November/December 2012
State Seed Reports

State Seed Reports

Colorado continues to increase seed potato production

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 tissue culture bank at the Colorado State University San Luis Valley Research Center. Disease free plantlets are distributed to ten 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 26 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 compose the total protocol to provide quality seed potatoes to customers.

The 2012 planting season in the San Luis Valley was good. Soils were dry after a winter with little snowfall on the valley floor. There was very little measurable precipitation prior to planting. Growers pre-irrigated to prepare the seedbed. Air temperatures were slightly warmer and soil temperatures were also slightly warmer. This prompted earlier than normal planting. Early planted and emerged plants were singed by a spotty frost on May 28st. Warmer than normal temperatures in May and June encouraged root and vine growth. Plant growth seemed to be 7 to 10 days ahead of normal through July. Vine killing by certified seed growers began in early August, sacrificing yields, but limiting the potential of virus spread via increasing aphid populations. Despite early and vigorous plant growth, preliminary harvest reports indicate approximately 7 percent to 10 percent below average yields. Growers blame this on delayed tuber set due to warmer weather. Tubers are fair to good grade quality, depending upon the variety. The top five varieties are Russet Norkotah selections, Canela Russet, Rio Grande Russet, Classic Russet, and Centennial Russet. An official 2012 certified seed directory is posted on line at An interactive version of the same certified seed directory is part of the new Colorado Certified Potato Growers’ Association website launched on November 1. See this directory and other certified seed grower information at

Total acreage in the San Luis Valley was 55,111 acres, up 1,131 acres from 2011. This includes 15,917 inspected certified seed acres, up 919 acres from 2011. San Luis Valley water issues continue to be a major factor affecting future potato crops.

Colorado growers are in the midst of potato crop management necessary to meet the requirements of the Colorado Seed Potato Act that became effective this year. 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.

Submitted by Kent Sather, Manager, Colorado Potato Certification Service

Idaho’s hot, dry summer

The 2012 season has been interesting and challenging for Idaho’s certified seed growers. Potato plants grew fast and had lots of foliage. Daughter tubers set on fast and bulked up quickly. Potato growers had to vine kill much sooner than in the past years. I can never remember in the 35 years I have worked for Idaho Crop Improvement Association, Inc. (ICIA) potatoes being killed as early as the 2012 crop. Harvest went well for most of our potato seed growers. Most seed potatoes have gone into storage mature and without field frost.

In Idaho in 2012, 35,889 acres were certified, about 10 percent more than the 34,766 certified in 2011. Russet Burbank remains the leading variety at 15,040 acres or about 41.9 percent of the total crop followed by Ranger Russet, Alturas and Russet Norkotah 3. A total of 192 varieties and selections were certified.

Post-harvest testing soon will be under way in southern California’s Imperial. This location has been in use since 2006 and has proven to be a reliable area for winter testing. Starting in 2007, the Idaho program made a significant change to the winter test protocol in that all emerged plants are leaf sampled and ELISA tested for mosaic (PVY and PVA) in the ICIA laboratory. Previously, only plants showing visual virus symptoms were lab tested. The advantage to testing all emerged plants for mosaic by ELISA is that the test detects viruses in plants that are not exhibiting disease symptoms. All other factors determining lot eligibility including percent of potato leafroll virus and seed-borne chemical injury are determined by visual row inspections. As it is no longer necessary to wait until sufficient numbers of plants have reached a size suitable for visual mosaic detection, testing and reporting can begin earlier in the winter.

Starting in 2009, another improvement in protocol began where about one-third of the lots were collected, treated and planted in mid-October. That is two weeks earlier than what was customary. The remaining lots were planted in early November. Leaf sampling takes place during January and early February. A field day also takes place in early February allowing seed growers and representatives of seed buyers an opportunity to visit the test plot and evaluate their test rows. Seed buyers often use a combination of lab results and visual observation of test rows when making buying decisions.

Submitted by Gary (Buzz) Smith, seed potato certification manager, for the Idaho Crop Improvement Association.

Maine revising certification regulations

As of October 2012, a total of 11,654 acres of seed potatoes, managed by 123 growers were entered for certification. The most common varieties entered were Frito-Lay propagated varieties, Russet Burbanks, and Atlantics. In Maine, 65 percent of the crop is sold for processing, with pre-season contracts, 20 percent is sold as seed potatoes primarily to East Coast producers and the remaining crop is sold as fresh/tablestock potatoes.

This year’s seed crop yield is expected to be average with quality being good to excellent. Everything is expected to store well. Last year, there was some storage issues because of the amount of rain during the season, but this season has been a drier year.

Our seed certification specialists are now busy collecting soil samples from seed growers who may want to export to Canada. Last year, 3,791 samples were analyzed at the USDA Laboratory in Avoca, N.Y., and all were again negative for potato cyst nematodes. In addition, staff has begun collecting tuber samples for post harvest testing at our farm in Florida.

We are revising our certification regulations to condense and make them more readable. In the process, we also plan to change our generation designations from N1 through N4 to the more widely accepted Field Year numbering system. These regulations will be finalized in early 2013.

Submitted by Dave Lavway, division director of the Maine Department of Agriculture, Conservation and Forestry, Division of Animal and Plant Health.

No late blight in Michigan seed area for 2012

Harvest was starting to wind down in the second week of October. We had a week of wet weather, the rest of the time it’s been pretty good. Yields overall are better than average. It was a short growing season. Plants matured faster with the hot growing days. Most of our guys irrigate, they struggled to maintain good moisture levels, rains were spotty, some areas got fairly decent rains, while others didn’t.

Potato seed quality is average to a little better than average. Incidence of scab is less. We didn’t see any late blight in seed areas; disease levels seem to be reduced from a year ago. Aphid populations were low this year.

Jeff Axford is the executive director of the Michigan Seed Potato Association.

Slight increase in Montana seed potato acreage

The Montana seed potato crop has all been harvested and growers are reporting an average size crop with excellent quality. Yields across the state were variable with some varieties negatively impacted by the hot, dry weather. All areas are reporting superb quality and a good size profile. The growing season started out very wet and cool for the first half of the summer in the Northwest area of the state while the rest of the state’s potato growing areas turned warm and dry by the third week of June with rainfall well below average.

Harvest conditions were very mild through the first week of October when the majority of the crop was harvested. Starting October 6 we sustained some colder nighttime temperatures. While the thermometer dipped into the high teens in the southern part of the state, the soil was still very warm and minimal frost damage occurred.

Montana seed potato acreage is up slightly this year with 10,427 acres compared to 10,187 acres in 2011. This represents the second highest acreage in program history, which was 10,879 acres registered in 2000. The generational composition of the acreage has changed dramatically in those 12 years with more early generation potatoes produced. While the total acreage was higher in 2000, during the current crop year, the acreage of G1 was 356 acres and the acreage of G2 was 2865 acres compared to 272 and 2080 acres for those generations in 2000.

In 2012, there were 70 varieties registered for certification. Russet Burbank is still king with 4,612 acres, followed by Norkotah, all lines, 1357 acres, Umatilla, 1283 acres, Ranger, 1066 acres, and Alturas, 742 acres. In addition, Montana produces a number of new Russet cultivars as well as heirloom and specialty varieties. Montana is expanding its marketing of both common and specialty varieties through publication and distribution of a directory specifically for garden potato seed. Our Montana Certified Seed Potato Directory and our Wholesale Seed Potato Directory (garden seed) can be found on our website at as well as information on our annual Seed Seminar which will be held November 9, 2012 at the GranTree Inn in Bozeman, MT.

Submitted by Nina Zidack, director of the Montana Seed Potato Certification program.

Norland selections continue to lead in North Dakota

In the second largest seed potato production area of the US, i.e. North Dakota, the growing season proved to be favorable. Processing growers took the opportunity to plant earlier. Irrigation was applied frequently. It was the first year in many years that dry-land potatoes were dry land. Early planting, dry and warm conditions kept late blight at bay. Generally yields were not disappointing.

In 2012 14,446 acres of seed potatoes were certified. Red potatoes were still the largest acreage with Norland selections counting around 3,500 acres. Other red varieties were Red LaSoda with 1100 acres and Sangre with just over 400 acres. Russet Burbank is still the most popular processing variety with almost 1,700 acres. Other processing varieties that have more than 400 acres of seed in North Dakota are Ranger Russet, Prospect, Bannock Russet and Umatilla. Dakota Pearl is the chipping variety most in demand with around 1,270 acres and Atlantic with around 470 acres. In the fresh russet sector the variety Russet Norkotah has over 750 acres certified including selections. North Dakota produces a large number of new varieties in acreages under 100 acres, such as: the chipping varieties, Harley Blackwell, Lady Claire and Monticello or russets such as Alpine Russet and Teton Russet, but mostly fresh market Colorado Rose and Dakota Rose and yellow flesh varieties such as Melody, Sierra Gold, Agata, Milva, Satina, Augusta, Ambra, Romanz, Bellarosa. The acreages of the different varieties can be found at

Late blight was not a problem this year. Its occurrence is cyclical related to the weather. Potato Virus Y (PVY) generally has not been a problem to the commercial sector, because certified seed potato producers kept the occurrence within tolerable levels. However symptoms of PVY are changing because the virus has developed new strains all over the world. In other areas of the world new strains have caused commercial lots to be rejected in the market due to tuber necrosis. Such cases are still exceptions in the US, but to prepare for the future an inventory of PVY is developed in a national research project. As part of this effort N.D. again carried out a summer leaf testing program of all seed potato fields for PVY to determine which strains of the virus are present in the N.D. seed production system. The percentage of PVY infected plants was 0.35%, which was higher than last year’s 0.25%. The winter test reading in January will be the final determination of what to expect of North Dakota seed potatoes. The National PVY Research Project has this website: .

The website contains some recommendations to control PVY such as: Planting seed potatoes with as low a PVY count as available. This necessitates planting at least “certified” seed. Planting and killing a seed potato crop as early as possible. Considering PVY symptom expression and susceptibility of a variety. Avoiding bare soil around seed potato fields, which can be done by planting a border crop in which the aphid may lose its non persistent Y-virus while probing. Applying oil on the crop regularly also helps limit PVY spread”.

Willem Schrage, North Dakota State Seed Department.

Cool, wet spring delays planting in Oregon

There were 2,708 acres of seed potato accepted for certification in Oregon 2012, up about six percent from 2011. The Klamath Falls area produced the most certified acres this year, 1183 acres, followed closely by Northeast Oregon at 1149 acres, then Central Oregon at 376 acres. The Klamath area has by far the most growers at 15, with 3 new seed growers this year. There are 3 growers in Northeast Oregon and 2 in Central. In the Klamath area, the preservation of lakeside areas for wildlife habitat that were previously used for potato production, along with the need for land with reliable season-long water sources, have pushed more seed and commercial potato production into the remote valleys northeast of Klamath Falls.

Planting in many regions was late this year due to the cool, wet spring, but the excellent growing conditions during the season resulted in very good yields of exceptionally nice looking tubers. The numbers of over-sized tubers were low, considering the low price for ‘overs’ this year. A hot spell in early September slowed down harvest somewhat, but didn’t seem to affect quality. Alternaria-like leaf blights were more prevalent in some areas, but relatively low levels of mosaic were observed during field inspections, and so far no Zebra Chip has been reported in the seed areas. Our harvest inspectors were impressed by the appearance of the tubers this year, with much lower than usual levels of scab and tuber rots than generally observed.

The backbone of the Oregon seed potato industry continues to be the production of high quality G3 class seed, though there is a growing trend towards the production of early generation seed, including mini-tuber, Nuclear, and G1 class lots. Concern over the high transport costs, and the quality of the incoming seed, is fueling this trend. We are also seeing increases each year in production of specialty varieties. Additional information on varieties grown in Oregon and acres certified may be found on our web site at:

Oregon potato inspector Randy Knight retired in 2012. He is now enjoying the good life in Bend, Oregon. Efforts are currently under way to replace this position. Those interested can contact our office manager, Julie Hendrix, at [email protected].

Jeff McMorran, Oregon Seed Certification Service, Program Coordinator

Washington seed potato acreage down

Washington State has two diverse certified seed potato growing regions that are separated by the Cascade mountain range. The Northwest region enjoys a coastal climate providing a diurnal cycle of moderate daytime temperatures with relatively cool nights. The Eastern interior enjoys a steppe climate with more consistent weather patterns in this temperate semi-arid region. Both provide ideal growing conditions for the production of vigorous seed potato stock.

A total of 2,924 acres of seed potatoes were entered for certification this year. This is 268 acres less than what was planted in 2011. Washington seed growers target niche markets by producing 117 different potato varieties, from heirloom to proprietary to standard large scale production varieties. The top five seed potato varieties by acreage grown are Chieftain (480), Russet Burbank (322), Umatilla Russet (233), Cal White (158) and Yukon Gold (140).

Normally the presence of Late Blight disease will occur mid to late summer in Washington state. This year the Northwest region endured a rain-filled spring, with wet conditions extending into July. Late Blight disease symptoms manifested very early in the spring, resulting in intensive control measures by seed producers throughout the growing season. Fortunately these efforts paid off by limiting the incidence of Late Blight to just a hand full of seed lots. Late Blight occurrence was not an issue at all in the Eastern region.

Aphid pressure in both regions was extremely low this year. That said, seed producers intensified pest control methods to include the more expensive neuroactive insecticides along with other control measures. Symptoms of Potato Leafroll virus infected plants were not noted in either region during field inspections this year. Potato Virus Y was noted in a few seed lots, but at lower levels than previous seasons.

Fall weather allowed for excellent harvest conditions for seed stocks going into storage. Inspections at storage revealed generally good quality with very few condition issues. Overall yields appear to be average with most seed lots falling into a uniformly smaller profile.

Seed shipments for winter production of commercial potatoes in California’s Imperial Valley began in October. Shipments for export to various South American countries will begin early winter. Export market demand from South American countries and British Columbia, Canada has been strong compared to previous seasons.

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

Wisconsin crop looks good for 2013

Warm summer temperatures produced an average yielding but high quality seed potato crop in 2012, with 8,605 acres passing inspections, slightly up from 8,278 in 2012. Rainfall was regular and allowed farmers to keep up with irrigation during early vine growth through bulking. Isolation from commercial fields and near exclusive use of ground spray rigs by Wisconsin seed growers typically keep the crop in good condition through vine-kill. This year was no exception with good vine health and only moderate disease pressure. No late blight was found in the seed crop during both growing season and harvest inspections.

Due to early planting, the harvest also began a little earlier. Progress on the harvest was very good with most growers finishing early with no delays or adverse conditions through the entire period. Night-time temperatures during the harvest were good for cooling as the crop went into storage. In general, field inspectors and growers alike indicate a beautiful crop of seed for next years plantings.

Submitted by Alex Crockford, program director of the Wisconsin Seed Potato Certification Program.

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


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