Normally we like to keep the greens, fairways, tees and rough nice and green. However, when dealing with the weed poa annua brown is good! About a year ago I made a post regarding this particular plant:
We have gotten a little bit more aggressive this year in it's control and are starting to see some results. Especially on the putting green, #1 green and #3 green where it is most prevalent. Here is a photo of the poa annua browning out a bit just to the right of the golf ball on #1 green:
While there is no herbicide on the market for complete post-emergent control, our goal is that the growth regulator we are using will allow the desirable creeping bentgrass to overtake the stunted poa annua.
So if you see some brown, not to worry, it's good!