I thought that was a Kentucky thing all these years... I've got plenty of family who says disk-ed, but those folks also went to wal-mark, or "the walmarts".. yeah.. the is in the name apparently.  They also use "Purt-near" in substitution for "almost", and one I never have figured out the meaning of is "By ned"  Pronounced By and like the name Ned.  
"well I'll tell you right now, I by ned won't be going back there again to do no tradin' ".  Looking at it now in print for the first time in my life, I think I now realize it's used in place of taking the lord's name in vain, just not the phrase people usually associate with that.