Comments by "EebstertheGreat" (@EebstertheGreat) on "How science saves sweet corn" video.
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Feed corn is just corn grown for use as animal feed. Similarly, fuel corn is grown for fuel. Field corn is any corn left to drop on the field before harvesting. Dent corn (aka grain corn), and flint corn are varieties of corn (distinguished genetically). Varieties and subvarieties of corn are also categorized by their intended use (rather than strictly cladistically). Wikipedia lists the "types" of corn as dent corn, flint corn, pod corn, popcorn, flour corn, and sweet corn, even though some of these are technically subvarieties of others (e.g. most popcorn comes from a subvariety of flint corn).
All of the varieties except sweet corn are called "field corn" because that is how they are harvested in practice. Sweet corn, however, is harvested early, as explained in the video. Feed corn is usually dent or flint corn. Corn sold at supermarkets is always sweet corn. Popcorn and flour corn speak for themselves. Pod corn is not grown at a commercial scale. And any kind of corn can be used for making spirits or fuel-grade ethanol.
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