Fungus Control....let it go and reseed?

Discussion in 'Pesticide & Herbicide Application' started by Teach123, Jul 16, 2012.

  1. Teach123

    Teach123 LawnSite Member
    Posts: 155

    After much research, an agronomist, entomologist, I finally think I have figured out what has been the culprit in my turf for 3 straight years. To make a long story short, there is a fungal problem (leaf spot melting out) Occurs in the same spots year after year. Question: I know Heritage and Compass have shown good control, but do I treat now as a curative? Or just rake out in Fall and reseed with good disease resistant cultivars via NTEP. Then use Heritage or the like in Spring (2 week intervals) as a preventative.

    I do know fungicides are $$$$$, but I also know I should alternate back and forth between a couple so that the fungus doesn't build up immunity. Would using a high-priced like Heritage/Compass and a low priced like Spectracide work??

    In addition, I am going to resist the temptation to dump N on the turf in spring and put the bulk of my fert down this fall. I think this cultural practice, coupled with a preventative fungicide should work.

    Ideas??
     
  2. RigglePLC

    RigglePLC LawnSite Fanatic
    Posts: 12,343

    Melting out is seldom a problem during hot weather. Get a second opinion. Be sure it matches the pictures like these:
    http://www.google.com/url?sa=t&rct=...sg=AFQjCNFd79ZVfdpBO700llzYEkPVmE0BAA&cad=rja

    The best control is to overseed with newer more disease-resistant bluegrass varieties. Avoid Parade and Newport--and all cheap seed. Include top quality perennial ryegrass if you wish--it comes up quicker and is not susceptible to melting out.

    Be sure you are not looking at red thread or brown patch disease.
     
  3. Teach123

    Teach123 LawnSite Member
    Posts: 155

    Riggle: The site you posted was the exact one where I found the address for Iowa State's disease identification center. I sent them a sample, and even though I am not a Iowa resident, they emailed me their findings and will send a follow up written evaluation.

    As far as seed...not gonna do PRG again. I'm going with 100% KBG. I will visit NTEPs site to see which ones show good disease resistance. I think the rye is what has the disease right now. The elite KBG seems to be doing great.
     
  4. DA Quality Lawn & YS

    DA Quality Lawn & YS LawnSite Fanatic
    Posts: 8,918

    Make sure it is not Necrotic Ring Spot. If it is, you will not want to reseed with KBG, or at least non-disease resistant KBG. And plan on a multiple year process to simply reduce the effects of the fungus. Far as I can tell, it can't be eliminated totally, I have tried almost everything.
     
  5. Smallaxe

    Smallaxe LawnSite Fanatic
    Posts: 10,082

    A lot of cool-season grass experts(midwest extension offices) agree that this cultural practice is best, for a number of reasons... in the case of fungus, it makes sense, becuz rapid watery growth is more subject to all kinds of disease problems...
    Personally, I'll startup fertilizer once things cool off in Aug,if the rains start then again in early Oct for a winterizer...
     
  6. Teach123

    Teach123 LawnSite Member
    Posts: 155

    Smallaxe, In the near future, I do want to hear about your Milo routine. I assume you are still using it. I think I am going to go mostly organic next year. I have soil sample pending (should get the results today or soon). I have recently made a homemade soil conditioner which is very similar to Aerify Plus and Kelp Help and I hope to make any soil amendments organically. Although, some calcitic lime may be the quickest way to sweeten the soil.

    As far as Milo, I know people have used it as various rates with success. I was thinking maybe bag rate on the first of each month. Again, hate to have disease issues, but the turf has to eat right?
     
  7. Pythium

    Pythium LawnSite Member
    from OHIO
    Posts: 166

    If you do choose the fungicide route..be sure to switch chemical families labeled for the disease to prevent resistance. Resitance issues usually arise after several (like all you use) repeat applications. Heritage and compass are both strobilurins same family very similar modes of action. OSU has a great chart on chemical families http://turfdisease.osu.edu/publications/turfgrass-fungicide-table-updated downloadable pdf
     
  8. Teach123

    Teach123 LawnSite Member
    Posts: 155

    Thanks for the link. I was told to stay away from the DMIs for some reason..I don't remember where I read that. Maybe from a study i read from Purdue regarding leaf spot. I believe the same study said Heritage had best results. So I guess I'll go with that and choose one from another family. Again, thanks for the link.
     
  9. Pythium

    Pythium LawnSite Member
    from OHIO
    Posts: 166

    DMIs can have growth regulating effects and other undesirable side effects if used incorrectly. Not sure if melting out is on their labels or not. High rate of resistance too, but so does heritage.
    Posted via Mobile Device
     
  10. Teach123

    Teach123 LawnSite Member
    Posts: 155

    Let me ask you this...Would applying at a curative right now be effective to save what healthy turf I have? Or is damage done so to speak. I mean, using good cultural practices now (i.e no N, watering to keep good turf, etc...) to wait it out until topdressing and reseeding this fall. My thought is that the disease attacked the non-elite KBG cultivars from previous sod and PRG that was there. The elite disease resistant cultivars of KBG are probably what is left. I seeded that last fall, but I think the PRG that was in the mix took over.

    Thoughts??
     

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