Light at the end of the tunnel (e.g., It's August)

It's been a busy week for golf course superintendents in the region as diseases are in high gear and the heat and temperature stress are causing many golf course putting greens to decline. We are hearing a lot of reports of yellowing and discoloration to bentgrass putting greens, possible nematode issues, and the typical diseases that we would expect to see at this time of the year.

Rain storms that swept through much of the mid-Atlantic provided some much needed relief from the drought we were in, but in many cases the rain fell too fast and basically moved via the surface. The good news from that was that many of you who had ponds that were getting low got a "refill". The bad news is that this did little for replenishing the soil and also washed out a few hundred bunkers. There were even reports in parts of southeast PA of flooding due to the massive storm that came through last week. On the other hand, there were also courses that DID manage to get the slow and steady rain that helped to wet the soil. Following these rains, dollar spot became VERY active and anyone not covered with fungicides saw cotton candy fairways on Tuesday.

Heat stress continues to be the biggest issue throughout much of the region and I can't stress enough that just because the turf is declining doesn't mean that it is pathogen related. In many cases, the soil temps are just too high and/or the growing environments too poor. As we hit the home stretch of summer, it is important to continue to be diligent on your water management. Yes, I know that it is not practical for many of you to get out there and hand-water everything as the courses with a $2,000,000 budget do, but the bottom line is that if you are using your overhead irrigation to "syringe" then you are probably over watering (this was from a USGA agronomist who I believe it going to write an article about it for an upcoming issue of the USGA Record).

Active right now: dollar spot, brown patch, Pythium blight, anthracnose, fairy ring, summer patch, others?

Website update: We are in the process of finalizing the details/construction of the new website for Turf Diseases. Some planned features include:

• More authors for more updates
• Restructuring of regional updates in line with USGA Regions
• New "Research" section for the latest research updates from the scientists
• New "Tech" section (you'll have to wait for the launch to find out more)
• Disease profiles and Image galleries
• Disease updates from superintendents

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.

Heat Wave Forecasted for Next Week

We have seen relatively few disease issues in the TDL the past month or so. Throughout Upper Midwest temperatures have been warm, but we have also been quite dry. However the forecast for next week is very different. Highs for next week will been in the low to mid-ninties, more importantly night time temperatures will exceed 72 for most of next week. I included a 7-day forecast from NBC 15 here in Madison, but areas west and south of us will likely experience even hotter temperatures. I know that doesn't compare with the excruciating heat experienced by those in the Southeast and Central US, but the forecast is significant for the Upper Midwest. Especially considering that many courses have substantial Poa annua populations.

IF YOU haven't done so already, this weekend or early next week is a great time to protect your plants against brown patch and Pythium blight. Environmental conditions next week will be ripe for these two diseases. Moreover, anthracnose, dollar spot, summer patch and leaf spot could also flare up depending on where you are with fungicide applications. I mention leaf spot because we have been dealing with a Bipolaris leaf spot in the Midwest for two or three years that does not respond well to applications of iprodione. This disease also remains active throughout the summer months and has been problematic primarily for older golf courses. The disease tends to be more severe on certain clones of older creeping bentgrass fairways causing a "splotchy" reddish appearance to fairways. It does not manifest into distinct symptom. An image of typical stand symptoms is below.

Last year we initiated a fungicide trial at a course in Wisconsin to investigate chemical control options and found that Heritage TL, Insignia and a tank mixture of Chipco 26GT and Daconil Ultrex suppressed symptoms when compared to the non-treated control. Chipco 26GT by itself did not suppress the symptoms, indicating that Daconil Ultrex was more effective in controlling this disease. Note that I use the word suppress we have not been able to prevent the development of this disease, only suppress the symptoms. Here is the report from last year's trial. This has been a difficult disease to work with because it only seems to affect certain clones. Thus it took some time to figure out how to rate it.

Some other things to consider for next week: limit mowing by alternating mowing and rolling, skip clean-up passes, raise the mowing height and absolutely avoid applications of DMI fungicides to putting greens.

A Blog and Disease Update

So far the summer has been very busy for all of us and I personally apologize for not posting as much as I would like. You would think that posting an update a week would be easy, but it is once again proving difficult with all of the research, internship visits, website development and other things that I am currently working on. The good news is that we are rolling out several new bloggers to the site in the next month. I will let them introduce themselves in their first post as Dr. Damon Smith did in his first post from Oklahoma. We are also working on a redesign and launch of a more substantial website (not sure of a roll out date, but at this rate it will be in 2012) which will provide even more information about turfgrass diseases and likely some other areas of focus. So look for that in the future and in the meantime please welcome our new bloggers as they start to post!

In terms of diseases around the region, there is still a lot of talk about the etiolation of bentgrass on putting greens in the mid-Atlantic (and other areas as well). While there have been reports of a bacteria found in association of these symptoms there are as many reports of the symptoms being present without any bacteria found. The bottom line is that the verdict is still out regarding the cause of these symptoms and the impact that this will have as we move closer to the middle of the summer. While I am still skeptical about topic as a whole, I concur that if you are experiencing these symptoms you should perform basic cultural practices to minimize stress as if you had bacterial wilt. These include:

• Raising mowing heights
• Utilization of a dedicated mower for the affected greens
• Mowing when the greens are dry
• Maintaining greens as dry as possible
• Avoiding abrasive cultural practices (e.g., topdressing, vertical mowing, etc)
• While there are no real control measures for BW, the use of Copper-based fungicides may help a little.

Additional diseases that are appearing at this time include your typical brown patch and dollar spot, an unusual basidiomycete associated with what has been called "thatch collapse" (image right), anthracnose, fairy ring, root pythium and probably others that I am forgetting. In general, this is the time when most of our summer diseases start kicking it into high gear.

For more information on Bacteria , you can visit a search I did on this blog.

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.

Mites, Weather, Australia, and Dollar Spot

I'm posting this from Australia where the winter is just beginning. At the Redlands Research Station near Brisbane today I saw plenty of dollar spot on seashore paspalum. Pictured is a plot of Sea Isle Supreme. These are the typical symptoms of dollar spot that occur when the growth of seashore paspalum is slow.

I also saw some interesting mite damage yesterday on bermudagrass (or green couch as it is called here). From a distance the area pictured below looked as if it were suffering from drought stress, but upon closer inspection these severely stunted shoots, so typical of mite damage, were found. Last year I saw mite damage at Bangladesh and wrote about it in this post.

At Thailand last week I visited four golf courses. There were two with zoysia greens and two with TifEagle greens. One had seashore paspalum fairways, one had zoysia fairways, another had bermudagrass fairways, and another had native grass fairways. I'm fascinated by the types of warm-season grasses that grow in different parts of the world, and clearly the weather has a lot to do with that. Some grasses thrive in one area, while others struggle. I put together a series of bubble charts that plot world cities by their climatological normals, the average weather data over a number of years.

I'll be updating these charts monthly on www.blog.asianturfgrass.com. As the northern hemisphere summer progresses, we will see that transition zone cities such as Atlanta, Osaka, Shanghai, and Tokyo move very close on this bubble chart to places where only warm-season grasses are grown such as Miami, Singapore, and Tahiti. The difficulty of managing cool-season grass during the summer is shown clearly when the average weather conditions are the same as in tropical cities.

Beautiful Weather, Finally?

This spring has been one of the coolest and cloudiest on record. Just last week I was in Stevens Point, WI and soil temperatures barely reached 60 F. Still prime time for take-all patch and fairy ring preventative applications. To be honest not much is happening around the Upper Midwest. We have had reports of brown ring patch, but thats about it. Derek Settle at the CDGA has reported brown ring patch and a bit of dollar spot. We have seen and heard of multiple cases of creeping bentgrass turning red this spring. We think it is a combination of proxy/primo or trimmit + DMI fungicides for take-all/fairy ring + cool temperatures. The symptoms are typically seen on older leaves and we cannot find spores of any kind in the samples. An image of the symptoms we are seeing is above, sorry the image does not show the symptoms very well. If anyone has any thoughts on this matter they would be welcomed and appreciated!

Finally I thought I would reiterate a former post Lane wrote. He presented a succinct description of diseases that typically affect creeping bentgrass and annual bluegrass putting greens. There has been concern in the Midwest with the substantial amounts of rainfall we have received that Pythium root rot could be a problem. Yes Pythium root rot could occur at anytime as long as the soils are saturated, but considering creeping bentgrass and annual bluegrass grow well during the spring I rarely think of Pythium root rot as an issue. This brings me to another point Lane made in a previous post, is Pythium root rot a disease. I think it is a disease because we would not see symptoms characteristic of root rot if the pathogens were not present. Keep in mind though once/if summer rolls in and we continue to receive significant rainfall, then we might see issues with this disease. I am not saying that fungicides are not warranted, but I do think it is unlikely that Pythium root rot would/did occur this spring in the Midwest.

Things are picking up FAST!

Yesterday (this was meant for yesterday, but new disease activity today [Tuesday] has me posting a day late) I had the pleasure of hanging out at the Rutger's Annual Golf Classic which raises funds for their research program. I even got to play a little golf with our Midwest blogger Jim Kerns. Having left State College on Sunday and not really seeing much of anything on the disease front at Penn State, I was excited to find out if there were any actual turf diseases in the field...we hit the jackpot in North Jersey.

While certain diseases like anthracnose, leaf spot and brown ring patch were very active, I was surprised to see active dollar spot and RECOVERING brown patch (looked like it was active about a week ago or so). I think that things have been some moist and humid that everything is just taking off at this point. This would definitely be the earliest I have ever seen brown patch in the mid-Atlantic region and is in general pretty early for dollar spot as well.

Thatch collapse

This morning I headed into the Valentine research facility in State College and was surprised to see a LOT of disease activity there as well. We still don't have any dollar spot and brown patch is definitely a ways off for us, but there are several things going on. First, seedheads are in full force right now and we will be rating our plots over the next few weeks to see what worked and at what timing. As for diseases we are seeing: red thread, leaf spot, brown ring patch (images below, we are confirming by isolation...update to come), thatch collapse (see next month's GCM issue), Microdochium patch, and probably something else that I am forgetting.

So diseases are here or just around the corner...we could be in for another long year.

A Cornucopia of Disease in Southeast Asia

I sometimes find such healthy grass that I have little disease to write about, but this week was an exceptional one. I went from Kanchanaburi to Bangkok, Singapore, and Da Nang, seeing a number of grasses and on them an assortment of pathogens. Click the thumbnails for a full-size image and description.

If there were an award for diseases, seashore paspalum would win this week, with two different unidentified diseases and slime mold and dollar spot, with a bonus for some extraordinary drought stress. In the image below, there is an unidentified patch disease and dollar spot on a seashore paspalum fairway in Bangkok. And you can see the drought stress in the drain lines going to the catch basin in the background. But wait! Can you see the patch of Zoysia matrella in the center-left of the photo? The Zoysia matrella that is free of disease and doesn't have the drought stress of the paspalum even though it is growing in the drain line? Seashore paspalum does not grow well at all in Southeast Asia in areas of low soil moisture content.

Seashore paspalum grows wild in tidal swamps and in intertidal zones. Which is exactly where I found it growing on the beach at Da Nang (below), in its natural environment, and free of diseases. But come in from the beach a short distance, where the high tide does not reach, and I found wiry Zoysia matrella growing in the dunes.

There was brown patch on bermudagrass at Vietnam and bermudagrass white leaf, which I think is the most unsightly disease, on bermudagrass at Singapore and Vietnam.

Most of the diseases, you notice, were on seashore paspalum and bermudagrass. I saw two types of broadleaf carpetgrass this week, both free of any disease. This grass thrives in the umbrageous conditions so ubiquitous in tropical Southeast Asia, as does zoysiagrass.

And for those more interested in cool-season grasses, you probably read with some interest the post from Dr. Kerns and Dr. Soldat a few weeks ago about managing potassium on cool-season turf. I'm fascinated by the Park Grass experiment and its results showing that potassium and lime application cause a proliferation of dandelions and other weeds, and the most recent issue of the Green Section Record has an article with some insights into that experiment and how the results "carry lessons of high importance in the growing of golf turf."

Healthy Grass = Little Disease

I've seen a lot of healthy grass in Asia over the past couple of months. This tends to be the driest season of the year for much of Southeast Asia, and no matter what type of grass is being grown, I haven't seen much disease. A bit of curvularia on Zoysia matrella in Thailand, some fairy ring on Tifeagle bermudagrass that was a trifle peckish, and the ubiquitous dollar spot, especially on seashore paspalum.

For management of dollar spot on seashore paspalum, assuming it is still warm enough for the grass to grow, I recommend keeping the leaves drier, the soil wetter, and applying a bit more nitrogen. We've looked at various treatments of calcium, potassium, nitrate vs. urea as a nitrogen source, etc., and we have detected no effect on dollar spot intensity of seashore paspalum. Creating a more salubrious environment for the grass invariably solves the problem.

Speaking of salubrious environments, I don't think there is a better place for a turfgrass conference than Thailand. Working on behalf of the Thailand Golf Association, the Thai GCSA do a great job putting together all the logistical details of the Sustainable Turfgrass Management in Asia conference and we get tremendous support from The R&A and from the golf course superintendents who travel from all parts of Asia to attend this educational event.

Dollar Spot Expedition to Southeast Asia

Route through SE Asia

Dalat Palace Golf Club

Last week, I travelled throughout Southeast Asia with Dr. Micah Woods, international blogger and Director of the Asian Turfgrass Center, and Mr. Matee Suntisawasdi, Marketing Director for Procrop T&O. We went on an Indiana Jones-style expedition that included four countries (Thailand, Vietnam, Malaysia, and Philippines) and over 50 hours in the air. We found dollar spot in every country and collected isolates from many different grasses, including creeping bentgrass, velvet bentgrass, bermudagrass, seashore paspalum, zoysiagrass, and carpetgrass, just to name a few.

I want to thank everyone that made this trip possible by hosting us at their facilities. I owe a particular debt of gratitude to Dr. Woods, Mr. Matee, and Dr. Beth Baikan, who did the vast majority of the planning. The samples we collected will undoubtedly teach us a lot about this important turf pathogen.

Some highlights of the trip included:

Roger Jones making sand at Twin Doves

Kasetsart University, Bangkok, Thailand. This university is forming a team of scientists to work on turf. We met with agronomists, plant pathologists, and nematologists that are interested in turf, discussed some potential collaborative projects, and toured their brand new lab facilities.

Dalat Palace Golf Club, Dalat, Vietnam. A resort course and luxury hotel in the mountain town of Dalat with ‘SR1020’ creeping bentgrass greens. But the highlight of the day was when the assistant general manager, Mr. Ahn, took us out for goat prepared 5 different ways and a case or two of Heinekin beer.

Mount Kinabalu Golf Club

Twin Doves Golf Club, Ho Chi Minh City, Vietnam. A brand new golf course on the outskirts of Ho Chi Minh City planted wall-to-wall with ‘Platinum’ seashore paspalum. Roger Jones, the Director of Grounds, showed us the procedure he developed to produce sand that meets USGA specs from a local river sand.

Camp John Hay Golf Club

Mount Kinabalu Golf Club, Malaysia. Dr. Baikan, a fellow Rutgers graduate and environmental scientist in Malaysia, greeted us at the airport and accompanied us to this location tucked in the side of Mount Kinabalu at 5,000 ft above sea level. The course only gets 900 rounds a year due to nearly constant rainfall. The cool, wet, misty climate was perfect for dollar spot and we saw the disease on nearly every grass species on the property!

Camp John Hay Golf Club, Philippines. Originally built as a resort the US military, this course was redesigned by Jack Nicklaus in 1998 and is now a popular tourist destination. Because they were restricted in the number of trees that they were allowed to remove during construction, they constantly struggle with shade problems. It was interesting to see their experiments with different grasses and management strategies to overcome this hurdle.

Manila Golf Club

Manila Golf Club, Philippines. This immaculate seashore paspalum golf course is an oasis in the middle of the booming metropolis of Manila.

Manila American Cemetery, Philippines. Right next door to Manila Golf Club, this is the final resting place for over 17,000 American soldiers that were killed in the Pacific Theater during World War II. We were lucky enough to get a personal tour from the facility manager, Bert Caloud, who is an encyclopedia of World War II history. I really admire the work that they do there to honor the memory of those who gave their lives for this country.

Manila American Cemetery

Khao Yai, Thailand. On the last day of the trip, we took some time to relax, go on an elephant ride, and get ready for Super Bowl XLV!

Khao Yai

Is Emerald a Poor Curative for Dollar Spot?

Over the years, I've heard a number of people say that Emerald is a slow or poor fungicide for curative control of dollar spot. I must confess that I've never understood what everyone is talking about.

Given that boscalid, the active ingredient in Emerald, controls fungi by depleting their energy reserves, it makes sense that it might be a little slow to work on a curative basis. However, in reality, I've always been impressed with it's activity on both a preventive and curative basis.

Let's look at a couple of examples. In this first curative dollar spot control study, we had an average of 40 to 45 dollar spot infection centers in each plot before initiation of treatments. That's not a huge amount of dollar spot on a 20 square foot plot, but certainly enough to warrant a curative fungicide application in a golf course setting.

On July 20, just 5 days after applying the low rate of Emerald, we reduced the number of infection centers down to 2 per plot, whereas the number in untreated plots held constant. So, the low rate of Emerald reduced dollar spot incidence by 95% in 5 days. I'd consider that to be pretty good curative activity! If you're expecting more than this out of a curative application, then you are probably expecting too much.

Looking at some older data, in 2006 we evaluated Emerald, Daconil + Emerald, and Daconil + Banner for curative dollar spot control. In this case, the dollar spot pressure was much more intense, with 150 to 200 dollar spot infection centers per plot before the initiation of treatments. After the first application on 19 Jun, dollar spot incidence declined in all of the treatments at a similar rate and none of the treatments were disease free until three weeks later on 10 Jul. And this is even though dollar spot disease pressure was much lower during late June and early July, as evidenced by the decline in the amount of disease in untreated plots.

Curative control of any disease is more dependent on the level of disease pressure, the amount of turf injury present, and the growth rate of the turf after the application. Which fungicide is applied probably isn't that important in most cases. In order for the disease symptoms to go away, the turf has to grow out of the symptoms and spread into the damaged areas. This, of course, takes time. There aren't any fungicides that will make dollar spot go away over night.

For a lot of reasons, we don't recommend controlling dollar spot on a curative basis. Perhaps the most important reason is that curative applications increase the risk for fungicide resistance to develop. If you find yourself in a situation where you need to make a curative application for dollar spot control, be sure that you are tank-mixing with chlorothalonil to reduce the potential for resistance to develop. This is especially important for products with a high resistance risk like Emerald.

Turfgrass Diseases in India

I spent this week in India and saw active dollar spot, fairy ring, probable bermudagrass decline, and also this unidentified disease on a bermudagrass green at Kolkata.


I suspect this is pythium blight, due to the apparent streaks of disease moving downhill with the drainage pattern, and because of its occurrence on two greens that appeared to have saturated soil conditions. Upon consulting with the conductor of this website, the possibility that this may be a leaf spot disease was also raised. And as I consult my Compendium of Turfgrass Diseases, I see that the environmental conditions for pythium blight and leaf spot diseases of Cynodon overlap to a large extent.


Disease control is obviously more difficult in a country such as India where there is not easy access to diagnostic laboratories. A disease such as dollar spot, seen on a bermudagrass fairway above at Bangalore, is easy to diagnose and control. But pathogens such as bermudagrass decline or leaf spots can be more difficult to diagnose with precision.

Two other factors further complicate disease control at India. First, many of the greenkeepers do not have ready access to information about turfgrass diseases and their control, nor do all greenkeepers understand what type of cultural practices can optimize plant health and minimize disease problems. Second, the types of sprayers used on many golf courses can be difficult to use, somewhat difficult to calibrate, and inconsistent in both droplet size and spray volume.

A tractor-mounted sprayer with a hand-gun is a typical agricultural sprayer found at many golf courses in India.

And the type of manual spraying system with a foot-pump as shown below is not the fastest or most precise way to apply products to the course, but if this is the only sprayer available, then it must be used.

There is a lot of golf development happening now at India and plans are underway for more greenkeeper training. One expects that greenkeepers will soon have access to more information about turfgrass diseases along with the types of maintenance equipment necessary to optimize the growing conditions and control turfgrass diseases more effectively.

Civitas Update....By Popular Demand

First, my apologies for the tardiness of this post. The pre-Thanksgiving travel crunch got the best of me last week, and of course I spent the entire weekend watching football and hockey, so I am just now getting caught up! Several people have asked what happened to the Civitas update, so here it is:

Civitas is a new product for disease and insect control in turfgrasses that was developed by Suncor, formerly known as PetroCanada. The active ingredient is mineral oil, otherwise known as 'horticultural oil', which has been used for management of plant pests for many years. It has just never been used in turf because of issues with phytotoxicity. However, Suncor developed a pigment product, called Harmonizer, that is mixed with Civitas to reduce the potential for phytotoxicity. The advantage of mineral oil as a fungicide is that it has very low environmental impacts due to its low toxicity and rapid breakdown in the environment.

Because it contains oil and pigment, Civitas has a very noticeable effect on the color and appearance of the turf. The Harmonizer pigment, depending on the application rate, is a very dark green, similar to that provided by an application of Triton Flo or Tartan. Some people have complained that transfer of the pigment to shoes and clothing has been a problem, but I haven't rolled around on our research plots yet to see how big of a problem that is.

The mineral oil component of Civitas also gives the turf a distinct greasy appearance, very similar to that caused by an application of a wetting agent like Cascade. This greasy appearance is most evident in the morning and persists for several days to a week after application. Because of these unique characteristics of Civitas, I suggest that people try it out on a nursery green or putting green before treating the whole course with it.

We've been evaluating Civitas for control of various turf diseases for three years now. For a summary of our previous results, please see my post from last year entitled Civitas shows promise for control of dollar spot and brown patch. Be sure to read the comments at the bottom provided by Wakar Uddin, Bruce Clarke, and others regarding their experiences with Civitas.

We continue to see similar results against dollar spot and brown patch in our trials. However, this year we ran into serious problems with phytotoxicity when Civitas and Harmonizer was tank-mixed with Daconil and Banner Maxx. The injury appeared very quickly after the first application in May and became more severe as time went on. As you can see in the graph to the left, it is also interesting to note that half rates of the mixture components did not reduce the amount of phytotoxicity observed. Based on this result, we definitely recommend that Civitas and Harmonizer should not be mixed with Daconil and Banner, or with other fungicides until we have the opportunity to evaluate more mixtures for their safety.

We haven't seen significant phytotoxicity from applications of Civitas and Harmonizer alone in our trials, but some users have reported injury during times of severe stress, with high temperatures consistently above 90F. It makes sense that it could create problems to coat the turf leaves in oil under these types of conditions.

To summarize, Civitas has good activity against several important turf diseases like dollar spot, brown patch, anthracnose, and leaf spot diseases. Although it does not provide acceptable control alone in most cases, my opinion is that it could be useful as part of a disease control program. Civitas and Harmonizer should not be mixed with other fungicides or applied to severely stressed turf, or severe injury could result. However, if you are interested in using products that pose less risk to environment, then Civitas is a good choice.

Honor (boscalid + pyraclostrobin)

Honor is a relatively new fungicide from BASF that contains the active ingredients boscalid and pyraclostrobin. Boscalid is the active ingredient in the excellent dollar spot fungicide Emerald and pyraclostrobin is the active ingredient in Insignia. Like Insignia, Honor will also be marketed under the umbrella of Intrinsic brand fungicides from BASF. If you have not heard of this, it basically states that pyraclostrobin may provide some additional plant health benefits aside from disease control. If you recall, John posted a blurb about our meeting at Farmlinks in October where we shown all the data behind the Intrinsic label. Although the data is a bit sketchy, there does appear to be some benefit to the plant. Before I go any further remember that these are fungicides and should only be used for disease control!

Disease Control

Honor is an excellent fungicide for broad spectrum disease control because it takes advantage of the dollar spot activity of boscalid and the brown patch and anthracnose activity of pyraclostrobin. Other diseases listed on the label are gray leaf spot, fairy ring, take-all patch and pink snow mold just to name a few. Therefore it could fit into a fungicide program for tees and greens at almost anytime of the year. However, I think it fits best during July or August when brown patch and anthracnose are likely to develop in the Midwest. Below are a few graphs highlighting the strengths of Honor against dollar spot. If you want to see how Honor's efficacy against anthracnose and brown patch compares to other fungicides, click on the diseases and you will see reports from Dr. Bruce Clarke at Rutgers University.

Curatively Honor (boscalid in particular) is slow to reduce the dollar spot epidemic, but overtime provides the best suppression. Preventatively Honor controls dollar spot well, but only provides acceptable control at the 1.1 oz rate under the pressure we experienced this year.

Summary

Honor is an excellent product especially for dollar spot and brown patch. I think the best fit for this particular product is during mid summer when dollar spot is still active and brown patch and anthracnose are just starting to get going. Plus pyraclostrobin also has activity against Pythium blight under lower pressures. Essentially this product could almost fit anywhere in a fungicide program in the Midwest.

Make your Friday night Reserve-ations

Book 7, part I … are you kids as excited as I am?

Maybe some of you went to the midnight showing last night?

My main post is about Reserve, but at the bottom I have some follow-up comments about granulars.

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RESERVE

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Last week I accidentally gave away a little bit of my story prematurely. Maybe it was my headachy/sleepy day, but I thought my fungicide assignment was Renown, not Reserve, and shared a little bit about a 2010 that included Reserve. You can look back at my post last week where Reserve was one component to a couple of program trials.

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What is Reserve? It’s a new formulation from Bayer that combines triticonazole (0.54 pounds active ingredient/gallon) and chlorothalonil (4.25 pounds a.i./gal) as well as StressGuard.

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It is labeled for quite a few diseases: anthracnose, brown patch, microdochium patch/pink snow mold, typhula snow mold, necrotic ring spot, red thread, rust, summer patch, take-all, large patch, and dollar spot as well as algae and summer decline.

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Like other triticonazole products, there is potential for damage to bermudagrass. The label indicates that it should not be used at all on ultradwarf bermudagrass varieties. In addition, the label says not to exceed 5.4 fl oz/1000 every 30 days on any type of bermudagrass, and, for golf courses in Florida, do not apply Reserve to bermudagrass greens when temperatures exceed 90. Lane talked about this topic awhile back, and you can read about it here:

http://turfdiseases.blogspot.com/2009/10/effects-of-dmi-fungicides-on.html

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How has Reserve performed in KSU trials? As I said, it worked well as part of the program trials this year, and you can see last week’s post.

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In 2010, we also compared Reserve with Concert, which is a formulated combination of propiconazole (0.3 pounds a.i./gal) and chlorothalonil (4.0 pounds a.i./gal).

Concert: applied at 5.5 fl oz/1000

= 5.9 grams propiconazole + 78 grams chlorothalonil/1000 ft2

Reserve: 2.5 fl oz/1000 = 4.8 g triticonazole + 37.7 g chlorothalonil/1000

______3.2 fl oz /100 = 6.1 g triticonazole + 48.2 g chlorothalonil/1000

______3.5 fl oz/1000 = 6.7 g triticonazole + 52.8 g chlorothalonil/1000

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The 2.5 fl oz rate of Reserve was applied 7 times, on 24 May, 9 June, 22 June, 28 June, 6 July, 14 July, and 20 July. The other treatments were applied 5 times, on 24 May, 9 Jun, 22 June, 28 June, and 14 July.

Disease in the untreated plots bounced around a little bit, peaking twice at around 9% severity. Except for a little bit of breakthrough (2%) in the lowest rate of Reserve, all the treatments held disease around zero (click to enlarge).

As you might expect, the repeated applications of the propiconazole-containing Concert did have some negative DMI-type growth-regulating effects that reduced quality. However, keep in mind that most people would be rotating, not applying the same product over and over. This is an artificial type of situation used in an experiment.

Here are two pics, one with plot borders shown and one without, showing the quality effects associated with the repeated applications of the propiconazole-containing product. The triticonazole-containing Reserve did not have such effects.

Results were pretty similar in a trial I conducted in 2009.

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Color splash or color crash? It’s not easy being blue-green?

I do have a final question about the StressGuard… I have heard from a couple of superintendents (like, literally, TWO) who don’t like the strong color that is apparent immediately after application. One guy said that he avoids products for that reason, and another said that he’ll water the products in a little bit to wash of the color. Anybody else have comments?

GRANULARS

I have a few comments related to Lane’s posting about granular formulations. I have a few observations for formulations of azoxystrobin.

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In 2008 I ran two trials for brown patch in tall fescue (lawn-height). In one trial, the applications were done on July 9 and August 5. The trial included Heritage TL at 2.0 fl oz/1000 (5.7 grams a.i./1000) and Heritage 50 WG at 0.4 oz/1000 (5.7 grams a.i./1000). On the morning of August 5, I rated the % blighting per plot before the treatments were applied. Disease in the untreated was at 32.5%. Here's a photo to show some symptoms:

Whereas both Heritage formulations knocked disease down to 0%, like in the plot below.

In a separate trial nearby, I applied Heritage G at either 2 or 4 pounds/1000, equivalent to 2.8 or 5.6 grams a.i./1000. Applications were done on June 30 and July 28, and disease was rated on August 5 (same as the other trial). In this one, the untreated was similar to the other trial, with about 40% blighting. The Heritage G treatments reduced disease to 7.5% (2 pound rate) and 4.5% (4 pound rate). So, while they did significantly reduce disease, it was not down to 0%. This photo shows some breakthrough with a granular treatment (blighted areas circled):

Of course, these trials were not set up to directly compare the granular with the sprayables, but it is consistent with Lane’s comments (and others) that granulars can lack the consistency that you might find with a sprayable formulation.

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