Anthrancose and summer patch are appearing in the southeast

In yesterday's post Dr. Kaminski asked, "Where is the summer heat?" Well, if you want heat we've got it here in the southeast. Brown patch has been raging for the last month, symptoms of fairy ring have been appearing sporadically, and we are just starting to see anthracnose and summer patch popping up.


A few samples of anthracnose on creeping bentgrass have been submitted to our Turf Diagnostics Lab at NC State, and we also have some developing on 'Dominant Plus' creeping bent at our research center. Conditions have fluctuated between hot and wet then hot and dry, which is ideal for anthracnose development. If you are growing a bentgrass cultivar that is susceptible to anthracnose, be sure that you have a solid preventive fungicide program in place as soon as possible.

Not all bentgrass varieties are susceptible to anthracnose. The Penn A and G series cultivars have good resistance to the disease, and problems are rarely seen on these grasses. Older varieties, like Penncross, Pennlinks, Dominant, and even Crenshaw and L-93, are most susceptible.

Beware that fungicide resistance is a common problem in anthracnose populations. Our recent survey of C. cereale populations in NC showed that resistance to the QoI class (Heritage, Insignia, Compass, Disarm) and thiophanate-methyl (3336 and equivalents) is widespread. In fact, we had a hard time finding populations that are sensitive! Bottom line - unless you know that your populations are sensitive to these fungicides, do not rely on them for anthracnose control. For other anthracnose control options, please see our Anthracnose Information Sheet on TurfFiles. Remember to avoid the DMI fungicides if temperatures above 90F are in the forecast.

If you would like to find out if your anthracnose population is resistant or sensitive to various fungicides, the NC State Turf Diagnostics Lab offers fungicide resistance screening. Please see our website for more details.



Right on time, symptoms of summer patch have started to appear in North Carolina as well. It seems like this disease always starts to appear right around the 4th of July. If you are managing Kentucky bluegrass or annual bluegrass, or have bentgrass greens with a history of summer patch problems, be sure to continue your preventive applications for this disease. The summer patch pathogen is active throughout the summer, as long as average daily soil temperatures are below 80-85F.

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.

brown patch, pythium, and summer stresses

Hot and humid is the big story this week. Waterlogged soils are an issue in some areas, both in sand-based greens and native soils.

We are starting to see lots of typical summer decline. Poa annua is checking out, and algae and hot spots are checking in. In areas where bentgrass has been stressed, it’s showing decline too. June feels too early to be dealing with this stuff, but that is what Mother Nature has dealt us this year. If June is kicking our butts, I'm worried what July and August have in store.

With the overly wet conditions, some guys are wanting to needle tine and topdress to get some air movement in their putting greens. But, it’s so hot, such cultural practices could seriously stress out the turf. We are all hoping for some cooler temps next week in order to sneak in some cultural practices. A dip in nighttime lows would really be beneficial. The lows over the past week have been in the 70’s in most of Kansas (a bit lower in western Kansas where humidity is lower), and soil temps at 4-inches are hovering around 80 degrees. We might get some highs in the upper 80's (gee, maybe I'll need a jacket or I might get chilly...) and lows in the mid-60's early next week. Then, the forecast calls for more scorching.

I had a couple of interesting diagnostic cases this week where turf was declining and, as is typical this time of year, no turf pathogens were to blame. In one situation, a surfactant was applied as part of a tank mix and then not watered in, and this may have led to some phytotoxicity especially in our hot conditions. A big clue was that the practice green WAS watered in, and that one was not showing damage.

In another, some extra N a couple of weeks ago kicked the turf into high gear on one putting green. The green got a little puffy, then got scalped, and now it is having a hard time recovering in these conditions.

The turf shown in the photo below is not happy to be drowning:

Here is this morning in pictures, to further illustrate the conditions

It’s SO humid…

* My camera fogged up when I first took it out of the case at the turfgrass research facility at 7:00 am. No that’s not real fog in the photo, that’s condensation on my camera lens. It took about 5 minutes to "equilibrate" to the outside air.

* The dew was thick to the point of sloshiness:

* I could hear the brown patch mycelium crawling around (well, not quite, but almost…):

* Pythium blight is making its first appearance: (mycelium had been present earlier)

Get Ready for Anthracnose in the West

Sadly, Farrah Fawcett passed away from cancer today at age 62. I bet you that just about anyone who was a teen in the 1970s had a poster (like the one to the left) in their room.

We probably invoke her name at least a dozen times a week here at UCR since we work in Fawcett Laboratory. Often, when explaining where to send samples, we tell people that: "it's Fawcett Lab, as in Farrah Fawcett" - which often goes right over the heads of those superintendents in their early- and mid-20s. For that matter, many John Holmes references - in relation to optimal root length - also go over those guy's heads too. I have got to stop using 70s-pop culture references so frequently here in our lab.


Anthracnose Management
Here in the west, anthracnose is starting to pop up more frequently in the UC Riverside diagnostic lab. It could signal the start of the anthracnose season already. Although anthracnose can pop up on just about any cool season turf species, it's impact is very different on different species being used for different purposes on the course.

For perennial ryegrass, the presence of anthracnose often signals low fertility, heat and drought stress. Here, anthracnose is usually just a secondary pathogen affecting stressed turf. It usually does not warrant control directly, but does often indicate that cultural conditions need improvement in these areas.

On creeping bentgrass, we typically see anthracnose on greens that are "lean and mean", especially when there is high humidity and overcast days. Again, in these cases, anthracnose is usually not the primary cause of damage but does signal that fertility needs to be increased and plant stress reduced. Typically, shutting anthracnose down with a fungicide application or two followed by increasing the fertility will solve the issue.

On annual bluegrass though, anthracnose is a real killer because its often the disease that puts the nail in the coffin for Poa greens.

Check out our presentation on chemical control options for anthracnose here: http://www.turfpathology.ucr.edu/Downloads/anthracnose_chemical_control.pdf

as well as the cultural management practices for anthracnose research being spearheaded by the group at Rutgers
http://www.turf.rutgers.edu/research/usga-anthracnose.pdf

Sucessful anthracnose management on annual bluegrass greens in the West should combine cultural practices like adequate nitrogen fertility and water management with a sound preventive fungicide program.

With regard to fungicides for anthracnose - there are plenty of ways to skin a cat, but in a nutshell - here's what has been effective for us in trials conducted over the past few years.

Early season preventive DMI applications (especially Banner MAXX) should be initiated before soil temperatures exceed 70F (65-68F is usually a good starting place).

Chlorothalonil fungicides, Medallion and Endorse are good choices for control when air temps are high and the risk of negative PGR effects of the DMI-fungicides are present (see Lane's recent entry on the DMIs). These should be applied at 14-day intervals in the summer.

Chipco Signature can be tank mixed with the fungicides listed above for added control and stress reduction. Although the mechanism for stress reduction provided by the combination of pigment and fosetyl-Al in Chipco Signature is still not fully understood, I'm going with the theory that it's "sunblock for Poa". Although results from trials in the east have shown a direct effect of phosphonate type fungicides on anthracnose - our trial results from California have shown that Chipco Signature applied by itself isn't very effective versus anthracnose and needs a good partner to maximize the effectiveness of the tank mix application.

Finally - I don't mean to kick a dead horse, but QoI and benzmidazole resistance appear to be pretty common for anthracnose in areas that have used them exensively for anthracnose control. Monthly applications of Heritage or Insignia are still very important for summer patch control in the summer, but don't rely on them exclusively for anthracnose control.

In Other News...
Brown Ring (Waitea) Patch was reported from Minnesota and diagnosed from Montanta this week. It sounds like this disease is continuing to pop up throughout many places in the U.S.

Signing Off from the Left Coast!

What it Actually Takes to get Pythium Blight on Creeping Bentgrass

Megan posted last Friday that hot, humid weather equals brown patch, which is absolutely correct! Our temperatures soared in the Midwest late last week and continue to stay hot and humid through this week. With the advent of hot, humid weather people started worrying about Pythium blight. Lane mentioned in a previous post (Summer fungicide programming) that many people spray for Pythium, but is probably a waste. Of course none of us believe that Pythium blight cannot develop, but the conditions that are required are so extreme that it rarely develops in shorter cut turfgrass.

For example, just this morning temperatures were well into the 80's and humidity levels were 90 % or more. Plus we have had over 4 inches of rain in the past two or three days. Of course everyone in the Upper Midwest has been worried about Pythium and are scheduling applications to control Pythium. Although we have diagnosed Pythium at a few courses, the extent of the damage is minimal. Symptoms appeared this morning on creeping bentgrass in close proximity to a drain in a fairway at a local Madison golf course. This particular area is also sheltered from air movement by a small pocket of trees. The picture in this post shows the extent of the symptoms, which basically amounted to a few small spots only in areas immediately adjacent to drains in fairways. The superintendent at this particular course is going to make an application of Subdue Maxx to clean-up these areas, but is not going to spray the entire fairways.

The other picture I have attached is from an area at the OJ Noer. This area was seeded with varieties of bentgrass earlier this spring. The plot is so wet that it could be considered a quagmire, but still symptoms are not that severe.

We are not advocating that Pythium is a problem of the past, but we are advocating that superintendents do not forget about other diseases. Brown patch can be very damaging in the conditions we are experiencing now, especially in fairways. If you have symptoms resembling Pythium blight or brown patch, have it diagnosed if possible. Both diseases can produced aerial mycelium and it has been our experience that brown patch is commonly mis-diagnosed as Pythium blight in the field.

As for other diseases, well the the stuff has definitely hit the fan. Dollar spot is raging on our plots at the OJ Noer and has developed at many courses we have visited. Brown patch has reared its ugly head at a few courses in the Madison area and Derek Settle has reported numerous cases of brown patch in the Chicagoland area. We have diagnosed take-all patch a few courses in Northern Wisconsin and it has developed at the OJ Noer. We will probably see a lot of take-all patch this year because soil temperatures were conducive for infection for a long time this spring. However, once take-all symptoms develop a fungicide application will not help alleviate the symptoms. Areas affected by take-all patch will need to be "nursed" through this warm spell by hand watering and possibly a light fertilizer application.

The weather in the Midwest continues to amaze me. Last week we were still measuring soil temperatures in native soil areas at 65 F. This week air temperatures soared up into the middle 90's during the day and nighttime temperatures in the upper 70's. Reminds me of North Carolina weather. Relief is on the way, as forecasts are predicting a slight cool-down this weekend. I think I may have to enjoy some beer and cheese curds!