John Dalton, age 8, of Farmville, Va., for his question:

WHY DOES CORN HAVE SILK?

Did you know that corn is the United States' most valuable crop? Corn covers 72 million acres of farm land and the crop is worth $6 billion each year. Although corn is grown in almost every state it primarily comes from the Corn Belt states of South Dakota, Ohio, Nebraska, Missouri, Minnesota, Iowa, Indiana and Illinois.

Corn is really a grass and belongs to the group of six true grains that include rye, rice, oats, wheat and barley. The plants grow up to 10 feet tall.

Ears of corn grow along the stock. There may be one ear to a stock or up to eight. The ears are covered with husks that serve as protection.

You've all seen how an ear of corn comes to the table and know it is made up of a corncob covered with rows of kernels. The kernels are actually the seeds of the plant and they usually grow in even numbers of rows: eight, 10 or 72.

When the ear of corn is growing, attached to each individual kernel is its own silk thread that runs from the kernel and sticks out at the top of the husk. We call this thread corn silk.

Corn silk plays a very important part in the development of the ear of corn. Every kernel has a hull, a germ or embryo for a new plant and an endosperm, the pulpy inside.  The thread of silk is attached to this kernel.

At the top of the corn plant is a tassel where pollen is produced. When the summer winds blow, dust like pollen is blown into the air and some of it sticks to the threads of corn silk that hang out of the young ears. The pollen grain then sends out a tiny tube that actually grows down each silk to the egg cell in the young kernel. The male cell in the pollen fertilizes the egg cell and the kernel starts to grow.

Hand breeding is also used often instead of allowing the wind to pollinate the corn plants. Certain tassels on some corn plants are covered with paper bags and then the bags are put over the young ears of other corn plants. This operation is used when certain ears of corn are to be used as seeds. Cross fertilization from one plant to another can bring out the best qualities of each.

Eighty percent of the corn grown each year is fed to poultry, cattle, hogs and sheep. That leaves 20 percent for man, and it is estimated that the average American eats about 45 pounds of the fine product each year.

Corn is also used to make adhesives, added to some cork products, felts, cleaning compounds, plywood and lots of other items. Corn sugar is used for tanning leather and in the manufacture of paper.  Today   is being widely used for producing ethanol for powering automobiles.