Thanks everyone for stopping by and leaving a message. Pyro is right about high humidity being a problem but other things can drag your plant's immmunity down as well and therefore make it more vulnerable to Alll sorts of prblems including bud rot. I consider perfect humidity in my grow about 30%. My favorite mold and mildew preventative is Serenade........follow instructions EXACTLY.....stuff is strong!

Fyi, that bud was broken in half vertically so the mold could be seen. From the 'outside" of the bud everything looked normal. Pyro mentioned pulling on a leaf and it pulled right off. That was the same way I discovered the bud rot. I don't attempt to fix problem at that stage; all moldy parts were dcestroyed: about 3 branches wortth.