It's Conference Season

Conferences are a great way to find out the latest research results from Universities and independent researchers in your region. Organizers generally arrange for a variety of different speakers and topics ranging from disease management to weed management to cultural management practices.
Although I have only been to a few conferences so far this year (with many more to come), they have all been full of useful information for turf managers. Below are some highlights of the most recent talk I heard:

Anthracnose basal rot (Dr. Jim Murphy, Rutgers @ Eastern PA Turf Conference): Dr. Murphy summarized some of the research that he and Dr. Clarke have been working on over the past few seasons. The most surprising results are that many of the traditional recommendations provided to turfgrass managers have actually been wrong. Some findings of their work include:

1. Topdressing can actually help to reduce anthracnose (presumably by burying and protecting the crown of the plant)
2. Greenspeed can be maintained and anthracnose reduced by increasing N fertility and rolling instead of lowering mowing heights
3. PGRs commonly used for suppressing annual bluegrass seedheads do not increase disease incidence and in certain years have decreased disease severity
4. Extremes in irrigation (too much or too little) can exacerbate disease activity

Over the next few months, associations around the country will be hosting various educational events.  Take advantage of these opportunities (and don't forget to bring your assistants too) to find some "nugget" of information that may help you this season.

To view some of the upcoming events that may be in your area, check out our calendar page.

Disease Update:
The snow has melted in many parts of the Northeast following some warmer weather revealing Microdochium patch and cool-temperature brown patch.  Golf course superintendents from around the area should also be cautious about the lack of protection on the exposed turf AND also watch out for any rapid thawing/freezing of ice...especially where annual bluegrass populations are high.

As for me, I am listening to the updates of the unusually cold and snowy conditions at the British & International Golf Greenkeepers Association meeting (Harrogate) in England.  Hopefully I will be able to give an International Update in the coming weeks with any useful information obtained from the meeting.

Signing off from the large island across the pond...

The Wow Factor, Seashore Paspalum and Dollar Spot

I hear or read a lot about the "Wow" factor of seashore paspalum (Paspalum vaginatum) in reference to the vibrant green color of the grass, but not so much about the other "Wow" factor associated with seashore paspalum -- it is highly susceptible to dollar spot. And it is dollar spot season now in many parts of Southeast Asia, with temperatures cooling down to 22 or 23 °C at night (about 73 °F) and rising to about 32 °C (about 90 °F) in the afternoons. During the hotter times of the year, when nighttime temperatures are warmer and rain falls more frequently, I see less dollar spot.

Why is that? You may not think these temperatures are cool, but this is the coldest time of year at places such as Bangkok, Ho Chi Minh, Manila, and Hong Kong, so the warm-season grasses (including seashore paspalum) grow a little bit slower. Also, this tends to be the dry season in parts of Southeast Asia, and seashore paspalum eventually slows its growth under deficit irrigation (applied irrigation less than evapotranspiration). So we have plants that are growing a little bit slower, slightly cool nights at an ideal temperature for the dollar spot pathogen to grow, and a susceptible host. It doesn't snow here (One of the many reasons I chose to work in Asia was because of the salubrious climate, so I savor my memories of snowy winters while I enjoy my winters in tropical climates) but sometimes the dollar spot is so severe that a fairway can look as if a light snow has fallen. That is the other "Wow" factor of seashore paspalum.

Seashore paspalum is generally quite susceptible to dollar spot, although there are differences among cultivars. Dr. Bryan Unruh's research with different seashore paspalum varieties in Florida (the research paper is available for download here) shows big differences among cultivars. SeaIsle Supreme was especially susceptible to dollar spot; SeaDwarf and SeaSpray were among the varieties with the lowest incidence of dollar spot. Dr. Philip Harmon has written a good reference on seashore paspalum diseases. That article was just published in the Green Section Record (download Challenges and Opportunities: Disease Management for Seashore Paspalum in Florida).

In the warmer parts of Southeast Asia, where the nighttime temperatures rarely drop below 20 °C, dollar spot on seashore paspalum can usually be managed (at least on tees and fairways) with minimal fungicides. If we can accept some damage from disease, applications of fertilizer and water to stimulate more rapid growth will usually allow the turf to grow faster than the dollar spot can damage it. In cooler parts of Asia, where seashore paspalum growth is more restricted in winter, then fungicides may be required to control the disease. On greens there is rarely a situation when the risk of severe dollar spot infection can be tolerated, so fungicides are almost always required on a preventative basis.

My management suggestions are:

• monitor the turf growth rate and scout for dollar spot daily
• on fairways and tees, apply fast release nitrogen (sources such as ammonium sulfate, urea, or calcium nitrate work well) to stimulate growth when dollar spot infections are more than you wish to tolerate
• ensure that soil moisture levels are in an optimum range for seashore paspalum growth
• on greens, follow the same practices and use fungicides as necessary to control and prevent additional infections

One thing to note is that bermudagrass and zoysiagrass are relatively immune to dollar spot in Southeast Asia. On golf courses I have never seen that pathogen on those grasses. So keep that in mind when choosing grasses for your course. If seashore paspalum is chosen for the "wow" factor of color, you may also see the "wow" factor of snowy fairways. With zoysia in January (see below), very little maintenance is required but the grass provides a great surface.

Now I remember....

For those who live in southern California, we know that the land of palm trees and plastic surgery is far from perfect. Smog, traffic, eathquakes, and high housing prices (plus a >$20 billion state deficit) make us often say "why are we living here?"
















(image from the LA Times)

After this last week of being in the east coast, now I remember. It's in the mid 60s to mid 70s in southern California and mostly sunny. Even in chillier northern California, it's still in the 60s.

Meanwhile, Iowa is getting buried by snow, it's -50F in the Dakotas, and it's been in the 30s all week long in Alexandria VA where I've been. Even in Florida, apparently it's so cold that"Iguanas are falling out of trees."

http://abclocal.go.com/kabc/video?id=7206353&rss=rss-kabc-video-7206353



Meanwhile in the Wong Lab, it's been quiet since we're just getting back on track from being away for the winter break and mandatory furloughs. Expect rapid blight, dollar spot and Rhizoctonia large patch to be the problems of the week throughout most of California.

Question of the Week



Hey Frank,

I stumbled across an article talking about Kikuyu Yellows (Verrucalvus flavofaciens). It appears to be exactly what happended to my fairways this last summer. Have you done any research on this?

Jeff @ da' Bell

Hi Jeff -

No, I haven't heard of this - but thanks for bringing it up to my attention. Apparently this is a disease described in Australia caused by a oomycete pathogen that's pretty different from other oomycetes (like Pythium) affecting turf.

http://www.pitchcare.com.au/magazine/article/74

This disease has not been reported in the Americas as far as I know of. We haven't seen oospores in yellowing kikuyugrass roots in samples from California - but we will be on the look out since you bought it up to our attention!

I did do some searching on the internet and found this:
http://www3.interscience.wiley.com/journal/120784659/abstract

Apparently you can also get this by Googling "Kikuyugrass", "Wong" and "Dick".

That reminded me that every once in a while you should google your own name and the term "a*****e" just to make sure no one out there is really upset at you.

Ok - thanks for the info and read - good stuff that I didn't know about!

Cheers,
Frank

Signing off from the Right Coast until next week....

Brrrrrrrrrr......Allow me to introduce myself

For those of you following Lane Tredway on the Turfgrass Disease Blog, I hate to disappoint you, but I will be guest hosting while Lane is off traipsing across the continents in search of those elusive turf pathogens. My name is Brandon Horvath, and I am a professor at the University of Tennessee in Knoxville. I was previously at Virginia Tech and located down in the Virginia Beach area, so I have been calling the transition zone my home for the last 5 years. In all seriousness, Lane will be making posts as an international blogger, since he is on his well-deserved sabbatical, and we here at the Turfgrass Disease Blog wish him safe travels.

So, I found myself wondering what I would discuss for my first post, and it looks like Mother Nature has decided for me: Wow! It's been really cold! I was in Michigan prior to moving down South, so the cold here is not too bad, but as my 4 year old, Alex, likes to say, "Daddy, its super, super, super, super, cold out!" That's kind of what I would like to think the bermudagrasses (esp. ultradwarfs) have been saying too, especially if you're in a situation where covering is a labor-limited situation and might not have been able to put the covers on fast enough. Here in Knoxville, the temperatures have hovered for the last couple of weeks with highs in the low-mid thirties, and lows in the teens. The real question that I am sure is not lost on many of you dealing with these conditions is, "Will my turf be alive in the spring?" The short answer is that we don't know enough to predict with a high degree of accuracy how bermudagrasses handle the cold. The newer varieties with improved cold tolerance (Riviera, Yukon, Patriot, etc.) haven't really seen much of these kinds of conditions since their introduction to the market, so it will be interesting to see how they fare next to standbys like 419 and Tifsport. The ultradwarfs (TifEagle, Champion, Mini-Verde, etc.) have moved somewhat North since the last major cold winter, so that will be interesting to observe too. I suspect that the really wet, soggy conditions at the end of the season, and the cold snaps we have had this winter are going to make for some pretty poor bermudagrass conditions this spring when it comes out of dormancy.

Many of you are probably already thinking, "So, how do I know how bad it will be, and can I do anything about it?" One of the easiest things you can do over the next couple of months will be to collect a few samples from turf areas you are worried about (e.g. shady areas on a fairway, low spots that collect water, etc.) and a few samples from areas that consistently perform well (e.g. well-drained areas, full sun, etc.) and begin to bring them inside and acclimate them to warmer conditions. The first step would be to bring them into an unheated, cold area sheltered from the elements in the maintenance facility. After a few days of slightly warmer temps, move them to an area that is warmer, but still cool (e.g. heated equipment storage areas). Following a few days, move them into a warmer area yet, and finally into an area in the shop that is warm enough that the plants (if alive) will begin to green up. You will need to keep them watered, not saturated, and monitor them for growth. Doing this every couple of weeks over the next few months will give you a good idea whether you will need to reserve some sod or sprigs for re-establishment or if those nightmares you had about whole fairways being dead was really just a bad dream. The important thing is to remember that by having some advanced warning of what you might be in store for will help you prepare your membership prior to any damage, and this will be a silver lining in an otherwise dark cloud.

I am looking forward to posting regularly on the blog, and look forward to hearing from many of you about problems and questions you might have as we tackle what's in store for 2010!

Colder than a witches...

...well you know the rest.  (Had to start with that as one of my former students at UConn heard it for the first time from her dad this past weekend).

Posting updates in the winter is a tough task as things are getting busier with conferences and classes start next week, but I wanted to at least provide a brief "weather report" for the region.  If you want to watch the real report, you can do so here.

Since talking about turf diseases is pretty much a bust in the Northeast region at this time of the year, I thought that I would revisit some things within the website that you may not be familiar with.  Here are some things that you may have missed...

1. Did you know that you can view images of turf diseases in our photo gallery?  Check it out here... or click on the camera logo at the top of the page.
   
2. Want to find out what turfgrass conferences are coming up?  Check it out here... or click on the calendar logo at the top of the page.
3. Have you missed some updates from GCSAA? If so, you can click on the GCSAA logo and get all the latest headlines from the various departments of GCSAA on the twitter feed.

Have you STILL not signed up for twitter?  Well, it's 2010 and I suggest you get with the times (or not)...either way, if you have an account, you can now follow turfdiseases or a group of others in the turf industry with one click (it may be 2 or 3, but who's counting).  Click below to follow more turfers...



OK, that's it for the first Monday of the new year.  As we progress through the year, please feel free to let us know how we can make the site better (by email or as a post in the comment...which ever works best for you).