Hybrid corn is a strain produced by fertilizing one variety of corn plant with the pollen from another. The result, if the technique is carried on properly, is a strain that combines desirable features of both parents and is far superior to either. Hybrid corn produces up to 30 per cent more corn for each acre. The ears are consistently larger and better formed than those produced by ordinary methods. Stalks and roots are stronger, allowing the plant better to resist toppling by the wind. Hybrid strains have been developed to produce plants adapted to such conditions as drought, dampness, or cold.

Much painstaking work must be done to produce an ear of hybrid corn. For this reason most farmers buy hybrid seed from specialized growers.

The first step is to inbreed a desirable strain of corn for five to eight generations. Inbreeding is done by pollinating the young ear with pollen from its own plant. To prevent pollen from other plants from contacting the silk, the tassels and young ears are enclosed in bags. Inbreeding produces strains of corn that are uniformthe offspring plants have exactly the same characteristics as the parent.

The next step is to select two strains of inbred plants, each with certain desirable qualities, and to crossbreed them. This is done by placing pollen from one strain on the silk of a plant of the other strain. Usually, alternate rows of the parent inbreds are planted. The tassels are removed from the plants that are to bear the hybrid ears, so that the female-parent plants will not receive their own pollen, but will get pollen only from the male-parent plants in the adjoining rows.

This crossbreeding produces hybrid ears. Their kernels are sold to farmers as seed for hybrid plants. When two hybrid plants are crossbred, the resulting ears are called double-cross hybrids. Some of the best varieties of corn are of this type.

Kernels from the ears of double-cross hybrid plants are not used as seed. The reason is that the offsping of these plants do not resemble the parents. Each season's supply of hybrid seed must be produced by crossing the original parent strains.