Discussion in 'Pesticide & Herbicide Application' started by CLC03, Jul 12, 2006.

  1. CLC03

    CLC03 LawnSite Member
    Messages: 30

    I have seen some lawns with small patches of bluegrass that are are very dark blue. Is this the start of a disease? Is it too much nitrogen? I would like to pinpoint what it is before it becomes a problem.
  2. Rtom45

    Rtom45 LawnSite Senior Member
    Messages: 456

    It could be a fungus problem, it could be too much nitrogen (in the form of animal urine for example). You could use a fungicide at a preventative rate if you've eliminated other possiblities. Or you could wait for additional indications and treat for a specific fungus at a curative rate.
  3. naughty62

    naughty62 LawnSite Senior Member
    from iowa
    Messages: 369

    I have scene the same thing on a few newer lawns the last couple years and only one of 5 turned out to be the onset of necrotic ring spot.necrotic ring spot likes younger sodded lawn on slopes with poorly prepared seed compacted or shallow seed beds .NCS can be common this time of year on poorly sodded lawns.Have the owner keep a eye on it. If the frogs eye pattern developes youll know .Cut back water to deep infrequent cycles ,acouple aeration during the year,use slow release fertilizers onlyfor couple can do curative fungicide thing , but your usually a day late and a dollar short.Idont know how bad the lawn is .we reseeded with p. rye in the fall.Like rust and red thread IPM is the key.the other 4 lawns just had a couple patchs of dark blue grass ????.I have talk to a few people that have seen the same thing ,but nver given me a definate answer answer.
  4. teeca

    teeca LawnSite Bronze Member
    Messages: 1,202

    bluegrass does tend to turn BLUE if it is over N, then it will just puke out! and open it up to diease, if this is the case keep it well watered. it could also be the onset of fairy ring, you might start to get a band of dark blue in the form of an arch about 1'-2' wide, and the tell tail mushrooms growing within the band. as far as just throwing a fungicide treatment at it is just plain poor IPM. take a sample to your local extension/university and have it checked. fungi's are one of the few lawn problems that can readily change form and become tolorant to treatments of certin fungicides, thats way it's recomended that you alternate your fungicides.
  5. teeca

    teeca LawnSite Bronze Member
    Messages: 1,202

  6. Chris Wagner

    Chris Wagner LawnSite Senior Member
    Messages: 252

    Just another possibility... if these areas were renovated at some point, a different cultivar of bluegrass might have been used. If that's true, you won't likely ever get an exact match as some cultivars of bluegrass are darker than others.

    I'm not discounting a fungus, PH, or some funky fertilization, but just opening the possibility that it could be as simple a different cultivar of bluegrass.
  7. 6'7 330

    6'7 330 LawnSite Bronze Member
    Messages: 1,821

    Are the darker sections like in a ring ?
  8. rider

    rider LawnSite Member
    from ohio
    Messages: 152

    pictures please, if possible

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