HOT HOT HOT
We've been cooking over the past week.
We are not as bad as Oklahoma. Just reading Damon's post made me break into a sweat, both with the thought of those high temperatures AND the thought of the number of samples he's dealing with. It hasn't been quite that extreme just a bit north, where I am located. But, this current week has been nasty, with more 100+ on the way.
Localized dry spot:
This photo was sent in with a subject line that said “Help!!!”
While I am not a fan of diagnosing based only by photo, the pattern made me suspect localized dry spot (hydrophobic soils) and I suggested that they do the “droplet test” which is described HERE. Indeed, that was the problem. A wetting agent will be useful, but unfortunately the turf itself will not be able to recover very well until these extreme temperatures go away… and that could take awhile.
Brown patch in creeping bentgrass:
Hot and humid, with high night-time lows = optimal conditions for brown patch. It’s active in greens, fairways, and lawns (fescue).
Dollar spot, in an unsprayed fairway area (creeping bent)
I've also seen some anthracnose in the past few days.