# Heat Stress or Fungus?



## Cajun71163 (Sep 17, 2019)

Second week of PGR, applied 19-0-8 after to counter the browning. The .5" HOC is beautiful but the 1.5" HOC has a brown tint. Thoughts? PGR effect? Ascochyta Leaf Blight fungus? Heat Stress?


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## verynate (Jul 29, 2020)

I'm not a pro by any means but if you are watering and you've ruled out root damage from pests, fungus would be my next thought. It appears to be widespread but also patterned a bit. Just my 2 pennies.


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## ShaneQi (Oct 9, 2019)

Hey I'm also in Dallas and found the same after yesterday's rain.
I was going to post this question and saw your post.

A couple of observations of myself:

1. The yellow/dead grass is totally 100% discolored (shown in my picture).
2. I'm pretty sure it's not fertilizer burn because the whole patch would be yellow instead of just a 'brown tint'.
3. I've also seen this last season, about the same time of the season.

My hunch is that it's caused by the combination of the heat and rain. 
But not sure if it's disease and what exact disease.


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## Cajun71163 (Sep 17, 2019)

I am just going to wait it out for a couple of weeks - I was reading that many people are having the same issue but my .5" HOC is awesome so I was just thinking Fungus. If it is Ascochyta Leaf Blight fungus it gets better on its own. Soem San Antonio yards are experiencing this fungus I understand. Maybe the Dallas rain had some acid in it. LOL


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## CenlaLowell (Apr 21, 2017)

I need advice instead of starting a new thread I'll ask here since it's on the same topic. Brown patch or drought. I went a week without watering and temps were between 91-95. I'm thinking drought myself because it's doesn't have any identifying signs like the circle, but what do y'all think







I'm under fungicide suppression for another 10 days with Luna Sensation. I started watering yesterday. Upon further examining only the tips have turn brown, in the areas I checked. Last mow was Monday.


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## FATC1TY (Jul 12, 2017)

Fungus.

It's just RIPE this year. I've got it, myself. Answers my own thread, because this time of year is primed perfectly. Seriously, go look at this time last year and see the threads.

Heat at night isn't helping, and the dew or late thunderstorms wreck havoc.


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## CenlaLowell (Apr 21, 2017)

FATC1TY said:


> Fungus.
> 
> It's just RIPE this year. I've got it, myself. Answers my own thread, because this time of year is primed perfectly. Seriously, go look at this time last year and see the threads.
> 
> Heat at night isn't helping, and the dew or late thunderstorms wreck havoc.


What fungus do you think brown patch because I never had that in my lawn before. Also what good is fungicide if I'm going to get the shit anyway frustrating


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## FATC1TY (Jul 12, 2017)

CenlaLowell said:


> FATC1TY said:
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> > Fungus.
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This time of year I'm seeing lots of brown patch, leaf spot( bipolaris), especially if you've irrigated and have lots of moisture on the leaf mid day.

Azoxystrobin and propiconazole should tackle a fair bit of it all.

I put down DiseasEX about 2 weeks ago as a preventative when I scalped and watered a lot, couple spots, mostly where I didn't get it down well like the hell strip.


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## CenlaLowell (Apr 21, 2017)

FATC1TY said:


> CenlaLowell said:
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> > FATC1TY said:
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Here's is the killer I'm supposed to be still under suppression for another 10 days from my last fungicide app


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## kb02gt (Aug 23, 2019)

Fungus most likely driven by dead grass. I'd say if the dead leaves are curled up, then there heat stress and drought. The areas of the lawn where the soil is more compacted and or the roots are shallow, will be the areas that are affected first.

The planted trees can also show signs of fungus as well.

But right now disease pressure is high, and if there is even a little bit of fungus in the soil, the right conditions will set it off. Such as dead grass for example. Toss in some wet dew in the morning, and the fungus will spread. If im not mistaken the azoxystrobin is labeled for 30 days, but under certain conditions its only 21 days. There is also a "melting out phase" of the grass that can occur after a fungicide is put down. The grass will begin to look worse before it gets better during the meltout. Cannot remember the biology behind why that happens though. The preventative rate i dont even trust unless im putting it down with another fungicide group. I did a preventative of azoxy and it lasted maybe 2 weeks. Thing is if there is any form of fungal resistance to the azoxy, plus the high disease pressure, plus it only being a preventative rate so if there is any fungus in the soil already that we do not see, plus a food source such as dead thatch, then those 4 things could contribute to a preventative not working as well.


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## CenlaLowell (Apr 21, 2017)

There's another lawn in the neighborhood with similar problems as mine, but I'm just going to let it ride until it's time for me to spray again. In no way I'm I ever spraying before time because of something like this. I really need to figure out how to prevent this so I can eventually spray pgr. This year is dead issue so maybe next year.

I only spray at curative rate


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## ionicatoms (Mar 8, 2020)

@CenlaLowell what's the deal with that first leaf? It's notched and missing some tissue like it's been eaten. The white spots on the tissue also concern me. I looked at these photos for quite awhile; it seems to me the disease is secondary to some other stressor.


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## ionicatoms (Mar 8, 2020)

CenlaLowell said:


> I really need to figure out how to prevent this so I can eventually spray pgr. This year is dead issue so maybe next year.


@CenlaLowell, which PGR are you thinking of? Do you already have one selected? I was looking in the 2020 Pest Control for Professional Turfgrass Managers and saw 2 products that specifically mentioned St. Aug.

One was for use in "Edging" but I am unfamiliar with this use of the term.


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## CenlaLowell (Apr 21, 2017)

ionicatoms said:


> @CenlaLowell what's the deal with that first leaf? It's notched and missing some tissue like it's been eaten. The white spots on the tissue also concern me. I looked at these photos for quite awhile; it seems to me the disease is secondary to some other stressor.


I truly don't know. I'm thinking the stressor is heat because it so spotty. It's in six areas and also in the Bermuda area, which never gets a diease. It could also be diease driven because I notice some GLS but not enough to have this result on the lawn. I'm due for a Fungicide next week so I'll spray Axozystrobin and 3336 together. Let me know if you come up with anything.


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## CenlaLowell (Apr 21, 2017)

ionicatoms said:


> CenlaLowell said:
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> > I really need to figure out how to prevent this so I can eventually spray pgr. This year is dead issue so maybe next year.
> ...


I have t Nex and paclo already. I need to get everything correct before I start spraying in the front lawn. I will maybe start next year.


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## ionicatoms (Mar 8, 2020)

CenlaLowell said:


> ionicatoms said:
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> 
> > @CenlaLowell what's the deal with that first leaf? It's notched and missing some tissue like it's been eaten. The white spots on the tissue also concern me. I looked at these photos for quite awhile; it seems to me the disease is secondary to some other stressor.
> ...


Check this out:
"Biochar was also found under certain circumstances to induce plant systemic responses to foliar fungal diseases and to improve plant responses to diseases caused by soilborne pathogens."


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## CenlaLowell (Apr 21, 2017)

ionicatoms said:


> CenlaLowell said:
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I have to look into this. I know I plan on spraying Humic and extreme blend alot next year hopefully this helps the soil as well. Also I've watched videos on peptides but I'm on the fence still.


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## CenlaLowell (Apr 21, 2017)

Sprayed fungicide yesterday and this was not there but this morning when im watering I notice a bunch of this


Comes and goes I guess.


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## LoveMyLawn (Oct 14, 2019)

That looks like Gray Leaf Spot


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## CenlaLowell (Apr 21, 2017)

LoveMyLawn said:


> That looks like Gray Leaf Spot


It's definitely what it is... I'm thinking this came up after I sprayed Axozystrobin and 3336. I wonder why???


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## LoveMyLawn (Oct 14, 2019)

I'm going to piggy back on this thread as well. I believe this is some type of fungus. I did a soap test last night and nothing came up. This is the only area in my yard that has it. It's also the last area to get sun so the morning dew/irrigation stays on the leaf the longest. I applied Scotts and 3336 both at the curative rate a week ago. We'll see how it does.


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## ionicatoms (Mar 8, 2020)

Would dew removal in the morning help with GLS? I read that it helps with DS on golf courses.


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## CenlaLowell (Apr 21, 2017)

ionicatoms said:


> Would dew removal in the morning help with GLS? I read that it helps with DS on golf courses.


I imagine it could but it's not practical on a big lawn. Man I would be tired


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## ionicatoms (Mar 8, 2020)

CenlaLowell said:


> ionicatoms said:
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> > Would dew removal in the morning help with GLS? I read that it helps with DS on golf courses.
> ...


LOL - I understand it is sufficient to run the sprinkler for a couple minutes to wash away (syringe) the guttation. See https://www.golfcourseindustry.com/article/gci0713-prevent-dew-destroying-turf/ for details on Dollar Spot. I haven't tried it, but in https://etda.libraries.psu.edu/files/final_submissions/8119 the best result was obtained by removing dew at 4AM.


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