down for part of my drive down to Newton, KS, for a turf-and-landscape meeting.

Then, Thursday... snow! 3-4 inches. Oh, and under the snow, some sleety-ice nastiness.









Oh, and I stumbled across an article co-written by John about the use of blogs in turf. Since John didn't post it (at least I didn't see it... maybe I missed it?) you can find it here:

http://www.joe.org/joe/2011february/rb7.php

Lower temps may mean MORE turf diseases

This past week was busy for the turf pathologists around the country. I was very busy dealing with samples, our Research Field Day, and scathing emails regarding my post about bacterial wilt being BS and the Wall Street Journal Article.  I should definitely clarify (which I attempted to do in a comment to my original post) what I was talking about.  Here are a couple of comments that I received about these posts.

Email received about my post about the WSJ article:

"I recently read your blog titled “Melting turf and Turf Pathology meeting”.  And I was a little confused on some of your statements.  In the blog you stated your read the article in the Wall Street Journal.  Then you later state some diagnosis was BS.  Were your referring to something in the WSJ article was BS or was that an entirely different matter?  I am not questioning you, just trying to clarify what you meant because when I read your blog it came across you were saying the WSJ article was BS.  Which I hope wasn’t the case as that article has definitely helped me in my current situation."

I thought that the WSJ article was a great one and anytime the popular press covers an issue like turfgrass being hard to maintain due to the heat of the summer, I think that it is good for superintendents.  The issue related to BW was totally separate and had nothing to do with the WSJ article.  In my follow up to the email I also mentioned some errors in the article, but when I went back and read the article I realized I was talking about an article posted by Lane in a previous post where they called Pythium a bacteria.

Email received about my post of bacterial wilt being BS:

"Wow John, doesn’t sound to Scientific! Better start doing some research to make a real Diagnosis.  I was at APS also, you should have come by if you needed validation. [sentence omitted for privacy]

Explain the Etiolation please, sounds like Penn State might be rubbing off on you. Lane still can’t explain why healthy plugs die in three to five days. If he has to you please let me know. Heat and Humidity right???? Hope you aren’t teaching that."

So my response to this was probably a little harsher than it should have been and I realize that superintendents are under a lot of stress.  I also don't take anything personally and do my best to try to help any way I can...and yes, I love Penn State (this happened long before I took the job here though). However, this brought up a good point about the whole bacteria wilt issue.  I am not saying that a potential bacterial wilt problem doesn't exist, however, I feel that many diagnosticians and superintendents are using this as a go-to answer for problems that can't be explained. In many cases (generally about 35-50% of our samples annually), thinning and/or dead turf can not be attributed to a biological agent.  That doesn't mean that something can't be done, it just means that spraying a fungicide is not going to be the answer. In many cases, the issues are related to shade, poor air movement, poor drainage, etc. Addressing these issues often times fixes the declining turf problem. A problem with many diagnostic labs is that they know diseases and diseases only...finding a lab that knows something about turf and agronomics is important. Click here to see all the comments regarding diagnostic labs.

Dollar spot was raging this morning in State College, PA

On to the disease issues:
Temperatures are dropping around the mid-Atlantic and Northeastern US, but this may actually bring more diseases than less.  At the turf plots this morning at Penn State, we had active mycelium on both dollar spot and brown patch, algae raging, anthracnose active, red thread in low fertility areas, and probably other things that I didn't have a chance to check out.  I also received an email while typing that a superintendent in the area may have a new outbreak of brown ring patch on their greens.  Temps in State College were relatively low this weekend, but RH was very high and things exploded last night.  I am sure that many of you are experiencing the same thing in your region.

Here is the 10-day forecast for some cities around the region:

Albany, NY: mid 70's to mid 80's
Boston: Low to mid 80's with temps dipping to 77^oF on Thursday!
Philadelphia: ~90^oF for the next two days then mid 80's
Pittsburgh, PA: 77-85 with nighttime temps in the mid 60's/low 70's
New York: Temps ranging from 80 to 91^oF
Washington, D.C.: Fluctuating between mid 80's and 90^oF

Finally, I am working on our Compendium Giveaway and should have something up by next week. The giveaway is being sponsored by Syngenta and will give a reader the opportunity to win a copy of the Compendium of Turfgrass Diseases.  Syngenta will also be donating $1000 to the Turf Pathology Student Travel Fund of the American Phytopathological Society.

Heat + Rain = Dead Grass

First, let me welcome Lane back;

I hope your sabbatical was productive and recharged your batteries! Second, I would also suggest a corollary to the equation, No Wind + Heat = Dead Grass, and that is: Heat + Rain = Dead Grass.

Another area where stress begins to rear its ugly head is in the area of water management- too much, and not enough.

All too often, we see situations where relative humidity is high, and "hand watering" is done to "cool the plants off". Unfortunately, when RH is high, very little of the water

you put down will evaporate, and this creates the potential for several bad things to happen. As Lane described in his post, fans are incredibly important especially in the Southeast because of the need to reduce the local relative humidity so that the plants can manage the heat.

Fungicide programs are also showing excellent differences, and you can tell the difference between those that perform and those that miss a key disease this year.

To give you an idea of just how we are doing this year, a superintendent in TN sent the following out to his colleagues, and I thought it was interesting:

"Over the weekend I had some fun with numbers. I pulled all my weather records for my course for the past 17 years. I counted the number of 90 degree or above days in the months of June , July and August. Pretty interesting. In 2004 we only had 5 days at or above 90 the whole year. 2006, 2007 we had 40 and 47 days respectively. The highest we had ever had in June was 13 in 1996. The highest ever in July was 28 in 1993. The highest ever in August was 29 in 2007.
1993 must have been a rough year because we has 54 days total, but we were closed, rebuilding our greens that year so it didn't hurt me any.

On average we have had 6.8 days in June at or above 90, 11 days in July and 11.5 days in August.

This year we had 18 days at or above 90 in June and we have already had 18 days in July with a week to go.

The numbers are probably a little different in other areas, but by my measure, that had to be the most stressful June for at least the last 17 years and with the exception of 1993, it looks to be the most stressful July. By far the most stressful two month stretch during that time.

Pass this along to others if you think it will make them feel better. Or just remind them that we are all in the same boat, and that football season is getting closer every day."

It seems to me that golf provides an adequate analogy for taking care of turf under this kind of stress. We have all heard some version of the saying, "The person that misses it the best will win", and I think an appropriate version of that for a summer like this is, "The superintendent who knows how to lose a little turf will carry the day". Like he said, "football season is getting closer every day". Try to stay cool everyone!

Weather! What the...?

For those of you not paying attention to the weather in State College (as I am sure most of you don't), all I can say is WTH. State College received the earliest snow on record and it was not met with much happiness. For one thing, the leaves are still on all the trees and the heavy snow caused a lot of damage. The image to the right shows some of the damage that I witnessed outside the house on my way to work. In addition to this, I was without electricity for 2 days. This wouldn't have been such a problem except to keep warm, I had the gas fireplace going only to wake up in the middle of the night with the carbon monoxide detector going off. Needless to say, I had some trouble getting back to sleep that night!

SO...as you can imagine there are not a lot of diseases in State College at this point, but around other parts of the Northeast golf course superintendents are preparing for snow mold applications. According to this weeks survey, superintendents are also participating in the numerous early-season purchasing programs offered by many of the manufacturers. This is one area that is gaining popularity and a few researchers are putting together programs related to the economics of turfgrass management.

SO...as I have tried to do all year (with little success due to the lurkers in here), I will once again try to find out what you (our readers) are planning for next year. For those of you buying on the early-order programs, what is it that you are looking for and how do you plan your purchases for the upcoming year?

If you feel inclined to do so, feel free to leave your answers in the comments.

AND...for those of you lurking and not feeling like answering, you can check out what others are doing with some superintendent blogs that I like to read!

http://therimgolfclub.blogspot.com/
http://cccpgcm.blogspot.com/
http://ergcm.blogspot.com/
http://geccgcm.blogspot.com/
http://creekmoormaintenance.blogspot.com/
http://greensuper.blogspot.com/
http://pinetreegm.blogspot.com/
http://sandstonegolf.blogspot.com/
http://sgccturf.blogspot.com/

New Design...Same Old Problems

If you have visited the Turf Disease blog in the past, then you will notice that the layout and overall look has changed. A few of the things that are new include:

1. Information buttons (top right): These buttons serve various purposes, but mainly allow you to access the blog by RSS subscribtion or via twitter, view disease images on our new flickr Turf Disease group, or share this information with others through Digg It, Stumble, and Technorati.

2. Search bar (top right): A search bar has been added that allows you to search the site for any topic that you may be interested in.

3. Navigation buttons (bottom left of header): We have added navigation buttons to help you select the content that is appropriate for you. These buttons include links to the home page and to each regional update section (NE = Northeast; SE = Southeast, etc).

4. Image Gallery: Perhaps the most useful addition is the image gallery link which contains various disease symptoms and pathogen signs that are used for identification purposes. We are contstantly working to increase the number of images in the gallery and will add more diseases as photos become availabe.

5. Disease Poll (right column): In an attempt to get the superintendents more involved in the blog, we will periodically post a poll to find out what troubles most are seeing in the field each week or other questions related to turfgrass disease management. Results of the poll are presented in real-time and this gives everyone some indication of what others may be seeing.

OK, as for diseases in the Northeast:

As you might expect, the warm weather and periodic rains are creating conditions favorable for your typical summer time diseases. Brown patch and Pythium are high on the list of potential problems in the field. While others may have seen summer patch for the several weeks, the first case that I had seen all year was last week in Pittsburgh. Also active in the Pittsburgh region was dollar spot and leaf spot.

Following a visit to the Buffalo area, last week was met with some cool morning temperatures and disease activity was relatively low. The only issues noticed was some dollar spot activity in the rough. The 10-day forecast has low and high daily temperatures of 60 and 80, respectively for that region. Throughout much of the Mid-Atlantic and Northeast, temperatures run a steady gradient from the upper 80s-90F in the Maryland region to the upper 70's-80F in Portland, ME. Along with these higher temperatures is the threat of precipitation which should bring along some serious disease pressure as we head into the home stretch of the season.

KEEP in mind that the threat of rain that can disrupt your ability to make preventive or curative applications should be monitored. Your window of opportunity to target serious diseases throughout August may be short and you should take advantage of any chance you get to take action.

Where is the summer heat?

Diseases normally typically appearing at this time of year will likely be on hold for another few weeks as temperatures in the Northeast continue to remain low. The main diseases that I have heard throughout the region include those typically seen in the spring. These include the leaf spots, red thread, take-all patch (although this will likely get worse when the heat does arrive), dollar spot and a reported case of copper spot in Jersey. Leave a comment below and tell me what you are seeing in your area.

For those of you dealing with dollar spot, please send some to State College! The disease showed up in typical fashion in early June and then just sat there. I walked my plots today and there was only about 10 infection centers in my untreated plots...not good for disease research.

I am still sticking by my guns and predicting that brown patch will start to move into the warmer parts of the region within the next week or so. This is also a good time to start (if you have not already) applying Pythium controls for your turf. Applications of the phosphite products have been successfully used to control Pythium on fairways, but preventive applications are necessary. On greens, the phosphites can effectively suppress algae (again when applied preventively). If the hot weather does come in fast, you will want to make sure you are covered for the hot weather diseases.

Finally, keep an eye out for next month's "PlayTurf" cover and the special interview guest. I will also be reporting on @johnkaminski from Saucon Valley and the Women's U.S. Open.

The Phantom Leaf Spot / When is it Going to Warm Up!

Not much going on in the Midwest. The weather has remained strange the past couple weeks. With day time highs in the mid 60's and lows ranging from the mid 30's to the mid 50's. Soil temperatures range from 58 F at 4 inches to 63 F at 2 inches in native soil areas. We are seeing a lot of leaf spot symptoms, but surprisingly enough we are not seeing a lot of spores in the samples. The samples have the characteristic reddish color with necrotic spots on the leaves, yet little to no sporulation on the leaf tissue. This has made diagnosis difficult because the plant and stand symptoms point directly at a leaf spot, but no signs of the pathogen. Each person that has submitted a sample has assured us that the area was not sprayed prior to submission.

However, if you do suspect leaf spot problems than an application of iprodione and chlorothalonil will do the trick, especially if the recent weather pattern continues. The forecast for this week if for warmer weather and more sunshine, which is usually the best medicine for leaf spots.

Turf managers that experienced winter kill are still trying to get areas to fill in. Because of the most recent weather pattern creeping bentgrass and annual bluegrass growth has been very slow. Going back to one of John's earlier posts, the weather drives almost everything in golf course management. The best quote I've heard this spring is from Pat Sisk "We need to be patient, we can put down everything we have but if the turf isn't growing than its not gonna work."

If I made magazines...

...then June's centerfold would be Sclerotinia homoeocarpa (not Candice Cassidy).

Dollar spot is starting to show up throughout the region. As you all know, this disease is a chronic problem for most and once established it can be tough to get under control. Some cultural and chemical strategies to help manage dollar spot are:

1. Remove dew whenever possible. Extended periods of leaf wetness has been shown to drastically increase the incidence and severity of dollar spot. If you can't remove dew from all fairways, at least consider removing it from the worst.

2. Tickle the turf with N. The belief that nitrogen will completely eliminate dollar spot just doesn't hold up. However, providing adequate nitrogen in the spring to encourage growth and then spoonfeeding N during the summer can help to reduce the severity.

3. Choose your PGR's wisely. Not all plant growth regulators are considered equal when it comes to dollar spot. In general, trinexapac-ethyl (Primo MAXX, others) is not going to provide significant control of dollar spot. However, paclobutrazol (Trimmit, others) or flurprimidol (Cutless) have direct fungistatic impact on the pathogen that causes dollar spot and these PGRs can significantly reduce disease severity. Routine applications of these PGRs are also great for those of you wanting more bent and less Poa.

4. Utilize preventive fungicide applications. When managing dollar spot, preventive fungicides are key to keeping it under control throughout the season. Curative applications often require higher label rates and short application intervals, so preventive applications can actually REDUCE your pesticide use and environmental impact over the course of a season.

While this brief list can help you reduce disease pressure, you may need to consider some other things as well including: fungicide resistance; species selection; sprayer nozzle type and application volume; among others.

Weather forecast for this week:

Connecticut
CT Shoreline: highs of 62-70; partly cloudy with chance of mid-week showers
Hartford, CT: highs of 72-78; mostly sunny, isolated showers Wed/Thur

Maryland/VA
Washington, D.C.: highs of 73-83; chance of isolated showers mid-week

Massachusetts:
Boston, MA: highs of 63-75; sunny to partly cloudy with chance of showers Wed
Springfield, MA: highs of 72-78; mostly sunny with chance of showers Wed

New York
Albany, NY: highs of 67-77; mostly sunny with slight chance of precip on Wed
Buffalo, NY: highs of 62-73; mostly sunny with chance of showers
Westchester, NY: highs of 70-79; chance of showers mid-week

New Jersey
Cape May, NJ: highs of 68-81; chance of showers all mid-week
Far Hills, NJ: highs of 73-82; sun and clouds with slight chance of rain mid-week


Pennsylvania
Philadelphia, PA: highs of 72-84; chance of isolated showers mid-week
Pittsburgh, PA: highs of 68-79; slight chance of showers on Tues/Wed (GO PENS!)
State College, PA: highs of 69-78; chance of showers on Wed

Way the heck up there
Burlington, VT: highs of 62-76; partly cloudy with slight chance of scattered showers
Portland, ME: highs of 60-71; sunny to partly cloudy with scattered showers Wed
Rumney, NH: highs of 61-75; mostly sunny with slight chance of showers Wed

Weather and golf course diseases

Anytime we talk about any plant diseases, we can't help discussing the disease triangle. A prerequisite for any disease are a suitable host, a pathogen, and the proper environmental conditions. While the presence of a host and a pathogen are important, the current and future weather is usually considered the most important factor (I will save the discussion about the importance of the host plant and pathogen for a future blog).

For golf course superintendents, monitoring the weather is usually high on the priority list of daily tasks. Conditions can change fairly quickly and encourage the rapid development of turfgrass diseases. To assist, turf pathologists have developed predictive models for a handful of turfgrass diseases. While none the models are perfect, they do provide managers with useful information about what diseases may possibly be on the horizon.

As we begin to enter the period in the Northeast where turfgrass diseases become more prevelant, take some time to check out the following site that provides weather-based predictions for various turfgrass pathogens.

Cornell's Forecast

Currently in the field: take-all patch, dollar spot (just starting), brown ring patch, leaf spot, anthracnose basal rot, red thread, and Microdochium patch.

Get ready for: dollar spot and summer patch (preventive applications).

Do you know of other disease prediction websites or services? Post links in the comments!