I stumbled across this on the intertubes:

On one occasion, I asked a Hopi woman at Munqapi if she selected only the biggest corn kernels of all one color for planting her blue maize. She snapped back at me, “It is not a good habit to be too picky... we have been given this corn -- small seeds, fat seeds, misshapen seeds -- all of them. It would show that we are not thankful for what we have received if we plant just certain ones and not others” (Nabham 1983 pp. 7)

Nabhan, G. "Kokopelli: the humpbacked flute player" Coevolution Quarterly, pp 4-11, Sp 1983.