With an early August birthday, my special meal dating back to my teenage years was an outdoor grilled hamburger, potato salad, a cola drink and fresh corn on the cob.
As I shucked an ear of corn this summer, I had a revelation when realizing each one of those pesky silk threads was connected to a kernel of corn. The cob of corn is actually the female flower whose silk threads are tubular receptacles for pollen from the male corn flower, called the tassel. Thousands of pollen grains released by the tassel are dispersed by the wind landing on the sticky tips of the silk threads. The pollen moves down the tube to fertilize the egg which becomes the familiar kernel.
An average ear of corn can have 500 kernels, each with a pollen tube. The next time you eat corn on the cob, look for undeveloped kernels along the rows which indicate failure of a pollen grain to land on and fertilize the kernel.
Article Photos
A probe points to the pollen tubes (silk threads) attached to the undeveloped kernels of corn.
Photo by Robert M. Ungerer
As an experiment, I counted 577 kernels on one ear but found only 453 silk pollen tubes. These figures as you notice do not add up perhaps because some tubes were short, and I missed them. Convincing evidence that a pollen tube connects to a kernel came from my careful dissection at the tip of a small ear of corn where fertilization did not occur. The kernel remained an undeveloped bud with the pollen tube still attached. The photograph accompanying this article demonstrates the tube connected to the immature corn bud.
Corn, which is properly called maize in global markets, has a fascinating history and even more remarkable place in human civilization. Indigenous people of Central America likely domesticated maize 7,000 to12,000 years ago. Botanists believe the short bushy plant, teosinte, was the ancestor of today's corn. A pod grew from the top of teosinte containing many individual kernels of corn, each enclosed in a separate husk. While evolution is not completely understood, the single pod of individual kernels coalesced into a large ear with hundreds of kernels enclosed in one husk.
When European explorers arrived in the Americas, they took corn back to Europe where its use spread throughout Africa and Asia. Corn adapted to a varied climate so that today corn production globally ranks first for grain including wheat and rice.
Corn has become pervasive in our culture. Americans eat corn flakes, 50 quarts of popcorn per person a year, corn grits, corn whiskey and corn bread.
Every day we consume food made with corn. Corn syrup, made from the starch of maize, softens texture and adds volume to ice cream, ketchup, and sausage. High fructose corn syrup, formed by enzymes acting on corn syrup, when added to soda pop makes it sweeter. Corn contributes to the production of ethanol, plastics, explosives, baby powder, paper, chewing gum, medications, dog food and livestock feed. Corn grown on local farms and the majority grown in the world is field or "cow corn" high in starch unlike "sweet" corn consumed as corn on the cob or as a frozen vegetable.
With permission from my neighbors, Bill and Pat, I cooked and tasted one ear of their field corn. It was tough, like chewing dry oatmeal, therefore, fit for a cow or explosives.
During the last 100 years botanists created hybrid corn by breeding different varieties of corn to produce plants with more vigor. Yields increased from 25 bushels per acre in 1930 to 120 bushels per acre in 1990.
Modern biological technology created genetically modified or altered corn plants. It is unbelievable but scientists can extract a gene from bacteria which creates resistance to the herbicide, "Round Up," and then insert the gene onto a corn chromosome passing resistance to the corn plant. After the corn seed germinates, the farmer can spray the corn field with the weed killer, "Round Up," but the corn plant survives and thrives without the competition from weeds for moisture and nutrients.
Corn, whether the delicious sweet variety or the more ubiquitous field variety, continues to beneficially serve mankind.