Fruit yeast starter

I've heard of "starters" from culturing fruit. Nancy Silverton did one using wild grapes, and you can easily find information about that, including youtube videos, through googling. I think people have also used apples and potatoes.

One of the critiques I've read of this approach to establishing a "starter" culture is that the yeasts on the fruit aren't sustained in an environment provided by grains, so eventually the culture is populated by yeasts and bacteria common to grains (as a sourdough culture would), and the yeasts and bacteria from the fruit dies out.

I'v not tried this: its only what I've read, and perhaps others have first-hand experience.

I'm not sure what you're asking - are you referring to making a sourdough starter?