If you visited the Horticulture Building at the Indiana State Fair, you likely saw some stalks of corn that appeared to be 20 feet tall. Actual measurement in the tallest stalk contest showed they weren't that far away from that number. Some of them had trouble fitting in the building.
In at least one of those cases the corn was actually a type that grows tall all the time. It would never be a commercial hybrid, but that doesn't mean it isn't useful.
There was also popcorn, strawberry popcorn and multi-colored corn, in ear form, on display at the fair. And there was still a healthy exhibit of 10 ears in a box, with the corn still on the cob, a throwback to the days when farmers selected the very best ears as their seed crop for the next year.
That was when corn was open-pollinated. If you try growing seed from a hybrid today you'll get erratic types of plants as the genetics begin to separate back out from the cross that was made to produce the hybrid.
All of this diversity visible at the state fair is just a snapshot of what is available in corn around the world. Dave Nanda, a consultant for Seed Consultants, Inc., says diversity is good because it gives corn breeders a greater pool of germplasm to select from when they are looking for specific traits.
In this case, "traits" means natural height or lack of it, ear height, disease tolerance and other key corn characteristics. A corn type that may never work to grow in the field might have a particular trait that modern hybrids don't have that could someday prove useful.
That's how conventional plant breeders have improved corn hybrids and yield over time, he notes. Yields were rising steadily with hybrid corn and as breeders made progress, long before GMO traits were introduced.