If it's not too hot I'm thinking of taking an early bowhunting trip to the farm in southwestern Kentucky where I hunt during the rifle season. Does anyone know if the bucks there are likely to still be in velvet during early September?

You have a 50% chance of catching them still in that opeing weekend.
I've seen some clean that weekend and some hold till mid Sept.  Most of my bucks finished up early this season so I'm not holding my breath on many having velvet past the Labor Day Weekend opener....

Best of luck to you if you travel down!

They have started to peel here in Maryland, I know its not Kentucky, but just another bit of news . . .

Most of the time, most of the bucks are still in opening day here in KY. However this year everything has been early, so it looks like we might have a early fall. Therefore my guess is that this year most of them will be out. I am in eastern KY.