Planting the Seed for the Wisconsin Potato Industry

Baked, scalloped, chipped or fried – whatever way you enjoy potatoes, they could have roots in a program partnering seed potato farmers with University of Wisconsin scientists.

“We estimate 5 percent of all potatoes grown in the United States have parentage traced back to Wisconsin’s certified seed potato program,” says Amy Charkowski, the program’s administrative director and UW Professor of Plant Pathology.

Potato farmers mechanically slice seed potatoes into pieces for planting, each piece producing a plant yielding many potatoes. The Wisconsin Seed Potato Improvement Association – the country’s first, started in 1905 – certifies that some 7,000 acres of seed potatoes in Wisconsin are disease-free.

It’s a significant certification, says potato farmer David Perkins.

“Potato viruses spread through infected seed potatoes, and viruses can build up in seed over the years,” says Perkins, whose family grows 5 acres of certified organic seed potatoes at Vermont Valley Community Farm LLC, in Blue Mounds.

Seed potato fields are inspected twice during the growing season for disease. At harvest, inspectors take samples from each field. Those samples are grown out over the winter in Hawaii and inspected again by the same inspectors.“There’s also an inspection of your farm’s seed storage bins during the winter for any signs of disease,” Perkins adds.

Monitoring certified varieties is only part of the program, in which scientists use traditional plant breeding to develop new varieties and laboratory techniques to clean up diseases in older varieties.

“Farmers help us identify the top priorities for the program,” says Charkowski. “The growers are very involved in the decision-making.”

A recent program development is MegaChip, a potato for processing grown for certified seed on 400 acres in 2013. Such developments support Wisconsin’s important processing potato industry, which demands a uniformly sized, long-storing potato.

Crandon farmer Justin Bula’s family grows about 100 acres of certified seed potatoes, including MegaChip. He has started a separate company that grows more than 75 specialty and commercial potato varieties, using hydroponic production methods in 2,000 square feet of protected (screened) greenhouses.

“You have to keep the greenhouse environment pest and insect free,” he says.

Pest exclusion is vital at the Lelah Starks Elite Foundation Seed Potato Farm, near Rhinelander, the center of certified seed potato production. The farm is geographically remote from Wisconsin’s major potato-growing areas, sheltering production from disease. And its greenhouses are protected from disease-bearing insects, especially aphids.

Potatoes grown at the farm start in UW labs where potato tissue cultures produce plantlets. “Those tissue cultures are tested for all major potato pathogens, so we’re not transporting any infected material to the Rhinelander farm,” says Charkowski. “The plantlets are grown hydroponically in greenhouses, where they produce ‘mini-tubers,’ used to grow the first, or nuclear, generation of a seed variety.”

The mini-tubers are then planted in the field at Rhinelander. Those plants are monitored and tested for disease through subsequent generations. Potatoes meeting the program’s strict standards gain an elite designation, ready for planting on nearby seed potato farms.

“Potatoes are heavy, which makes shipping seed expensive. So it’s important to have disease-free seed near seed potato farms,” says Bula, who estimates 90 percent of the state’s seed potato production occurs near Rhinelander.

While Wisconsin’s certified program is the country’s oldest, similar programs exist in 17 states.

“Potatoes are unique among our major food crops, because their seed production is mainly in the hands of family farmers and the public system,” Charkowski says.

Pioneers In Seed Potato Certification

Much of the early research work on potato diseases and how they spread was done in Germany and Holland around the turn of the century. Scientists found that, through careful monitoring of the crop and removal of unhealthy plants, they could maintain a vigorous, healthy stock indefinitely. Similar research soon was being conducted in the United States.

Efforts by Wisconsin growers led to the establishment of the Wisconsin Seed Potato Improvement Association in 1905. The Wisconsin College of Agriculture had been engaging with the grower community already to improve potato production through special teaching railcars that traveled through potato areas in northern Wisconsin, called “Potato Specials.” The college programming emphasized the standardization and purity of potato varieties. A convention was held in Rhinelander in November 1913 to discuss “Pure Seed of Standard Market Varieties for All Commercial Purposes.”

At this convention, a formal plan for inspection and certification of potato seed was put into place. The first of now many official seed inspection programs in North America was established and fully implemented with field inspections in 1914. The same objectives of “varietal purity” and “freedom from disease” determined from field inspections remain today.