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We designed a short, 5 minute survey to better understand how golf course superintendents build and implement their putting green fungicide programs. Your valuable responses will be used to guide our future efforts to develop online tools and utilities for golf course turfgrasses.

One lucky participant will be selected at random to receive 2 free sample diagnoses from the NC State Turf Diagnostics Lab, a $200 value. But you must take the survey by March 21 to be eligible to win, so don't delay!

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Thank you in advance for your assistance on this project!

Greetings from the Midwest

Hello from the Midwest! I have been on hiatus from the blog because of a family issue that popped up. The main news from the Midwest has been the extremely warm spring. Most places in the Midwest experienced the second or third warmest spring on record. Samples have been rolling in to the Turfgrass Diagnostic Lab (TDL), but there has not been a consistent trend in our diagnoses. In other words, no single disease has dominated the Midwest. With the recent weather conditions, at least in Wisconsin, turfgrass is very happy! The picture to the right documents the average daily temperature from May 17 to now, which has been fairly warm for us.

We have seen a little bit of brown patch develop a few weeks ago when we were very hot and humid. Dollar spot has been seen throughout the Midwest and was first observed about two weeks ago. What a difference a year can make! Last year we were still dealing with snow mold and winter injury this time last year. This year we are already fretting over brown patch and dollar spot.

We have had a few samples already with symptoms characteristic of take all patch. After looking at the samples we had to do a double take, because it is way too early for take all patch. Again we had to keep in mind the extremely warm and early spring we experienced. We have had a few samples submitted complaining of small, yellow, irregular patches that developed in mid to late April. Typically the patches persist until early to mid-June and were on fairly young putting greens. We did not observe much pathogen activity in the foliage or root tissue, but isolations seem to indicate that a fungal or fungal like organism is associated with these symptoms. Dr. Lane Tredway has seen similar symptoms in North Carolina and did not find significant pathogen activity. Maybe later this week or next we can figure out what the fungus (fungi) is associated with the affected tissue.

Although we have had a warm spring, we have had significant, localized rainfall amounts . So some golf courses have experienced increased play volumes, while others have noticed similar levels to last year. The weekend forecast does not look promising for the Madison area, which stinks! Especially considering the fantastic day we had yesterday, it was 60 degrees with rain all day.

I'm glad I am back to the blog and plan to post weekly once again! The one main point I wanted to make this week was if you have not made your first dollar spot application, tomorrow would likely be good timing considering the forecast for the weekend. Have a good week and weekend! On a final note, remember the Wisconsin Turfgrass Association Summer Field is July 27th, so mark your calendars.

Pythium Root Rot....Is it a disease or not?

Hot and wet weather during July and August typically brings outbreaks of Pythium root rot on creeping bentgrass and bermudagrass putting greens in the Southeastern United States. Symptoms of this disease usually appear as a yellow to orange, irregular dieback that is most severe in poorly drained or stressed areas. In some cases, however, Pythium root rot can develop in distinct spots and patches. These patches may be yellow, orange, or even purple in color.

Pythium root rot requires wet soils in order to develop, either from poor drainage, over-irrigation, or frequent rainfall. In fact, some pathologists argue that Pythium root rot isn't a real disease; they believe that the saturated soils are killing the turf and that the Pythium is simply colonizing dead roots. It's a 'chicken and the egg' type argument - no one knows for sure which came first.

I tend to believe that Pythium root rot is a real disease, simply because curative fungicide applications help to stop the problem and encourage turf recovery. That being said, if you have chronic problems with Pythium root rot, the only effective way to manage this disease long term is to improve soil drainage. All of the fungicides in the world will not provide adequate control if the soil is continuously saturated.

From the descriptions above, it is clear that Pythium root rot symptoms are highly variable and can be confused many other problems. Because of this, it is almost impossible to definitively diagnose this disease in the field. Curative fungicide programs for Pythium root rot are expensive, so a misdiagnosis can be costly. If you suspect that you have Pythium root rot, send a sample to a diagnostic lab for confirmation.

Few fungicides are labeled for Pythium root rot control, and there is virtually no scientific data regarding their effectiveness. For preventive applications, applications of mefanoxam, fosetyl-Al, or propamocarb every 14 to 21 days are recommended. An occasional application of ethazole is never a bad idea, especially during periods of wet weather.

For curative applications, I recommend an application of ethazole to provide quick knock-down of the disease, followed a few days later with a mefanoxam application. This is a program that I 'borrowed' from Bruce Martin at Clemson several years ago, and it works like a charm.

To minimize the potential for foliar burn, ethazole must be watered-in immediately after application with at least 1/8” of water. Applications of mefanoxam or propamocarb should also be watered-in, but fosetyl-Al should be applied to the foliage for best results.

For more information about Pythium root rot, please refer to TurfFiles.

Where is the summer heat?

Diseases normally typically appearing at this time of year will likely be on hold for another few weeks as temperatures in the Northeast continue to remain low. The main diseases that I have heard throughout the region include those typically seen in the spring. These include the leaf spots, red thread, take-all patch (although this will likely get worse when the heat does arrive), dollar spot and a reported case of copper spot in Jersey. Leave a comment below and tell me what you are seeing in your area.

For those of you dealing with dollar spot, please send some to State College! The disease showed up in typical fashion in early June and then just sat there. I walked my plots today and there was only about 10 infection centers in my untreated plots...not good for disease research.

I am still sticking by my guns and predicting that brown patch will start to move into the warmer parts of the region within the next week or so. This is also a good time to start (if you have not already) applying Pythium controls for your turf. Applications of the phosphite products have been successfully used to control Pythium on fairways, but preventive applications are necessary. On greens, the phosphites can effectively suppress algae (again when applied preventively). If the hot weather does come in fast, you will want to make sure you are covered for the hot weather diseases.

Finally, keep an eye out for next month's "PlayTurf" cover and the special interview guest. I will also be reporting on @johnkaminski from Saucon Valley and the Women's U.S. Open.

Should I water that in?

This is easily the most frequent question I get from golf course superintendents during the growing season. It is a difficult question, and there isn't always an easy answer.

We know that watering fungicides into the root zone is important for effective control of root diseases. However, in the real world, golf course superintendents apply fungicides to control a combination of root and foliar diseases, but we don't always know what effect watering-in has on foliar disease control.

To answer this watering-in question, you need to identify the primary disease you're trying to control, know where this pathogen attacks the turf plant, and understand how the selected fungicide moves in the plant after application.

In most cases, if a root disease is the primary target for a fungicide application, then it should be watered-in immediately after application. Once the spray dries on the leaves, it will be locked into the foliage and will not get into the root zone. Exceptions to this rule are the true systemic fungicides, like fosetyl-Al and the phosphite salts. These products are translocated downward in the plant and do not need to be watered-in.

The Fungicide Selection Tool, a new feature on our TurfFiles website, can help you select the best application technique for your fungicide applications. After selecting your turf species and the diseases you are trying to control, a list of fungicides is displayed. The list is ordered based on average efficacy against the selected diseases. After selecting a product or products to apply, you are taken to a page that displays mode of action, efficacy rankings, risks for fungicide resistance, rates and application intervals, and application instructions for each selected disease.

It's not too late to prevent fairy ring and Pythium root dysfunction

If you haven't made your preventative fungicide applications for fairy ring and Pythium root dysfunction yet, it's not too late, but it will be very soon.

Although symptoms of these diseases are most common during the heat of summer, we've found that the pathogens are most active during the spring and early summer. Fungicides are most effective when applied during these periods of pathogen activity.

Pythium root dysfunction is a common problem in the southeast on creeping bentgrass putting greens built within the last 10 years. The pathogen infects the roots during the fall, winter, and spring when soil temperatures are between 50 and 75 degrees.

Remember that Pythium root dysfunction is a stress-induced disease. Low nitrogen inputs (less than 3 lbs per year), drought stress, close mowing, and infrequent aerification are common sources of stress that compound the disease. Maintaining a healthy turf plant with sound agronomic practices goes a long way towards reducing problems. All the fungicides in the world will not provide acceptable control of PRD if the turf is continuously stressed.

Preventive fungicide applications should be made in the fall, winter, and spring when average daily soil temperatures between 50 and 75 degrees. For details on recommended fungicide rotations, please refer to our information sheet on TurfFiles. Remember that fungicides should be watered into the soil right away for best results.

We've made excellent progress in fairy ring management over the last 5 years. The DMI fungicides, such as Bayleton, Eagle, Tourney, Trinity, and Triton, have been providing excellent control in the southeastern United States. For best results, these products should be applied when 5-day average soil temperatures are between 55 and 65 degrees. However, as long as they are applied before symptoms appear, they will provide good control in our experience.

Just like with PRD, fungicides must be applied to the soil for best results. Applications should be watered-in as soon as possible with 1/8" to 1/4" of irrigation. We do not recommend tank-mixing the DMIs with wetting agents or soil surfactants, as we've observed reduced control from these combinations. Wetting agents should be applied separately as part of your normal program.

For more information on fairy ring prevention, please refer to the Fairy Ring Disease Profile on TurfFiles.

Don't neglect your nozzles!

As your college interns start to filter to the course from academic studies, now is the perfect time to fire up the sprayer in preparation for the 2009 season. This gives you the opportunity to ensure that your equipment is in proper working order AND gives the students the opportunity to get hands-on experience with calibration techniques that many have only heard about in the classroom.

Many websites and books are available to assist in the calibration of your equipment. In preparing for this update, I also came across a calibration software package that TORO offers for download from their website. While calibration of your equipment is important, another factor that should not be overlooked are the nozzles that you select to control turfgrass diseases.

Research conducted in the past few years has revealed that nozzle selection plays an important role in the suppression of turfgrass diseases (Read GCM Article). In particular, the control of foliar diseases such as dollar spot and brown patch can be improved by selecting nozzles that improve spray coverage. One major problem with this is that nozzles producing excellent coverage generally have increased potential for drift. Our research has shown that utilizing nozzles that incorporate air into the droplets (air induction) provide the best of both worlds. Here are some keys to improving disease control.

1. Consider the location of the pathogen. Fungicides for root diseases generally need to be applied in greater volumes of water (>2.0 gal/1000 sq ft) and/or watered-in following application. Foliar pathogens should be suppressed with a nozzle that produces excellent coverage.

2. Air induction nozzles provide excellent control of foliar pathogens and have relatively low potential for drift. TurfJet nozzles (typically supplied with many sprayers) generally offer poor disease control, especially where lower water volumes (~1.0 gal/1000 sq ft) are utilized.

3. Nozzles should be changed at least once per year (twice per year in some cases). Always buy an extra nozzle to use as a comparison when determining if your nozzles need to be replaced.

Gearing Up for Another Growing Season!

Spring has sprung in the Midwest! The trees are blooming and budding, the flowers are emerging, and the grass is finally growing. This winter was pretty harsh, with many places receiving significant amounts of snow fall. Consequently, snow mold was quite severe this year. However, most are on the road to recovery from any snow mold damage. Another major issue was ice damage and desiccation. Many golf course superintendents through out the Upper Midwest claim the damage from ice and desiccation was as bad as they've ever seen. So before implementing a plan of action to start the road to recovery, you need to determine if the area will come back. To do this, take a cup cutter plug from the damaged area and place them in a window. Keep them moist and MAKE sure the window ledge is not directly above or below a heat vent. The drastic change temperature can cause shock that can kill the plants. Monitor growth from the plugs for two weeks and if green tissue has not emerged by then, the area will likely need to be repaired.

Now is also the time of year for preventative applications targeting fairy ring and take-all patch. If you are not familiar with preventative fairy ring applications, Lane Tredway's group at NC State is finding that two applications of Bayleton at the low label rate effectively limits fairy ring development throughout the summer. Initiate the first application when 5-day average soil temperatures are between 55 and 65 F, then follow-up with the second application 28 days later. All applications should be irrigated in with 1/4 inch of water immediately after application. Wetting agents should be applied on a regular basis during the summer, but NOT tank-mixed with the preventative applications.

Spring Dead Spot: What can I do now?

Spring has sprung in the southeastern US, and severe cases of spring dead spot have been reported throughout the region. The relatively severe winter is likely to blame, as cold temperatures tend to bring out spring dead spot symptoms.

The frustrating thing about spring dead spot is that the damage is done and the disease cannot be controlled once the symptoms appear. However, there are several things that can be done NOW in preparation for next year:

1. Consider converting severely affected areas to a cold-tolerant bermudagrass variety. Varieties of bermudagrass that have been bred for cold-tolerance, like Patriot, Yukon, and Tifsport, are affected by spring dead spot less severely. They still get the disease, but patches are generally smaller and recovery is quicker. This simple solution can save a lot of time and money in the long term.

2. Map severely affected areas for fall fungicide applications. Spring dead spot fungicides, like Rubigan, are very expensive. You can save a lot of money and avoid unnecessary fungicide use by only treating the affected areas.

3. Avoid the use of DNA herbicides for annual grass control. Some crabgrass herbicides reduce bermudagrass root growth and can slow recovery from spring dead spot. Use a pre-emergence herbicide like oxadiazon, which does not have this effect.

4. Aerify and/or spike severely affected areas every two weeks. Breaking up the layer of dead turf and thatch will help the bermudagrass to spread into the patch more quickly.

5. Choose your nitrogen carefully. The type of nitrogen you apply can have a major effect on spring dead spot development. We have traditionally recommended ammonium sulfate to suppress spring dead spot, but our recent research is providing some interesting results. After 4 years of applications, ammonium sulfate is only suppressing spring dead spot caused by Ophiosphaerella herpotricha and is having NO EFFECT on O. korrae. Calcium nitrate, on the other hand, is doing an excellent job of controlling spring dead spot caused by O. korrae, but is having no effect on O. herpotricha. Stay tuned for updates on this research.

Brown Ring Patch or Yellow Patch?

Disease activity is relatively slow at this point, but there are some reasons to believe that this will change soon. So far, several cases of brown ring patch and yellow patch (i.e., cool temperature brown patch) have been identified from Pennsylvania to parts of New England. A quick way to distinguish between these two diseases is to incubate a cup-cutter plug in a tuperware container overnight. If mycelium is present in the morning, you are likely dealing with brown ring patch as yellow patch does not produce much visible mycelium.

Main areas of interest throughout the region have focused on annual bluegrass seedhead suppression and the application of early season fungicides for the control of dollar spot or fairy ring. In situations where chronic disease activity occurs, these early season fungicide applications have been shown to reduce the severity of each disease later in the year.

If you are in the Northeast and experiencing other disease problems, feel free to let us know in the comments section.