Remember that schoolyard rhyme, "If it's yellow, let it mellow, if it's brown, flush it down"? Well, if it's green, what's that mean? Sometimes in the aftermath of a brown ring (Waitea) patch outbreak on Poa greens, even if you've controlled it with fungicide applications, you can get some strange green patches that form. (Image to the left courtesy of PJ Kaner at Santa Teresa Golf Club in San Jose).
We're attributing this to the pathogen breaking down thatch as it develops on greens, giving a fairy ring like effect in he areas that it's grown through. Often these areas will be softer and spongier than the rest of the green.
Often, when we examine these areas - we'll find lots of Trichoderma (a fungus known for parasitizing other fungi and the active ingredient in some biocontrol products), black sclerotia (next image to the left, courtesty of Larry Stowell - PACE Turf Research Insititute - www.paceturf.org) and other junk fungi colonizing the previously affected area. This can confuse diagnosticians if you send in samples from these areas - and often no 'real' pathogens can be found in these areas.
The key for avoiding this "by product" of brown ring patch infections is to treat early with fungicides when you see symptoms to prevent extensive thatch colonization on greens. You can also bump up your N fertility or even apply some chelated iron in combination with N to mask these symptoms.
Whew! We made it through the 4th of July!
Lane mentioned to me earlier this week in an email that life is good if you make it through the 4th of July without losing any fingers. I can say the same about avoiding disasterous anthracnose outbreaks over the 4th of July on Poa greens out in the West.
Fortunately - no 911 samples came in on Monday morning with anthracnose. There were a number of fairy ring samples, take-all on bentgrass and Bipolaris leaf spot that did show up. These are diseases that typically will cause more damage on heat and drought stressed turf - so it did get hot here in California, but it looks like most of our guys avoided big anthracnose outbreaks on Poa greens.
Also - no gray leaf spot yet!
Hot Inland, Mild on the Coast
The California weather outlook will be basically 70-80s on the coast and 90-100s in Inland Valley s and if you're out in Palm Springs 100-110s.
Expect to see a continuation of dollar spot, Waitea patch and rapid blight in coastal areas. Anthracnose and summer patch will be threats in Inland and Central Valleys. If you're in the desert - bermudagrass should be booming with cool season grass all but disappearing in the summer heat.
Le Tour de France - It's Not Golf, but....
The big race started in Monaco this last Saturday and continues on for another 3500 km for the next three weeks. Lance Armstrong is back after a 4 yr hiatus - maybe to claim an 8th overall victory. There's probably more Americans in the race this year than ever and Team Columbia-HTC, based out of San Luis Obispo, CA is dominating the early flat stages in the race. Lance's team (Astana) took 1st place in the team time trial on Tuesday and Lance sits a mere 0.22 seconds behind the current race leader Fabian Cancellara (Team Saxo-Bank). Friday brings the first of the mountain stages and we'll see how the overall leadership of the race changes as these guys put on their best mountain goat impersonations through the Pyrénées mountains.
Signing off from the left coast until next week.....
If it's green, what's that mean?
Posted by
Frank Wong
at
11:43 PM
Thursday, July 9, 2009
Labels:
anthracnose
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brown ring patch
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Poa
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