Yellowing in known problem area

[Adam_M]

Hi!

I'm not sure what's going on in this area. It's on top of a very small high spot, and is one of the areas the perpetually gets hit with what I think is summer patch in July/August, but declining this early is new. I didn't start the companion/serenade yet - although it was in the works for the weekend.

This doesn't look like summer patch, and it's not warm enough for it anyway, so any other ideas what could be happening and suggested course of action?

So far, this year:
10-20-20 Late April 1/2lb N/k (Grass was awake)
Milo 1 week later (followed by a cold spell, so I bet it just sat there)
Top dressed with 32 bags of peat moss. the next week. ugh.
19-19-19 last weekend (4 weeks from the 10-20-20) 1lb N/k

We've had plenty of water, but we haven't had rain for a couple days. Temperatures are in the 60's.

All mowing this year has been at 2.75", but as the grass has finally decided to start the spring flush, I'm taking it up to 3.25" this mowing and up to 3.75" before the heat really sets in.

[Adam_M]

It got worse today, so I pulled a few leaves off and pulled one plant up to see the roots and did some reading.

It seems like it could be: Melting out (caused by Bipolaris sorokiniana) based on this paper from Purdue:
https://www.extension.purdue.edu/extmed ... -103-w.pdf
typically appears in April and May during cold,rainy weather. High nitrogen fertilization during the middle weeks of spring also favor the disease.

It's May, Cold, rainy, and I just put down some Nitrogen.

The linked paper recommends Heritage (among others) and I have a bag of disease Ex, which has the same AI, here.

Seem like a reasonable plan to drop Disease Ex at a curative rate?

I also had plans for a dose of Milo + boron this weekend - should I hold off on that?

Thanks!

[LeftField11]

I'm dealing with the same thing here in south central PA, and I've also come to the conclusion that it's leaf spot / melting out. I treated it a week ago with propiconazole based on a recommendation from this forum, but this source says azoxystrobin (Heritage, DiseaseEX) is more effective, http://www2.ca.uky.edu/agcomm/pubs/ppa/ppa1/ppa1.pdf.

Since the application of propiconazole, my situation has not worsened. Yesterday I sprayed Serenade at 4 oz. / 1000 sf. I figured that for $100 I could buy enough Serenade to treat my lawn in a preventative measure all summer (2.5 gallons from Seven Springs Farms). One application of fungicide costs almost as much. And the Serenade isn't going to hurt anything.

My lawn also needs some fertilizer right now and I wasn't sure how to handle that. Yesterday I put down a Milo knock-off (ProActive) at a rate of about .8 lbs N / 1000 sf. My thought is that it's slow-release so hopefully it won't worsen the melting out. We'll see.

Temps go up next week and it looks dryer, I'm hoping that helps to clear up the melting out. Since my reno in 2016 I've never actively dealt with fungus, I always let it run it's course, and I always regretted that. So I'm very much experimenting my way through this, don't take anything I say as guidance, I'm generally just commiserating with you.

[bernstem]

Leaf spot seems to be very common this year and right now. Summer Patch would be early, but if it has been very dry you could be seeing some. Ideal treatment window for Summer Patch is early spring. The fungus does its damage to roots then, but you don't see it until it gets hot as the turf is able to compensate with lower temperatures and generally wetter conditions.

[mvftw]

Would Prophesy fungicide (0.72% propiconazole) be good for this...

[Adam_M]

This spot has spread in spurts - and it seems to get worse with heat. I've been supplementing mother nature with 1" of water - all at once (measured) I dropped disease ex shortly after the original post held back the fertilizer until yesterday (the rest of the yard looked hungry).

The problem spot is the edge of a very small rise (maybe 4-6") - could it be as simple as this spot needs more water? It doesn't normally look any different than the surrounding grass does before it declines.

[Adam_M]

I grabbed some pictures while I was out cutting the grass. The declining areas are in separate parts of the yard, photos attached. I dropped another batch of disease ex, and the grass doesn't seem to care - so if it's fungus, it doesn't appear to be sensitive to the AI (anymore). I don't think it's water, the rest of the grass is fairly green?

The soil is bad - The grass is growing in basically what you see in the area that has been excavated, unfortunately. I'm topdressing. Do the images help? I feel like I've hit a wall in how good the yard can look because I lose these spots every year and have to baby them back to health. They will die some more in August, and then when the heat breaks, I'll pour milo on, and they'll fill in by the end of the year. Can you help me break the cycle?