EEUU: Seed potato health certificate contains up-to-date status of certified seed

Purchasing certified seed potatoes is the most important first step in reducing risk to your crop and, at the same time, ensuring that you get optimal yield and quality. But realistically, not every certified seed lot is created equal, however.

In the modern-day data-driven world, it is imperative to attain the most information possible on the health status of seed potatoes you are purchasing. Seed potato certification programs across the U.S. and Canada have responded to growers’ needs for information on seed quality by implementing disease tolerances and sophisticated testing protocols to define the health status of seed lots.

An unbiased source of seed potato health information can be found on the North American Seed Potato Health Certificate. The format for this certificate came out of cooperation between the joint U.S. and Canada Potato Association of America seed sub-committee. It evolves as new diseases emerge and the needs of the industry change.

Information included on the health certificate, which is typically provided to the buyer from the seller at the time of sale, includes seed lot identifiers that allow trace back to the specific farm and seed lot, as well as the seed class or years in the field. Information on summer inspection and, where applicable, summer pathogen testing is conducted are detailed and include visual readings for mosaic, leafroll, blackleg, varietal mixture and fungal diseases which affect tubers.

Postharvest data is also included and, depending on the individual states or provinces, both visual and laboratory results are reported. The form allows for customization depending on the type of data the specific program collects. Also, it gives the history for occurrence of bacterial ring rot, late blight and root knot and golden nematodes.

Another benefit of the Potato Health certificate is that it fosters better communication between the seed suppliers and buyers. Seed potato producers face heightened challenges with the emergence of aggressive virus strains that have the capability to not only reduce yield, but affect quality. Perfect scores for virus diseases — especially mosaic caused by potato virus Y — are much harder to attain due to strains that produce very weak symptoms and varieties that are both highly susceptible and asymptomatic.

As seed growers face these challenges, the health certificate is a good place to start the discussion with customers as to how they are approaching management of these important diseases.

— Nina Zidack, Ph.D., is the director of the Montana State University Seed Potato Certification Program and an associate research professor of plant science and plant pathology for the university.