Got a call from a customer last night who had irregular rings in his perinneal ryegrass yard. Today I went and looked at it and from what I can tell it is gray leaf spot but unsure. There are about 8-9 rings in the yard and the ring area is darker, greener turf in a band about 8-16 inches wide. The rings cover areas of 40-300 square feet. The leaf blades have all the spots/symptoms of gray leaf spot(honestly most of the grass in the rings look perfect) but my turf book says nothing about rings going along with it. There is no fuzz or mold on the turf, and the lawn is in full sun with plenty of air movement. Customer mows at about 3.5 inches and keeps it in outstanding shape. He called late for treatment this year so I have only done a round of trimec 992 + 13-0-7 Barricade at the very end of April. It was treated by another company last year. Sorry to go on but the more info the better. Here are some pics that I took, the grass leaves I brought home dried up by the time I got home so no pic of them. Thanks for looking.