State Seed Potato Reports

Published in the January 2014 Issue Published online: Jan 17, 2014
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Kent Sather, Manager, Colorado Potato Certification Service

Colorado’s San Luis Valley is an ideal location for seed potato production. Its 7,600-foot altitude, cool days and high summer sunlight intensity allows for high altitude vigor. Certified seed lots begin with extensive testing of tissue culture plantlets maintained by the Colorado Potato Certification Service (PCS) tissue culture bank at the Colorado State University San Luis Valley Research Center. Disease-free plantlets are distributed to 10 Colorado grower-owned/operated tissue culture/greenhouse facilities. Their greenhouse minituber production serves as the foundation for one to six years of field increase for 25 Colorado certified seed potato growers as well as other certified seed growers in the United States. Detailed historical documentation of seed lots, laboratory serological disease testing, three summer visual inspections, storage inspections, post-harvest test inspections and shipping inspections comprise the total protocol to provide quality seed potatoes to customers.

Colorado saw 9,722 acres accepted for certified seed. The top five varieties are Canela Russet, Russet Norkotah selections, Rio Grande Russet, Centennial Russet, and Classic Russet. Certified seed growers submit post-harvest test seed lot samples for every seed lot destined for recertification or sale as certified seed. This year, Colorado’s plots will be located at the North Shore of Oahu, Hawaii. An official 2013 certified seed directory is posted online at This lists second inspection results of all seed lots passing summer inspections. An interactive version of the same certified seed directory is part of the Colorado Certified Potato Growers’ Association website. See this directory and other certified seed grower information at

Colorado growers continue potato crop management necessary to meet the requirements of the Colorado Seed Potato Act, which became effective in 2012. The stated purpose is to control and minimize the spread of contagious community diseases by reducing the overall inoculum pool present in potato crops. It is further intended to comply with seed potato standards set forth in the State/National Harmonization Program.



Alan Westra, Southeast Area Manager, Idaho Crop Improvement Association

Idaho’s season began with early to normal planting, followed by a warm, dry growing season. Seed produced at higher altitudes benefitted from the warmer growing season and delayed frost. Harvest was completed in a timely manner, with yields reported as being average to very good this year. Seed quality going into storage is reported to be above average to very good.

A total of 32,890 acres were accepted for certification this year, an anticipated reduction of 8 percent from 2012. A total of 193 varieties, line selections and advanced clones are represented in this acreage. The top varieties are Russet Burbank (43 percent of total acreage), Ranger Russet (15 percent), Russet Norkotah (all, 13 percent), and Alturas (5 percent).

The 2013 season includes a major change to the Idaho program in that the post-harvest test location is being moved from California to Waialua, Hawaii. The change in venue will result in faster turnaround and improved service for Idaho seed potato producers and their customers. Planting of the winter test plot was completed on Nov. 17. Leaf sampling for PVY and visual assessment of all other factors were in mid-December and field days for viewing winter test samples were Dec. 19 and 20. It is anticipated that the final results of the winter test will be completed and available in early January, approximately one month earlier than would have been possible at the California location.

With the addition of new equipment this past spring, the lab is now accepting tuber core samples for bulk Bacterial Ring Rot testing using PCR technology. PCR testing is a very sensitive method of detecting a small amount of the bacterial pathogen which causes Bacterial Ring Rot, even in a large number of tubers. This test can be used for both seed lot screening and confirmation of suspected Bacterial Ring Rot.

This service is being offered to both commercial and seed potato growers at a reasonable cost. If growers are interested in submitting a sample or would like more information, they can contact the lab manager, Sherry Laug, at (208) 522-9198 or


Ellis B. Additon, Director, Maine Bureau of Agriculture, Food and Rural Resources

Seed potato growers in Maine eventually wrapped up the 2013 harvest season after a slow start. Wet weather delayed the season slightly, but very dry, favorable fall weather conditions allowed the harvest to proceed briskly once it started.

As of Oct. 28, 11,181 acres have been entered for certification by 122 individual growers. Seed inspectors report the crop to be an average to slightly above average yield and quality appears to be very good. Frito-Lay varieties continue to be the largest acreage entered, along with Russet Burbank, Atlantic, Snowden and Superiors.

Preseason contracts for the processing market account for about 65 percent of the total potato crop in Maine. Certified seed makes up about 20 percent of the industry, and the remaining crop is sold to the fresh/table stock market.

Certified seed inspectors are finishing up soil sampling to test for potato cyst nematode to allow growers to provide seed for export.

Maine originated one of the first and one of the toughest certified seed programs in the country several years ago. Several states have adopted Maine’s model. Maine certified and foundation seed are grown from disease-free nuclear stock. Maine’s northern climate ensures a hardier and more vigorous seed.

In November of each year tuber samples are planted by our seed inspectors on our Florida farm. The inspectors will return in January to “read” the plants for PVY virus content and to determine eligibility for sale as certified seed.

This past winter the 126th Legislature passed into law changes to make our certification regulations more readable and to change our generation designations from N1 through N4 to a field year numbering system more in line with the rest of the industry.



Nina Zidack, Director, Montana Seed Potato Certification Program Potato Lab, Montana State Univeristy

An excellent crop of seed potatoes was harvested in Montana in spite of some radical weather events across the state. The Gallatin growing area received a severe hailstorm Aug. 1 and the Dillon area received hail later in the month. The potatoes demonstrated amazing recuperative potential. While yields may be slightly reduced, seed quality is excellent. An early fall storm slowed down harvest in much of the state, but by the third week of October harvest was complete.

Montana seed potato acreage is down slightly to10,136 acres compared to 10,426 acres in 2012. The biggest varietal shift is in the Norkotahs where there is movement away from the standard and Colorado lines to the Texas lines. This year saw a slight increase in Umatilla and Ranger acreage and slight decreases in Russet Burbank and Alturas. A total of 64 varieties were registered for certification.

In Montana, production of seed with very low virus levels is enhanced by our growers’ practice of planting all Generation 1 potatoes as family units. Each unit is planted with the daughter tubers from a single nuclear generation plant. Over the summer, each unit is 100 percent tested for PVY and PVA. If a test comes back positive, the whole unit is removed. In addition, all Generation 2 fields are tested for PVA, PVY and PVX; Generation 3 fields are virus tested if they are being grown for recertification. We also test for all three viruses in the winter grow-out which will be planted in November on the island of Oahu, Hawaii.


North Dakota

Willem Schrage, Potato Programs Director, North Dakota State Seed Dept.

The 2013 seed potato crop in North Dakota had challenges during the 2013 growing season. A late cold spring followed by dry weather with high temperatures made it look like it would be a small crop susceptible to bruising if rains would not come in time to soften the soil. Rains did come and the quality of the red crop is better than expected.

However, the seed potato crop has been harvested a bit later than usual. There was some frost but damage was limited. The 2013 North Dakota seed potato acreage was 14,169.97. The variety with the largest decline in acreage is Russet Burbank. The largest seed potato varieties in North Dakota, with over 1,000 acres are Norland (Dark Red and Red), Dakota Pearl, a chipping variety from NDSU, the processing varieties, Bannock Russet, Ranger Russet and Umatilla Russet. Red LaSoda also had more than 1,000 acres grown in North Dakota. A few new arrivals on the scene in the state are Agata, yellow flesh, Teton Russet, processing, and a bright red clone from NDSU called ND8555-8R.

The increase of share in the fresh market of red potatoes is good news for the Red River Valley, where traditionally red varieties are popular. Red seed potatoes started moving south immediately after harvest.

North Dakota’s winter test is still in Florida, where the ND Certified Seed Potato Growers own land. There is an excellent cooperation with the grower in a tradition that goes back many years. The North Dakota State Seed Department will do more leaf testing on request of the industry, but also allows sprout testing when there is concern that current season infection in Florida shows as a positive test without any symptom expression.

The list of North Dakota seed potato varieties can be found at, where a list of growers is also available. The seed potato directory can be requested from the North Dakota State Seed Department

Contact: North Dakota Seed Department, P.O. Box 5257, Fargo, ND 58105 or (701) 231-5400.



Jeff McMorran, Oregon Seed Certification Service, Oregon State University

Oregon had a total of 2,781 acres entered for certification in 2013, of which 2,442 passed final certification (as of Nov. 4). Most lots not making final certification were withdrawn for chemical or variety issues. No lots were rejected for bacterial ring rot, one lot was rejected for nematode, and several for excessive mosaic found during the second inspection. Overall mosaic levels observed in 2013 were low. Harvested yields were normal to above average depending on the production area. For the most part quality was excellent; however, some growers experienced problems with oversizing or hollow heart development.

Early planting went well, but some wetter than usual weather in late spring delayed planting in some areas. Early harvesters experienced a week of very hot weather in early September that delayed or shut down harvest until cooler weather arrived. With the exceptions of some heavy rain and storm events in some seed areas, the conditions during the rest of the harvest season were exceptional.

Processing and fresh market Russet varieties continue to make up the bulk of Oregon’s seed acreage (about 60 percent). Varieties used in chip production have shown considerable increase in the past few years, now making up about 25 percent of the Oregon seed production. There also continues to be expansion in the acreage used for early generation specialty varieties. Oregon’s topography, with its many very remote locations suitable for potato seed production (provided irrigation is available), continues to attract parties considering FY1 and FY2 production sites. Specific information on the varieties produced and acreage can be found at

The year 2013 was a year of transition for Oregon Seed Certification (OSCS) potato inspection staff. We lost one of our long-time crop inspectors, Iraj Motazedian, to kidney cancer this fall. His inspection skills, hard work ethic, and contagious smile will be greatly missed. Randy Knight, another of our field inspectors, retired to central Oregon but continues to help as needed during the summer months. As replacements, OSCS hired two new full-time inspectors, Andrew Altishin and Mary Beuthin. Their training has gone well and we are pleased to have them on board.

The year 2013 was also one of transition for OSCS activities. Oregon began a joint project with Nevada Department of Agriculture to certify early generation seed grown near McDermitt, Nev. In this arrangement, both Nevada and OSCS personnel inspect seed fields, and OSCS conducts the winter grow-out of harvested tubers in our greenhouses in Corvallis, Ore. OSCS is likewise in the process of developing a new program that will streamline the introduction of FY1 material derived from multi-line sources into the standard certification channel for further testing by seed growers.



John L. Wraspir, Plant Services Program Supervisor, Washington State Dept. of Agriculture

Washington State currently has eight certified seed potato producers, including one organic growing operation. Growers planted 3,038 acres with over 120 different potato varieties to meet demands from niche markets to large-scale commercial potato production. This is an increase in production by 74 acres from last year.

Seed potato production in Washington benefited from relatively mild weather conditions throughout this growing season. With summer’s mostly dry weather and unusually warm nights, late blight disease detection was negligible. Most seed lots exhibited strong plant vigor with low plant disease incidence as the season progressed. Weed pressure was generally low. Few PVY positive plants were noted during field inspection after rouging.

With harvest complete by the end of October, storage condition issues are minimal and manageable at this time. Overall quality is very good with a size profile that is generally on target, along with average to above average yields noted in most seed lots.  

Rules for the certification of seed potatoes in Washington are set in administrative codes with the state legislature granting authority to the Department of Agriculture to set standards. Rules for the production of certified seed potatoes are ever evolving to meet the demands of industry trends and buyer expectations. 

This year WSDA, in collaboration with our Certified Seed Potato Commission and represented seed potato growers, strengthened the rules for post-harvest testing. In addition to existing rules, all Generation 1 lots exceeding 0.25 acres and all seed lots sold for re-certification are required to be post-harvest tested as well as ELISA tested for Potato Virus Y.