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UI Extension part of trials to select varieties for making potato chips

By John O’Connell

University of Idaho

In a basement kitchen at University of Idaho’s Aberdeen Research and Extension Center, scientific aid Chelsey Lowder sliced a white-fleshed, tennis ball-sized tuber into translucent circles, allowing them to dry before dropping them into a fryer.

Once the hot oil stopped bubbling, Lowder removed the basket and placed the finished chips in a row adjacent to a color chart. Her colleague, UI Extension potato variety development specialist Rhett Spear, explained the chips were a tad dark but still within industry’s acceptable color range.

Frying snack foods for careful evaluation is a recurring chore among the scientists with the U of I and USDA-Agricultural Research Service collaborative potato breeding program based in Aberdeen.

The team devotes the bulk of its time toward developing russet potatoes for making French fries, but the pipeline also includes a steady stream of spuds for chipping.

U of I makes a significant contribution toward filling bags with America’s No. 1 snack food.  

Aberdeen is one of a dozen public potato breeding programs throughout the U.S. that participates in a nationwide program, known as the National Chip Processing Trials, to identify the next great varieties for making potato chips,

Rich Novy, a USDA-ARS potato breeder, estimates chippers comprise 10-15% of his breeding crosses.

Spear oversees the exhaustive process of evaluating spuds in the breeding program.

“Chips in general are made from potatoes with a high specific gravity which gives a better chip texture,” he said. “They want a round potato, and usually it’s a white-fleshed potato. We’re looking for high tuber set and tuber size somewhere between a racquetball and a baseball.”

The variety development process starts with Novy making a cross in a greenhouse setting. Though potatoes are clonally propagated by industry, breeders harvest true potato seeds from berries, which they plant and germinate in a greenhouse to yield seedling tubers.

Those seedling tubers are planted in the field during the next growing season, and chipping clones are selected in the field for better agronomics, which start the process in the development of a new chipping potato variety. 

Researchers and representatives from the industry, such as American Falls-based R & G Potato Co. and Michigan-based Walther Farms, assist in selecting the best specimens for retaining in the program from the plots of chippers raised in Aberdeen.

In the Pacific Northwest, the U of I, USDA Agricultural Research Service, Washington State University and Oregon State University potato breeding programs collaborate in the Tri-State Potato Breeding Program.

A nonprofit corporation called the Potato Variety Management Institute handles licensing and royalties of Tri-State varieties.

After several field generations in Aberdeen, the best crosses move on to the Tri-State Trials and are grown in all three states. The best of those varieties graduate to the Western Regional Trials, which also include Colorado, California and Texas.

Potatoes USA spearheads the National Chip Processing Trials, which include hundreds of entries, evaluated by each participating program on about 20 variables, such as yield, quality, storage attributes and fry color.

“Those candidates are in the system for five or six years, and after about year four a handful that look really good go into our SNAC (Snacking, Nutrition and Convenience) Trials,” said John Lundeen, research director with Potatoes USA. “The first year in the National Chip program, you’re looking at 17 hills. That’s like one row of potatoes. By the time you get to the SNAC Trials we are committing a third of an acre – that’s what they need to run through a chip plant to see how they process.”

The trials wrap up before an annual meeting hosted in early December in Chicago, where researchers and industry meet to discuss the results.

“You go from tens of thousands down to just a handful in final testing, and not even all in that handful get commercially released,” Lundeen said.

The Tri-State program has released three chipping varieties in its history – Gem Chip in 1989, Ivory Crisp in 2002 and Willamette in 2003. The most popular of the varieties, Ivory Crisp, was initially selected and developed out of the Aberdeen program, with its release as a Tri-State potato variety.

Novy made the initial cross of another Aberdeen breeding line that’s showing great promise, A13125-3C.

A facility based at Michigan State University is in the process of developing pathogen-free tissue culture plantlets for the production of certified seed for more intensive evaluations of that line by the National Chip Program.

“Potato chips are the greatest snack,” Lundeen said. “Just think of how many sandwich restaurants you go into where there’s a whole display of chips, and think how many kids’ lunch bags have a small bag of chips in them. They’re a very important product that the American people love.”