The corn plant can be sown by all pawns immediately. Each plant requires 20.86 full days at optimal light and temperature range to reach maturity in normal, 100% fertile soil and yields units per plant, before modifiers for Difficulty and Plant Harvest Yield.
As a raw food, corn can be be eaten raw, with a flat 2% chance of giving food poisoning, or cooked into a meal with a food poisoning chance dependent on the skill of the cook and the cleanliness of the kitchen. Animals are immune to food poisoning from raw food but not from meals. When used in food recipes that require specific types of nutrition, such as fine meals, corn is classified as a vegetable.
Corn takes 60 days to rot without refrigeration, double that of most other vegetarian foods.
Corn is the least labor-intensive food crop per item of food produced. This is balanced by a long grow time, with the risks from raiders, events, and weather. This typically makes it useful late game where a stock of food is built up in case of famine, and where switching to corn frees up pawn time or means more pawns can be supported for the same labor.
In terms of absolute food per tile per day, rice is slightly better in regular soil, and becomes much better in hydroponics, where corn can't be planted. However, this comes at the expense of massively more work - in most instances simply making a corn field bigger is a more efficient choice, with small fields of rice being used to make up any immediate needs for food.