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.