No kind words for September

The average high for yesterday (Sept 1) is 87. We beat the old record (107) with a high of 108. Yuck. I kept thinking "Just wait til September... just wait til September." Well, September, I have some special words for you, but I'm too much of a lady to type them in this public blog. Click on the image below to zoom in on our summer-of-fun. This particular data is from here in Manhattan.




This time of year can be marked by extremes. The record lows are in the 40's, but there have been triple digit record highs almost all through September. Wild mood swings.

Fungicide trial

This year my PhD student Ken Obasa and I have been conducting a fungicide study on the putting green looking at a couple of fungicide programs, and a new product called Velista which should be released soon. All treatments are applied every two weeks. Velista is tested at 0.3 and 0.5 oz/1000. Here are the programs:

Program 1:

10 May Honor 1.1 oz

2 June Insignia SC .7 oz

17 June Spectro 90 5.75 oz

30 June Signature + Daconil 4 oz + 3.2 oz

14 July Insignia SC .7 oz

28 July Signature + Daconil 4 oz + 3.2 oz

11 Aug Chipco 26GT 4 oz

25 Aug Honor 1.1 oz

Program 2:

19 May Headway 3 oz

2 June Heritage TL 2 oz

17 June Spectro 90 5.75 oz

30 June Signature + Daconil 4 + 3.2 oz

14 July Heritage TL 2 oz

28 July Signature + Daconil 4 oz + 3.2 oz

11 Aug Chipco 26GT 4 oz

25 Aug Headway3 oz

Program 3:

19 May Disarm M 1 oz

2 June Disarm .36 oz

17 June Spectro 90 5.75 oz

30 June Signature + Daconil 4 + 3.2 oz

14 July Disarm .36 oz

28 July Signature + Daconil 4 + 3.2 oz

11 Aug Chipco 26GT 4 oz

25 Aug Disarm M 1 oz

Program 4:

19 May Tartan 2 oz

2 June Compass .25 oz

17 June Spectro 90 5.75 oz

30 June Signature + Daconil 4 + 3.2 oz

14 July Compass .25 oz

28 July Signature + Daconil 4 + 3.2 oz

11 Aug Chipco 26GT 4 oz

25 Aug Tartan 2 oz

We had a severe brown patch epidemic in early/mid August, and brown patch reached about 40% severity in the untreated plots. All the programs and the two Velista treatments held the disease to 0%.

Dollar spot pressure has been fairly low but with cooler temperatures I suspect it will flare up in the next week or two and probably though most of September. I’ll post some details later on.

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Is it Starting to Feel Like Groundhog Day?

So I bet many of you in the south are feeling like Bill Murray in the 1993 movie “Groundhog Day”. I know I am. Everyday we look at turfgrass samples with the same problem. Heat-related stress and decline and severe nematode populations! Many superintendents that I have spoken to are getting as frustrated as me. This heat is getting old. We are now sitting at 45 days above 100F here in Stillwater. In the Oklahoma City area they are knocking on the all-time record of 50 days! Everyday the same thing…

The OSU Turfgrass Diagnostic Laboratory has churned through a bunch of creeping bentgrass putting green samples in the last couple of weeks. The large bulk of samples have extremely short root systems. The heat has really taken its toll on creeping bentgrass in much of the south central U.S. Throw in some nematodes damaging what roots are left and we have a lot of turfgrass in serious decline. Very high populations of stunt (Tylenchorhynchus spp.) and ring (Criconemella ornata) nematodes have been observed in many of the samples submitted. We have seen populations of stunt nematodes as high as 4,000 individuals in 100 cc of soil. This is about 26 times the threshold we consider the “danger zone” on creeping bentgrass. Ring nematode populations have been coming in as high as 2,000 individuals per 100 cc soil, which is about four times the “danger zone” population level. So as you can see, things are getting tough here at the end of the summer in the south. Many are praying for cooler weather and rain. Although, those that have gotten rain have been struggling with wet greens and hot weather, which makes for a whole different set of hurdles.

Other issues in the diagnostic lab have been few and far between, but we did have one sample with Pythium root rot. This was an odd situation where the greens got dry and severe wilt began. To compensate the newly hired assistant superintendent turned the irrigation system on and severely over-irrigated multiple times. When you have lots of soil moisture and high temperatures in the rooting zone, Pythium root rot can help finish off the already declining plants. So while, not the initial cause of the problem, we did identify something other than nematodes. In our research plots, brown patch has also been active and dollar spot comes and goes pretty much as the humid weather comes and goes.

The long-term forecast is showing cooler temperatures, if we can just get through this weekend. As Dr. Kaminski has said in a previous post “there is light at the end of the tunnel.” So keep your head up and your fingers crossed for cooler temperatures, I think we will be there soon!

A plant pathologist's dream come true - patch-a-rama

Hello out there,

I don't have too much to report, but we are having an impressive outbreak of brown patch this week at our research facility. I wanted to get a lawn chair and just sit out there on the research green and take it all in. Here are some images, smoke-rings included.

With moss:

With dollar spot:

With scalping injury:

The temperatures have dropped, with highs in the coming days in the 90's and even some 80's in most of Kansas. In southern Kansas it looks like there will be a few more days of ~100 then some 90's and 80's. Poor Oklahoma still looks super hot, though. Ugh.

Some parts of Kansas also got some rain yesterday and today, but many areas missed out. Our KSU turf field day got rained on yesterday in the Kansas City area.

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Hot

Hello everyone.

Wow, I can't believe it's the last Friday in August. Where has the time gone? Here at KSU we are gearing up for our field day which will be Thursday, Aug 4, over at the Olathe Horticulture Center (near Kansas City). For me, field day always indicates that there are only a few more weeks to get through before cooler temps set in.

Here is a summary of recent high and low air and soil temps here in Manhattan:

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You can see we've had a lot of 100+ days. And, perhaps more importantly, we've had some very "high lows". That is, the overnight hours don't provide much relief.


I have just a few photos from the past week.


As far as diseases go, brown patch continues to be active.

Anthracnose spore-producing structures in creeping bentgrass sample

Hydrophobic soil

From the landscape side of things:

Geraniums bleaching out from the heat. I’ve seen this in greenhouses where there were heater issues. I’ve never seen it in the field. But, it's been stinking hot. The plants should recover and be just fine.

Alcoholic slime flux. No, that is not John Kaminski's new favorite drink. (Or, is it?). If you put one of those little umbrellas in it... maybe.

More on Nematodes in The Southern U.S.

The heat is still cooking us here in Oklahoma and the rest of the south-central U.S. We also have been receiving many samples in the OSU Turfgrass Diagnostic Laboratory. Most of the samples are suffering from severe heat-related stress. This past weekend has been one of the hottest we have seen yet here in Stillwater. According to the Oklahoma Mesonet station summary for Stillwater, we topped out at 105 F on Saturday and 107 F on Sunday. As I said in my previous post, if you are experiencing these temperatures and still mowing everyday at ultra-low heights, making cleanup passes on edges of greens, have your grooved rollers on, and are doing anything else that causes unneeded stress on turf plants, STOP! These practices will facilitate a quick decline of putting greens under these sustained high temperatures and there is nothing you can do to facilitate recovery until cooler temperatures (high temperatures less than 85 F) prevail.

In addition to samples that are under severe heat stress, we have been receiving many samples with high nematode populations. I talked about this in another post and Dr. Tomaso-Peterson also wrote a great synopsis on nematodes. We have been receiving some questions on how nematodes cause damage to plants so I’ll attempt to explain a bit using creeping bentgrass as the host of interest.

Nematodes cause damage on creeping bentgrass by feeding on the roots. Feeding by these tiny animals (roundworms) can injure and impair root functions such as water and nutrient uptake. Nematodes may feed externally or internally. Utilizing a specialized spear-like feeding structure (stylet), nematodes puncture plant cells in the roots, causing discolored areas (lesions) or swellings. Nematode activity also can predispose the grass to attack by other pathogens such as fungi and can cause the plants to be more prone to heat-related stress. Some of the most common plant pathogenic nematodes we find in putting greens in the southern U.S. include lance (Hoplolaimus spp.), ring (Cricinemella sp.), spiral (Helicotylenchus sp.), stunt (Tylenchorhynchus spp.), sting (Belonolaimus spp.), sheath (Hemicycliophora spp.), and root knot (Meloidogyne spp.). Female nematodes can lay many eggs (up to 500 eggs), which in turn hatch into juveniles. These juveniles will then mature through a series of four molts then becoming adults. Nematodes are motile in the soil for very short distances. Long distance spread occurs through surface water runoff and movement of infested soil from location to location. In non-tilled soil environments such as on a golf course, movement of infested sod is a primary method of dispersal. Generally speaking, sandy soils are more likely to have nematode problems than soils with a high clay content. Therefore, sand-based putting greens are a great environment for nematodes to flourish.

Above ground symptoms of nematode induced diseases will often resemble drought stress, general lack of vigor and little to no response to irrigation, fertilization or even fungicide applications. Symptom expression is directly related to the number of feeding nematodes. Nematode populations can increase very quickly in the summer months. The length of the nematode life cycle is partially regulated by temperature. As temperature increases, life cycles get shorter and the population of nematodes can increases at a faster rate. In addition, if we consider creeping bentgrass plants, as the heat increases, root and shoot growth can slow or stop. If roots have stopped growing (and maybe dying) due to high temperatures and there is a lot of nematode feeding, it is easy to see how creeping bentgrass plants can die very quickly without much warning. Further complicating matters, is the presence of multiple groups (genera) of plant pathogenic nematodes, which can have a synergistic effect on disease severity and symptom expression. The best way to confirm a nematode problem on a stand of creeping bentgrass is to have a soil sample evaluated. These assays are usually expressed in numbers of individuals of different nematode genera per volume of soil. Various treatment threshold numbers have been established for some nematode genera on certain turfgrass types.

Management options:
Few chemical fumigants/nematicides exist as options for controlling plant pathogenic nematodes. Therefore, superintendents should practice methods to promote a vigorous root system on creeping bentgrass plants in the spring before stressful growing conditions prevail in the summer months. I have written before about managing nematode-induced stress. However I will reiterate here. Cultural management should include raising mowing heights (.160 in. or more would be advised), adjustment of the frequency of mowing and rolling to reduce the amount of stress applied to the turf stand, and continued frequent, light applications of fertilizer and water are recommended. Any practice that reduces stress and damage to turf plants will assist the plants in surviving the additional damage that nematode feeding causes. Regular soil assays should be done if nematode activity is suspected.

Dr. Nathan Walker and myself have various experimental chemical treatments that we are evaluating for efficacy toward nematodes. In future posts I hope to comment and show some data. Hopefully we will have something positive to present. Until next time…

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.

Summer stress and diseases

HOT HOT HOT

We've been cooking over the past week.

We are not as bad as Oklahoma. Just reading Damon's post made me break into a sweat, both with the thought of those high temperatures AND the thought of the number of samples he's dealing with. It hasn't been quite that extreme just a bit north, where I am located. But, this current week has been nasty, with more 100+ on the way.

Localized dry spot:

This photo was sent in with a subject line that said “Help!!!”

While I am not a fan of diagnosing based only by photo, the pattern made me suspect localized dry spot (hydrophobic soils) and I suggested that they do the “droplet test” which is described HERE. Indeed, that was the problem. A wetting agent will be useful, but unfortunately the turf itself will not be able to recover very well until these extreme temperatures go away… and that could take awhile.

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Brown patch in creeping bentgrass:

Hot and humid, with high night-time lows = optimal conditions for brown patch. It’s active in greens, fairways, and lawns (fescue).

Dollar spot, in an unsprayed fairway area (creeping bent)

I've also seen some anthracnose in the past few days.

The Heat is On!

You “Beverly Hills Cop” fans will recognize that title from the soundtrack of the 1984 hit movie that Eddie Murphy starred in. This song also seems appropriate for much of the mid-west and southern plains, as the number of turfgrass samples coming in to the OSU Turfgrass Diagnostic Laboratory has increased over the last several weeks. Obviously, the spring and summer growing seasons are typical periods when diseases of various turfgrass species are of most concern. Currently, most of the samples arriving in the laboratory are cool-season turfgrass species (fescue and creeping bentgrass). Many of the submitted samples are suffering from summer-heat related stress and are in general decline. Remember that cool-season grasses, especially fescue and creeping bentgrass grow best during the cooler seasons. When ambient air temperatures become hot (90 F+), growth of these grasses will dramatically slow or stop and can go into rapid decline. Root growth of cool-season grasses will cease when soil temperatures are above 80 F.

Currently, the average 2-inch under-sod soil temperatures for much of Oklahoma are in the low-to-mid 80s according to the Oklahoma Mesonet weather station network. In Stillwater, we are averaging around 90 F. Thus, root growth on cool-season grasses is not occurring. Research has also shown that as air and soil temperatures rise above 90 F roots will start to die. With high temperatures yesterday (June 10) in the triple digits and low temperatures not falling below 70 F (except for the pan handle) throughout Oklahoma, root mortality on cool-season grasses is going to be common in the coming days. For some areas the situation has been made worse due to prolonged drought and early onset of heat. According to the Oklahoma Climatological Survey, the month of June was the 2^nd warmest and 4^th driest on record since 1895. We have an average statewide precipitation deficit of 3.08 inches. 

Turfgrass plants that entered summer without a sufficient root system are more likely to not sustain growth, turn yellow or brown and go into general decline (see images). Symptoms of decline can resemble diseases caused by pathogens. Patch symptoms due to summer stress may look much like take-all patch. Turf can appear off color or golden brown and in areas where the plant stand is thin algae formation is common (see images). When roots are examined no evidence of the pathogens that cause these patch diseases are typically present. While evidence of root inhabiting fungi will often be noted, many of these fungi are simply naturally occurring root-inhabiting organisms that are not pathogenic. Also beware that while it may appear to the naked eye that the grass plant has deep or healthy roots this may not be the case. The vascular portion of the root is resistant to decay and may appear to be healthy when in fact it is dead.

To manage summer stress we are recommending good water and fertility management. Where appropriate, water very deeply and as infrequently as possible, while hand watering “hot spots”. ”Spoon feeding” may be necessary to sustain turf until temperatures are more favorable for cool-season grasses. Avoid damaging activities such as dethatching, aerifying, and any other management technique that can cause injury to turfgrass until it is again actively growing. A fungicide (such as Fore or Daconil) may need to be applied to keep algae formation under control on areas devoid of grass. Also, mowing heights should be raised. When the membership complains about slow greens, remind them that playing on slow greens might be better than playing on no greens.

Weather conditions in general have been too hot and dry for most turf pathogens. However, we did have one case of Pythium blight on a putting green where a severe case of scalping occurred and excessive irrigation was applied for multiple days. This resulted in an excessively wet environment that favored Pythium development. We also have observed brown patch on our research putting greens in Stillwater. Brown patch epidemics began this weekend and have increased over the last day or so.

Hopefully the heat will pass soon and we will have a nice cool August. Hey, stranger things have happened…

Strangely quiet

Hello,

I have not been receiving too many samples or questions on turf. It has mainly been a few of the usual suspects such as brown patch or dollar spot.

It's been hot, but there have been some breaks. For example we had some 100+ days in Manhattan but then we've had some days with highs in the 80's and lows in the upper 60s. A few nights were in the upper 70's (ugh). My number of "three shirt days" seems lower than last year (that is a highly scientific unit of measure, by the way. How many times do I have to change shirts.)

In Hutchinson (south central) and Garden City (southwest) the days have been hotter but nights cooler ( due to lower humidity).

Here in Manhattan, our average 2-inch soil temps are about 81 and our average 4-inch is at 83. Last year, during this same week, it was similar (80 and 80).

As such, as far as stress goes, it hasn't been to drastic so far. But, who knows what the rest of July will bring.

In contrast, based on Damon's comments, it sounds like the stress is on not too far away in Oklahoma.

So, I haven't been posting much, but that fact that things haven't been hitting the fan is a good sign!

I'll try to gather some research updates for next time.

dollar spot, brown patch, a bit of heat, and what do you do when you don't have a sprayer?

Hello,

I am back in the US after an agriculture development trip to Tajikistan. If any of you are curious about that, you can check out this website where I have some notes and photos. The photo above is me with the Tajikistan-Afghanistan border mountains in the background.
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https://picasaweb.google.com/mmkennelly/TajikistanVisit2011?authkey=Gv1sRgCMvxxJn_moCCKg

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Anyway, back here on the home front dollar spot is active in putting greens and fairways. Though I have not seen it yet with my own eyes, I have had a few reports of brown patch activity as well.

In addition, with some of the recent heat and wind there are some hot spots cropping up. Even though the irrigation is on, the hot dry winds may be reducing the water that actually gets down onto the surface in all spots. When it comes to hand-watering, make sure to put an experienced crew member on the task, since it can be kind of an art.

I keep thinking back to 2010... you want to minimize turf stress now before the really nasty summertime comes along.

In addition to hot spots, localized dry spot may be appearing in some places. The droplet test is always a good indicator:




No sprayer?

I had an interesting question today from a low-budget course that is having dollar spot issues. The course is in a small town in Kansas, and the place is so low-budget that they don't have a sprayer. They are relying on granulars.

Of course, one issue with that is that they aren't going to get the same coverage as with a spray. Then, it limits the chemistries that they can use. Not many materials are available in granulars.

It sounds like they have used a lot of thiophanate-methyl. Unfortunately, in some recent work in Kansas, I observed that most isolates are resistant to that mode of action.

The course has also used a lot of a granular triadimefon. As we all know, the DMI's can have resistance problems as well. The other granular they have used is iprodione.

So, there could be some resistance issues, and there are definitely some application-method challenges that may not be fixable.

It is an interesting situation, and I'll welcome any suggestions by you folks out there in the blog-o-sphere.

Zebra patch

Hi,

I don't have a lot of news, but I wanted to share these very cool photos that were sent by Darin Pearson at Eagle Bend Golf Course in Lawrence. The course is stripping zoysia into rye, and you can see how the large patch is expressed in the susceptible turf (zoysia) while leaving the rye seemingly untouched.

Starting tomorrow I'm off to Tajikistan for about 10 days.

I wonder how the turf world will change while I'm gone. It could be cool and rainy, hot and dry, hot and sticky... we'll see. It's always interesting to see how quickly diseases can come and go in our variable climate. So far, there hasn't been any dollar spot here in our research plots, for example, but it could take off soon... or not, depending on what Mother Nature does.

Stormy skies

The major news around here this week has been the weather. No, that's not a photo of the Mother Ship come to take me home, that's the back of one of the many storm fronts that passed through this past week.

I'm sure you have all heard about the devastating tornado in Joplin. Other communities in the region were also struck.

Along with the violent winds, hail, etc, abundant rain has accompanied some of the storms. The University of Arkansas talks about wet conditions in their area. They also shared some images of flooding from some storms a few weeks back.

http://turf.uark.edu/turfhelp/archives/052511%20Rain.html



Here are some examples of how dark the sky got on Monday here in Manhattan. The clouds were so dark (at 10:00 am) that streetlights and car headlights were coming on:









Large patch

I was out and about earlier this week and saw some large patch symptoms:





At this site, the symptoms were a lot less common than they were in 2010. 2010 was extremely wet, and I think that's a big factor. After this week's cool, rainy weather, I expect to see a rise in symptoms.


Wet conditions also prohibited mowing, leaving a purple haze of several days of zoysia flowering heads:

In the dicot world: (oops, I mean non-turf world)

Those of you who deal with ornamental plantings might be interested in these observations about freeze damage in peonies and iris from a cold snap a couple of weeks ago. The pics and commentary are from one of my colleagues in the Kansas City area:

http://www.ksuturf.org/blog/2011/05/freeze-damage-in-iris-and-peony/

First app of 2011

First spray of the year

On Monday I drove to one of our zoysia large patch study areas at a golf course about 90 minutes away. I had been kind of dreading it. I just have NOT been feeling ready for the field season.

But, it was a beautiful day and I realized that I'm pretty lucky that my job allows me to work outside (even though some of those days can get pretty long). The superintendent, assistant superintendent, and staff at this course have been fantastic trial hosts over the past few years.

The large patch was not "hot" yet, but near the study area there was a "shadow" of a patch that was there before (last year), and will probably become active again soon, maybe after this week's rains.

This is a small trial with 6 treatments and an untreated control, and I can share results later.

"Shadow patch"


Active patches like this, with orangey margins, should be coming soon:




"Landscape, with Tidy Cats Bucket and Truck" (my artwork for the day)




Bermudagrass is continuing to green up, too.

Here's our KSU football practice field (bermudagrass) on April 6:


April 16:


I would have taken another today, but it was pretty gloomy and rainy.


Fertility Legislation

I came across an article about fertilizer legislation in Virginia, New Jersey, and Washington:
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http://www.turfmagazine.com/article-6727.aspx
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Any comments from folks in those areas?
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