About a week ago, i started to notice "browning" in the lower 1/2 ish growth on of MOST of my lawn. The top growth remains green, but the under growth seems to be struggling with what i can only assume is the start of a disease/fungal issue.
From above, the afflicted areas show minimal damage (aside from a bit of thinning) since most of the brown is covered by the green top growth:
https://postimg.cc/image/syn19dmgz/
Once you expose the lower growth, you can see the browning:
https://postimg.cc/image/5huzp6zwb
Along the edging, you can see how it transitions from a non-issue-area of lower green growth (left of half of picture) to the issue-present brown lower growth (right half of picture). the top growth appears to be shade more yellow in the right side where the lower browning is present:
https://postimg.cc/image/arq11192t
Here you can see the edging that has the brown lower growth pulled back:
https://postimg.cc/image/t6992n0fx
From my initial inspection and research, i'm leaning towards:
I applied my first app of Serenade concentrate at 4Oz/k before/right around the same time i noticed the issue. I don't see "Rhizoctonia blight" listed in the targeted diseases on the serenade label, but the label seems to use some "common" names rather than the scientific nomenclature... If this does infact target whatever it is that I have (still going to do more research for a positive ID) i'll probably change my plan to weekly apps rather than every other week.Rhizoctonia blight
Pathogen: Rhizoctonia solani AG1-A, AG 3
Susceptible grasses: bluegrass, annual bluegrass, fescues, ryegrasses
Symptoms: first appears as small, irregular brown patches or rings that can enlarge to many feet in diameter; centers might recover resulting in rings of diseased grass; leaves and sheaths become water soaked, wilt, turn light brown, and die; in light infestations, roots usually not infected and plants often recover; soil-inhabiting fungus that forms fine, fungal threads in soil or on turfgrass
Conditions favoring disease: excess thatch and mat along with high temperatures (80°– 95°F); high humidity; soft, lush growth due to excessive nitrogen; most common in warm, inland areas
Prevention: reduce shading and improve soil aeration and water drainage; water appropriate length of time to a depth of 4–6 inches; avoid excess nitrogen; maintain thatch less than 1/2 inch
Chemical treatment: fungicide useful if disease severe in past or for seedlings in young turf
Am i on the right track?