Lots o' Heat and Brown Patch

Well it looks like most of the country is in the grip of this heat wave now. We are working on day 29 of days over 100 F for 2011. According to the Oklahoma Climatological Survey map, we average approximately 15 days per year over 100 F. Our record is 50 days and we haven't even made it to August when we typically have our "hot and dry" weather. So….it is going to be a tough summer season again this year.

In our diagnostic lab we are getting a lot of creeping bentgrass samples with high nematode populations and/or suffering from good old summer stress symptoms. I predict that these issues are going to persist for us for the near future and putting greens will continue to become increasingly stressed. Remember, if you have that “big tournament” coming up and the membership is asking how fast they will be rolling, remind them to expect slow. The last thing you want to do during the weather we are having is try to make the greens roll ultra fast and throw a bunch of traffic on them when it is 105 F and the wind is blowing 25 mph! Again I say slow greens are better than no greens. Hopefully everyone has their smooth rollers on and they have reduced mowing as much as they can to manage plant stress. Be sure to have a good preventative fungicide program in place for Pythium diseases and brown patch.

Speaking of brown patch, we have a pretty good epidemic going on most of our research putting greens at the Turfgrass Research Center in Stillwater. Last week we had several evenings that we had humidity above 85%. For the entire month of July we have not dropped below 72 F at night in Stillwater. These conditions have been perfect for brown patch development. As most of you already know, preventative fungicide programs are the best strategy for managing the problem. So what is a good program for the Oklahoma area? Well, each year we conduct various dollar spot and brown patch trials on creeping bentgrass putting greens. These programs are often elaborate and often not cheap! Here are some brown patch data from our 2010 program trials. These trials were on a 'Penncross' putting green with a USGA sand/peat base located at our Turfgrass Research Center in Stillwater. Brown patch data were most severe on the July 16 rating, so I'll focus on that rating and on only the products applied up to that rating. You will find the products and the application dates in the table. Note that all applications were on a 14-day interval. For good control of both dollar spot and brown patch we don't recommend stretching your fungicide interval much past 14 days in our neck of the woods. Also, the DS ADVISORY treatment was an experimental exercise where we were targeting control of only dollar spot by advising sprays using a statistical model. Therefore, no brown patch products were applied resulting in high levels of brown patch.

So what happened? Well, highest levels of brown patch were recorded in the non-treated check plots with an average of 60% of the plot area symptomatic. Somewhat lower levels of brown patch were recorded in plots treated according to the ADVISORY program, but remember this program really doesn’t count when we are talking about brown patch control. All other plots treated with fungicide had significantly lower levels of brown patch and were not different from each other. Although, the OSU2 program had the lowest levels of brown patch (5% severity). Average turfgrass quality was lowest in plots not treated with fungicide and was considered unacceptable. Marginally higher levels of quality were recorded in plots treated by the ADVISORY. All other plots treated with fungicide had the acceptable levels of quality, however, the BASF1 and BAYER1 programs were a bit lower than the others. No symptoms of phytotoxicity were observed. So what this demonstrates is that if you start off with a good preventative fungicide program and make a reasonable decision about the products relative to the pathogens you expect to control, you will be reasonably successful at managing a disease like brown patch.

How do you prepare for the weather?

First, I'd like to welcome Maria Tomaso-Peterson to the blog. She posted the other day and you can catch it here if you missed it.

It's been a while since I have sat down and looked at the weather since I've been traveling, but I got a quick glimpse of what Megan, Jim, and Damon were referring to when I looked at the forecast for this upcoming week. According to weather.com's 5-day forecast, temps are going to peak Thursday through Saturday and everyone from Washington, D.C. along the coast and up to Boston are going to be hit with temperatures in the high 90's to over 100.

As we move into the heart of the summer, we have to watch out for the typical diseases such as brown patch, summer patch, Pythium and the like. After a good lesson that many golf course superintendents had last summer regarding how much their turf can be pushed and perhaps what to do to prepare, I decided to call out to those on twitter to ask the following:

"...how are you preparing for the upcoming weather. 140 or less."  

(for those of you losers not on twitter, '140 or less' refers to the number of characters you can type).  

 

As you can see from some of the posts, people find different things important, but a few things that stood out to me included the importance of irrigation, communication, and maybe a little prayer. Thanks to the following twits for helping (sorry if I missed yours): Greg Shaffer, Mike Jones, Bob Porter, Sam Green, and Ryan Cummings. If you're on twitter, be sure to follow these turfers.

Leave in the comments anything else YOU can add to the list of preparations prior to a major heat wave!

Regional Updates:
USGA Northeastern Update
USGA Mid-Atlantic Update

Weather forecast video

Dead Bentgrass Makes Headlines

Well, you know things are rough when the local media is writing about Pythium, aerification, and MiniVerde bermudagrass. Unfortunately that's where we are here in North Carolina and many other parts of the southeast. Check out the following article from last Thursday's Charlotte Observer: 


Hot Weather Turning Putting Greens to Toast


Overall, I think its a pretty accurate description of the struggles that golf courses are facing in the region. I'd be curious to hear everyone's thoughts. There are also a couple of factual errors in the article. I'll give a prize to the first people to point them out by leaving a comment on this post!


A lot of people have been asking about converting their greens to ultradwarf bermudagrasses. They are definitely a good option in certain situations, and several courses in the area have made the switch with great success.


My only advice is this: if you can't maintain good bentgrass greens because of problems with shade, air movement, or soil drainage, then you won't be able to maintain good bermudagrass greens either. The courses that have been most successful in converting to ultradwarfs also removed trees, improved air movement, and corrected drainage problems. Who knows, maybe bentgrass would be doing just fine with these improved growing conditions?

Heat wreaking havoc on golf courses nationwide

A message from Clark Throssell and the GCSAA!

Prolonged periods of high temperatures, and in some cases, excessive rainfall, and high humidity have made life uncomfortable for golfers and golf courses alike, with Mother Nature holding all the cards for true relief.

"The simple fact is the cool-season turfgrasses such as bentgrass, fescue, bluegrass, annual bluegrass (Poa annua) and others are stressed when temperatures climb and humidity is high," Clark Throssell, Ph.D., director of research for the Golf Course Superintendents Association of America, said. "Golf courses in many parts of the country experience this every year, however what makes the situation so dire this year are the high levels of extended heat and humidity, and the sizeable part of the country affected (Midwest, Mideast, Northeast and Mid-Atlantic)."

According to Throssell, golf facilities and those entrusted with managing the golf course – golf course superintendents – are not alone in this battle with the elements. However, the nature of their product makes their challenge greater.

"We are certainly seeing homeowners, athletic fields and businesses suffer turfgrass damage brought on by the conditions," Throssell said. "What makes it more difficult for golf facilities are the mowing heights are much lower and traffic is much heavier. That just adds to the stress on the turfgrass."

Throssell indicates that golf course superintendents are addressing the issue with a variety of management practices to make sure turfgrass survives. While there may be some short-term impact on playability of the course, the alternative is the loss of grass, the closure of the course and the additional costs of re-establishing playing surfaces (primarily putting greens).

He also cautioned golfers from thinking that water, whether from rain or irrigation, is the answer to the ills. There is a difference between heat stress and drought stress. Adequate irrigation will alleviate drought stress. Adequate irrigation will not alleviate heat stress. It is not only possible, but likely, for a turfgrass plant to be adequately watered and still suffer from heat stress under extended periods of high temperatures.

Among the practices that superintendents are implementing to manage golf courses include:

•Raising the mowing heights of playing areas, most notably putting greens.
•Alternating daily practices of mowing and rolling putting greens, with consideration to skipping a day if the schedule of play allows.
•Forgoing double mowing, topdressing, verticutting or grooming greens.
•Watering to provide adequate soil moisture, but not over watering as saturated soil will cause the turfgrass to decline rapidly.
•Hand watering as much as feasible. If a green has a dry spot or two, superintendents will hand water the dry spots only and will not water the entire green. When the entire green shows stress from a lack of water, superintendents use the overhead sprinklers and water the entire green.
•Avoid aerifying using large diameter tines that penetrate deeply into soil and remove a core of soil. If a superintendent feels the putting surface is sealed, venting using small diameter solid tines or other similar technique is employed.
•If fertilizer is required, small amounts of fertilizer are applied via a sprayer and observation of the response occurs before fertilizing again.
•Monitoring and adjusting golf car traffic patterns to minimize stress to turf.

Throssell indicated that during periods such as this, it becomes easy to compare golf course conditions and pressure decision makers into actions that might prove detrimental to the long term health of the playing surface.
"Communication is vital," Throssell said. "Superintendents, golf professionals, owners, managers and others must be in constant contact with golfers to educate them on what is happening at the facility. But golfers must also understand that golf courses are like snowflakes – no two are alike. Some courses may be able to withstand the challenges of Mother Nature better than others because of better drainage and soil conditions, better air flow due to the placement of trees, less traffic or the presence of greater financial resources.
"We know the weather conditions will become more agreeable. What is important right now is to manage the golf course in a manner so that turf can be kept alive until that point."
GCSAA is a leading golf organization and has as its focus golf course management. Since 1926, GCSAA has been the top professional association for the men and women who manage golf courses in the United States and worldwide. From its headquarters in Lawrence, Kan., the association provides education, information and representation to more than 20,000 members in more than 72 countries. GCSAA's mission is to serve its members, advance their profession and enhance the enjoyment, growth and vitality of the game of golf. The association's philanthropic organization, The Environmental Institute for Golf, works to strengthen the compatibility of golf with the natural environment through research grants, support for education programs and outreach efforts. Visit GCSAA at www.gcsaa.org.

For more information contact:
Clark Throssell, Ph.D., GCSAA director of research, 800-472-7878

Spray, but watch the burn

With temperatures in the high 90s or even triple digits throughout many parts of the mid-Atlantic and Northeastern United States has many scrambling to protect their turf from potential diseases. In addition to the uncharacteristic high temperatures is equally unusual low relative humidity. One common thing in calls that I received this weekend was that everyone was scrambling with hoses.

Another interesting point that I generally don't think about when applying fungicides for field studies is the potential for burn when spraying. In many trials, we only apply a couple of products at a time and rarely mix to the degree that many golf course superintendents. I always joke at meetings about how the record number of items that one superintendent put in the tank was 23! So in light of this and in light of the fact that many are trying to get that next spray out, I received a couple of questions about potential burn when spraying.

In a past post, Lane spoke about the potential negative impact of some of the DMI's on cool-season turf in the summer. In past trials, we have seen some severe leaf tip burning when certain products are mixed together. One product that has gained in popularity is the various phosphites on the market. In some field work, we found that these products can be "hot" and burning can occur specifically when these are mixed with certain products like the DMI's as well as PGRs. Additional things to consider include the use of wetting agents and other products that can add to the potential for phyto. Please leave us a comment or follow the discussion that I started on the Facebook Page here.

Finally, I received a call from a couple of golf courses this week that were concerned about some uncontrollable summer patch on their greens this week. While summer patch may start to show up in this weather and would be fairly typical for this time of year, I call attention to a post on an unusual Pythium species that I wrote about last year. This is something that is relatively new and little is known about it. I can say that it is a real issues, however, and those of you relying on Signature for your sole Pythium control should read this post!

For those of you that follow the LPGA, check out this week's US Women's Open at Oakmont. I am here in the hotel now and ready to spend the practice rounds with John Zimmer's staff and the USGA. Wake up call tomorrow morning at 3:30AM...I am rooting for Christina Kim who just missed out on a win this past week in a four-way playoff!

Check out these photos from last year's Women's Open at Saucon Valley

It's gettin' hot in herre ....

Too dry? Too wet? Both can be trouble!
With temperatures hitting the 90s and 100s in many parts of California, summer stress & water management on greens are becoming more and more of an issue. As soil temperatures start to get into the 70s, cool season turfgrass – like creeping bentgrass and annual bluegrass - starts to slow or even shut down physiologically.

(Photo by Bob Vaughey, GCS, TPC Valencia)

Hot dry conditions can damage plants by pushing them past the point of permanent wilt, killing plants in the process. On the other hand, water saturated soils can lead to anaerobic conditions in the rootzone and superheating of the top layer of soil, effectively cooking plants on greens.

A key to summer heat management is the judicious management of irrigation. Creeping bentgrass can tolerate wilt and drought stress to a higher degree than annual bluegrass, while annual bluegrass still requires light frequent irrigation to compensate for the shallow root systems.

An important part of managing both turf species is syringing with light amounts of water during the hottest parts of the day. A light misting on plants during the day can drop canopy temperatures several degrees. On very hot, dry days, syringing can be performed a few times a day between play to maintain canopy temperatures at an acceptable level. However, if you overwater these areas (which is easy when irrigation technicians are aggressively trying to manage hot spots) – you can end up oversaturating the soil profile with water and scalding the plants.

A Shout out for Fairy Ring
Fairy ring and the development of localized dry spots can further complicate water and plant management on turf. Professor Mike Fidanza (Penn State University), one of the nation's experts on fairy ring, will be presenting a short web seminar on fairy ring this next Tuesday, July 21 from 1:00 – 1:40 PM EST (that's 10:00 – 10:40 AM for us West Coasters). Check out this link for more information: https://www2.gotomeeting.com/register/512391482

What Else is Going On?
Here in California, summer patch and anthracnose on annual bluegrass are starting to roll into the diagnostic lab at a higher frequency. No great surprise given the high tempertures we're having in many parts of the state. Southern blight is firing on a few locations in southern California, and Pythium is active in the Central Valley as night time temperatures are staying above 68F at night.

All I can say is batten down the hatches, because we're a long way away from the Fall and the summer disease season is only getting started here.

Signing off from the Left Coast until next week!

P.S. - I couldn't think of anything scatalogical for this week's update. Megan, the door's wide open for your Friday update if you so desire.