The pulp temperature of fresh potatoes coming out of the ground was only about 63 degrees around 8:30 a.m. Tuesday.
That means harvest can continue for a while, said Pasco farmer Randy Mullen.
Once the pulp temperature reaches 75, Mullen said harvest is done for that day. Otherwise, farmers risk damaged potatoes.
Mullen Farms' potato diggers started July 16 and will keep going until October. Mullen, vice president of the National Potato Council, said he is one of the earliest to harvest, thanks to the microclimate of what is known as Block 1 in Pasco. Block 1 was the first to get irrigation water in the 1940s from the newly formed South Columbia Basin Irrigation District.
Mullen said the microclimate can give him an advantage because his fresh potatoes can be the first on the market during the harvest season, generally when prices are highest.
"This is a good area for fresh potatoes," he said.
Potatoes are Washington's third largest crop. Last year, farmers produced about 9.8 billion pounds of potatoes, with most going to processors.
Potatoes had a $4.6 billion effect on Washington's economy in 2008, according to a recent Washington State University study.
Washington, the first to start harvesting potatoes, has the second-largest volume in the nation, growing about 21 percent of U.S. potatoes, behind Idaho, which produces about 28 percent, said Chris Voigt, executive director of the Washington Potato Commission.
Franklin County has about 33,000 acres, while Benton County grows about 27,000 acres of potatoes, according to the U.S. Department of Agriculture.
The potato growing season started slowly this year thanks to a cooler spring, but the plants really started to take off with recent weather, Voigt said.
"It's been a good growing season," said Mullen, who started planting his potatoes during the last week of February.
Having days between 80 and 85 degrees this time of year is just about ideal, he said.
While the weather has been good, the market isn't looking so hot.
Mullen, Voigt and others are concerned that prices could drop dramatically with a possible oversupply of potatoes.
All signs indicated there were just enough potatoes from last year stored to meet demand until this year's crop became available, Voigt said. Prices weren't too steep for consumers, but still made the crop profitable for farmers.
However, more potatoes were left than anticipated. So instead of just the new potatoes, Voigt said there still is some of the stored crop, causing depressed prices.
But Voigt said he is concerned what will happen once other states start harvesting. Potato prices are sensitive to over- and undersupply, he said.
"We are all a little nervous, but it's not doom and gloom yet for the growers," Voigt said.
About 90 percent of Washington potatoes are grown on a contract basis, Voigt said. So those farmers know what they will get as long as their yields are OK.
But a dramatic price drop will still affect the state's farmers and could cause some farms to go into the red, he said.
Mullen said he is hoping to break even. He does have contracts for some of his potatoes but still would be affected by low prices.
Washington is unusual because farmers can grow more potatoes per acre than anywhere in the world, Voigt said. The national average is about 397 sacks per acre, but Washington farmers get an average of 615 of the 100-pound sacks, and some fields can get more than 1,000.
It's a combination of good weather, low humidity, the right amount of sun, rich soil and irrigation, Voigt said.
"We are just the best place in the world to grow potatoes," he said.
This week, Mullen's workers were harvesting a gold-skinned potato marketed as Gold Dust by Green Giant.
Mullen grows a number of varieties, including minis, gold, red and russet. He said his personal favorite is a newer variety called Victorias, a gold-skinned potato that isn't quite as pretty as some varieties, but Mullen thinks it doesn't need butter. Most Victorias he grows go to restaurants and are made into home fries.
A dog-tongued blade that looks like a giant shovel cuts the ground underneath the digger, bringing potatoes, dirt and withered plants onto the chains of the machine.
Dirt and plants fly out behind the tractor-propelled digger while the potatoes are moved up an elevator. Potatoes ranging in size from jawbreakers to a fist make their way to the nearby semi on a boom, which looks like a conveyer belt.
The diggers haven't changed drastically since Mullen started farming potatoes in 1984. He came back to farming after working in the grocery store industry, taking over land his father started farming in the 1940s.
It takes only 15 to 20 minutes to fill one of the trucks, which Mullen said carry about 21 tons of potatoes. On average, Mullen said he gets about 25 to 30 tons per acre. Potato harvest for Mullen Farms involves about10 people.
The potatoes will be stored for at least several days so the pulp temperature is lowered, said Mullen, a potato commission board member. That is part of controlling the quality of his potatoes.
Harvest Fresh Produce in Othello, co-owned by Mullen, will start packing potatoes next week. Potatoes are packed in 5- and 10-pound bags and 50-pound boxes.
Ideally, Mullen said he wants about70 similar-sized potatoes making up a50-pound box.
While some will be packed soon, potatoes also will be stored and packed into next June, Mullen said. Mullen's fresh potatoes are sold under the banner of Green Giant. Most make their way to grocery stores or restaurants.
But Mullen and other growers hope to open Mexico to fresh potatoes. Recent efforts have shown the most progress that Voigt said he's seen in awhile. Mexico limits importing of U.S. fresh potatoes to 26 kilometers into its country.
The United States exported potatoes worth about $35.3 million to that area of Mexico in 2010, according to Rep. Doc Hastings' office. Exports could reach as much as $150 million a year if the limitation was lifted.
Mexico has promised to take a look at the issue, which likely will take a year. So next year, Washington potato farmers could have more access to the Mexican market than before, Voigt said.