Spudman Magazine -- February 2003

Aberdeen’s Efforts
Well-known research and collaboration continues
By Marcia Wood Agricultural Research Service
Agricultural Research Service’s (ARS) potato-breeding effort at Aberdeen, Idaho, about 200 miles southeast of Boise, is among the best known in the nation. Since 1949, the Aberdeen scientists and collaborators have offered superb new potato varieties uniquely suited to key potato-growing regions of Idaho, Oregon, Washington, California and Colorado.

The team’s Ranger Russet, for instance, is one of their most successful. Developed with university colleagues and made available in 1991 to breeders and potato-seed growers, Ranger Russet is now the third most widely planted potato in the United States.

What makes a potato perfect? The qualities of the perfect potato mostly depend on its intended use, says plant pathologist Dennis Corsini. He recently retired from ARS at Aberdeen and is now a collaborator.

“For baking or processing into fries,” he says, “you want a potato that has relatively little water and more of what we call solids. These are compounds such as starch that give a potato its texture. High-solids potatoes tend to absorb less oil when fried.

“On the other hand, for boiling to make whipped potatoes or potato salad,” says Corsini, “you want a potato that has more water and comparatively fewer solids.”

Sidestepping Storage Dilemmas
How a processing-type potato responds to long-term cold storage is critical. “Most potatoes grown for processing are harvested at about the same time all across the country,” Corsini says. “Since they can’t all be processed at the same time, most end up in storage, often for as long as 10 months.

“Once you dig them up,” he explains, “all potatoes begin converting their starch into sugar.” The best potatoes for processing into fries or chips are those that convert starch into sugar very slowly. During frying, these lower-sugar potatoes are unlikely to darken and develop an unwanted burnt-sugar flavor. Higher-sugar potatoes are more likely to have those problems.

Cool storage temperatures inhibit rot and other potato diseases and thwart sprouting. A technique called reconditioning has to be used for some potatoes that don’t do well in cold storage.

Besides needing little - if any - reconditioning, candidate potatoes also need to be free of defects like knobs, growth cracks, or hollow heart - the odd cavity that sometimes shows up in a potato’s center. Disease resistance is also key. “Some of the potato cultivars we’ve recently released are moderately resistant to tuber rot caused by the late-blight fungus,” says ARS plant geneticist Richard Novy at Aberdeen. “Most are also resistant to an early death from diseases like verticillium wilt.”

The process of breeding and testing potato varieties and making them available as seed can easily take 12 to 15 years. This work could take even longer if it weren’t for the collaborations of ARS scientists and their university and industry colleagues. For example, the Aberdeen scientists are part of the unique Tri-State Potato Variety Development Program. It links their expertise with that of co-investigators at Oregon State University, Washington State University and the University of Idaho. Varieties from the program are released jointly by ARS and the universities.

“This alliance,” says Novy, “has a big impact because growers in the three-state region produce about 50 percent of the U.S. potato harvest.” Since 1985, when the program began, 17 Tri-State varieties have been released. The collaboration includes colleagues from the University of California-Davis, Colorado State University, North Dakota State University, and Texas A&M University.

“These collaborations among scientists from different regions and disciplines,” says Novy, “save time and money by speeding the process and preventing duplication of effort.”