The corns that I grow are not heirlooms, but they are grown in traditional ways...
My sweet corn is called Astronomy Domine. We took several hundred varieties of heirloom sweet corn, and modern hybrids, and planted them into the same field and allowed their genetics to mix things up. Then I selected for shorter season, and for great growth in my garden, for resistance to bugs, blights, fungi, skunks, racoons, pheasants, and turkeys. I selected for great taste, and for early colors.
Here's what I ended up with...
Partial harvest of Astronomy Domine Sweet Corn for 2015.
Fresh eating stage:
This basket of sweet corn is what converted me to landrace
gardening. It is one of my all-time favorite garden photos.
I also grow flour corn in a similar manner. Thirty years ago some plant breeders (Cargill) gathered together corns from across South America, and adapted them to be able to grow in temperate climates. I crossed 4 populations of those corns and hybridized them with a similar collection of corns from North America. So while again it is not an heirloom, it is full of heirloom genes, and I am allowing it to adapt to modern growing conditions on my farm rather than expecting that a highly inbred corn that was developed for XYZ region before I was born will do well in my garden with modern growing conditions and pests.
South American Synthetic Composite.