Plenty of snow mold in the Northeast

View of St. Francis Links and St. Francis Bay in South Africa

Things have been very hectic around here so I have not had much of a chance to post anything in a while. Following a week long trip to South Africa (more on this next weekend), I fired up the old (actually it is only a few months old) computer to have it completely crash on me. That was about 10 days ago and I have yet to get it back. Shouldn't there be some sort of insurance on these things for lost work time. If I were running a business and relying on a single computer (luckily I have a backup) then I would be totally screwed.

Gray snow mold pressure in 2011 fungicide trials

Anyway, since coming back I have been busy putting research protocols together and also wrapping up research studies from last year. In particular, I was able to drive up to Yahnundasis Golf Club located near Utica, NY to rate my snow mold trials from last fall. Depending on your perspective this was a great year for snow mold and disease pressure was upwards of 80% in select plots. Our data is kind of perplexing as PCNB didn't really do all that much. While some plots didn't look all that good, several treatments resulted in excellent control with some even providing 100% control. This report should be up on the Penn State website relatively soon (relative in academia means by June).

Most of us are now in recovery from any problems, but I have seen several courses this year that are greening up pretty nicely and look great. It's already turning into a strange year. We have had unseasonably cold weather with individual days of extremely warm temps. Today in State College, the weather is about 75F while tomorrow is going to peak at 51F. Despite this fluctuation, our GDD at Penn State hit 289 yesterday and probably picked up several more today. Therefore at least according to the GDD we are right in the early stages of Poa seedhead control. We have a study at the Penn State Golf Course now looking at GDD timings for various products and a new experimental product. Hopefully we can get a better handle on what works in terms of timing for our region. For some reason, the GDD timing used in Michigan as part of Ron Calhoun's program doesn't seem to work well here...at least we haven't been able to dial it in. I hope to continue to put out these trials to figure out the best timing and products for our region...any feedback that you can provide regarding what works for you would be great!  If you want to learn more about Ron's GDD Tracker site, I encourage you to visit it at www.gddtracker.net. It is a great site and a valuable resource for those in his region.

Poa annua management strategies (Part 2)

Last week I introduced the topic of annual bluegrass management practices that are gaining momentum in the United States and other parts of the world. While these practices have been met with some controversy, they have also made us as researchers spend a little more time investigating the implications of these practices for golf course superintendents.

One program that has emerged among many superintendents (many with a strong voice on twitter including @nccturf, @MinikahdaTurf, among others) is the incorporation of various management techniques that seek to favor the bentgrass over the weaker Poa annua spp. While there is much variation in the programs and none are identically alike, a general overview of some of the practices incorporated into the program were discussed in last week's post.

As I also mentioned in last week's post, those of you managing Poa (regardless of your management goals) usually have a very vocal and firm belief of why your program(s) works. As an academic, I try not to jump on anecdotal claims, but do like that they can serve as a catalyst that drives research. For me, it's about trying to figure what works and what doesn't (again based on research) and then trying to fine tune those results into programs that are repeatable across a variety of regions and under different management and environmental situations. So, in 2010 we initiated several studies looking at the management and suppression of Poa under golf course putting green conditions.

Kyung Han assessing Poa populations

Four studies were initiated investigating the interactions between and among the following variables: 1) low and normal/high seasonal nitrogen rates (low and high are about 0.5 and 2.2-3.0 lbs N/1000 sq ft/year); 2) plant growth regulators (none, Primo, and Cutless); and 3) Ferrous sulfate rates (0.0, 0.25, and 1.0 lb/1000 sq ft every 3 weeks).  There are a lot more details to the trials, but since this is only the first year and we have another full year of the study (and hopefully several years more, funding pending) I will save the details for the publication. Other common factors in the study include: routine topdressing, no disturbance, routine venting with solid tines, minimum irrigation where possible, no phosphorous applications, pesticides only where needed, and probably others that I am forgetting. The studies were setup as a 2x3 or 2x3x3 factorial with four replications.

Trials were initiated on a research putting green at the Joseph Valentine Turfgrass Research Center to investigate the interaction of N rates, PGRs, and Fe rates on annual bluegrass populations on a putting green.

So as not to bore everyone with a ton of data, I have included one slide showing results of the 3-way factorial study which included all factors. Data shown is only a single date and it should be pointed out that tremendous seasonal variation in Poa annua was observed between summer and fall timings. Total Poa was estimated at 20 to 25% throughout the area at the beginning of the study and here are the results after the first 5-6 months of initiating the first treatments.

Poa annua populations following the seasonal application of various N rates, Fe rates, and PGRs. Data were collected monthly, but peak annual bluegrass ratings taken in October 2010 are shown here.

Now there is a lot of data to be analyzed and interpretation will definitely be reserved for AFTER we have two full years of data, but here are the general summaries that I have based on this first year:

1. Nitrogen rate (0.5 vs. 2.2 lbs N/year) appeared to have an slight impact on Poa annua populations with lower N resulting in lower % Poa in October.
2. PGRs had the greatest impact with Cutless treated plots (as expected) reducing Poa the greatest. Interestingly, the Primo-treated plots appeared to reduce populations when comparing low to high N plots, but these data need to be subjected to contrasts which have not yet been done to determine the significance of this effect.
3. Ferrous sulfate so far does not appear to have any impact on the Poa annua populations. Many utilizing this program are suggesting that these applications are important to reducing Poa, but based on this first year data it does not seem to have much impact. Having said this, the turf color/quality in plots receiving low N levels started to decline and in plots where Fe was applied it did appear to help improve the overall color...although quality was still a little suspect.

So, this is the first look into the data that we have from the first year of our Poa management study. There are probably a lot of questions about some of the details of the study, but I am leaving that for another time as I hope to continue this work for several years.

The main questions that I have regarding the long term impact of this study will be the assessment of organic matter buildup, changes to the pH (of which we have seen none yet), and the development of side problems such as black layer due to the sulfates. I have also been told that this program will result in a substantial reduction in disease severity and therefore a reduction in the overall use of pesticides. These will all be things that we look at as the study progresses this year and beyond. In addition to these studies, we will be looking at more chemical-based means of suppressing the weed as well...we can't rely on just one method and most likely it will take a combination of chemicals (or "poisons" as our friend "Poa annua" on facebook calls them) and sound management practices to get Poa populations where you want them.

Acknowledgements

As many of you know, funding for these research projects can be expensive. This research could not be possible without the support of The Penn State College of Agriculture and Department of Crop and Soil Sciences, The Center for Turfgrass Science, The Pennsylvania Turfgrass Council, SePro, and the USGA.

Lot's of talk about Poa this spring

Winter damage can be a big problem in Poa.

While some golf course superintendents are still seeing the last remaining traces of snow on their turf, most are starting to assess the impact of winter and potential damage. With the predominance of Poa annua as the primary species on many golf courses throughout the region, the potential for winter damage is always high and it appears that the winter of 2010/2011 may be as damaging as that in the summer of "the year that shall not be spoken". According to a recent Northeast Regional update from the USGA's Adam Moeller, it appears that many golf courses have "discovered moderate to severe winter damage on putting greens."

So much of the discussion on Facebook and Twitter has shifted to assessing the damage and fixing it.  In cases where damage was not observed the focus has been on seedhead suppression. The bottom line for those managing turf in the Northeast, the focus surrounds the suppression and/or management of Poa annua.

Regardless of whether you want to manage or suppress Poa, you probably feel pretty strongly about your beliefs!

While this has always been a major interest of mine, the shift to Penn State has given me the opportunity to focus more research efforts on managing this species on golf courses. For those not familiar with our state, Pennsylvania is made up of two major factions: those in the western portion of the state (e.g., Pittsburgh) love their Poa and believe it is the premier species for putting quality while those on the eastern side of the state (e.g., Philadelphia) generally consider this a weed problem and go to great lengths to suppress it (there are always exceptions to the rule, so don't you superintendents in Pittsburgh trying to control Poa yell at me telling me that I am wrong). That leaves me and others at the University trying to figure the best management practices for both those that want to get rid of it and those that want to promote it. And while there are many people that claim to know how to accomplish this, a lot of research-based information is still needed to determine best management practices that meet your specific needs (whatever your needs may be).

So over the next two weeks, I will try to provide some insight into what is generally known about managing/suppressing Poa in our region and provide some insight into research that we have initiated to further assess management options.

Here is a list of what is generally known or believed about Poa management:

Trimmit-treated stand of bent/Poa

PGRs
Primo and Trimmit/Cutless are the three most common growth regulators applied to turf during the season. Primo is believed to have little impact on Poa (other than making it stronger), while Trimmit and Cutless have been show to favor the growth of bentgrass over annual bluegrass when used a repeated application program.

Herbicides
There has been no silver bullet herbicide for managing annual bluegrass. Preemergent herbicides effective against Poa are generally not recommended for use on putting green turf. Postemergent herbicides such as Prograss and Velocity have been used with varying results, but again are not labeled for use on putting greens. Various experimental products (cumyluron, methiozolin, others) are currently being evaluated in the United States and have shown great promise. For example, methiozolin is currently labeled for putting green turf in Korea and has excellent efficacy in preliminary studies, but more studies looking at the use of this product are needed.

Coring can create an ideal Poa seedbed

Cultural practices
This is where we get into the relatively ongoing controversy of management programs. In recent years, there has been a resurgence of programs that involve minimal disturbance (no hollow tine aerification or deep vertical mowing), low nitrogen and phosphorous programs, high ferrous sulfate (and other sulfates) applications, and others. Unfortunately, many of these recommendations are based on "theory" and have not be thoroughly evaluated in controlled research environments.

The general feeling regarding cultural practices for suppressing Poa as I understand it are:

1. Low nitrogen will favor the bentgrass over the annual bluegrass and in turn result in less accumulation of organic matter. ADDED CONTENT: (Low P will also favor bent...thanks Dr. Koski for pointing this out)
2. Ammonium sulfate as a primary N source will result in acidification and therefore further favor bentgrass.
3. Fe, Mg, and Mn sulfate will help in an acidification of the foliage (not sure where this came from) and therefore favor bentgrass AND help to offset color deficiencies in low N programs.
4. Core aerification surrounding times when annual bluegrass germination is optimal should in general be avoided. Many of these new Poa management programs dictate that greens be vented often, but that any disruption should be avoided.
5. To further help dilute the potential build-up of organic matter, frequent topdressing is generally recommended to encourage the development of a manageable "mat" layer rather than a puffy "thatch" layer.
6. I have no idea where this fits into the program, but many seeking to reduce Poa populations are lowering their mowing heights. This seems counter intuitive to me, but that's what I'm seeing and hearing.
7. As would be expected, irrigation is minimized to further stress the Poa and favor bent. In this entire program, this one seems like a no-brainer to me and the diligent and thrifty use of water is in general a good idea for limiting Poa as well as associated turf diseases.
8. There are probably other things that I have left out, but this post is already getting too long...add your "#8" in the comments or on Facebook.

So now you have a general overview of some of the techniques that superintendents and greenkeepers are using around the United States and around the world. Please feel free to add to the comments any additional positive or negatives you see with these management practices. Some of them are controversial to say the least and I have seen people swear by all or a selection of these practices to help "favor the strong species while eliminating the weak" and I have seen others who after several years on the program(s) lose a significant amount of turf.

Next week, I will share some preliminary results of our modified version of the program above which investigates the interaction of nitrogen rates, ferrous sulfate rates, and plant growth regulators on Poa annua populations.

Cool Temperatures Bring a Sigh of Relief!

Temperatures in the Midwest are finally cooling down. This week has been a godsend as I heard from a superintendent this afternoon. Yes temperatures are going to rise again this weekend, but the nighttime temperatures are supposed to remain below 70 degrees. I agree with John that this is the time to start overseeding, fertilizing and maybe even aerifying to bring the greens back to life before winter. However, I do not think this is the time to start bringing the mowing heights back down and starting on paclobutrazol programs. I tend to be very conservative and I think this week is an ideal time to allow the plant to grow under the least stress possible.

This week’s cooler, dry weather has shut down most of the diseases we have dealt with this summer. I don't know this for certain for every location in the Midwest, but I do know that my phone was very quiet the last few days. We still are getting samples of Poa annua crapping out either from heat stress or summer patch or a combination of both. This was an exceptionally difficult summer for golf course superintendents. Most the turf loss this year was due to heavy rains in June and July coupled with high day and nighttime temperatures. Soil temperatures in many locations I visited exceeded 95F, which is not a good growing environment for any cool-season grass to say the least.

The major lesson I learned this summer was the importance of establishing a written set of maintenance and playability standards. By putting categories like day-to-day green speed, firm, fast or green, lush gives the golf course superintendent a lot of flexibility. For example, a hypothetical course has established a maintenance standard of 9 foot green speeds every day. By simply stating this standard allows the golf course superintendent to vary practices to achieve this ball speed. Viable options would be alternating mowing and rolling, switching to smooth rollers, and raising the mowing height in an attempt to minimize turf loss. I do understand that setting maintenance standards may not work for each situation, but it may be something to try especially at a public play facility. You may think I am crazy for talking about this, but based on my observations this summer establishing a set of maintenance standards seemed to work.

This is also the time to start thinking about snow mold applications. Here is a link for our snow mold trials for 2009-2010. The key with these reports is to look at the treatments that provided the best control (lowest disease severity) at the site closest to your site. We test a wide variety of chemicals and combinations at five locations in order to provide golf course superintendents with a plethora of options. We do not distill the reports down to the top ten best products because the best products and combinations may not be within the budget of many golf courses. So we always recommend finding the product or products that provide the best control and fit within the constraints of your budget.



Timing of snow mold fungicides was a fairly hot issue early this spring, largely due to some perceived failures of very good snow mold fungicides. We still do not have a great answer, so are initiating a fairly large fungicide timing experiment this fall. We expect to see good control from systemic products when they are applied well before snow cover, and good control from contacts closer to snow cover. We will let you know next spring, so stay tuned.

Another Successful Field Day and Poa annua takes a dump!

Welcome back Lane!

It seems like the entire US is struggling with heat, rain and dead grass. I left for Scotland on July 14th and the sample total in the TDL was fairly normal. The week I was gone we received over 50 samples. WHOOPS! Anyway it seems like Poa annua just crapped the bed because of the relentless rainfall followed by intense heat (at least intense for us). So I agree with Brandon and Lane's equation of No Wind + Heat + Rain=Dead Grass-especially Poa annua. The roots of affected plants are short, black and pitiful looking. We have had golf course superintendents reporting soil temperatures in excess of 95 F within the top 2 inches. When this occurs there is really nothing that can be done to save Poa annua!

If you are losing grass please consult John's post earlier this week. He posted a lot of nice cultural practices that will help. Like raising the mowing height, alternate between mowing and rolling and carefully monitor soil moisture levels. However the most important point, is constant communication with the members, golf pro, general manager, owner, etc. Get them prepared for a loss in density and losing Poa annua. I know it sounds negative, but that is really the best thing to do. Especially since we have not had a hard summer in the Midwest for 3 years.

As far as diseases, we are seeing just about everything. This is sick for me to say, but this summer has been a pathologist's dream. We have diagnosed brown patch on creeping bentgrass, fine fescue and tall fescue. We have seen oodles of fairy ring through the Midwest and summer patch has just begun to show its ugly head. This has been another reason Poa annua is struggling so much in the Midwest. We have even seen a few cases of Pythium blight. We have not seen a lot of anthracnose however. The difference between this year and last year has essentially been temperature. Last July our average high temperature was 72, yet this year we are hovering closer to 82. When I was at NC State I helped Lane teach a turfgrass pathology class in the two year program and he always strongly emphasized to the students that the most important thing to a fungus is water. We had that last year, but temperatures were not conducive for growth. This year has been a different story. We have not been as hot during the day as North Carolina, Tennessee, Kansas, or even Pennsylvania, but our nighttime temperatures have consistently remained above 68 degrees. This is good weather for fungi and bad for turfgrass growth.

Yesterday we had the 28th annual Wisconsin Turfgrass Field Day at the OJ Noer Center. It was a fantastic day with great attendance. The topics ranged from Alternative grasses as a pest management strategy to Hydroseeding with Tenacity. We were really happy to have so many attendees considering the recent weather!

Now it is time to have a wee dram of whiskey to conclude my evening.

Above Average Rainfall in 2010 in California; Brown Ring patch on Bent?

Finally, after being delinquent for over a month, I'm getting back into the habit of regular blog posting. It's been a hectic month with travel in the Pacific Northwest, California, Pennsylvania, New York and New Jersey.

As far as diseases in the West, it looks like things have been fairly "calm" disease wise. Brown ring patch seems to be active on Poa greens, but other than that, it doesn't seem like anyone is screaming about diseases (although I've heard that with the ups & downs in weather conditions in the West, Poa seedhead production has been coming and going over an extended Spring season this year.

California is Above Average!
(Well, rain wise anyways)

I was watching the Amgen Tour of California bike race over the past few days on Versus and thought about how rainy or overcast it's been looking on the stages from Davis to Santa Rosa and San Jose to Modesto. Looking at the The National Oceanic and Atmospheric Administration website, I pulled off the info for California's rainfall from last July to now and it looks like we're about 7% above normal (or average) rainfall in the state based on the locations presented. Compared to 2009 (which was about 28% below normal), we are in much better shape.


* PON = % of normal rainfall

As a result, I am hoping that we'll be free of any emergency water restrictions that were present last year. One big added bonus to all of this rainfall is a definite lack of rapid blight diagnoses in the West this spring. Normally, we'll pick up rapid blight fairly regularly in the spring and it will often start picking up quickly in late April as overcast days mixed with temps in the 70s and 80s create conditions great for the disease on salt affected sites. I am really hoping that the rainfall this year will have really knocked the sodium out of many locations and we can look forward to less salt and rapid blight issues going into this late spring and early summer.

By the way, wouldn't you know it, just as we got some research funding from some of the California GCSAs to do some rapid blight work, the disease disappears. Apparently, I still have the ability to scare away diseases (and bikini clad supermodels) on research locations.

Waitea Think About This?



As mentioned previously, brown ring patch (Waitea circinata var circinata) is active in the West. Comments on our Facebook page also say that the disease is pretty active in other parts of the US. I got a little treat by email this week from a superintendent in southern California who sent in a picture of disease on his 2 year old bentgrass greens. Although the rings are not what we typically see with brown ring patch (BRP), this really looks like the pattern of the disease. Although bentgrass is normally more resistant to the disease, BRP has been diagnosed from creeping bentgrass in the West a few times this last year. Anyone else seeing this on creeping bentgrass this year? We're still confirming Waitea or not, but dang, that would be something new if BRP starts becoming more active on creeping bentgrass!

How Many Facebook Friends You Got?



Finally, just some concern and observations. As you know, our blog is linked to The Turf Diseases Facebook Page . You may have also noticed that there is a Facebook page for Poa annua and Creeping Bentgrass.

Current Friend Count:
Creeping Bentgrass: 254
Poa annua: 587
Turf Diseases: 649

So...just an observation, in the world of Facebook, Poa is more popular than Creeping Bentgrass. Turf Diseases is more popular than both of them. If we were in high school, that's be kind of like the nerds being more popular than the homcoming queen. How much longer do you think that Turf Diseases will have more friends than Poa annua? If it's anything like how the real world is, I have the feeling that Poa annua is going to spread much faster than Turf Diseases will!

OK, that's all for this week! Signing off from the Right Coast until then....

Bacterial wilt, or not wilt? That is the question.

There's been a flurry of phone calls coming in to the lab in the last two days regarding bacterial wilt taking out Poa and bentgrass greens in Southern California this last week.

With temperatures hitting 90's and 100s in parts of SoCal last week, it's no surprise to see some death and destruction, but bacterial wilt may not necessarily be the cause. Here's some basic info about the disease that may help you recognize this potential issue.

Bacterial wilt is caused by Xanthomonas translucens or X. campestris, and tends at attack stressed, shaded or low fertility turf under warm or hot conditions. High humidity and mositure make the disease more severe. Symptoms start off as small yellow to whiteish spots that can spread and eventually turn into small reddish dead spots.

Two highly informative articles on the disease, symptoms, and control can be found here and here.

Control of the disease can be tough since there are no chemicals that offer complete control of the disease.

Because of our relatively dry west coast conditions, I would say that outbreaks of bacterial wilt are kind of like coordinating a trainwreck. You need some very specific conditions for the disease to fire, but when it does, the results can be spectacular.

Although the pathogen is difficult to control directly with chemicals - cultural controls such as raising mowing height, managing irrigation, reducing mechanical stress and avoiding mowing wet greens, can be implemented.

Most importantly, an accurate & timely diagnosis needs to be made for this disease. Symptoms can be identical to those caused by other stresses and it's difficult to accurately diagnose once the infected tissue is already dead (which is especially true if you let the disease explode before you take a sample). If you suspect the disease - get samples sent to a diagnostic lab right away.

In Other Local News....
The weather is getting a little better through much of the state with temps cooling down into the high 70s to 80s in most parts of the state, although parts of the Central and Inland Valleys will see 100s this week .

Not much change in expected, diagnosed and reported diseases. Anthracnose is still pretty active, and we have some gray leaf spot brewing in Orange county on both perennial ryegrass and kikuyugrass. Night time temperatures above 68F in southern and central California could mean Pythium outbreaks on cool season turf. Watch for this disease on low lying areas or those where drainage is poor/water accumulates.

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

Dans la Merde in the West

Dans la merde is a colorful French term that basically translates into "in the sh*t" and is a good term to describe superintendnets who are currently behind the eight ball fighting active foliar anthracnose outbreaks on annual bluegrass greens in the West.

Right now, anthracnose is coming into our diagnostic lab left and right. It's likely a result of the up and down heat spikes and we've had throughout the summer here in the west.

Although anthracnose should be managed with a combination of solid cultural practices (see www.turf.rutgers.edu/research/GCM-BMP-Anthracnose.pdf) and a solid preventive fungicide program, summer stress and common practices related to tournament prep (low mowing heights, holding back N, drying down greens, etc.) or just high traffic and play can put superintendents in a bad spot. If you find yourself dans le merde, here are three suggestions that may help you get back on top of anthracnose before it's too late

(There are additional things you can do to help pull yourself out of an anthracnose outbreak, these are just three of the most common things to consider - I'd welcome any additional comments from the NE, SE, M and SC as well!)

1. Fungicide applications
If you have active anthracnose on greens, chlorothalonil is your friend. Inexpensive and not at risk for resistance, it can be used aggressively as a "eradicant" application to kill spores in acervuli and prevent new infections. Label rate applications 7 days apart should be made to halt infections in their tracks. You can mix chlorothalonil fungicides with other anthracnose-active fungicides like Medallion and Endorse safely in a rescue type situation. Chipco Signature tank mixed with chlorothalonil can also be a good option. DMI-fungicides like Banner MAXX can also be mixed with chlorothalonil, but be aware of potential PGR-effects when using these at high rates or high temperatures. Beware of using QoIs (Heritage, Insignia, Compass, Disarm) or thiophanate-methyl containing fungicides (Clearys 3336, Fungo, etc.) by themselves as rescue applications. Resistance is a problem for these already and using them as rescue materials is a good way to lose them due to resistance (that's a GCSAA class all to itself). In any case, chlorothalonil can do a lot of work for you as a rescue fungicide, and also beat back any other secondary pathogens coming in to the damaged areas or algae that can fill into thinned areas on greens.

When using contact fungicides like chlorothalonil, it's very important to get good coverage. Apply fungicides in at least 2 gallons of water per 1,000 sq ft for adequate penetration of the fungicide to the lower leaves and crown. Flat fan or air-induction flat fan type nozzles, that produce smaller sized droplets, are much more effective than rain drop or flooding wide angle nozzles for getting the best coverage with contact fungicides.

2. Fertility
Assuming that you can get sufficient knock down of he pathogen, it's important that surviving Poa has enough N to push back and recover from injury. Light applications of N (0.125 to 0.25 lb N/1,000 sq ft) should be made to get your Poa back on its feet. Apply as needed to get regrowth and recovery from damage; but excessive amounts may cause some excess growth and scalping if you're not careful. Although N is the most important component, additional P and K can also help. A 20-20-20 may be a good choice for recovery from anthracnose damage.

3. Irrigation
Once you're hit with anthracnose, don't overwater damaged areas in hopes of increasing damage recovery. Overwatering is just as conducive for anthracnose as is drought stress. Irrigate based on ET-needs, but make sure to mist/syringe greens in during the hottest periods of the afternoon to minimize heat stress on weakened plants.

Hopefully, with some TLC (plus fungicides, nitrogen and irrigation management), you can get outta the merde and back to normal practices on greens. Often, anthracnose is linked to other environmental conditions or agronomic practices (compaction, black layer, drought stress, etc.), so make sure to address those issues as well while you are in "rescue" mode.

Just an observation: If your anthracnose if plowing right through preventive Heritage, Compass or Insignia applications…. Guess what, your anthracnose is probably QoI-resistant. If your anthracnose is plowing through preventive 3336 applications (or any thiophante-methyl containing material), you've probably got benzimidazole resistance. Check out our anthracnose powerpoint here if you haven't already seen it for some chemical control alternatives: http://www.turfpathology.ucr.edu/Downloads/anthracnose_chemical_control.pdf

Other Merde...
Over the last week, we've been absolutely slammed by diagnostic samples in the lab. In addition to anthracnose, the usual suspects are still active, such as brown ring patch, summer patch and rapid blight. Samples coming in with Bipolaris, Curvularia, and Leptosphaerulina (especially on fairway and rough samples) are indicative of summer heat stress on cool season turf.

With temps in the 70s and 80s in coastal locations, I would suspect rapid blight be pretty active in salt affected locations, as well as brown ring patch and even dollar spot. The Central Valley (Fresno) and deserts will have to contend with night time temperatures high enough to flare Pythium on cool season turf. Expect anthracnose and summer patch to be calling on your annual bluegrass greens through out the state.

Signing Off From the Left Coast Until Next Week....

The Pacific Northwest Heats Up and Magic Plastic Baggies

Portland Here We Come!
Although many of the nation's turf pathologists have been in Chile this week at the International Turfgrass Research meeting, next week many of us turf pathologists will being attending the American Phytopathology Society Annual Meeting in Portland, Oregon.

Call it an unexpected coincidence, but the Pacific Northwest has been hammered with very very high temperatures this last week with Portland hitting 103F and Seattle getting up into the high 90s, likely bringing death and destruction to cool season turf in the area. Usually, courses west of the Cascades see only mild summer heat, but this blast of hot weather will have likely brought a round of anthracnose and maybe even Pythium to the area.

On Saturday, some of us will be touring Portland Golf Course and Waverley Country Club with superintendents Forrest Goodling and John Alexander (respectively). I'm looking forward to seeing what problems the summer heat has brought to the area and to some pathologists geting to see how the guys in Portland grow grass. Thanks to Gordon Kiyokawa (Columbia Edgewater Country Club) for helping us coordinate this outing.

Besides having the chance to see turfgrass culture in the Pacific Northwest, Portland is one of the best coffee and baked good towns in the U.S. One such example is Voodoo Doughnuts, a local shop that dares to put crispy bacon on maple bars and offer other "non-conventional" fried and glazed goodies. I'm looking forward to taking some turf pathologists there next week. Maybe they still have the Pepto-Bismol donut there, well unless the FDA stopped them from offering donuts loaded with what technically qualifies as "pharmacueticals". (Pictured here is one of their "voodoo-doll" donuts - www.voodoodoughnut.com). Check 'em out (and other great places like Stumptown Coffee Roasters, Pearl Bakery and Crema) the next time you're in Portland.

Meanwhile, Back in California....
The diagnostic lab here at UCR has been hopping crazy with samples this week. You know things are bad when superintendents are dropping samples off at 6am, have 2-3 drop-in visits from local supers and 2-3 visits from both FedEx and UPS before noon every day of the week!

We're seeing a lot of heat and dorught damage on cool season turf here coming in from around the state. Disease-wise, anthracnose and brown patch are showing up in the lab on greens and fairway/rough samples (respectively). Although we have yet to see gray leaf spot on perennial ryegrass, we've had a fair share of anthracnose coming in on perennial ryegrass samples from collars, fairways and roughs - maybe reflecting both the heat and local water restrictions that might be really puttting a beating on ryegrass in the state.

The forecast for the week is hot in the Valleys and cool on the coasts. Expect to see hot temperature diseases like anthracnose on poa greens in inland locations including Riverside eastern San Diego Co., and the San Joaquin and Sacramento Valleys.

Central California is hot enough at night to have conditions favorable for Pythium, so watch out for that one there. Coastal locations will continue to have dollar spot, rapid blight and brown ring patch pressure.

On the other hand, winter-y conditions will present in Monterey and San Francisco where pink snow mold may be found on cool humid days below 65 degrees.

Isn't it funny that we can have winter and summer diseases active in this state within 60 miles of each other? I continue to be amazed by this state - even as a native born left-coaster.

Amaze Yourself with the Amazing Magic Plastic Bagggie
Although the best way to identify disease problems is sending samples to disease diagnostic labs, the "magic" 1 gallon plastic baggie can be a very useful tool for helping to diagnose a few common summer diseases in a pinch.

Often, fungal mycelia can be seen in the morning in diseased areas, but more often than not - the mycelia will disappear as the canopy begins to dry out. The magic plastic bag (MPB) can help you better identify some of the potential diseases that you may have and also confirm some of the diagnoses you are getting from labs.

Wet your samples down (usually a cup cutter sized plug) and stick them in a plastic bag, seal it and pop it in a warm or room temperature location overnight. The next day, pull out your plugs out and examine them. If you see lots of mycelia growing out of the samples - you know you have active foliar fungal pathogens growing. Depending on what you see - the location and even smell of the mycelia and turf color can help you identifiy some common diseases. (Photo by Scot Dey, Shady Canyon Golf Club)

Mycelia mainly in the foliage, affected leaves look black and greasy, sample smells like fish = Pythium blight

Dense mycelia in the foliage and thatch = brown patch

Dense mycelia in the thatch and soil (or just soil), smells like button mushrooms = fairy ring

Small clusters of mycelia, looks like small cotton balls = dollar spot

Of course - the MPB isn't very good for diseases that don't produce a lot of mycelia, but it's a quick and useful trick for seeing if you have diseases like Pythium blight, brown patch, dollar spot or fairy ring.

Ok - I'll post more tips and tricks using the MPB next week.

Until then, keep and eye out for those diseases and rock on!

Beware of the DMI Fungicides

As temperatures climb in the southeast US, it is time to put the DMI fungicides on the shelf until fall. All of them.

The DMIs can cause significant damage to bentgrass and bermudagrass putting greens if temperatures exceed 90 degrees after an application is made. Note that the temperature at the time of application is not important, it is the weather in the days and weeks after an application that leads to problems.

The DMI fungicides include Banner, Bayleton, Eagle, Rubigan, Tourney, Trinity, and Triton.

All of the DMIs have growth regulating properties. The effects are minimal when the turf is healthy and actively growing, but significant thinning of the canopy can occur during hot weather, even on otherwise healthy turf. Combine a DMI application, hot weather, and severely stressed turf and the consequences can be disastrous.

Several new DMI fungicides have been released in the last two years, and many of them are promoted as "safe". Admittedly, they are safer, but by no means are they safe. Severe damage has been observed where these new DMIs were applied to stressed cool-season grasses prior to or during hot weather. We have also observed that these new DMIs are more injurious to bermudagrass than the older DMIs. Tourney, Trinity, and Triton are not labeled for application to bermudagrass greens for this reason.

Most golf course superintendents in the southeast don't need DMIs during the summer anyway. Effective alternatives are available for control of most diseases, but anthracnose is an exception. Many superintendents with older bentgrass varieties or Poa annua greens battle this disease, and most anthracnose populations have become resistant to the QoI and benzimidazole fungicides. If you are in this situation, you pretty much have to use a DMI. The newer DMIs (Tourney, Trinity, and Triton) are very effective against anthracnose and should be worked into a preventative anthracnose program. Just be sure to use low rates, tank-mix with chlorothalonil to prevent algae invasion, and do not apply more than once a month to minimize the potential for injury.

Summer Fungicide Programs for Cool-Season Putting Greens

Summer is approaching quickly in the Southeast, and golf course superintendents are shifting their focus from growing grass on bentgrass or Poa greens to just keeping them alive. Having a solid fungicide program in place to control summer diseases is an essential part of this. Here are a few diseases to keep in mind as you put your program together:


Pythium blight. While this is a major concern on Poa greens, Pythium blight is not a common problem on creeping bentgrass. A huge amount of money is wasted every year to control Pythium blight on bentgrass greens. If you have Poa greens, keep in mind that although several of the QoI fungicides are labeled for Pythium blight control, they only provide 7-10 days of protection.

Pythium root rot. This is a persistent problem on bentgrass and Poa greens that are poorly drained. However, Pythium root rot can also occur even on well-drained greens during periods of wet weather, so nobody is immune. Of the Pythium fungicides, mefanoxam (Subdue, Fenox) is most effective against Pythium root rot. For curative control, we often recommend an application of ethazole (Koban, Terrazole), followed a few days later by mefanoxam. Remember that these applications should be watered-in since the pathogen is active in the soil.


Pythium root dysfunction. For golf courses with bentgrass greens less than 10 years old, Pythium root dysfunction is the most common problem during summer. This disease is best managed during the fall and spring when the pathogen is actively infecting roots. If symptoms are observed during the summer, relieving stress by raising mowing heights and increasing fertility levels is essential. Curative applications of Insigna, Segway, or Signature + Banol can also help to suppress symptoms, but only if steps are taken to relieve stress at the same time.


Anthracnose. This is a major concern for those with Poa greens and older cultivars of creeping bentgrass. Golf course superintendents are running out of options for anthracnose control due to fungicide resistance. Most anthracnose populations are already resistant to the benzimidazole and QoI fungicides, so do not rely on these products unless you know that your population is sensitive. The NC State Turf Diagnostics Lab offers fungicide resistance testing if you would like to find out for sure. Fortunately, most new bentgrass cultivars are very resistant to anthracnose so this disease is becoming less common in the southeast.


Fairy ring. Hot and dry weather during summer tends to bring out Type I fairy ring symptoms, decline or death of turf in ring patterns. In most cases, symptoms are the result of hydrophobicity that has developed in the thatch layer. Fungicides are not very effective for curative suppression of fairy ring, unless they are combined with wetting agents or cultivation practices to re-wet the soil profile.

Nematodes. These are a common problem on sand-based putting greens across the southeastern United States. In fact, I am convinced that nematode problems are much more common and widespread than anyone realizes. If you've never had a nematode assay done, I'd encourage you to spend the $5 or $10 to do one. You may find that chronic problems you've battled over the years are actually the result of nematode activity. While the options of nematode control are limited at this time, effective products are on the horizon.

Brown patch. Thanks to the QoI fungicides, brown patch is no longer a significant problem on putting greens. As long as you rotate the QoIs or other strong brown patch fungicides (chlorothalonil, ProStar, Endorse, Medallion) into your program once in a while they will keep brown patch in check.

Watching and Waiting

Well things in the Midwest are starting to appear "normal". We have had quite the weather the past few weeks, with severe winds and significant rainfall. There is very little to report from the Upper Midwest. Most golf courses are on the road to recovery from any winter kill, however there are still some spots here and there.

As I mentioned, the spring storms have been severe and many golf course superintendents find themselves working on tree clean-up. Not much in the way of disease activity in the Midwest. We've had a few reports of yellow patch, leaf spot and dollar spot in Mid to Southern Illinois, but nothing major yet.

However, this is the perfect time for take-all patch and fairy ring preventative applications. Soil temperatures at a Madison, WI golf course were 57F on Tuesday morning. Now is also the time to monitor nitrogen fertility levels if you have a significant stand of Poa annua. Poa has started to seed at a few golf courses and with that expenditure of energy those plants may need some nitrogen. If the plants start to look chlorotic, than a light foliar feeding may be necessary. This has been shown to reduce anthracnose severity by Dr. Bruce Clarke's group at Rutgers University in New Jersery.

Odds and Ends

Parts of the Midwest have been relatively cool and wet and as a result we have seen a lot of Microdochium patch in our diagnostic clinic. If the weather remains cool and wet than Microdochium patch can become fairly severe and may warrant a fungicide application. There are many fungicides that work well curatively against Microdochium patch. For more specific information please consult our webpage: http://www.plantpath.wisc.edu/tdl/. At our webpage you can access our research reports, from which you can see what chemicals performed well in our snow mold trials this spring.

A few courses in Wisconsin have reported some minor leaf spot symptoms on creeping bentgrass. After talking with the superintendents, the symptoms were not severe enough to justify a fungicide application. Many superintendents throughout the Upper Midwest are still dealing with winter injury of Poa annua. One particular superintendent has implemented a fairly aggressive cultural program to encourage re-growth. He has aerified and dimple tined greens, along with a fairly heavy fertilization and a light topdressing. He has seen significant improvements and is well on the road to recovery.

Finally, Derek Settle at the Chicago District Golf Association has observed brown ring patch at several locations in the Chicago land area. Outside of Derek’s report, we have not heard reports of brown ring patch anywhere else in the Midwest yet. If you are struggling with brown ring patch or suspect you may have this disease please feel free to contact us. You can find our contact information on the website posted above.