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....

If I made magazines...

...then June's centerfold would be Sclerotinia homoeocarpa (not Candice Cassidy).

Dollar spot is starting to show up throughout the region. As you all know, this disease is a chronic problem for most and once established it can be tough to get under control. Some cultural and chemical strategies to help manage dollar spot are:

1. Remove dew whenever possible. Extended periods of leaf wetness has been shown to drastically increase the incidence and severity of dollar spot. If you can't remove dew from all fairways, at least consider removing it from the worst.

2. Tickle the turf with N. The belief that nitrogen will completely eliminate dollar spot just doesn't hold up. However, providing adequate nitrogen in the spring to encourage growth and then spoonfeeding N during the summer can help to reduce the severity.

3. Choose your PGR's wisely. Not all plant growth regulators are considered equal when it comes to dollar spot. In general, trinexapac-ethyl (Primo MAXX, others) is not going to provide significant control of dollar spot. However, paclobutrazol (Trimmit, others) or flurprimidol (Cutless) have direct fungistatic impact on the pathogen that causes dollar spot and these PGRs can significantly reduce disease severity. Routine applications of these PGRs are also great for those of you wanting more bent and less Poa.

4. Utilize preventive fungicide applications. When managing dollar spot, preventive fungicides are key to keeping it under control throughout the season. Curative applications often require higher label rates and short application intervals, so preventive applications can actually REDUCE your pesticide use and environmental impact over the course of a season.

While this brief list can help you reduce disease pressure, you may need to consider some other things as well including: fungicide resistance; species selection; sprayer nozzle type and application volume; among others.

Weather forecast for this week:

Connecticut
CT Shoreline: highs of 62-70; partly cloudy with chance of mid-week showers
Hartford, CT: highs of 72-78; mostly sunny, isolated showers Wed/Thur

Maryland/VA
Washington, D.C.: highs of 73-83; chance of isolated showers mid-week

Massachusetts:
Boston, MA: highs of 63-75; sunny to partly cloudy with chance of showers Wed
Springfield, MA: highs of 72-78; mostly sunny with chance of showers Wed

New York
Albany, NY: highs of 67-77; mostly sunny with slight chance of precip on Wed
Buffalo, NY: highs of 62-73; mostly sunny with chance of showers
Westchester, NY: highs of 70-79; chance of showers mid-week

New Jersey
Cape May, NJ: highs of 68-81; chance of showers all mid-week
Far Hills, NJ: highs of 73-82; sun and clouds with slight chance of rain mid-week


Pennsylvania
Philadelphia, PA: highs of 72-84; chance of isolated showers mid-week
Pittsburgh, PA: highs of 68-79; slight chance of showers on Tues/Wed (GO PENS!)
State College, PA: highs of 69-78; chance of showers on Wed

Way the heck up there
Burlington, VT: highs of 62-76; partly cloudy with slight chance of scattered showers
Portland, ME: highs of 60-71; sunny to partly cloudy with scattered showers Wed
Rumney, NH: highs of 61-75; mostly sunny with slight chance of showers Wed

It's a Mix Out There!

With all of the wacky weather we've had in California, we're seeing a mix of spring and summer diseases in the lab here and through reports from superintendents.
Rapid blight and Waitea are still active on Poa greens as is pink snow mold here and there in Northern California.

Anthracnose still hasn't shown up from Poa greens just yet - but has been seen on stressed perennial ryegrass samples from roughs and on a bentgrass green in Idaho.

In this bentgrass case - low fertility contributed to the disease popping up on mechanically or weather damaged turf.

Bermudagrass samples are starting to show up in the lab with decline or other ETRI on the roots. As we get further into the summer transition to bermudagrass, superintendents are starting to see weak areas thinned out by pathogen activity on the roots over the winter. A healthy dose of sun, heat and water will probably get thinned out areas of bermudagrass to fill in, but take note of these areas and see if you can improve compaction, fertility or drainage here; environmental factors that usually contribute to decline, spring dead spot or ETRI damage on bermudagrass.

It's all about your roots: good roots now means less summer stress later
Already, we've been getting samples in the lab showing heat and summer stress. With rapid changes in weather and conditions, greens can go from looking good to looking like crap in a very short period of time. Often the first heat spell will show where you have good roots. The more roots you can put down before the summer heat starts the better. That means additional solid tine aerification, addressing dry spots will handwatering or soil wetting agents and most importantly, adequate nitrogen fertility. Poa/bent greens need at least a quarter pound of nitrogen per 1,000 sq ft/month and even up to half a pound if you have a lot of play or traffic. Give cool season turf enough food to grow now, because when we start going into the 90s and 100s, cool season turf will start to shut down and you may be in trouble if you don't have enough roots or plant mass to make it through the summer.