This is a seashore paspalum putting green in Hawaii. You can click the photo to view it at a larger size. Can you identify the cause of the spots on the green?
This looks a lot like dollar spot, which is common on seashore paspalum, and many people guessed that. The correct answer, however, was salt used as a herbicide to control Eleusine indica. Three people got the answer right, all at about the same time:
@asianturfgrass salt damage when used as a herbicide.— Turfgrass Diseases (@TurfDiseases) January 29, 2013
I described this in a post a few years ago, At Hawaii ... More About Salt Applications to Seashore Paspalum. And this is what the salt applications do to Eleusine indica without damaging the seashore paspalum.