Potato certification tests find success in Hawaii

Kathy Davis
Communications 

Kay Oakley inspecting seed potato grow fields in Hawaii.

A business trip to Hawaii may sound luxurious. But maybe not so much if what you’re there to do is plant and inspect potato fields. 

Benita Matheson and Kay Oakley with WSDA’s Plant Services Program traveled to Oahu, Hawaii in November and January to help ensure Washington’s seed potato growers have disease-free planting stock. Their trips were completely funded by grower fees paid into the seed potato certification program. 

Seed potato growers can volunteer to have WSDA certify their seed stock. It requires that some of their seed potatoes be grown out during the winter months and inspected for viruses. 

In the past, these post-harvest grows and testing were done indoors in greenhouses. This is the first year that WSDA collaborated with the Canadian Food Inspection Agency to try outdoor planting. 

The team from Washington, Canada and Hawaii planting
post-harvest seed potato trial field.

“Hawaii has the perfect climate for grow out,” said Matheson, plant inspection supervisor. “Almost all the major seed potato producing states and Canada have been taking their potatoes to be tested there. This puts Washington State’s growing protocol in line with other seed producing states in the nation.”

Seven participating Washington growers provided several pallets of seed potato samples, which were sent to Hawaii by ship, along with the Canadian potato samples. 

In late November, Matheson and Oakley met up with three Canadian growers and staff from E.S. Cropconsult at Twin Bridge Farms on the north shore of Oahu to plant two fields of samples. 

The farm and the Canada-based consulting firm are working with WSDA to understand the unique growing conditions of Hawaii.

Checking paperwork for seed potatoes
ready for shipping to Hawaii. 

 

“Their knowledge of how quickly the plants would grow helped us figure out when to plant and when to come back to do our visual inspections,” Matheson said. 

WSDA plant inspectors returned to Hawaii in January to inspect and test the seed potato field grow-outs. The outcomes have been positive. 

“Growers were happy with the results from this year’s post-harvest testing,” Matheson noted. “They received their test results earlier than previous years, which allows them to make adjustments to their inventory if needed.”

Benita Matheson with a jar of snakes
while visiting Hawaii ag department offices

The success confirms that WSDA will continue to use the Hawaiian field location for future post-harvest testing. 

“We hope to strengthen our seed potato program and provide healthy planting stock,” Matheson concluded. 

Growing healthy potato crops through seed potato certification

Cindy Cooper
Plant Services Program 

WSDA’s Plant Services Program works with the potato industry year round to grow seed potatoes, certifying they are inspected and tested for harmful diseases or pests that could ruin a crop. Each year, Washington farmers produce thousands of acres of commercial potatoes, and it all starts with certified seed.

Farmers don’t plant traditional seeds to grow potatoes, they plant a part of the potato itself and it’s critical that these seed potatoes be healthy to ensure a healthy crop.

Visiting the annual seed potato lot trials in Othello.

Last week, several specialists with our Plant Services Program participated in the annual seed potato lot trials near Othello. For these trials, potato growers submit potato seed in lots to be planted and 'read' for virus and fungal disease symptoms. The reading results are then published so they are available for potential buyers.

These trials are a collaboration involving researchers with Washington State University, Oregon State University, University of Idaho, the U.S. Department of Agriculture, the Washington Potato Commission and other potato industry groups.

This year's trials included a USDA-sponsored demonstration planting of seed potatoes inoculated with different strains of the PVY virus, or Potato Virus Y. This plant disease has varying effects on different potato varieties, sometimes showing disease symptoms, like spots, on the foliage and, in some cases, remaining latent with no visual symptoms at all. The virus only affects plants, not animals, but can be spread through aphid activity.

Examining the demo plot of PVY infected plants. 

The USDA demo and training for seed potato inspectors in Washington and neighboring states is part of a national training effort to combat the spread of PVY.

About 17 states certify seed potatoes for interstate planting. Washington has about 3,500 acres of certified seed this year, with 10 growers participating in the program.

A complete list of all the seed potato lots certified in the past year is available on our website. You can visit our Plant Services Program webpage for more info.

Thanks to Plant Services Program environmental specialist Sue Welch for the photos.