COLUMBUS, Ohio — Corn yield potential has increased as much as 2.5 percent per year over the past half-century due to 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 factors involved. And with some ignored corn diseases on the rise and more value-added opportunities becoming available, the need to select the right hybrids for a grower's operation 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," said Thomison.
For example, certain corn hybrids are earmarked to cater to the growing interest in ethanol production in Ohio and the niche market of silage production. Additionally, growers are being encouraged to seek hybrids that show resistance to northern corn leaf blight and diplodia ear rot — diseases pushed to the back burner by genetic improvements that are now making a comeback.
"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 points out the following key factors important 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 dry-down," said Thomison.
• 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," said Thomison.
• 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," said Thomison. "Hybrids with poor stalk quality should be avoided even if they show outstanding yield potential."
Thomison said that many Ohio growers have already chosen their corn hybrids for this season or are finalizing their selections. The prospect of dealing with soybean rust this season is holding up some growers' planting intentions.
"Some growers are probably deciding if soybean rust could cost them more than planting continuous corn," said Thomison. "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 anywhere from a 5 to 10 percent reduction in yields.