Growers have long been advised to plant two or three corn maturities to spread weather risks at pollination time. But what else should you consider when selecting hybrids?

"Look at the mid-silking dates as well as relative maturities," answers Dave Haines, senior agronomist for Dekalb Genetics, Bluffton, IN.

"You can have hybrids of different relative maturities yet still have similar silking dates, and you want to avoid that," Haines points out. "For example, one 106-day hybrid may flower with the 102-day maturity hybrids, while another may flower more like 109-day hybrids. They both mature at the same time but the earlier flowering hybrid has a longer grain-filling period."

The point, says Haines, is to consider both relative maturity and mid-silking dates when trying to spread pollination timing. Ask your seed supplier for this information.

Also, match the hybrid to the field, says Haines.

"Fields that typically are harvested late, due to factors such as poor drainage, need hybrids with exceptional stalk and root strength," he notes. "Cattle, hog and dairy farmers may be delayed in harvest due to livestock responsibilities, and they, too, need strong-standing hybrids."

Don Breuker, crop consultant at Rock Rapids, IA, also urges farmers to select hybrids on a field-by-field basis.

"Resist the temptation to go strictly with the hot numbers and to plant them anywhere and everywhere," Breuker cautions. "Choose hybrids based on your tillage methods and fertility conditions."

No-till farmers, in particular, need hybrids with fast, uniform emergence, says Breuker.

"I've seen the emergence differences among hybrids as I walk fields," he says.

If fields are low to extremely low in phosphorus and potassium, choose hybrids that develop root systems fast and can take best advantage of marginal fertility, adds Breuker.

Spread genetics as well as maturities, advises Jeff Renk, corn research director for Renk Seed Co.

"If you simply spread maturities, you may not necessarily have differences in genetics," he points out.

"It's often not possible to determine genetic differences among hybrids by looks alone," says Renk. "One hybrid might look similar to another and still have genetic differences, or two hybrids may look different but be related. Ask a seed company technical representative for guidance in picking a lineup of hybrids with genetic diversity."

Renk says hybrids of 107-day relative maturity and earlier tend to have more genetic diversity than later hybrids. That's because soils and growing conditions vary more in northern areas and researchers have bred corn to fit those conditions.