Source: AgAnswers, an Ohio State University and Purdue Extension Partnership

Corn yield potential has increased as much as 2.5 percent per year over the past half-century because of genetic improvements in hybrids. But getting the most out of a crop's performance involves more than just relying on advances in agricultural research.

Peter Thomison, an Ohio State University Extension agronomist, said that hybrid selection is driven by farm production: corn acreage, soil type, tillage practices, desired harvest moisture and insect and disease pressures, just to name a few. And with some forgotten corn diseases on the rise and value-added opportunities expanding, selecting the right hybrids is becoming more important.

"With old diseases coming back, increasing marketing opportunities and new issues that arise, new opportunities present themselves for producing certain hybrid characteristics," Thomison said.

For example, certain corn hybrids are earmarked for ethanol production in Ohio and the niche market of silage production. Additionally, growers are being encouraged to seek hybrids that show resistance to plant diseases that had been pushed to the back burner by genetic improvements.

"The most important situations with hybrid selection involve growers choosing more resistant varieties to diseases like northern corn leaf blight and diplodia ear rot," said Pat Lipps, an Ohio State University research plant pathologist with the Ohio Agricultural Research and Development Center. "We've seen a significant increase in the state over the past four to five years of both diseases. Not all hybrids available have good resistance, so a grower has to ask for them."

In addition to choosing hybrids based on disease resistance, Thomison said growers also should consider the following factors in hybrid selection and management:

* Maturity -- Growers should choose hybrids with maturity ranges appropriate for their particular production environment. "Using relative maturity, growing-degree-day ratings along with grain moisture data from performance trials, will help growers determine differences in maturity and grain drydown," Thomison said.

* Yield potential and stability -- Growers should choose hybrids that generate stable/high yields across a range of locations and/or years. "Hybrids of similar maturity can vary by as much as 50 bushels per acre in any given year," Thomison said.

* Stalk quality and lodging -- Traits associated with improved hybrid standability include resistance to stalk rot and leaf blights, stalk strength, short plant height and ear placement, and high "staygreen" potential -- a plant's potential to stay healthy late into the growing season.

"This factor is important in Ohio where stalk rots are a major problem," Thomison said. "Hybrids with poor stalk quality should be avoided, even if they show outstanding yield potential."

Many Ohio growers already have selected their corn hybrids for this season or are finalizing their choices, Thomison said. The prospect of dealing with soybean rust this season is holding up some growers' planting intentions, he said.

"Some growers are probably deciding if soybean rust could cost them more than planting continuous corn," Thomison said. "We estimate that less than 5 to 10 percent of the growers in Ohio will make the switch from soybeans to continuous corn."

Research has shown that continuous corn production means more disease issues, higher fertilizer costs and a 5 percent to 10 percent reduction in yields.