Turfgrass Diseases in India
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.
6 Things I Learned in 2010
For those of you who read the article in Golf Course Industry, you probably now know that I have issues sleeping. For the last 4 to 5 years I have generally gotten up and spent 3 hours or so learning new social media, video and photo editing, html, and other things that I wouldn't normally have time for during the day. For the last month, I have been able to sleep through the night with little problem. My conclusion? I would rather be up at night!
A Project365 is essentially a photo project that you do on your own to see if you can take 1 photo per day for an entire year. In 2010, I set out to complete this project as a way to better understand the settings and use of my camera. Well, the excitement quickly turned into a chore and I ended up failing after 263 days (continued from 2009). I plan on trying again beginning in 2011.
Attendees to the International Turfgrass Society conference in France, 2010. |
This year I had the opportunity to travel more than I had ever in the past. Presentations, Conferences, Trade Shows, etc. took me all around the United States, Canada, England, Scotland, South Africa, France and other places. Despite having some hiccups along the way (getting stuck in Paris due to the Volcanic Ash), it gave me the opportunity to meet new people and make new friends in the turfgrass business. Although the world is relatively large, the commonalities among turfgrass managers worldwide makes our group a small and personable one.
Although the Turf Disease Blog was launched in May of 2009, it wasn't until 2010 that it really took off. This site, comprised of 5 pathologists and a few other guests, was meant to be a way to share timely information for those in the golf course industry. What started out with humble ideas is slowly progressing into much more. Last year, we had over 100,000 page views and visits from people in more than 120 countries. We now have our own website (www.turfdiseases.org) and will continue to expand on the project in 2011. The last month has given me a lot of time to think of the direction that I want to go with the site and I think that over the next year we are going to roll out some nice additions that will make the information even more useful.
I can't thank everyone enough for all of the feedback (positive and negative) that we have gotten over the last year. The blog has caused me to reexamine many things in my research, teaching and education program and has given me many opportunities and new ideas for future work. I look forward to continuing the evolution of the site in the coming months and years.
Enjoy the Holiday season and I wish everyone a Happy New Year!
We don't swim in your toilet, don't P in our pool. I mean, no P in our soil.
I have some quick news today, just passing along two links about recent fertilizer legislation in Michigan and New Jersey.
According to the articles linked below, golf courses in New Jersey are exempt. In Michigan, it appears that P is allowed if a soil test shows that it is needed, for golf, home lawns, farms, or other sites.
Any comments from those of you in those states? Or in states like Wisconsin or Minnesota where legislation has been on the books for awhile? It is not anything like the complex regulations John talked about for Ontario, but I'm curious how these things are affecting your operations or might in the future.
Michigan: For article click HERE
New Jersey: For article click HERE
Kansas Turf Conference
I'd like to send an official thank you to Lane, who came out to speak at our Kansas Turf Conference this week. Lane gave some excellent presentations there, then he came over to the university and gave a research/academic seminar over here in my department. Five presentations in 2 days didn't seem to faze him too much, though he did appear happy when beer time arrived last night. Well, beer time arrived each night, but I think on the final night it was best, with all the work finished.
So, thanks again Lane!
Our other out-of-state speakers were Chris Williamson (U of Wisconsin, entomology), Michael Dukes (Florida), and Dave Minner (Iowa State). If any of you guys are reading this blog... thanks! It was great to see you all, and our Kansas turf managers sure appreciated your time and energy.
Ontario IPM Accreditation Program
Starting the program off, Dr. Nailor asked for everyone having to fill out the numerous forms (upwards of 120+ for some) to stand up so she could give them a "tip" on how to make things easier on them during the process. "Move your one arm across your chest, while pulling with your other hand..." said Nailor as she led each of the form-filers through a series of excercises to stretch out because the superintendents would be "spending that much time in from of your computer." She then got serious and started relaying the updates from the MOE (Ministry of the Environment) and the Ontario IPM Accreditation Program. IPM Accreditation is mandatory for all golf courses by April 22, 2012.
The program is "to recognize both individuals and golf courses that have demonstrated a knowledge and commitment to the principles of IPM through a process of certification, auditing and professional development." the program consists of 1) Certified IPM Agents and 2) IPM Registered Golf Courses and Facilities
Below are the forms and procedures that must be completed:
- Desk Audit Checklist: Just a list to ensure that you have filled out all of the forms below...essentially a form for a series of forms.
- Scout Forms: Must be filled out once per week and includes environmental conditions, location, pest or condition, # of pests observed, possible contributing factors, and action taken.
- Product Application Forms: Basically a pesticide application form similar to what everyone usually fills out. Forms must include 2 reasons for fungicide use, calculation of the actual active ingredient used and follow-up observations 3 to 7 days after application.
- Equipment Calibration Form: One for backpack and one for a boom-sprayer must be completed and a minimum of 3 calibrations must be completed on each piece during the season (unless used less than three times during the season, in which case, you must calibrate once)
- Hot Spot Management Record: I'm not sure how this is different from the "Scout Forms", but superintendents must keep a "record of observations and actions taken to manage a problem area throughout the year and future management plans"
- Annual Report: A summary of the total of all pesticides AI used, expressed in kg ai. This must be public and posted in public and made available at the annual public meeting.
- Map: A detailed visual map of EVERY pesticide application made to all areas of the golf course summarized by total AI applied to each area (more on this below).
- Training Documentation: Documentation of all training completed for anyone applying pesticides or scouting for diseases. It was pointed out at the meeting that no one really knows what constitutes training
but I would believe that spending 20 minutes per day on this blog should suffice.
Example diagram that may be used to explain pesticide use on golf courses in Ontario? |
The BIG problem with all of this is going to be the required "Public Hearing" which must occur for each club. This must be done before November 20, 2012 (and after January 31, 2011) and must be open to anyone who wants to come. Details of the meeting must be published in a newspaper 2 weeks prior to the meeting and all neighbors within some distance (I believe 200 meters of the course) must be notified individually (the newspaper will not suffice). At the meeting, the Annual Report and accompanying Map must be made available.
From my observations during her talk and from a brief visit to the program's website it is obvious that while the program seeks to reduce the use of pesticides on golf courses (and I am fine with that idea by the way), they have absolutely NO idea of the impact that this is going to have on golf as a business and probably NO understanding of what this will have on the environment as well. I would say that a strong majority of the superintendents have a solid IPM program in place. A mandatory program with this much paperwork (with little to no assistance) and a mandatory "town hall" style meeting is not going to cause changes based on science, but rather emotion. While I think that some of this reporting and documentation will be good, it is likely that the public display will result in more stringent restrictions based on emotion and likely put some Mom-and-Pop golf courses out of business. Dr. Nailor's suggestion to anyone considering using the Ontario IPM Accreditation as an example was to "Take your time when developing regulations and ask for phase-ins." If there was anything that I took out of this was that the superintendents were lucky to have someone like Brenda and the University of Guelph there to help with all of the complications that are bound to arise from this program.
Civitas Update....By Popular Demand
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.
100,000 Page Views Reached!
Thanks again for all of our readers and contributors and thanks to Syngenta who was our sole sponsor for the year. Their support of our Turfgrass Compendium Giveaway contest helped to raise money for the Student Travel Fund within the American Phytopathological Society which helps to offset travel costs for turfgrass pathology graduate students.
Renown: Broad Spectrum Activity via Azoxystrobin and Chlorothalonil
Renown Fungicide - Broad Spectrum Control of Foliar Diseases
Renown is a fungicide pre-mix recently labeled by Syngenta for use in the U.S. The active ingredients in Renown are azoxystrobin and chlorothalonil, which are the active ingredients in Heritage and Daconil fungicides respectively. When it comes to broad spectrum activity, you can't get much broader spectrum than both of these two active ingredients. Azoxystrobin is a QoI that is effective against a number of ascomycete, basidiomycete and oomycete pathogens. Chlorothalonil, as you all know, pretty much takes care of most foliar pathogens (including algae) but not foliar Pythiums.
Renown has a wide range of activity against a number of diseases including: algae, anthracnose, brown patch, copper spot, dollar spot, gray leaf spot, large patch, stem rust, stripe rust, southern blight, yellow patch, yellow spot, zoysia patch, leaf rust, leaf & sheath spot, melting out, Microdochium patch, pink patch, powdery mildew and red thread.
Because azoxystrobin is a systemic fungicide while chlorothalonil is a contact, the best use of Renown would be for foliar disease control. Also, if the product is applied in 2 gal water per thousand, that should also be enough to cover diseases that reside in the thatch, mat or upper root zone on closely mowed turf types (i.e. grees and tees). When targeting deep soil and root infecting pathogens like fairy rings, it may be better to use a different fungicide this purpose. Watering-in a Renown application to get soil activity from the azoxystrobin component could cause you to lose the benefit of the chlorothalonil for foliar disease control.
Renown comes as a suspo-emulsion formulation containing 0.32 lbs of azoxystrobin and 4.84 lbs of chlorothalonil per gallon. Use rates are 2.5 to 4.5 fl oz which is equivalent to 1 fl oz Heritage TL plus 2 fl oz Daconil Weatherstik and 1.8 fl oz Heritage TL plus 3.6 fl oz Daconil Weatherstik, respectively.
Renown has looked very good in our anthracnose and pretty good for dollar spot as you can see in the next few slides.
Two applications of Renown also appeared to be effective in controlling brown ring patch in 2008 trials in San Diego: archive.lib.msu.edu/tic/gcman/article/2009aug74.pdf
The benefit for using Renown would be in the control of multiple diseases where the combination of azoxystrobin and chlorothalonil would put you at a distinct advantage. For example, when leaf spots and brown patch are active at the same time, or gray leaf spot and Southern Blight, etc. There are some specific situations where using Renown would also make sense as described below.
Fungicide resistance. For certain diseases like anthracnose and gray leaf spot, where QoI-resistance is a problem, the pre-mix would be of an advantage. For both of these diseases, QoI-resistance has been a problem in a lot of locations, but the addition of chlorothalonil in the application would help control those resistant isolates. For other diseases, where QoI-resistance is not yet a problem, the mixture would aid in helping to delay resistance due to the dual mode of action.
Dollar spot. Although the WG formulation of Heritage is not particularly effective vs. dollar spot, it appears that the liquid TL formulation has better activity against the disease. The additional of chlorothalonil would help in controlling the disease. This would be valuable when there are other diseases like brown patch are active.
Non-DMI for summer disease control. Renown can pick up a lot of the mid- & late-summer diseases you would face on cool season and warm season turf like leaf & sheath spot, melting out, anthracnose, etc. Although highly effective, there can be times in the summer when a non-DMI would be advantageous for use in these situations.
Keep in mind that applications of Renown count towards the yearly limit of chlorothalonil use on turf. Each application contains 1.5 to 2.7 oz chlorothalonil, and recall that there is a 9.5 oz, 19.1 and 26.8 oz chlorothalonil per 1,000 sq ft yearly limit for roughs& fairways, tees, and greens, respectively.
Damn it's Cold on the West Coast
Although we're still a few weeks away from the official start of winter, it's been pretty damn cold in the West. Seattle got snow last week and Portland was pretty much frozen last Tuesday and Wednesday. Temps in the 50s-60s are present in much of the Golden State with below freezing night time temps being seen in the Central Valley.
Pink snow mold is likely to be coming in these cold wet conditions and so is freeze and winter damage.
Other than that, I hope everyone had a great Thanksgiving holiday! I'll see some of you in Portland this Thursday at the Oregon Pesticide Seminar.
Until then, signing off from the Right Coast....
Trinity and Triton
Trinity,Triton, & Turkey
Hello,
I hope you all had a lovely holiday with your families and/or friends. Having met the extended Wong family, and seeing their passion for food, my guess is that Frank et al are all still in a food coma today.
Trinity and Triton are two of the newer DMI products in turf. Frank did a nice job summarizing these materials recently and you can check it out here:
http://turfdiseases.blogspot.com/2010/06/get-yer-t-ts-out-and-use-them-for.html
Since I don’t think I could put the “review” any better than Frank did, I’ll let you read his description above. So, I’ll skip right to some of my own experiences. I’ve had a few trials with these products and I’ll mention a couple of them here:
2009, Triton Flo
The study was conducted in ‘A4’ creeping bentgrass. Applications were made at 14-day intervals beginning 28 May with the final application on 20 August. Fungicides were applied with a CO2-powered boom sprayer equipped with two XR Tee Jet 8004VS nozzles at 30 psi in water equivalent to 2.0 gal/1000 ft2. Plots were 4 ft × 10 ft and there were four replications of each treatment. Plots were rated by visually estimating the percentage of each plot affected by dollar spot or brown patch symptoms.
Dollar spot was present on several rating dates. All materials reduced dollar spot to zero except for a trace amount in the Reserve 2.8 fl oz treatment on 17 Jul and 12 Aug. Brown patch symptoms were visible on only one rating date, 17 July, at low levels, and all fungicides reduced disease to zero.
The results are summarized here, and you can click to enlarge:
2009, Trinity:
This study was conducted in a stand of Cato-Crenshaw. Disease became quite severe in the untreated. The photo below shows treated plots surrounded by untreated, and the graph shows disease progression in the untreated. All treatments reduced disease to zero on all dates:
Name | Rate (oz/1000) | Interval |
Insignia + Trinity | 0.5 + 0.1 | 14 days |
Emerald | 0.13 | 14 days |
Emerald | 0.18 | 21 days |
Honor | 0.83 | 14 days |
Honor | 1.1 | 21 days |
Triton Flo, 2010
Triton Flo was part of a fungicide program study in 2010. You can check my post from 2 weeks ago.Last note: potential phyto on bermudagrass
OH, don't forget, as I mentioned last week when discussing Reserve, triticonazole products can put the hurt on bermudagrass so read those labels and be cautious.
.
.
Honor (boscalid + pyraclostrobin)
Concert (chlorothalonil + propiconazole)
Below are the results of some research findings from Penn State and Connecticut.
One of the things that is worth pointing out is that these field studies are done to determine disease control with single products. Due to this fact, most of our studies are carried out in a manner that results in repeated applications of products that would otherwise not be sprayed that often. So it is not uncommon for injury to appear in our studies. Having said that, I found that the differences in injury among studies can often vary as was the case in two separate studies conducted at Penn State and UConn. In the Penn State study, no differences were observed between any fungicide and the untreated control, but there was a separation among fungicides. Namely, those products that contained the pigment in StressGard had improved quality relative to plots receiving Concert.
On the other hand, field studies at Connecticut showed significant injury from repeated applications of other fungicides including Triton (a DMI) and Reserve (DMI + chlorothalonil). Injury was observed within the plots treated with Concert, but the phytotoxicity was not different from the untreated control. No injury was observed when either of the actives in Concert were used along. So I guess the lesson here is that perhaps Mr. Hoff is correct and the new formulations developed during the creation of the "Pre-Mix" packages do influence different aspects of the product.
You can read the full research reports here:
Inguagiato, J.C., R. Blake and J.E. Kaminski, 2010. Preventive anthrancose control in putting green turf with various fungicides.
Kaminski, J.E. and T. Lulis. 2009. Impact of fungicides on teh control of anthracnose basal rot, turfgrass quality and algae on a golf course putting green.
What Syngenta said (slideshow):
Concluding thoughts:
Concert is an effective fungicide against a wide array of turf diseases and can be used as an integral part of a disease resistance management strategy due to the inclusion of chlorothalonil. Diseases that it would be effective against would be brown patch, anthracnose, dollar spot, gray leaf spot and others. Repeated application of this product may be met with a couple of problems. First, seasonal use rates of chlorothalonil should be closely watched. These tank mix partners can confuse or at least make it more difficult to figure out how much actual active you have put out, especially when using different products all containing chlorothalonil. Additionally, the repeated use of any of the DMI's should be avoided due to potential phytotoxicity issues. Most of the research protocols that I have seen have been built with Concert in mind as a component of an overall fungicide program. Golf course superintendents should develop similar programs for their golf courses that target the primary problems they are facing. In the right situation, Concert can be an effective product in a sound program.
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.
.
RESERVE
.
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.
.
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.
.
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.
.
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
.
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.
.
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
.
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.
.
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.
.
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.
.
.
Fungicide Review: Polyoxin D
Polyoxin-D zinc salt is the active ingredient in two turfgrass fungicides: Endorse (Arysta) and Affirm (Cleary Chemical). There’s been some switching around of names and products since 2009 (as discussed last year) when Arysta LifeScience took back the distribution rights for the 2.5% WP formulation and Cleary’s introduced Affirm, a 11.3% WDG formulation, that contained the same active ingredient. Either way, both formulations have the same range of disease control and I haven’t seen any data so far to suggest that the two formulations have any significant differences in disease control between them. Polyoxin D is classified as a FRAC Group 19 fungicide (polyoxin antibiotics) and presently, only polyoxin D is registered as a turf fungicide in the U.S. (Image to the right taken from alanwood.net)
There are a number of other polyoxins out there (polyoxin A, polyoxin B,…polyoxin J, etc.), and they all share a common “ancestry” as far as being discovered as metabolites of Streptomyces bacteria (which are commonly called Actinomycetes). Streptomyces are typically soil inhabiting bacteria and are potent producers of some very important anti-bacterial and anti-fungal antibiotics. Interestingly, antibiotics derived from Streptomyces species account for two-thirds of our commercially available antibiotics including streptomycin, chloramphenicol, tetracycline and vancomycin (anti-bacterials) and nystatin and amphotericin B (anti-fungals).
Polyoxin D was discovered in 1965 as a fermentation product of Streptomyces cacoi var. asoensis (Suzuki et al 1965 Journal of Antibiotics Ser. A), so interestingly, this molecule has been around for a long time! Commercial fungicides containing polyoxin D utilize this active ingredient in the form of a zinc salt. Why, may you ask? Because the polyoxin D molecule is extremely water soluble and it would wash off of plant surfaces easily; the zinc salt form of polyoxin D is much more stable and enhances the longevity of the fungicide on the plant surface.
Biochemically, polyoxin D inhibits the formation of chitin, which is the main component of the cell walls of true fungi (Ascomycetes, Basidiomycetes, etc.). You can see from the photo here (taken from Endo et al. Journal of Bacteriology 1970), that fungal cells treated with polyoxin D (top photo) are unable to make functional cell walls and thus can’t function normally like the untreated ones (bottom photo).
Since Oomycetes like Pythium don’t use chitin in their cell walls, polyoxin D won’t affect these “water mold” type fungi. Polyoxin D is considered a local penetrant fungicide, and does not translocate easily upwards in plants like some other systemic fungicides, so coverage is important when applying these.
The earliest use of polyoxin D was for the control of rice sheath blight (Rhizoctonia solani) in Japan back in the 1970s. Not surprisingly, for turf diseases, Endorse and Affirm would be considered strongest against Rhizoctonia diseases like brown patch, large patch and yellow patch and the Rhizoctonia-like Waitea diseases like brown ring patch and leaf and sheath spot.
In a large patch trial we did in 2008, you can see that Endorse was very good in controlling large patch.
Applications made 16 Apr and 6 May to bermudagrass
In a brown ring patch trial also conducted in 2008, Endorse provided some of the quickest control of the disease, but didn’t have as much residual as some other treatments. We suggest tank mixing Endorse or Affirm with another fungicide like a DMI (Banner MAXX, Tourney, Triton or Torque) to get good knock down and added residual.
One curative application made on 26 Apr
In our California trials, we’ve seen it been pretty good against anthracnose and although other materials seemed to be better, Endorse and Affirm could certainly be added into the summer rotation.
Six applications total from Jun to Aug, 2005 data
Other diseases on the labels include pink and gray snow molds (it seems like they are best tank mixed with another fungicide for the best control, but ask Jim about that one), red thread, leaf spots, gray leaf spot, and fairy ring.
Endorse looked pretty good vs. fairy ring in trials conducted by myself and Mike Fidanza :www.gcsaa.org/gcm/2007/may/pdfs/treatingFR.pdf
However, I can’t say that I’d recommend polyoxin D by itself for gray leaf spot, I just haven’t seen enough data to say it’s a good choice for this disease when other fungicides are available.
OK – that’s enough geeking out for tonight – until next week, signing off from the Right Coast….
Instrata (Chlorothalonil + Propiconazole + Fludioxonil)
New Granular Fungicides for Turf
Two things were limiting the usefulness of granular fungicides: a limited selection of products and low-tech carriers that weren't very effective for foliar disease control. As a result, my standard recommendation has always been that if you want good disease control, you should spray instead of spread. As an example, look at the tall fescue plots to the left that were both treated with triadimefon at the same rate of active ingredient per acre. Triadimefon is not a very effective brown patch fungicide to begin with, but the sprayable formulation (Bayleton) is much more effective that the granular formulation (Fungicide VII).
Things changed quickly, though, and today many more products are available on granular carriers, including recent products like Armada, Disarm, Heritage, and Headway. Several others are currently being tested as experimentals. Furthermore, these new products take advantage of modern granular formulation technology that makes them more effective against foliar diseases by increasing foliar absorption of the active ingredient.
We've evaluated a number of these new granular formulations, mostly against brown patch in tall fescue in a lawn care scenario. I will include a couple of examples here. I would summarize by saying this: these new granulars are more similar to their sprayable counterparts for brown patch control, but generally their efficacy is a erratic and they require more frequent applications. I still think that if you have the capability to spray, it's still better to spray. But these products provide more options to turf managers in situations where spray applications are not possible or practical.
Another possible advantage of a granular formulation is for control of root diseases like summer patch, spring dead spot, fairy ring, take-all patch, etc. To control these diseases most effectively, you obviously want the active ingredient to be in the root zone. With a granular, you can make the application and then water in later at your convenience, rather than having to worry about running the heads right behind the sprayer before it dries on the foliage. While we haven't tested these newer products against root diseases, we always used to see very effective spring dead spot control from granular formulations of Rubigan.
I'd like to hear some comments from our readers on this topic: What are the advantages and disadvantages of these granular formulations in your experience? If you are using these products, how and for what are you using them?
Interface (Iprodione + Trifloxystrobin)
Turfgrass color. Turfgrass color (which excluded the impact of disease within each plot) was rated on 27 Jul (2 weeks after the third application). All plots treated with Interface and Tartan had improved color when compared to the untreated plots and those treated with Iprodione Pro.
Overall, dollar spot suppression within this trial was good to excellent with products containing Iprodione. A slight rate effect with Interface treatments was observed. Moderate suppression of dollar spot was achieved within plots treated with Tartan. This is likely due to a known reduced sensitivity to fungicides within the DMI chemistry at this site. All treatments containing the green pigment StressGard improved turfgrass color and quality throughout the study.
What Bayer had to say:
- Consistent Disease Control
- Turf Safety
- Turf Quality
- Disease Control
- Best Leaf Spot Product
- Great Dollar Spot and Brown Patch Performance
- Great rotation product for Anthracnose Programs (including Basal)
- Top Snow Mold control for < 150 days snow cover with earlier green up in the spring
An added strength of Interface® is the addition of the StressGard technology. While I still don't know exactly how and why this provides improved plant health, the benefits of this additive are consistently observed in the improved turfgrass quality and color following application.
Overall, I think that the combination product will be useful for controlling common turfgrass diseases during the summer months and will be effective in a rotational program. In situations where its use is effective against anthracnose and/or other diseases where known resistance may occur, it will be important to rotate fungicides from other chemical classes. Although this is not specifically related just to Interface, the Pre-Mix packaging of fungicides is becoming more common. A primary concern of mine with this is the potential overuse of certain fungicides where resistance is known to develop relatively rapidly (namely the strobilurins). Golf course superintendents should pay close attention to the active ingredients within the various Pre-Mix products and make efforts to truly rotate chemistry when developing their seasonal fungicide programs.
Download the pdf Fungicide Label.