Field corn, technically known as Zea mays var. indentata or dent corn, is the most widely grown variety of corn in the United States and is a major global commodity. It is primarily defined by its high starch content and is not typically consumed directly by humans off the cob like its sweeter relative. Instead, it serves as the foundational ingredient for a massive array of products. These products include livestock feed, ethanol biofuel, and industrial starches.
The Field Corn Plant: Structure and Height
The field corn plant is a robust grass, exhibiting a stature far exceeding that of typical garden vegetables. Its stalks are thick and sturdy, often reaching impressive heights between 8 and 12 feet tall at full maturity. The plant features large, broad leaves that densely cover the stalk, creating a deep green canopy during the summer growing season. As the plant matures and the grain hardens, this deep green color transitions to a signature golden-brown, a sign that the corn is drying down and approaching harvest.
Defining Characteristics of the Kernels
The most defining visual characteristic of field corn is the small indentation, or “dent,” that forms on the crown of each kernel. This depression is a direct result of the kernel’s internal structure and drying process. Each kernel contains both hard starch on the sides and soft, floury starch in the center that extends to the crown. As the ear dries naturally in the field, the soft starch center shrinks more rapidly than the hard outer shell, causing the top of the kernel to collapse inward and create the concave dimple. Mature field corn kernels are hard, starchy, and possess a dull, opaque appearance, unlike the glossy look of sweet corn. While deep yellow is the most common color grown commercially, white varieties are also cultivated, especially for specific food products.
How Field Corn Differs from Sweet Corn
Field corn and sweet corn represent two distinct genetic lines of the same species, bred for entirely different purposes that result in stark visual and textural differences. Field corn is harvested when the kernels are hard and dry, maximizing its starch content for processing. Sweet corn, conversely, is a genetic mutation that prevents the conversion of sugar to starch, creating the plump, juicy kernels the public enjoys. It is harvested when the kernels are at their “milk stage,” while they are still moist and the stalk is green, before the sugars begin to convert. The appearance of sweet corn kernels is smooth, round, and turgid, lacking the signature dent of its field-grown counterpart. Field corn is left to dry in the field until the entire plant is brown and brittle, often in the late fall.