Industrial farmers buy seeds every year (hybrids don't reproduce). Amish save their own — generation to generation.
How
Best corn ears → select kernels → dry → store cool → plant in spring. 200 years. Same varieties great-grandfather brought from Europe.
Significance
If tomorrow companies stop selling seeds — industrial farmers have nothing to plant. Amish do. Their own seeds. For 200 years. Genetic diversity the world lost — the Amish have in their barn. In glass jars. Labeled in pencil. 'Grandfather Jacob's corn, 1847.'