The record pumpkins aren't grown 'naturally' They are fed with a stem sucking an unending supply of high potency liquid nutrients (in the old days milk)......
I remember that now that you mentioned it. Dig a depression under the vine, put a bowl of milk in it, slit the underside of the vine and connect the bowl to the vine with cotton cord. Right?
I think the record pumpkins today are those pink colored squash, not the traditional orange pumpkins we knew when we were kids.