Cool-Season Overseeded Disease

Discussion in 'Pesticide & Herbicide Application' started by cpa4t9r, Oct 2, 2009.

  1. cpa4t9r

    cpa4t9r LawnSite Member
    Messages: 124

    I've got what appears to be Pythium (root rot) or some sort of damping off/melting out in my own backyard. Irrigigated TTTF/KBG turf. Slit-seeded/dethatched/plugged first week of September with TTTF/KBG and added some fine fescue due for shade tolerance. Seed germinated fine BUT about the time I reduced my watering schedule, got hit with about 2 weeks of damp rainy weather. Now I've got thinning/dying areas.

    Question: Its still warm enough to put more seed out but should I do a curative fungicide app? My main concern is the impact of the presence of disease. Temps are mid-70s during the day and lower-50s at night (dipped to 48/49 a few times). I don't want to waste an app or seed/fert for that matter.

    Any advice would be appreciated.
  2. suzook

    suzook LawnSite Member
    Messages: 147

    i would try a fung app, and some N, not too much though.
  3. greenskeeper79

    greenskeeper79 LawnSite Member
    from PA
    Messages: 46

    temps seem too cool for pythium to me
  4. Smallaxe

    Smallaxe LawnSite Fanatic
    Messages: 10,082

    You guys actually can grow KBG and fescue down there? Does it go dormant in the summer?

    KBG is susceptible to just about every fungal disease. Too much water during humid times is a good spark for symptoms. By the time you seed germinates the conditions may have changed and the new grass will be unaffected.
  5. cpa4t9r

    cpa4t9r LawnSite Member
    Messages: 124

    Thx for the responses.

    Smallaxe - we're in the transition zone so most everything is fescue. I've been adding the hybrid KBG for the past few years with success. Has irrigation too. You're right about KBG - TTTF fescue's big 3 in NC is brown patch, gray leaf spot and pythium. Dollar spot can be a problem in the spring - there were a lot of outbreaks.

    Greenskeeper - I was thinking the same thing about the nighttime temps, but ~2-3 weeks ago when it probably got started it was more low-60s which is still warm enough.

    Don't think its dollar spot as I didn't notice any lesions.

    Upon further thiught, it probably is damping off, which is caused by either pythium or rhizoctonia fungi. That would make sense with the overseeding and soil saturation. I'll do a fungicide seedbed treatment with a light seeding/fert app to the affected areas - I have some Heritage which I've seen recommended for treatments in NC with spring seeding of cool-season grasses.

    I'm open for any other suggestions/feedback.
  6. karlgrooms

    karlgrooms LawnSite Member
    Messages: 140

    Man! What a tough late season we are having in WNC... way too much rain and not enough sunny breezy days to dry things out. If you over seed a diseased lawn does the new seedlings suffer same plight or refuse to come up? Should I consider letting it run its course or treat with fungicide asap.
  7. mdlwn1

    mdlwn1 LawnSite Silver Member
    Messages: 2,443

    Propiconizole works great for damping off.
  8. cpa4t9r

    cpa4t9r LawnSite Member
    Messages: 124

    Karl - I'm in Forsyth County, which is getting near the foothills, but still classified as Piedmont. Your question about the seedlings is basically the same as mine. The seed should still germinate if conditions permit but I think it would be susceptible to disease with it being weakened. That was my problem - a lot of areas the seedlings and existing turf were doing well, but everything was too wet with a week straight of steady/heavy at times rain. Turf never seemed to "tighten" up. Now some areas are still flaccid and others have the dead patches indicative of pythium root rot/damping off.
  9. karlgrooms

    karlgrooms LawnSite Member
    Messages: 140

    Thanks...Not trying to jack your thread but having the same issues and can sympathize with your situation....I think the disease has progressed to the point that the turf is completely void of some areas. What grass I have left is very sparse and flaccid as you mentioned. That is why I am asking about the treatment, I don't have a license and was wondering about the course of treatment if any. If treatment is necessary can I pick up the product and treat? This is in my yard which survived the drought last year and flourished this spring.
  10. cpa4t9r

    cpa4t9r LawnSite Member
    Messages: 124

    Heritage is not RUP but it is spendy (can get it pretty cheap on eBay sometimes).

    Summary: Control of Damping-Off with Fungicides
    • applications on seed or at seeding provide up to 14 days of
    • a follow-up application is needed at the time of seedling
    • applications at emergence provide the most effective and longlasting
    control of damping-off
    • azoxystrobin provides effective control of damping-off caused
    by Pythium and Rhizoctonia species

    Here's a link to a pdf (spring seeding but still good info) - its too big to attach.

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