# Brown Patch and Nitrogen



## Sinclair (Jul 25, 2017)

I am experiencing brown patch pressure, and through much googling and youtubing, I have found conflicting information on what to do with brown patch.

Some say a moderate application of synthetic nitrogen helps the plant recover, while others say do not apply nitrogen to brown patch at all.

Has anyone here applied nitrogen to patch and had it grow out successfully rather than make the problem worse? What would the correct rate be?

I've already applied a light spray of Sulfur solution (it's the best I can do in Canada on a weekend), but would like to avoid ordering more potent fungicides online.

Thanks.


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## jha4aamu (Oct 16, 2017)

Sinclair said:


> I am experiencing brown patch pressure, and through much googling and youtubing, I have found conflicting information on what to do with brown patch.
> 
> Some say a moderate application of synthetic nitrogen helps the plant recover, while others say do not apply nitrogen to brown patch at all.
> 
> ...


i have a strip of grass in my front yard that has BP and i dropped some synthetic N at 1lb/k 2 weeks ago and it didnt do anything to combat the BP. quite possible that my app rate wasnt appropriate for BP?


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## g-man (Jun 15, 2017)

I think it is best a dual approach. Apply something that prevents/cures the bp and nitrogen to aid in the recovery of new growth.


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## Sinclair (Jul 25, 2017)

I applied some urea before the rain overnight, and we have cool temps all week, so hopefully the grass out grows the BP.

I'll do another sulfur spray as that's likely washed off the foliage and into the soil. My soil is basic, so it's beneficial either way.


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## Delmarva Keith (May 12, 2018)

Sinclair said:


> I am experiencing brown patch pressure, and through much googling and youtubing, I have found conflicting information on what to do with brown patch.
> 
> Some say a moderate application of synthetic nitrogen helps the plant recover, while others say do not apply nitrogen to brown patch at all.
> 
> ...


The confusion amd conflicting information comes from, at least in part, a need to have adequate plant nutrition in the soil so it has a best chance of fighting the disease while not providing excessive nutrition that leads to overly lush growth and the increased possibility of dollar spot and pythium (along with more brown patch). In my experience, aside from really bad cases, turf recovers from brown patch but not dollar spot or pythium. So what you do with the fert makes a big difference and at the end of the day, there's just no clear cut answer. Sometimes it comes down to a judgment call and some degree of chance.

If the plant is not otherwise showing signs of nitrogen deficiency, might be best to wait on the fert. Conversely if it is showing some fertility stress, a low rate of fert (again, a judgment call. A half pound N per 1,000 is typical but I don't know what your weather is like. If it's headed into hot, maybe as low as 1/4 lb N per 1,000) makes a lot of sense.

If you do decide to apply fertilizer, make sure it contains potassium and not just nitrogen. The turf can use some potassium to recover. I've seen suggestions as high as 1-0-2 ratio but whatever you decide to use, basically don't ignore the plant's potassium needs. I would avoid anything with much lower potassium than a 2-0-1 ratio.


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## Sinclair (Jul 25, 2017)

@Delmarva Keith

I didn't mention earlier that I also sprayed liquid starter fert, because I wanted to get more than just N into the grass and it was going to rain anyhow.

Between that and the urea, I applied the equivalent of ~26-12-13 at 0.5lb N / 1000 rate.

Thankfully we are coming into a period of cool days and cold nights, so that alone should slow down the brown patch and favour turf growth.

I just ordered some propiconazole to have on hand as a very last resort. I'd rather not use it.


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## Sinclair (Jul 25, 2017)

Thanks for your responses.


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## nclawnguy (Jun 27, 2017)

I would avoid synthetic nitrogen right now, especially if you see brown patch. Clear up the disease first using fungicide with Azoxystrobin. To help recover after, use milorganite or light dose of synthetic N (0.25 lb N / 1000 sq). Brown patch will not kill the plant, should recover.


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## Delmarva Keith (May 12, 2018)

Sinclair said:


> @Delmarva Keith
> 
> I didn't mention earlier that I also sprayed liquid starter fert, because I wanted to get more than just N into the grass and it was going to rain anyhow.
> 
> ...


Sounds good. Like I said I just don't think there's really a clear cut answer. It comes down to a judgement call and you are gaining experience to make better and better decisions based on what you see on the ground as time goes on.

In the future, I'd make sure the N applied was slow relase (I should have mentioned that). Urea (and likely a liquid starter fert) can cause a growth flush that you may not want. No harm done but just something to watch as the grass recovers - based on what you did, watch what the turf does and make whatever adjustments are needed. Maybe a quick dose N was exactly what it needed and it does great; maybe it's a little too lush so for next time you'll know; you'll see soon enough. Keep an eye on soil water content - don't let it stay too wet if you can help that.

I have to disagree with NClawnguy on the Milorganite (sorry NClawnguy) :mrgreen: . Milorganite is missing the potassium the turf really needs, this time of year especially. It also has a lot of phosphate that most soils don't need, and excessive use can lead to iron deficiency (not to mention polluting streams and bays). A good balanced synthetic with a decent percentage of water insoluble N is fine. If you want the micros and probiotics, throw the same weight of a quality seasoned compost out as you would one of the "bio-ferts" - basically the same effect.

I've had very limited success with fungicides despite many epic battles with fungus. I might go back to planning a program but man that can be a lot of work that seems to usually end in heartbreak anyway.


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## nclawnguy (Jun 27, 2017)

I maintained a flawless tttf lawn in NC by never applying synthetic N in the spring/summer and rotating fungicides. I only applied milorganite, spring and summer. Also maintained kbg for a year with zero issues same way.


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## Delmarva Keith (May 12, 2018)

nclawnguy said:


> I maintained a flawless tttf lawn in NC by never applying synthetic N in the spring/summer and rotating fungicides. I only applied milorganite, spring and summer. Also maintained kbg for a year with zero issues same way.


Glad to hear that! But without a control, it's an anecdote. What worked for you may not work for someone else, somewhere else.


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## g-man (Jun 15, 2017)

GerogiaDad (from around the yard) had an amazing KBG lawn for years in Georgia. It is very doable.


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## nclawnguy (Jun 27, 2017)

It's cool, it's your lawn and you can treat how you want. I am pretty sure my method would work anywhere though, since I live in North Carolina where bp pressure is high. Good luck to you, I'll follow to see you progress.


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## social port (Jun 19, 2017)

Delmarva Keith said:


> nclawnguy said:
> 
> 
> > I maintained a flawless tttf lawn in NC by never applying synthetic N in the spring/summer and rotating fungicides. I only applied milorganite, spring and summer. Also maintained kbg for a year with zero issues same way.
> ...


Anecdotal may be the best way to describe it, but I like having information like this. I like to know how others are finding success, even if we can't say for sure what is causing that success.


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## social port (Jun 19, 2017)

Delmarva Keith said:


> I've had very limited success with fungicides despite many epic battles with fungus.


Very good to know. This is one of several reasons why I am not using a fungicide: There is no promise of cure.



Delmarva Keith said:


> The confusion amd conflicting information comes from, at least in part, a need to have adequate plant nutrition in the soil so it has a best chance of fighting the disease while not providing excessive nutrition that leads to overly lush growth


Interesting. That makes a lot of sense.



Delmarva Keith said:


> If the plant is not otherwise showing signs of nitrogen deficiency,


Do you, by chance, have any tips for identifying nutritional and/or nitrogen deficiency? I think many of us follow a recommended schedule for N, but it would be helpful to know when the schedule isn't meeting the needs of the plant. I know that I have wondered a few times this year: Am I giving my grass the N it actaully needs? 
I imagine that it is tricky to make the distinction between N deficiency vs heat stress, for example. I know that I can't do it.


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## Delmarva Keith (May 12, 2018)

social port said:


> Do you, by chance, have any tips for identifying nutritional and/or nitrogen deficiency? I think many of us follow a recommended schedule for N, but it would be helpful to know when the schedule isn't meeting the needs of the plant. I know that I have wondered a few times this year: Am I giving my grass the N it actaully needs?
> I imagine that it is tricky to make the distinction between N deficiency vs heat stress, for example. I know that I can't do it.


Nitrogen is mobile in the plant so when deficient, you will see the older growth start to turn the lime green as the new growth emerges. Other mineral deficiency (like iron deficiency) is different because the iron isn't mobile and it's the new growth that will start to look slightly chlorotic in the early stages. Another tipoff for nitrogen deficiency is (in addition to the color starting to pale a bit) is more profuse seeding. Complicating it, if the plant is deficient it will need to take up more water trying to get what it needs from the soil. This can lead to a drought stressed appearance even though the underlying issue is a soil deficiency.

Heat stress is where the plant can't metabolize the carbs it needs because it's too hot for the chemical processes necessary formthe plant to do so. Entire blades may needle and go brown like drought stress or the tips will start to yellow progressively down the blade as the crown pulls in carbs (and water) from the leaves. Here again the plant will need to use more water which can lead to a drought stressed appearance even though the underlying issue is heat stress.

You're not the only one who can't tell for sure exactly what's wrong with a plant. Actually nobody can tell for certain and the only actual "test" is to do an actual test. Apply whatever it is you suspect is deficient to a small area and observe the respose about four days later. If you get a response, it is deficient. Doesn't mean there aren't other potential deficiencies, but the plant is deficient for what was tested.


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## Sinclair (Jul 25, 2017)

@Delmarva Keith

You just described parts of my lawn to a tee.

There is definite brown patch in the middle of the stand, but also near the curb and driveway (i.e. heat reservoirs) there's needling, yellowing from the tip, and a greyish hue to the grass as if it is drought stressed, even though it's had plenty of water.

I'm happy to report that after a dose of N and a good thunderstorm last night, today was cool and dry, and the turf looks much better already.


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## Sinclair (Jul 25, 2017)

The other #pisseroffer ($1 to @wardconnor ) is that the perennial rye tends to rip when it is stressed instead of cutting cleanly, even though my mower blade is always freshly sharpened.

The poor cut quality then in turn doesn't help with the patch problem.

This is tempting me to go 100% KBG this fall.


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## social port (Jun 19, 2017)

@Delmarva Keith awesome to have this information. Very helpful to know. I will reference this in the future, OK? 
One question: is there a situation in which a small section of lawn wouldn't look better after a little N supplementation? This is in reference to the test you pose: Assuming, for example, that, in a given instance, browning is due to drought stress, wouldn't the browning section respond favorably, given that it will receive N and some water? Both inputs improve plant health, so how does one decipher which one led to the recovery-something that must be known in order to diagnose the source of the problem?
I'm just trying to make sense of how I would use this test.


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## social port (Jun 19, 2017)

@Sinclair PRG tends to rip when stressed? Wow. This thread is full of good info.


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## Sinclair (Jul 25, 2017)

@social port

Here's a super close up of an area with brown patch.

This is one day after mowing with a sharp blade.

Cut ends highlighted, PRG red, KBG blue.


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## social port (Jun 19, 2017)

@Sinclair
:shock: 
What a great observation.


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## Sinclair (Jul 25, 2017)

I can't take credit for the observation - I read somewhere that the veinous nature of PRG blades makes them more susceptible to tearing and fraying. Now I am just seeing it in practice.


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## Delmarva Keith (May 12, 2018)

social port said:


> @Delmarva Keith awesome to have this information. Very helpful to know. I will reference this in the future, OK?
> One question: is there a situation in which a small section of lawn wouldn't look better after a little N supplementation? This is in reference to the test you pose: Assuming, for example, that, in a given instance, browning is due to drought stress, wouldn't the browning section respond favorably, given that it will receive N and some water? Both inputs improve plant health, so how does one decipher which one led to the recovery-something that must be known in order to diagnose the source of the problem?
> I'm just trying to make sense of how I would use this test.


So, let's say we have five lots. One is drought stressed, no other deficiencies. One is N deficient, no other deficiencies. One is iron deficient, no other deficiencies. And one is both N and iron deficient, no other deficiencies. One is potassium deficient, no other deficiencies. We need to figure out what's wrong at each one so as not to overapply something it doesn't need and not apply something that acually could harm it.

On each lot we have five small test areas (say one to a few sq ft each): apply respectively water, N, iron, potassium, nothing.

In the following, "perks up" means the chlorotic or slightly chlorotic areas of live blades improve, or for drought stress, still live but needled blades unroll or unfold.

On the drought stressed lot we see the watered test perk up. None of the other test areas do much.

On the N deficient lot we see the N test area perk up, none of the other test areas do much.

On the iron deficient lot we see the iron test area perk up. None of the other areas do much.

On the N and iron deficient lot we see the iron test area perk up and the N test area possibly actually decline. The added N to an N and iron deficient lot will force growth with insufficiemt iron. None of the other areas do much.

On the potassium deficient lot we see the potassium test area improve. None of the other areas do much.

On the control area with nothing applied, we use that to compare the other areas.

In real life you are likely going to see combinations and degrees of change in each little test area because it's unlikely to have such neat and perfect complete deficiencies or complete sufficiencies. You use what you see to gauge what to actually apply to the whole lot, but the point is each test area is kept separate for each input if you want to isolate what is wrong. If you apply N to an area not deficient in N, you won't see a marked response from the turf (but you may get even more fungus).

Note that simply knowing there is some N deficiency doesn't mean you should add N. Like we were talking about with fungus, you want to keep the plant reasonably healthy but not overly lush when there is high fungus risk. If the turf looks like crap and is thinning out and you identify N as a deficiency, yes, add a low rate of slow release N.

Potassium and iron deficiencies would be treated differently. Potassium and iron can help the plant fight stress. If it needs potassium or iron or both, give it potassium or iron or both.

You can also have a lab do plant tissue tests which can tell you what's deficient in the plant tissue and thus generally in the soil. From there you can make a decision about what's "wrong" and what to do about it. Using small test areas as outlined above is generally simpler and faster.


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## social port (Jun 19, 2017)

@Delmarva Keith thanks for that excellent outline. As a homeowner, I don't imagine myself pulling off anything that elaborate, but it is very helpful to have an idea of how the testing scenario might look and to have an idea of what to look for and do in these various situations. 
:clapping:


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