sealPurdue News
_____

February 13, 1998

Don't bet the harvest on El Nino, corn expert warns

WEST LAFAYETTE, Ind. -- Corn producers trying to protect themselves against a prospective El Nino-driven drought are mulling over pre-emptive strategies. One is to use lower seeding rates, according to Purdue University Cooperative Extension corn specialist Bob Nielsen.

"The idea is that a thinner stand will better tolerate the stressful conditions of a major drought," he said. But Nielsen isn't buying into the strategy.

"Because there's not a clear consensus among weather forecasters about the effects of El Nino on the weather in Indiana, corn producers probably should not make drastic changes in their typical crop inputs for the 1998 growing season," he said. "Someone once said 'if you plan to fail, you will,' and that is sort of the way it is with seeding rates in corn."

Nielsen said for most soils and productivity levels in Indiana, optimum grain yields of 125 to 150 bushels an acre will occur when final plant populations are between 26,000 and 30,000 plants per acre. Assuming a 95 percent germination rate and 95 percent survival of emerged seedlings, growers generally need to plant 29,000 to 33,000 kernels per acre to get those final plant counts, he said.

For fields in which soil conditions or other factors limit the potential productivity to 100 to 125 bushels per acre, Nielsen said there is no benefit in trying to increase final plant populations beyond 18,000 to 24,000 plants per acre. Therefore, seeding rates of 20,000 to 27,000 kernels per acre are recommended in such fields.

Regardless of field conditions, Nielsen said, producers need to be mindful of the high caliber of the corn varieties being planted these days.

"Today's hybrids have an inherent ability to better tolerate the effects of prolonged dry periods than did the hybrids of years ago," he said. "Unless you feel extremely confident in the predictions of your favorite meteorologist, I suggest you base your seeding rate decisions on the historical yield levels of the fields that will be planted to corn in 1998."

Nielsen maintains a World Wide Web site called the Corn Grower's Guidebook (http://www.agry.purdue.edu/agronomy/ext/corn/). It contains a variety of corn-related information and links to other agronomic Web sites.

Source: Bob Nielsen, (765) 494-4802, e-mail: rnielsen@dept.agry.purdue.edu
Writer: Amy H. Raley, (765) 494-6682, e-mail: ahr@aes.purdue.edu
Purdue News Service: (765) 494-2096; e-mail, purduenews@purdue.edu

* To the Purdue News and Photos Page