July 1, 2008

Replanting for US corn farmers carries too much risk

US corn farmers who wish to replant their corn after the floods in the Midwest may want to rethink their decisions, according to a study by Iowa State University.

With thousands of corn acres flooded out, many farmers may have it in their minds to wait for the waters to recede and replant.

However, yield simulations run by the Department of Agronomy at Iowa State University show that replanting carries with it some major risks.

"Corn planted this late has an early frost damage risk of around 40 percent in the southern part of the state and as high as 66 percent in the northern areas," says Roger Elmore, ISU professor of agronomy and ISU Extension corn agronomist. "An early frost could mean the difference between 130 bushels an acre and 24."

Simulations of yield potential for corn acres planted by July 1 show early season hybrids will be the only reasonable option for anyone who finds it economical, and worth the risk, to replant.

However, these varieties are less suited to Iowa's environmental stresses and disease, posing another risk.

With perfect weather, corn planted by July 1 may reach yields of 100 to 130 bushels an acre. But grain moisture content could be high, which means farmers would have to incur additional costs drying them.

Elmore advises US farmers to consider other crops besides corn since most grains are at high prices currently. Choices include soy, sorghum and other forage crops.