Brown patches - Root cause ?

Discussion in 'Pesticide & Herbicide Application' started by bperl, May 17, 2012.

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Brown patch - Root Cause

Poll closed Jun 6, 2012.
  1. Too much herbicide

    0 vote(s)
    0.0%
  2. Blunt Mower blades

    0 vote(s)
    0.0%
  3. Beetles and grubs

    0 vote(s)
    0.0%
  4. Excessive fertilizer

    8.3%
  5. Fungus

    100.0%
Multiple votes are allowed.
  1. bperl

    bperl LawnSite Member
    Posts: 37

    I've dug up 1 sq ft of grass along with roots & soil and took the sample to a reputed Nursery near my home. An 'expert' saw the grass under microscope and googled brown patch and said it must be brown patch. He advised me to apply "BAYER ADVANCED FUNGUS CONTROL FOR LAWNS READY-TO-SPREAD
    GRANULES II". I've asked if its dollar spot or melting out as you've suggested. He said either way "Bayer Advanced" will work.

    I've spread the granules today morning. However after doing more research, looks like its more of melting out and/or dollar spot. You have recommended heritage G - but looks like Heritage G is ineffective and clearly doesn't work for Dollar spot.

    http://commodities.caes.uga.edu/turfgrass/georgiaturf/publicat/PCRP2011/Turf%20Disease%20Control.pdf

    I understand I would have to rotate the fungicides every other application. What are couple of broad fungicides in different groups that can cover brown patch, melting out and dollar spot.
     
  2. bperl

    bperl LawnSite Member
    Posts: 37

    I've seeded on September 28th. It started to germinate after 10 days. Winter was very mild around here and the grass was green pretty much through the winter into the spring. I've started noticing couple of brown spots in my backyard about 45 days back. But the spots were more visible in my front yard in the 10 days or so when it rained heavily (1.6 inches in 24 hrs).

    Any chart or source where it lists the fungicides, their groups and what diseases they cure ?
    If the so called experts at my nursery who charge arm and length can't confirm the disease even after looking at the sample, then I guess its better to learn myself and deal with it. The 'expert' even made me buy 4 bags of Bayer advanced (Propiconazole 0.51%). Good thing I read about fungicide groups, resistance and the need for rotation before applying them back to back.
     
  3. phasthound

    phasthound LawnSite Platinum Member
    Posts: 4,576

    Originally Posted by lawnrx
    Check for insects. Looks like insect damage. Spray insecticide just to rule it out ASAP.
    Are either of you professional LCO's? I hope not.
     
  4. kirk1701

    kirk1701 LawnSite Gold Member
    Posts: 3,981

    45 days ago???
    Not brown patch, 45 days ago the temps were still cool and not warm enough to activate the fungus. For the fungus, brown patch to activate it has to first be warm enough to thrive, add your temperature + Humidity together and if it comes out to above 150 you best have a fungicide on the yard to protect it.

    Otherwise your looking at a curative application.
     
  5. Duekster

    Duekster LawnSite Fanatic
    from DFW, TX
    Posts: 7,961

    I believe it could have started last season and survived over the mild winter. Still looking like a fungus to me. While I have a licenses, I am not that strong on these thing. Puts that on my to do list.
     
  6. kirk1701

    kirk1701 LawnSite Gold Member
    Posts: 3,981

    SURVIVED!!!!

    Bud I hate to tell you but yea it survived, its in the soil and will forever be in the soil and come back each year if not treated.

    I'm not licensed and very strong in this area, spent years experimenting with it.

    http://www.lawnsite.com/showthread.php?t=377207&highlight=clearys
     
  7. Duekster

    Duekster LawnSite Fanatic
    from DFW, TX
    Posts: 7,961

    We treat take all patch in St Augustine with Brown Canadian Peat Moss. Top dress with 1/2 inch and water in. It controls for 3 years.
     
  8. dcgreenspro

    dcgreenspro LawnSite Senior Member
    from PA
    Posts: 689

    just my two cents= dollarspot. The active mycelium is what your "expert" should have been looking at underneath a microscope to positively identify what is wrong. Lesions on the leaf blade could also be used but in this instance, for my money, I want the mycelium. I am sorry for not reading all the way thru but I stopped when you were advised to start treating this problem with the bayer stuff even though you have not positively identified the problem. I think tht your next round of fert should do the trick.
    too many times I read about people not correctly identifying the problem and throwing stuff down to see if it works. That is not how turfgrass should be maintained.JMO
     
  9. bperl

    bperl LawnSite Member
    Posts: 37

    I've read about dollar spot. Looks like insufficient nitrogen can also be a cause for this. But generally they say not to fertilize during summer. So, should I go-ahead and fertilize the lawn now or can I wait till fall when I wanted to Over seed and fertilize. Considering that seeding was done 8 months back, I'm worried if the turf could survive this disease till fall.
     
  10. kirk1701

    kirk1701 LawnSite Gold Member
    Posts: 3,981

    Bperl
    I got off replying to the wrong person and thinking Duekster was the original poster, sorry.

    I just took a second look at your photo's, when did this start? I take it was not 45 days ago and more recent?

    I'm looking around the pic's at your's and neighboring yards and looks like it stops at the property line on each side of you and don't carry over into your neighbors yard? Diseased don't discriminate, much like a cancer it will spread unless your neighbors yard is treated with a preventative application.

    I'm also seeing the second pic down on the left which looks like two green stripes and two yellow stripes all the way across the yard, did you spray anything or spread anything? The pic on the right of that looks like yellow grass and brown patch won't do that it will be green and only a circled area effected.
     

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