# Rhizoctonia in zoysia?



## Monocot Master (Feb 28, 2021)

This problem began to manifest itself in my zoysia lawn last year in early August in SE coastal NC. Most signs were pointing to large patch except online resources indicated it was too early soil temp wise. Not sure what the soil temp was at the time but would guess 80 deg or so. We were in a period of average rain events, and temperatures for that time of year. I did split apps, granular propicanozole and then azoxystrobin 2-3 weeks later. That was in September. That seemed to keep the progression in check. Based on my description and photos, am I correct that my problem is fungal? I want to get ahead of things this year with a progressive approach to prevention, no matter what the cause. Thanks in advance!


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## Spammage (Apr 30, 2017)

@Monocot Master looks like a leaf spot instead of large patch. Patch attacks the crown, so the entire leaf turns off color and then dies. When you pull at those infected areas, the shoots come out easily with black slimy yuck at the base.


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## Monocot Master (Feb 28, 2021)

Thank you for the input! The only leaf spots I know that I have had are dollar spot and gray leaf spot. This looked like neither of those two. The stems would pull out easily while the top was in some stage of die back. Like the stem in the picture. Not saying that it is not a leaf spot disease, but I never could get it dialed in based on the symptoms. Those patches would never get very large (baseball-basketball sized) but there were quite a few of them. It was late enough in the growing season that they did not recover. Coming out of dormancy now, so hopefully will fill back in quickly. Just want to be prepared this year.


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## Monocot Master (Feb 28, 2021)

It appears that whatever I had going on in my lawn last summer is still active. I took a closer look at the bare spots caused by my issue last year and new growth in those areas is dying back again. It shows first at the leave blade tips. But the big issue is at ground level and below. Everything there looks to be rotting away. See the last picture in my original post.


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## Spammage (Apr 30, 2017)

@Monocot Master what is your pH? That might be TARR. I would also suggest a soapy water test to see what (if any) insects are present.


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## Monocot Master (Feb 28, 2021)

pH is 6.5-7. I had a healthy mole cricket population last year and this spring. But I had good results with Bifen several weeks ago. Otherwise, I have not turned up any insects on my soap flushes. I know a little about TARR, but will research that some more. Thanks for your help. This lawn issue is pretty worrisome. Hopefully I can get it sorted out.


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## Monocot Master (Feb 28, 2021)

I stand corrected on the pH. I took a few readings and mostly in the 5.5 range. The image is what my trouble spots are looking like, and my Kelway meter


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## Greendoc (Mar 24, 2018)

Stick in the ground soil probes can read high salts as low pH. I would get an actual soil test from a reputable lab to confirm.


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## Monocot Master (Feb 28, 2021)

Gotcha. Good to know. The last soil test from the state soil lab was in the 6.5 range. What say ye in regard to TARR or other fungal pathogen, or whatever is afflicting my zoysia? The centipede front lawn and the centipede contamination in the zoysia seems unaffected by the ailment.


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## Spammage (Apr 30, 2017)

Monocot Master said:


> Gotcha. Good to know. The last soil test from the state soil lab was in the 6.5 range. What say ye in regard to TARR or other fungal pathogen, or whatever is afflicting my zoysia? The centipede front lawn and the centipede contamination in the zoysia seems unaffected by the ailment.


If you have healthy centipede, then the pH is probably accurate or at least close. That pH should rule TARR out as well. You might want to put another fungicide app down now as a preventative. With the damage from last year, it will take longer than normal to look good again. With some temps above 85-90, you should start to see the areas look better.


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## Monocot Master (Feb 28, 2021)

Thank you folks for your input. I am past due for a soil test, so it may be time to pull some samples. If the problem persists, I can also have pathology testing done. Hopefully, I will not have to do that one.

Regarding a fungicide application, I did a blanket spray of Clearys about one week ago. At what I think is a fairly low rate however (2.5 oz/1000 sq ft). That is the only fungicide I have applied this year. I also have a bag of Pillar G in ready reserve.


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## Monocot Master (Feb 28, 2021)

So my fungicide rotation worked pretty well this year, but I am a little overdue and beginning to see a little bit of the same issue I had. I have had almost no signs of dollar or gray leaf spot this year. I made three 3336 apps and still have one more if needed before reaching the recommended annual max. And made one application of the Pillar G in July. Doing another Pillar G in the next day or so. I do wish I knew for sure what disease organism I was dealing with. The plant seems to be affected at the ground level initially. Then leaf dieback which starts at the tip as seen in the 4th picture in my original post. Any input is greatly appreciated.


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## rvczoysia (Jul 18, 2021)

Every time I have a fungus issue, which is often..lol, I think it may be something other than large patch. I send a sample to the local extension office and it's always large patch. Whether the leaves look bleached or the roots look dark.


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## TampaBayFL (Jul 24, 2020)

From what I have learned, from others and my own experience for the past year or two, if it is Zoysia, pretty much just assume it's fungus, LOL. It almost seems like the only sure fire approach is to be very proactive and never really stop applying fungicides. That has definitely worked for me this year.


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## rvczoysia (Jul 18, 2021)

TampaBayFL said:


> From what I have learned, from others and my own experience for the past year or two, if it is Zoysia, pretty much just assume it's fungus, LOL. It almost seems like the only sure fire approach is to be very proactive and never really stop applying fungicides. That has definitely worked for me this year.


lol!! Yep good approach


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## Monocot Master (Feb 28, 2021)

@rvczoysia Thanks for that bit of info. I think I am going to assume that mine is large patch and just move on + continue the preventative fungal treatments during the growing season.

@TampaBayFL My zoysia is also Empire. Sometimes I wish it was centipede. The Empire is a love/hate relationship!


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## TampaBayFL (Jul 24, 2020)

Monocot Master said:


> Regarding a fungicide application, I did a blanket spray of Clearys about one week ago. At what I think is a fairly low rate however (2.5 oz/1000 sq ft). That is the only fungicide I have applied this year. I also have a bag of Pillar G in ready reserve.


What I have found works on my end is roughly----

2 oz/1k Propiconizole

2 oz/1k Thiophanate methyl (Clearys)

4 lb/1k Disease EX (Azoxystrobin)

I apply each of these roughly once every three or four weeks and it appears to have completely solved any fungal issues in empire zoysia.


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## TampaBayFL (Jul 24, 2020)

Monocot Master said:


> .
> 
> @TampaBayFL My zoysia is also Empire. Sometimes I wish it was centipede. The Empire is a love/hate relationship!


I wish mine was gravel sometimes!

In seriousness, for most of my lawn care life previously I always had St Augustine and that was much much easier to keep looking nice. Sure, there were periodic problems with it, but it never seemed as temperamental.


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## Redtwin (Feb 9, 2019)

Monocot Master said:


> @TampaBayFL My zoysia is also Empire. Sometimes I wish it was centipede. The Empire is a love/hate relationship!


I'm loving my Empire. No disease issues so far even with the crazy wet months we had this summer. I'm almost to the point of wishing my whole yard was Empire but I'm not about to give up on the 419 just yet.


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## TampaBayFL (Jul 24, 2020)

@Redtwin That looks gorgeous! I can't tell from your photo but it looks like you are maintaining at something less than 1 inch? Mine takes on that same color when I cut below an inch, when I maintain higher it always looks a different hue of green.


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## Redtwin (Feb 9, 2019)

@TampaBayFL That photo was from today. I am cutting at 3/8" right now and will probably maintain that until winter. With PGR, the color is normally very close but not quite as dark as the Tifway 419 on the other side of the sidewalk. I let it come out of regulation and the color immediately changed as soon as it rebounded. Another problem I'm having is my mowers are in dire need of maintenance so my after-cut appearance is pretty rough.

My neighbor who has the same cultivar rotary mows between 1" and 1.25" and the color is completely different. We have compared notes and the only difference is the PGR.


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## Monocot Master (Feb 28, 2021)

@Redtwin How often are you having to cut your regulated zoysia? How often would you be mowing without PGR? With the heat and rain in Florida I am sure your turf never takes a break!

I mowed every 5 days this year with a 1" HOC. But this is the first year that I have been able to really control the top growth and still have a dense stand with good color. I think that I am at about 2.5 lbs N for the year and that will be it for the N.


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## Redtwin (Feb 9, 2019)

I mowed the Zoysia about every 3 days but I was barely cutting anything off. I'm pretty sure that with T-Nex I could get away with once a week since it doesn't scalp like the Bermuda. It's hard for me to say since this has been an establishment year and I think I was probably pushing through the PGR with the extra N. I have put down about 1.5 to 2 lbs of N over the whole season but I have been pushing growth through several sand applications and have dealt with significant rain and soil wetness where the grass was under water for days. It will probably be less than 1lb N next season if all goes as planned. I was using the T-Nex more for color and density than for control of top growth.

BTW... I was applying T-Nex at .25oz/1000sf which is on the high end for Zoysia.


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## TampaBayFL (Jul 24, 2020)

Dang.....I have had periods where I was
putting down 1 lb N/1k every week!


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## TampaBayFL (Jul 24, 2020)

Redtwin said:


> . I let it come out of regulation and the color immediately changed as soon as it rebounded.


Did it get darker looking?


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## Redtwin (Feb 9, 2019)

TampaBayFL said:


> Redtwin said:
> 
> 
> > . I let it come out of regulation and the color immediately changed as soon as it rebounded.
> ...


No, the color turned a very light green when it rebounded. It gets super dark with the T-Nex.

I spray any extra along the side of my driveway next to my non-LCN neighbor and even the centipede over there gets super dark green.


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## Redtwin (Feb 9, 2019)

TampaBayFL said:


> Dang.....I have had periods where I was
> putting down 1 lb N/1k every week!


Whoa! That's way too much for Empire. That might explain your fungus problems.


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## Spammage (Apr 30, 2017)

Redtwin said:


> BTW... I was applying T-Nex at .25oz/1000sf which is on the high end for Zoysia.


Soft. I've been as high as .45oz/1000 with no I'll effects. 

It honestly didn't make much difference from .25oz/1000 though.


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## TampaBayFL (Jul 24, 2020)

Redtwin said:


> TampaBayFL said:
> 
> 
> > Dang.....I have had periods where I was
> ...


I should have noted that this was after scalping, normally I don't put down anywhere near that.


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## TampaBayFL (Jul 24, 2020)

Redtwin said:


> TampaBayFL said:
> 
> 
> > Redtwin said:
> ...


Interesting, I've been sitting on about 8 oz of Primo to try and have held off. I've been hesitant to slow down a grass that is already slow to recover, LOL.

Without PGR, mine definitely looks a deeper darker green the longer I let it get. When I start cutting it down about 1.5 inches or less, it's not the same dark green as when it is 2 inches or more.


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