Grafting is a method of reproducing a grapevine by taking a cutting from one vine and joining it to the phylloxera-resistant rootstock of another vine. Grafting is universally applied to varietals around the world to prevent phylloxera (a root-eating louse) from destroying an entire vineyard. It's an expensive process, but so far is the only way known to prevent phylloxera infestation. See also clone.