BARNEY (AP) - Retired farmer Allan Braaten remembers when corn was grown only in North Dakota's southeast corner, and harvested by hand. He's thrilled about what's happened with his favorite crop in recent years.

While wheat remains king in North Dakota, "There's so much interest in corn now," Braaten said.

North Dakota farmers planted a record 1.7 million acres of corn in 2006, nearly double the 880,000 acres of 2001. The U.S. Department of Agriculture projects acres this year in the state at 2.6 million, up 54 percent.

The booming ethanol industry is the main reason for a surge in corn acres nationwide. Interest in corn is so strong that there are shortages of some varieties of corn seed.

Historically, North Dakota is not part of the Corn Belt. Only the state's southeastern corner provided sufficient moisture and an adequate growing season for the crop. But new varieties of corn require less moisture and fewer growing days.

"A lot of producers who couldn't grow corn before either are starting to grow it or taking a good look at it," said Andy Swenson, farm management specialist with the North Dakota State University Extension Service.

Much of North Dakota's corn is still grown in the southeast. Richland County led the way last year with 225,000 corn acres, and Cass County was second with 140,000 acres.

But corn's popularity is rising elsewhere. For example, Grand Forks County farmers planted 40,500 acres last year, up from 19,000 in 1996.

One of the reasons for the spread of corn acres is the NDSU corn breeding program. It had 15 active breeding locations across the state last year and could have as many as 20 this year. The goal is to develop varieties better suited to the state's climate.

The program also has a winter nursery in northern Argentina in cooperation with a seed company operating there. The Argentine site helps North Dakota in two ways, said NDSU breeder Marcelo Carena.

Because it's in the southern Hemisphere, where North Dakota's winters and summers are reversed, the site provides additional growing time, Carena said.

The site also is in an area that receives almost no rain. Corn grown there relies on irrigation, which enables researchers to regulate the amount of moisture a plant receives.

"This is very important as we try to better develop drought-tolerant corn," Carena said.