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The turf is chillin'

I was at Oklahoma State University yesterday to give a couple of presentations at a tree workshop. ("Are you pining for healthy pines?" hah, clever, eh?? maybe not...). My OSU colleagues Damon Smith (plant path), Eric Rebek (entomology), and Mike Schnelle (hort) were great hosts and they also gave some excellent presentations.


Just outside the door.... was the OSU turf research center, and I was excited to find this symptom (in the above photo) in some bermudagrass.

What is going on here?

This is a form of chilling injury. Chilling injury like this usually occurs when temps are between about 32 and 54 degrees. Symptoms tend to appear 24-48 hours after the chilling event. The bleached out areas are due to degradation of chlorophyll. Why the funky pattern? Nobody knows for sure, but it may have to do with small-scale differences in where the coldest air settles.

Ohio State has a collection of podcasts, and there is one that addresses chilling injury.,com_wrapper/Itemid,78/

Then, go to the December 2006 section of the archives (blue list on the right).

Or, go to this site:

And scroll down about halfway and you’ll see the file for Chilling Injury. You can click and either run it or download it to view later.

The Most Wonderful Time of Year

We are in the midst of snow mold season in the Midwest, or at least Paul and I are traveling all over Wisconsin, Minnesota and the Upper Peninsula of Michigan. This year we have two sites in Minnesota- Edina Country Club in Minneapolis and a golf course in Baxter. The site in Baxter Minnesota is 100 miles from Fargo North Dakota and we have ventured up there to get a better handle on snow scald control. We received a lot of samples from that part of the country and superintendents have had difficulty controlling that disease.

We have two sites in Wisconsin-Sentryworld Golf Course in Stevens Point and Milwaukee Country Club in Milwaukee. Sentryworld is our old faithful site as it usually yields good snow mold pressure every year. However, we found out last year that treatments that work in Stevens Point may not necessarily work under extreme pressure. So we decided to venture to the UP of Michigan. Last year the snow mold pressure was intense in Champion Michigan and I suspect it will be again this year. We travel to all these sites to provide golf course superintendents the best possible recommendations for snow mold in there area. So check back with us next year when we finalize our trials, should be interesting.

On another note, I agree with Frank- the flu sucks! I have come down with the flu and I think it is the first time I have had the disease. Wow does this disease take the wind out your sails. I know I promised posts on all the different snow molds and I will do so starting next week. Sorry for the short post this week.

Effects of DMI Fungicides on Bermudagrass Putting Greens

Those of you that follow this blog know that I am not a big fan of using DMI fungicides on creeping bentgrass and annual bluegrass putting greens during the heat of summer. The impacts of these fungicides on bermudagrass greens, however, are not as well understood. Some of the newer DMIs, like Trinity, Triton and Tourney, are not labeled for application to ultradwarf bermudagrass varieties. Even though these products are safer on the cool-season grasses, they can cause severe phytotoxicity and thinning of 'Champion', 'Tifeagle' and 'Miniverde' greens.

A recent trial we performed on 'Champion' bermudagrass in Rocky Mount, NC showed some unexpected results. Each fungicide was applied once, on August 20, the day after the greens were hollow-tine aerified and topdressed. The plots were evaluated for phytotoxicity, turf quality, and recovery from aerification on September 1.

Not surprisingly, plots treated with Trinity, Tourney, and Triton FLO exhibited significant phytotoxicity and reduced turf quality as compared to the untreated control. Banner and Bayleton had similar effects, just not as severe as the others.

What was unexpected was the effect of the DMIs on recovery from aerification, as measured by the number of aerification holes still visible on Sept 1. Plots treated with Trinity, Tourney, and Triton FLO recovered almost as quickly as the untreated plots, whereas both Bayleton and Banner dramatically slowed recovery, especially Banner.

So, the take home message is, even though Bayleton and Banner are labeled for application to bermudagrass greens, these products can have adverse affects on the turf, in this case, slower recovery from aerification. More research is needed to fully characterize the effects of the DMIs on bermudagrass greens. In the meantime, I'd recommend avoiding applications of DMI fungicides either before or after hollow-tine aerification practices.

Oh Man, the Flu Sucks....

Just a short one today guys.

Last week's diagnoses pretty much read: rapid blight, rapid blight, rapid blight from both northern and southern California. It looks like the rains have helped as we've seen almost no rapid blight in the lab this week. Dollar spot and some brown patch and large patch activity has been reported sporadically here and there.

I have heard about a number of superintendents fighting Pythium in Oregon and Washington right now. It's been really wet up there and according to Gwen Stanke at WSU "[It's the] Worst year I’ve seen in my 20 years here".

Other than that - I've been clobbered something this week. I'm hoping it's just a really bad cold and not H1N1 (since I already got my regular flu shot this year). Sometimes I think flying on airplanes is a great way to get sick.

Signing off from the left coast until next week.......

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! 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. 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!

Fall is Finally Here!!!

Whoa, what's that stuff coming out of the sky? Ash from fires? Glassy winged sharpshooter exudate? Bird poop?

It's been so long that we've had rain in California, that many of us have forgotten what it looks like! By last count, Los Angeles got over 3 inches of rain, while San Francsico had just over 2.5 inches this week. (Photo of flooding on I-5 in Sacto, Associated Press)

With the rain, we should have gotten some significant leaching salt from greens, which is a good thing since rapid blight was just about the most common disease coming into the lab for the last 3 weeks.

The rain, cooler weather and aerfication = fall is here.

Creeping Bentgrass and Bermudagrass Fall Disease Prevention Practices
For those with creeping bentgrass greens, start thinking about preventive fungicide applications for take all patch control. Also - see Lane's prior post on preventive applications for Pythium root dysfunction here. We have not yet definitely diagnosed this disease from creeping bentgrass in California, but are highly suspicious that it's here. Along with fellow blogger Jim Kerns, we did diagnose this disease last spring from a location in eastern Washington. If you have had some unexplained spring/early summer collapse of creeping bentgrass greens; it may be worth it to have your roots examined for the presence of PRD this fall and winter, and try to integrate some control options this fall that will help with both take all and PRD.

Also - now is a good time to focus on spring dead spot control on bermudagrass. Check out Lane's recent posts on the disease here and here.

Desert Overseeding

Just ask superintendents like David Major, Gil Stiles, Paul Mayes, Willie Lopez and a host of others - if I set up a disease trial on a course, 9 of 10 times, the disease will not show up (10 of 10 times, bikini clad supermodels won't show up either). Now add Tom Shephard at Desert Falls CC to that list. No Pythium in Coachella in our trials started a few weeks ago. I just might start asking superintendents for $1000 bucks a pop to set up trials on their course next year; there'll be a 90% chance they'll have absolutely no disease while I'm there.

Although there have been just a few nights over 68F during the last two weeks in Coachella, for the most part, nights have been in the low 60s and 50s, and daytime temps below 100 (as low as the 70s recently). (Photo of Silver Rock Resort, Riverside Press Enterprise)

Although no Pythium has been reported from the desert, that doesn't mean that the overseed isn't problem free. The cool weather is certainly delaying perennial ryegrass establishment - I hope that the courses there are able to get it up before the courses are set to open. Just to warnings though, please adjust irrigation scheduling on the turf in the cooler weather to prevent other issues from arising, and try to limit play on newly emerged areas if possible. Overwatering and traffic on tender plants this year would certainly do more damage on turf than Pythium this year.

The Bacterial Wilt Mystery Continues - Is There a New Kid in Town?
A few weeks ago, there was a big scare in California regarding potential outbreaks of bacterial wilt on Poa. Although the damage we saw was definitely real, we have not been able to isolate the bacterial wilt pathogen, Xanthomonas translucens, from diagnostic samples. It could be a case of getting to the party too late, but it's hard to draw any conclusions yet based on the limited data we have. We're continuing to work with Dr. Larry Stowell on this issue.

On the other hand, working with Larry & UCR's new Plant Bacteriologist, Dr. Caroline Roper, we have been able to isolate and identify a Pantoea species of bacteria from a few of the diagnostic samples. Some Pantoea species are known to cause diseases including Stewart's Wilt of Corn and a blotch of sudangrass. We'll know in the next few weeks what role these bacteria play in the damage that was observed on a few courses this last summer.

Single No Longer!
Just in case everyone was wondering why I've been running around like a chicken without a head for the last few weeks:

I've been doing new husband-y stuff and it's great.

Thanks to everyone for all of the well-wishes!

Old Man Winter Decends on Midwest

Not much going on in the Midwest last week or this week. Temperatures are 20 to 30 F below normal and we actually had appreciable snow this past weekend!! I have to apologize for not posting last week, I was traveling to North Carolina and did not have a chance to write my post. This week will be a short post too. Not much going on with respect to diseases in the Midwest, too dang cold!

The only good day the last couple of weeks was last Monday. We had the Wisconsin Turfgrass Association Golf Outing at North Shore Country Club in Mequon, WI. The weather was fantastic and considering the economy we had a nice turnout. I believe we had 84 participants, which included myself. The proceeds from the outing go to support the Wisconsin Distinguished Graduate Research Fellowships. We have four fellowships at the University of Wisconsin-Madison- Robert Newman (Horticulture), Wayne Kussow (Soils), Jack and Flora Berbee (Plant Pathology, and the Kurth (rotating). For a state with only 5.5 million people we have a fantastic industry!

Sorry if this sounds boastful, but after last week I felt the urge to talk about our industry. Next week I plan to start a series of posts detailing the different winter diseases. The first three posts will be detailed descriptions on the three major winter diseases-gray snow mold, Microdochium patch, and snow scald.

On a final note, I would like to Congratulate Frank Wong and his wife Caroline! I wish you guys all the best!

Prevention of Pythium Root Dysfunction in Bentgrass Greens

For golf course superintendents who've struggled with Pythium root dysfunction in the past, now is the ideal time to initiate a preventive fungicide program. Pythium volutum, the most common PRD pathogen in our experience, starts to actively infect bentgrass roots in the fall when soil temperatures consistently dip below 75 degrees. That, combined with plenty of moisture throughout the Southeast, means that the pathogen is almost certainly active now.

Not very many products are effective against PRD. Even though it is caused by a Pythium, some of the standard Pythium fungicides like mefanoxam, propamocarb, ethazole, and fosetyl-Al are not very effective when applied alone.

Instead, the QoI and Qii fungicides have been most effective against PRD in our trials. The QoI fungicide Insignia (0.9 oz) has historically been the most effective product. We have also seen good control from Heritage TL (2 fl oz) and Compass (0.25 oz) but only on a preventive basis.

The QiI class of chemistry is relatively new, and there is currently only one product available in this category: Segway, which contains the active ingredient cyazofamid. Applications of this product at 0.9 fl oz per 1000 sq ft have also provided very good control of PRD. Segway is an important addition to our arsenal against PRD because it gives us another chemical class to rotate with to prevent the development of fungicide resistance in Pythium volutum.

Tank-mixtures of fosetyl-Al + propamocarb (Signature, 4 oz + Banol, 2 fl oz, for example) and fosetyl-Al + mefanoxam (Signature, 4 oz + Subdue Maxx, 1 fl oz, for example) have provided good control in our trials or based on superintendents' observations. These tank-mixtures, although expensive, should also be worked into your program to help prevent fungicide resistance.

As mentioned above, a preventive program should be initiated in the fall when soil temperatures consistently dip below 75 degrees. Repeat applications on 21 to 28 day intervals as long as soil temperatures are between 50 and 75 degrees are recommended where PRD has been a persistent problem. Less frequent applications may be sufficient where the disease has only been a minor problem or where growing/management conditions are less stressful during the summer. Since PRD is a stress-induced disease, there is no "one size fits all" fungicide program to control it.

Note that applications of Insignia and Segway should be watered into the soil immediately to drive the fungicide into the root zone. Approximately 0.125" of irrigation has worked well in our trials. Since fosetyl-Al moves downward in the plant, tank.mixtures including this product should be left to dry on the foliage for best results.

Congratulations Dr. Wong

For those of you who have been following this blog, you should be well aware of Dr. Frank Wong's humorous posts. Keeping everyone up to date on the West Coast, Frank does a great job of mixing the specifics of the disease with some local flare.

Well, Frank is getting married this weekend to a wonderful woman and I hope all of the those that find this blog useful will join me in congratulating him on him marriage to Caroline.

Frank, as always...You Da' Man!

Cooler Temps and Microdochium Patch

I waited until today to post this because I wanted to confirm the diagnosis, but Microdochium patch is now active in PA (and probably many other areas). The cool wet weather that we have had over the past few weeks has brought on a few cases of Microdochium patch on putting greens and tees.

I will refer you to Jim's post last week for more information on the disease and also to the Photo Gallery. The photo gallery is a great place to check out images from various diseases and they include both signs and symptoms of the disease.

Other than active Microdochium patch, many are in recovery mode from old dollar spot damage. Depending on your geographic location, you may even be fighting active dollar spot symptoms. Cooler temperatures, however, should mean that the end is in sight for this disease. For those in the mid-Atlantic region (Northern VA, Maryland, and the Philadelphia area), you may need to stay alert as moderate to severe dollar spot outbreaks occurred very late in the year in 2008.

The only other disease that I have seen in abundance in the field is lingering cases of rust on perennial ryegrass and Kentucky bluegrass. At one regional golf course, the roughs had been thinned out some by the disease. However, the real trouble were the complaints from the golfers about the orange "stuff" on their shoes. Had I been there to hear the complaint, my comment may have been "You're not supposed to be in the rough anyway."

Mazel tov! It’s nozzle talk!

I recently finished writing up a study about the use of different nozzle types and water rates for dollar spot in putting greens. When working on a presentation about this awhile back, I noticed that “nozzle talk” sounded like “Mazel tov!” and so that was a running joke in my house for a few days.

I worked with a colleague in our Biological and Agricultural Engineering Department, Dr. Bob Wolf. Bob has done a lot of work with nozzles and spray technology in field crops such as corn, but he also works with turf. We also had some valuable discussions with Matt Giese from Syngenta as we were selecting nozzles and working out the protocol. We did the studies in 2007 and 2008. Other researchers have examined nozzles and water volume previously, and I won’t get into that for the moment. That might be a good topic for a winter/off-season discussion. John has done a fair amount of work in this area with Mike Fidanza, for example, and others have too. I’ll just describe our KSU study. It is published in the online journal Applied Turfgrass Science.

We did the work on an A4 creeping bentgrass green that was maintained at 0.156 in. We looked at 5 nozzle types, and each nozzle was used with 0.5, 1.0, and 2.0 gal/1000. We used Daconil Ultrex at 1.8 oz/1000. This is the low rate and was used so that there was enough disease pressure to allow us to see some differences. That is, with a high rate we may not have seen enough disease to tease apart differences.

The nozzle types we used were:

*Extended range flat-fan (XR)
*Air Induction
*Turbo Twin Jet
*Turbo Drop Twin Fan

Each nozzle was used in 02, 04, and 08 flow rates to give 0.5, 1.0, or 2.0 gal/1000. The flow rate is usually printed on the nozzle (as shown in the next photo) and represents gal/minute at 40 PSI. 02 = 0.2 gal/minute for example. The Turbo Twin Jet is not available in 08 orifice size, and therefore a Turbo Duo adapted with two Turbo Twin Jet 04 nozzles (TT11004) orifices was substituted. (Basically, we used two Turbo Twin Jet 04’s stuck together).

The TurfJet nozzle produces coarse droplet sizes and usually has less complete coverage, and in some previous studies it has provided less disease control than others. The XR is commonly thought to provide very complete coverage and is widely used and thus was selected as the comparison “standard.” The Air Induction nozzle is designed for drift control. In air induction nozzles, air is drawn into the nozzle body and combined with the spray solution to form large, drift-resistant “bubbles” which explode upon contact with the plant. The Turbo Twin Jet (with a pre-orifice design to reduce drift) and TurboDrop Twin Fan (another air induction design) are recently-developed nozzles used more in field crops that have not been tested for disease control in turfgrass systems. They produce a “twin stream” of water as is shown in the photos.

In our studies, the 0.5, 1.0, and 2.0 gal/1000 water rates all performed similarly with few significant differences. That is, for most nozzles on most rating dates, all water rates performed equivalently. In addition, for the most part all the NOZZLES performed similarly except for the TurfJet nozzles which had poorer disease control on some rating dates.

The images below show how we collected some spray coverage data. Bob then scanned the water-sensitive papers and ran them through an analysis program.

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