November/December 2019
Seed Potatoes Report 2019: Western United States

Idaho experienced a somewhat challenging growing season. Planting began at the normal time, but was interrupted by a two-week period of rain. Additionally, late frosts and cooler temperatures delayed the development of those crops planted before the rain. However, heat later in the season helped the crop to catch up. With harvest currently under way, some growers are reporting average to good yields, while others are reporting lower than average yields. Quality going into storage is reported as good to excellent. Overall, the 2019 crop appears to have a very nice size profile. Seed health is steady from 2018. The number of seed lots with visually detectable levels of PVY in the field increased only slightly compared to last year, and there were no BRR detections during field inspections.

At the conclusion of the second round of field inspections, a total of 29,974 acres are eligible for final certification this year. This is essentially unchanged from 2018. Excluding proprietary genetics, the 2019 acreage accepted for certification represents a total of 119 varieties, selections and advanced clones.

For 2019, the top varieties were Russet Burbank (39% of total acreage accepted), Russet Norkotah (all strains, 18% of total), Ranger Russet (12%), Clearwater Russet (5%), Alturas (4%) and Umatilla Russet (2%). Significant movement occurred in Clearwater, Alturas and Umatilla acreage (+38%, +26% and -12%, respectively) compared to the 2018 crop. A complete listing of this year’s seed potato crop is available in the 2019 Idaho Certified Seed Potato Directory, posted on the Idaho Crop Improvement website.

Seed buyers should be reminded that the nomenclature used to describe Idaho seed potato generations was changed to a “field year” system, effective with the 2019 crop. This nomenclature is similar to that currently used by a number of other certification programs and is intended to promote standardization and transparency within the seed potato industry by designating generations by the actual number of years that the seed has been produced in soil. Please note that there are no changes to the tolerances associated with the various field generations.

— Report by Alan Westra, Southeast Area Manager, Idaho Crop Improvement Association

Top seed cultivars grown in Idaho in 2019 by acreage: 

  1. Russet Burbank 11,707 acres
  2. Russet Norkotah 5,049 acres
  3. Ranger Russet 3,076 acres
  4. Clearwater Russet 1,439 acres
  5. Alturas 1,085 acres

RELATED: Certified seed potato reports from the Eastern & Central U.S. 


This summer proved to be cooler than average. With mild conditions, there was very little stress to crops throughout the state, and growers are reporting very strong yields and good quality. Some growers received hail in August but most crops were far enough along that yield was not reduced dramatically. While many other potato growing areas experienced wet conditions and frost before the end of harvest, Montana growers were fortunate to have about 95% of their potatoes harvested before a severe freeze.

Seed potato acreage has held very steady over the past 10 years at just over 10,000 acres. In 2019, Montana seed potato acreage is up slightly to 10,440 acres which represents a minor increase when compared to 10,355 acres in 2018. Russet Burbank is still the dominant variety but is down slightly from 3,921 acres last year to 3,786 in acres in 2019. Umatilla is the second-most widely produced variety in Montana but has dropped from 1,789 acres in 2017 to 1,376 acres in 2019. Ranger Russet acreage is up from 1,172 acres in 2018 to 1,284 acres in 2019.

Clearwater acreage continues to rise and is up from 1,016 acres in 2018 to 1,211 this year. It is now firmly in fourth place in terms of acreage, displacing Alturas from the top five varieties two years ago. Norkotah Russet selections were up from 997 in 2018 to 1,116 acres in 2019. Alturas rebounded slightly this year increasing from 558 acres in 2018 to 623 acres in 2019. Standard Norkotah accounts for only 41 acres.

Norland and Dark Red Norland remain the most widely grown colored varieties in Montana at 110 acres combined. Traditionally, chip varieties have not been widely grown in Montana in the past, but are currently increasing with Atlantic, Snowden and Lamoka together making up 99 acres of Montana seed. There are 55 varieties of potatoes registered for certification.

Montana conducts its post-harvest test on Oahu, and in the past few years, has performing additional dormant tuber testing using PCR. For the 2018 crop, Montana revised certification rules to require more samples for early generation seed potatoes.  Sample numbers were doubled for G1 and one additional 400 tuber sample is now collected for G2 seedlot. For the G1 and G2 samples, growers are strongly encouraged to send one sample to the lab for dormant tuber testing. All remaining samples are tested in the field grow out in Hawaii. One year in, growers are indicating that they have benefited from having the early tuber data and believe that their post-harvest test results are more representative of virus levels due to increased sample numbers. This is allowing them to make better decisions for recertification and improve the information they can provide to customers.

— Report by Nina Zidack, director, Montana State University Seed Potato Certification Program


The 2019 growing season was a bit cooler than normal in Colorado.

All field-grown certified seed in the state is produced in the San Luis Valley in south central Colorado at an elevation of 7,600 feet. It was preceded by an above-average snowpack in the mountains surrounding the valley, which was a welcome change from the record-setting drought last year. Seed inspections started June 25, which was one week later than last year.

Certified seed growers began killing vines in late July and continued through early August, limiting potential spread of virus by late season aphid flights. As of Oct. 20, all potato seed acreage was harvested. Overall yields and sizing have been average or slightly below average, due in part to the cool spring and summer weather.

Certified seed growers have submitted their seed samples for state-required post-harvest testing, which takes place in Oahu. Certified seed potato acreage was down overall from 8,813 acres in 2018 to 6,756 acres in 2019. The 2019 accepted certified acreage after summer field inspections was 6,180 acres.  Rejections were primarily the result of PVY/mosaic, with a few rejections caused by blackleg and variety mix. Total potato acreage — both certified and commercial — in the San Luis Valley was 48,573 acres, down from 51,785 acres in 2018.

The 2019 top five certified varieties:

  1. Russet Norkotah 1,893 acres
  2. Canela Russet 548 acres
  3. Teton Russet 371 acres
  4. Alegria 266 acres
  5. Centennial Russet 231 acres

A wide range of potato varieties are certified in Colorado including multiple varieties of russets, reds, yellows, chippers, fingerlings, and specialties.

Colorado requires all seed lots imported into the state to undergo a post-harvest test or winter grow-out. Also, a PVYN tolerance of 1.0% is in place for all imported seed. If you are a seed grower intending to ship seed into Colorado, contact your certifying agency for submitting samples for post-harvest testing.

Also, there is a late blight quarantine in effect for all seed coming into the San Luis Valley. If you are planning on shipping any seed into the valley, this test needs to be conducted by a qualified lab prior to shipment.

See for testing specifics and an official certified seed directory.

— Report by Andrew Houser, manager, Colorado Potato Certification Service


A total of 3,570 acres of seed potatoes were entered for certification during the 2019 growing season. This is a 111-acre decrease from last year.

Top four varieties grown were:

  1. Ciklamen 576 acres
  2. Chieftain 387 acres
  3. Russet Burbank 349 acres
  4. Umatilla 228 acres

The total acres planted include 179 different potato varieties ranging in size from partial acre plots to 88-acre fields. Most seed lots are less than 20 acres in size and include numbered clones, table stock, processing and heirloom variety potatoes. This year saw 472 individual seed lots from eight farms entered for certification.

Pacific Northwest weather and Washington’s maritime climate, in particular, provided ideal growing conditions. Washington State Department of Agriculture (WSDA) staff noted that late blight and blackleg disease pressure was slight to non-existent. Complete field inspection results are available at

Harvest began the third week of September, with rains and other factors slowing harvest for a time. Harvest was expected to be finished by the end of October. Growers enjoyed average to above-average yields with generally good quality, size and condition of seed lots going into storage. Seed shipments to southern climates will begin in late fall and will continue into the winter months, with the majority of seed to be shipped in early spring.

Washington’s post-harvest test will take place in Oahu for the first time.

— Report by Benita Matheson, Plant Services Program Supervisor, WSDA Plant Protection Division


In 2019, 2,683 acres of seed potatoes were accepted for certification by the Oregon Seed Certification Service (OSCS). This was slightly down from our 10-year average of 2,722 acres.

No lots entered for certification this year were rejected (as per the field inspections) though several lots were withdrawn by the growers for various reasons generally related to very poor stands. A few lots entered were not accepted due to lack of grower approval by the variety owner. Summer field readings for disease were again low in 2019. No lots were downgraded or rejected for disease. A few lots were downgraded due to not meeting isolation requirements for the class produced. Very little blackleg was observed however there seem to be an increase in the amount White mold related stem rots, and in some areas wet soil related rots required increase diligence on the sorting line. Other than a rain-delayed start of planting is some areas, the growing conditions during the summer months was near ideal this year.

Yields were good to fair, with sizing profiles falling on the small side. For the first time in two years the skies were not filled with smoke! Oregon seed areas were also not hit with the at-harvest heavy rainfall or snow that many other areas of the country experienced, though the later harvested seed may have experienced some chilling/freeze injury.

The No. 1 single variety produced in Oregon this year was Gala, a yellow skin-yellow flesh variety sold into the fresh market, with 269 acres, however 330 acres of various Frito-Lay varieties were certified. Other than Gala, most of Oregon’s certified varieties are russet white-fleshed varieties for processing or fresh market. Specialty varieties, including reds, purple and fingerlings for the fresh market are produced in Central Oregon and the Klamath Falls area. A complete listing of the varieties and acres produced in Oregon can be found at

OSCS was finally able to fill the local part-time seasonal positions of harvest Inspectors. These

individuals are located in our four main production areas of Klamath Falls, Central Oregon, North Central and Northeastern Oregon and inspect tubers in the fields and sorting sheds during harvest. They principally look for diseases that would not necessarily show up during the field inspections in the summer months such as nematode, bacterial ring rot and evidence of internal necrosing viruses.

— Report by Jeff McMorran, Oregon Seed Certification Service Specialist

75 Applewood Dr. Ste. A
P.O. Box 128
Sparta, MI 49345


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