If you play golf in the next couple days, you make notice the brown tire track on the front of #18 approach...
What is it? The grass is simply tip burned.
What caused it? During the last couple weeks of heat and humidity, we made a couple application of a wetting agent- basically a soap concentrate that reduces water tension, allowing irrigation water to penetrate dry soils. If these products aren't irrigated in immediately, they do have some burn potential. In this case, the sprayer unfortunately drove through the area to make another pass, causing additional contact between the chemical and grass. It was irrigated immediately but the residue on the leaf blade remained at a high enough concentration to create tip burn.
Is it serious and how long will it last? This is a minor blemish that will be gone in 7-10 days, once the turf grows out of it. Below the tip burn, the grass alive and very healthy, much like the surrounding turf.