> Although not grown primarily for human consumption, people do pick ears of field corn when its sugar content has peaked and cook it on the cob or eat it raw. Ears of field corn picked and consumed in this manner are commonly called "roasting ears" due to the most commonly used method of cooking them.
So: Only in a brief window? Maybe, though I doubt it. (Unless you're trying to say that, in the form of corn on the cob, it won't keep for all that long, which is true.) With commercial processing? Hardly. (Unless you are trying to say that we can't, say, can it or freeze it in quantity without commercial processing, which is true.)
All that said, people would happily eat field corn on the cob if it meant that they got to eat. It may not be the whole answer to a food shortage, but it's an answer that could help a significant amount.