Dans la Merde in the West

Dans la merde is a colorful French term that basically translates into "in the sh*t" and is a good term to describe superintendnets who are currently behind the eight ball fighting active foliar anthracnose outbreaks on annual bluegrass greens in the West.

Right now, anthracnose is coming into our diagnostic lab left and right. It's likely a result of the up and down heat spikes and we've had throughout the summer here in the west.

Although anthracnose should be managed with a combination of solid cultural practices (see www.turf.rutgers.edu/research/GCM-BMP-Anthracnose.pdf) and a solid preventive fungicide program, summer stress and common practices related to tournament prep (low mowing heights, holding back N, drying down greens, etc.) or just high traffic and play can put superintendents in a bad spot. If you find yourself dans le merde, here are three suggestions that may help you get back on top of anthracnose before it's too late

(There are additional things you can do to help pull yourself out of an anthracnose outbreak, these are just three of the most common things to consider - I'd welcome any additional comments from the NE, SE, M and SC as well!)

1. Fungicide applications
If you have active anthracnose on greens, chlorothalonil is your friend. Inexpensive and not at risk for resistance, it can be used aggressively as a "eradicant" application to kill spores in acervuli and prevent new infections. Label rate applications 7 days apart should be made to halt infections in their tracks. You can mix chlorothalonil fungicides with other anthracnose-active fungicides like Medallion and Endorse safely in a rescue type situation. Chipco Signature tank mixed with chlorothalonil can also be a good option. DMI-fungicides like Banner MAXX can also be mixed with chlorothalonil, but be aware of potential PGR-effects when using these at high rates or high temperatures. Beware of using QoIs (Heritage, Insignia, Compass, Disarm) or thiophanate-methyl containing fungicides (Clearys 3336, Fungo, etc.) by themselves as rescue applications. Resistance is a problem for these already and using them as rescue materials is a good way to lose them due to resistance (that's a GCSAA class all to itself). In any case, chlorothalonil can do a lot of work for you as a rescue fungicide, and also beat back any other secondary pathogens coming in to the damaged areas or algae that can fill into thinned areas on greens.

When using contact fungicides like chlorothalonil, it's very important to get good coverage. Apply fungicides in at least 2 gallons of water per 1,000 sq ft for adequate penetration of the fungicide to the lower leaves and crown. Flat fan or air-induction flat fan type nozzles, that produce smaller sized droplets, are much more effective than rain drop or flooding wide angle nozzles for getting the best coverage with contact fungicides.

2. Fertility
Assuming that you can get sufficient knock down of he pathogen, it's important that surviving Poa has enough N to push back and recover from injury. Light applications of N (0.125 to 0.25 lb N/1,000 sq ft) should be made to get your Poa back on its feet. Apply as needed to get regrowth and recovery from damage; but excessive amounts may cause some excess growth and scalping if you're not careful. Although N is the most important component, additional P and K can also help. A 20-20-20 may be a good choice for recovery from anthracnose damage.

3. Irrigation
Once you're hit with anthracnose, don't overwater damaged areas in hopes of increasing damage recovery. Overwatering is just as conducive for anthracnose as is drought stress. Irrigate based on ET-needs, but make sure to mist/syringe greens in during the hottest periods of the afternoon to minimize heat stress on weakened plants.

Hopefully, with some TLC (plus fungicides, nitrogen and irrigation management), you can get outta the merde and back to normal practices on greens. Often, anthracnose is linked to other environmental conditions or agronomic practices (compaction, black layer, drought stress, etc.), so make sure to address those issues as well while you are in "rescue" mode.

Just an observation: If your anthracnose if plowing right through preventive Heritage, Compass or Insignia applications…. Guess what, your anthracnose is probably QoI-resistant. If your anthracnose is plowing through preventive 3336 applications (or any thiophante-methyl containing material), you've probably got benzimidazole resistance. Check out our anthracnose powerpoint here if you haven't already seen it for some chemical control alternatives: http://www.turfpathology.ucr.edu/Downloads/anthracnose_chemical_control.pdf

Other Merde...
Over the last week, we've been absolutely slammed by diagnostic samples in the lab. In addition to anthracnose, the usual suspects are still active, such as brown ring patch, summer patch and rapid blight. Samples coming in with Bipolaris, Curvularia, and Leptosphaerulina (especially on fairway and rough samples) are indicative of summer heat stress on cool season turf.

With temps in the 70s and 80s in coastal locations, I would suspect rapid blight be pretty active in salt affected locations, as well as brown ring patch and even dollar spot. The Central Valley (Fresno) and deserts will have to contend with night time temperatures high enough to flare Pythium on cool season turf. Expect anthracnose and summer patch to be calling on your annual bluegrass greens through out the state.

Signing Off From the Left Coast Until Next Week....

Check out the smoke ring on July's Centerfold

It just doesn't get any better than this. Just before the 4th of July weekend, brown patch made its appearance in the Northeast. In this case, however, disease activity was more a factor of a unexpected irrigation schedule then the typical hot and humid conditions. Despite moderate conditions as far south as Maryland (I was unable to hear the mycelium crawling around like Megan stated in a previous post), brown patch was active on sites with poor air movement and excessive moisture. While the temperatures are anything but typical for July, certain factors can continue to influence the appearance of these diseases. Brown patch, caused by Rhizoctonia solani, is a foliar blighter and generally does not kill turf. Additionally, the addition of the QoI (strobilurin fungicides) has made controlling this disease relatively easy. For those of you who have increased the use of Tall Fescue in the roughs or introduced colonial bentgrass on select fairways in the Norhteastern US, this may be one that has not caused much concern for you in the past. These two species, however, are highly susceptible and fungicides are often necessary to maintain adequate turf quality.

In addition to brown patch, the usual suspects keep moving along including anthracnose basal rot, dollar spot, fairy ring (generally Type II [those with the green rings]), and a few other unknown problems. In one case (picture right), samples were sent to just about every lab in the Northeast as well as other labs without a clear answer to the problem. After a visit to the course, the problem does appear to be disease related, but no signs of any turf pathogen could be found. This just goes to show you why all of the turf pathologists will be in business for many years to come. Once you get a handle on one disease, another one comes out of no where to make its mark. Examples of this include summer patch in the 80's, gray leaf spot in the 90's, rapid blight and bentgrass dead spot in the late 90's and early 00's, and probably various others too. If I find out more about the mystery disease, I will pass along this info.

OK, I am getting on the road to Saucon Valley to follow Stan Zontek and the rest of the Mid-Atlantic USGA around the course as they prep for the Women's U.S. Open. Follow the practice rounds with me on twitter @johnkaminski.

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.