Please help! Fungus / leaf spot??

Kentucky bluegrass, Fescue, Rye and Bent, etc
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papa_bear_1164
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Please help! Fungus / leaf spot??

Post by papa_bear_1164 » May 19th, 2020, 3:37 pm

Hi all! New guy here and my tall Fescue (mostly) lawn was looking pretty good until recently. Can anyone help me identify this unsightly problem? I know it's impossible to say for 100% certainty without running tests, but my research indicates that it may be leaf spot... Thoughts?


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HoosierLawnGnome
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Re: Please help! Fungus / leaf spot??

Post by HoosierLawnGnome » May 19th, 2020, 5:45 pm

Probably?

It's that time of year for fungus. What's your fungus preventative approach?

papa_bear_1164
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Location: Central VA (Transition Zone)
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Re: Please help! Fungus / leaf spot??

Post by papa_bear_1164 » May 19th, 2020, 6:10 pm

Thanks for the reply, Hoosier. About a month ago I put down Jonathan Green fungicide (thiophanate-methyl) granular at better than preventative rate. Then about 2 weeks ago put down disease-x (azoxy) at better than preventative rate. Just 3 days ago I put down a curative dose of propiconazole (although I was weary since I've used it 2-3 times over the past year). Hasn't seemed to put a dent in it... as it has been raining for the past 24 hrs, I can literally watch it spreading hour-by-hour throughout my lawn as it continues to steadily pour :(

I also have put down insecticide including grub-ex, since I've had some issues there previously. I'm pretty sure it's a fungus since I did a light overseeding and a few bare spot patch jobs, I've been spot watering those areas twice daily to ensure the seed germinated and is holding strong, but nothing too crazy. Last year I had a heavy bout of brown patch (had it tested to confirm) so my guard is up!! 98% sure it's a fungus, just can't identify it for sure myself and was hoping for some feedback/shared thoughts on if Leaf Spot appears to be the culprit.

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HoosierLawnGnome
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Re: Please help! Fungus / leaf spot??

Post by HoosierLawnGnome » May 19th, 2020, 8:35 pm

One thing that will help is sharpening the blades. Those tips look shredded a bit.

You are hitting it about as hard as you can with fungicide. Maybe back off the fert and let it dry out a bit.

papa_bear_1164
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Re: Please help! Fungus / leaf spot??

Post by papa_bear_1164 » May 19th, 2020, 8:50 pm

Great catch!! I noticed that as well and sharpened the blades not long after taking this pic a few days ago. They are only a year old but a bit dinged up so just got some new blades yesterday and will definitely be putting them on before next mow. I never would have believed it but it did seem to make the problem noticably worse.

Thanks so much for the feedback and insight. Gonna let it dry out pretty good and allow nature to run its course. I'm getting alot of conflicting info though about pushing fert with leaf spot (assuming that is the issue)... Some say that forcing growth will push up the damaged parts of the blades so that new disease free grass will emerge and wait 2 weeks to mow... after next mow, problem solved. Some say too much fast nitrogen can make the fungus worse... Considering trying carbon-x or pro peat for the first time and seeing how that goes in this situation. Thoughts?


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HoosierLawnGnome
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Re: Please help! Fungus / leaf spot??

Post by HoosierLawnGnome » May 20th, 2020, 2:38 pm

I'm getting alot of conflicting info though about pushing fert with leaf spot
You're not getting that in this thread, nor any peer reviewed literature from reputable universities of which I'm aware.

Leaf spot (melting out) is encouraged by N fertilization. It's not like rust or dollar spot.

If you're not bagging up debris when you mow, that's another way to decrease infection.

Let it dry out, back off the N fertilization, don't spread it with clippings, get good clean cuts on the blades that don't invite infection as easily, etc etc

Dargin
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Re: Please help! Fungus / leaf spot??

Post by Dargin » May 20th, 2020, 3:35 pm

Resist the urge to chop the grass if you get tired of looking at the fungus while things play out. The fungus will still be there and have less leaf and stem to work with before potentially spreading to the crowns. Warmer temps coming too.

Just saying, I know a guy who did that once...

papa_bear_1164
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Re: Please help! Fungus / leaf spot??

Post by papa_bear_1164 » May 20th, 2020, 6:57 pm

Thanks for the feedback. I've been bagging every mow thus far this year! The technique of pushing N to help it "grow out" quicker was one I saw from a reputable YouTuber... He said hit it with fast urea nitrogen And let it grow for 2-3 weeks, then scalp it. I'll follow your advice though, Hoosier, and keep it off and just let it dry out. Definitely don't want to risk letting it spread to the crowns, that sounds like the worst!! (Sorry about "that guy" you know who did that once, Dargin)

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