I don't remember that my grandmother dusted her potatoes with anything.

I do remember that she left them outside in the shade to dry for about a week before adding them to a bed of straw in the root cellar. She also brushed them off with a short handled broom to get the dirt off; she wouldn't wash them because she said to get them damp would cause mold.

Then she put them in straw, added more straw and then covered them with an old burlap feed sack.
They lasted all winter long that way, bedded in the straw; but I really don't remember dusting them with anything, just brushing the biggest part of the soil off.

Good for you for growing those potatoes!!

all I remember is it was white like flour,Ill have to check around some more.

Probably something to keep them dry so mold wouldn't form.
I just can't remember.

Remembered.Storing potatoes above ground or in a root cellar is often more successful when lime is used. Pickling lime, an edible form of calcium hydroxide, is safe for use in storing potatoes. Pickling lime is often used in Southern climates to prevent the growth of some types of mold. Southern climates aren't ideal to store tubers while keeping them cool and dry.

Makes sense. We wouldn't have used them in the mountains of SE Kentucky. It is much cooler there.

That explains why we have different memories.
Thanks. I never even thought of that.