High-yielding hybrids produce uniform kernel rows on long, girthy ears. The High Yield Genetic Family crossed with the Southern Genetic Family produces a hybrid with the highest-yielding genetic potential under favorable growing conditions.
Yield potential is extremely important in the production of profitable corn. However, in hybrid placement strategies, it must be considered along with stalk quality. Hybrids that deposit a larger percentage of sugars and starches into the grain have fewer nutrients remaining for rind and pith development. Conversely, hybrids with large stalks and thick rinds have fewer sugars and starches remaining to produce high grain yields. For this reason, plant breeders select high-yielding hybrids with enough stalk size and rind strength to produce acceptable stalk quality, but they rely on staygreen to keep the hybrid alive as long as possible.
Generally, the highest yielding genetic type of hybrid is the High Yield Genetic Family crossed with the Southern Genetic Family. High Yield adds girthiness to the ear and the Southern Family adds length. Long, girthy ears have the most yield potential. For this high-yield potential to be expressed, the High Yield x Southern hybrid needs plenty of heat and moisture, well-drained soil with plenty of nitrogen, and a disease-free growing season. Without any of these criteria, other genetic family selections would be better choices.
For a hot, dry growing season, the Western Genetic Family would be better. If it is cool as well as wet and the soil becomes saturated, and if plant populations are aggressive enough, Eastern and Northern would be better. If disease is present, Early Health and Late Health Genetic Families add disease resistance.
The best genetic families for any field and any particular year depend on the soil type, the plant population and the growing conditions. And if the harvest season favors stalk rots that generate severe stalk lodging, planting genetics with strong disease tolerance and thick rinds is important.