Corn (Zea mays) serves as a foundational crop globally, underpinning both human diets and livestock feed production. Successful pollination is fundamental to corn reproduction. The method of pollination determines the genetic stability of the resulting seed, which defines the various types of corn grown today.
Understanding Open Pollination
Open pollination describes the natural process where plants are pollinated by the random distribution of pollen, primarily via wind or insects. In corn, which is a monoecious plant, the reproductive organs are separate male and female flowers on the same plant. The male flower, known as the tassel, sits at the top of the stalk and releases pollen grains into the air.
The female flowers are the silks emerging from the developing ears lower down on the stalk. Each individual silk strand is directly connected to a single ovule, which will become a kernel if fertilized. Pollen must land on these silks and travel down the silk tube to achieve fertilization. Since corn is predominantly wind-pollinated, it is typically planted in blocks rather than single rows to maximize the chance of pollen reaching the silks.
If a plant population is isolated from other varieties, the resulting seed will produce offspring that are genetically similar to the parent population. This consistency is referred to as “breeding true” or “true-to-type.” While individual plants are genetically diverse, the overall characteristics of the variety remain stable from one generation to the next. This genetic stability is a hallmark of open pollinated varieties.
Open Pollinated Versus Hybrid Corn
The difference between open pollinated (OP) corn and hybrid corn lies entirely in how the seed is produced and how the resulting generations behave genetically. Hybrid corn is created by intentionally crossing two distinct, inbred parent lines, often labeled P1 and P2, under carefully controlled conditions. The seeds resulting from this initial cross are the first filial generation, or F1 hybrid.
The F1 hybrid generation often displays a phenomenon called heterosis, or “hybrid vigor,” which can lead to increased yield, better disease resistance, and noticeable uniformity across the field. The best hybrid varieties can produce 20 to 40 percent more than comparable non-hybrid varieties. This uniformity and high performance have made F1 hybrids the dominant choice in commercial agriculture.
The primary drawback of hybrid corn is seen when growers attempt to save and replant the seed. The seeds saved from an F1 hybrid plant are the F2 generation. During reproduction, the genes inherited from the two distinct inbred grandparents segregate randomly. This genetic mixing causes the F2 generation to lose the uniformity and high performance of the F1 generation, resulting in substantially lower yield performance.
In contrast, the genetic makeup of an open pollinated variety is inherently stable, even though the population itself is genetically diverse. Because OP corn is the result of random mating within a stable population, the resulting seeds maintain the variety’s characteristics year after year. This key difference eliminates the need for farmers to purchase new seed annually, a requirement imposed by the genetic instability of hybrid F2 generations.
Benefits of Growing Open Pollinated Corn
The most immediate practical advantage of open pollinated corn for growers is the ability to save viable seed from their harvest for future planting. This practice offers substantial cost savings by eliminating the need to purchase new seed every season. By selecting the best ears from the strongest plants each year, growers can gradually adapt the variety to their specific local soil and climate conditions.
Open pollinated varieties inherently possess a wider range of genetic variation than the highly uniform F1 hybrids. This inherent genetic diversity provides a natural form of resilience for the crop. The varied gene pool means the overall population is better equipped to withstand localized pressures, such as a new pest outbreak or periods of climate stress like drought or heat.
Growing open pollinated corn also supports the preservation of heirloom varieties, many of which are centuries old. These older corn landraces often possess unique characteristics, such as specific colors, textures, or flavors, which have been bred out of modern commercial hybrids. They are often sought after for niche markets, including specialty flours or craft distilling, adding value for smaller-scale farming operations.