(UPDATED COVERAGE, 8:31 a.m., July 19) U.S. fall potato plantings will likely top 1 million acres and be up 46,000 acres from last year.

And with at least normal yields expected, finding enough demand to meet that extra volume could be a challenge, raising the specter of continued low russet prices, some industry officials fear.

Just over 1 million acres were planted for this fall, the most in five years, according to the U.S. Department of Agriculture’s National Agricultural Statistics Service’s annual July forecast.

Acreage is up in all of the nine top-producing states. Industry leader Idaho saw a jump from 320,000 acres in 2011 to 345,000 acres this year.

Washington’s acreage increased from 160,000 to 165,000; North Dakota’s from 84,000 to 88,000; Wisconsin’s from 63,000 to 63,500; Maine’s from 57,000 to 59,000; Colorado’s from 54,000 to 55,100; Minnesota’s from 49,000 to 51,000; Michigan’s from 45,000 to 46,000; and Oregon’s from 40,000 to 41,000.

Idaho’s estimate might actually be closer to 341,000 acres, said Frank Muir, president and chief executive officer of the Eagle-based Idaho Potato Commission.

While processsing could take a bigger chunk of acreage this year, fresh acreage will almost certainly also be up for the 2012-2013 season, Muir said. And as of mid-July, the commission had received no reports of heat-related problems affecting yields.

“We’ve had large crops like this before, and we’ll be very proactive in moving this crop,” Muir said. “Our primary purpose is to keep the pedal to the medal on demand, and I think we’ve demonstrated over the past nine years that we can do that.”

The USDA acreage estimates for Colorado and Wisconsin are close to what industry officials in those states are seeing on the ground.

Extreme heat had taken some of the luster off of what had been shaping up to be an “excellent” Wisconsin crop, but it was still looking “very good” in mid-July, said Duane Maatz, executive director of the Antigo-based Wisconsin Potato & Vegetable Growers Association.

With the prospect of at least normal-sized yields, in Wisconsin and elsewhere, Badger State growers were facing another marketing challenge in 2012-2013, Maatz said.

“It certainly is a concern in my office,” he said. “We need to have growers make money. I would expect a good level of cooperation within the shippers in the state, and hope we can take care of ourselves.”

Jim Ehrlich, executive director of the Colorado Potato Administrative Committee, Monte Vista, agreed that growers and officials are worried about the size of the fall U.S. crop.

“Everyone’s concerned that there are going to be a lot of potatoes in the marketplace,” he said. “We need to do a better job of increasing demand, because the product is going to be there.”

Despite the severe drought in much of Colorado, most potato growers have adequate water supplies, and Ehrlich forecast a “very good crop” as of mid-July.