Increasing quality, diversity and seed availability of potato varieties for small-scale farms

Final Report for LNE08-272

Project Type: Research and Education
Funds awarded in 2008: $176,434.00
Projected End Date: 12/31/2011
Region: Northeast
State: New York
Project Leader:
Michael Glos
Cornell University
Elizabeth Dyck
Organic Growers' Research and Information-Sharing Network
Dr. Keith Perry
Cornell University
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Project Information


To identify varieties that perform well in both field and market, 310 specialty potatoes were evaluated, of which 48 were trialed by a network of 113 small-scale growers. Through multi-year, free-choice trialing, the growers documented relative yield of 27 potato varieties. By project’s end, 46 growers had adopted one or more of ten varieties new to the region. These high-performing potatoes include an American heirloom variety and cultivars originating from Europe, Peru, Alaska, and Cornell. They exhibit an array of tuber sizes, shapes, and skin/flesh colors, thus substantially adding to the diversity of potato choices for both growers and consumers in the Northeast. One double-certified (i.e., organic and state certified) potato seed grower started production in 2009 and is focusing on specialty varieties. As indicated by an end-of-project survey, 23 growers adopted one or more improved potato pest management practices (including extended rotation, increased row spacing for improved air flow around plants, roguing of volunteer potatoes, and use of clean seed and resistant varieties) that had been advocated at project outreach events.


Diversified organic/sustainable vegetable farmers in the Northeast report that consumers are especially interested in potato varieties that are flavorful and have novel traits in terms of skin and flesh color, shape, and size. In New York State, such specialty tablestock varieties when organically grown can fetch $2 per pound even in rural areas, and prices can reach up to $4 per pound in urban markets.

Growers have expressed need for potato varieties that combine these novel characteristics with good productivity under organic management. This need was highlighted by the 45 growers who participated in potato variety trials sponsored by NOFA-NY and Cornell in 2007. However, a limiting factor in identifying and bringing to market high-performing specialty potato varieties is the availability of disease-tested seed.

Potatoes are a vegetatively propagated crop, and any pathogens introduced in the current season will be transferred into the next year’s crop with saved seed (for potatoes, ‘seed’ = tubers). To circumvent this problem, growers purchase certified seed. The production of certified potato seed is a long process that begins with disease-tested laboratory tissue culture plants and culminates with state inspection of production fields and harvested tubers. Consequently, certified seed is rarely available for potato varieties not in demand by larger-scale commercial farm operations, which would include most novel and heirloom varieties.

This project was developed to assist growers in identifying specialty potato varieties that perform well in their fields and markets and to make available quality potato seed of these varieties for continued production. To accomplish these goals, project activities included 1) collection, disease-testing, and bulking of specialty potato varieties, 2) distribution of promising varieties for multi-year trialing by growers, 3) development of a potato seed-sharing network among growers to allow access to desired varieties until commercial production can begin, and 4) facilitating start up of double-certified (organic and state certified) potato seed production enterprises.

Performance Target:

Performance Target

Through the cooperation of 80 growers, organic seed potato producers, NOFA-NY, and Cornell University Departments of Plant Pathology and Horticulture, 180 heirloom and new potato varieties are evaluated, resulting in the adoption of a minimum of 10 varieties among the 40 cooperating growers. Commercial organic seed producers and a potato seed-sharing network work with growers to ensure a sustainable potato production scheme from seed to table.

Several components of the performance target were not only met but exceeded. A total of 310 potato varieties were evaluated at Cornell of which 48 were trialed by growers. Cooperating growers numbered 113. In terms of variety adoption, the target was also met: an end-of-project survey documented adoption of one or more project varieties by 46 growers. Of these varieties, six were adopted by 11 or more growers and four by more than three growers.

The formation of a potato seed-sharing network was disrupted by a severe outbreak of late blight during the 2009 season. However, a fledgling sharing network was begun in 2011 with four growers sharing seed of several varieties. One double-certified seed grower started production in 2009, however the goal of establishing two new double-certified seed enterprises by project’s end was not met.


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  • Elizabeth Dyck
  • Don Halseth
  • Kate Mendenhall
  • Keith Perry


Materials and methods:

Potato varieties were acquired from seed savers, state potato programs, and the USDA potato genebank at Sturgeon Bay, WI. Varieties were tested for disease, cured of virus as needed, and planted out at the Cornell Freeville Farm for at least two seasons for observation and seed increase. Project staff (which included one commercial organic potato grower and one organic gardener) used multiple criteria (yield, appearance, disease tolerance, and taste) to select varieties to be trialed by growers.

Grower variety trialers were recruited through emails sent out to the NOFA-NY membership, notices in the NOFA-NY newsletter, and at organic conferences and workshops. Both commercial vegetable producers and gardeners who grew potatoes were recruited. Growers were asked to agree in writing to record yield and complete written evaluations of potato varieties before they were sent germplasm.

Each year from 2008-2011, growers participated in single-replicate, “free-choice” variety trialing: They could choose to trial up to five to eight varieties from a list of 20 or more varieties that changed annually. They were also required to grow a control variety. Growers were sent their choice of either 10 or 20 tubers of each of the varieties they selected along with trial instructions, a four-page trial report to be completed, and plot stakes and flags. Although growers were urged to use their typical management practices, the instructions asked growers to use planting, growing, and data-recording procedures that lessened the risk of differential treatment of the varieties and optimized the accuracy of reported yields (see Methods Attachment 1). In the trial report, growers were asked to 1) provide information on their location, size of operation, and soil type and on management and marketing practices, 2) rate the varieties on such criteria as emergence, vigor, pest tolerance, taste, and consumer reaction, 3) describe growing season conditions, and 4) measure yield. (See Methods Attachment 2.)

In 2009 and 2010, following the adaptability analysis method of Hildebrand and Russell (1996), a subset of growers (26 in 2009 and 22 in 2010) were recruited to grow a single-replicate set of the same four varieties, with each grower’s environment serving as a block. Otherwise, these growers followed the same trial instructions and used the same trial report as the free-choice trialers. Project staff visited each of these trialers during the growing season to 1) verify that trial planting and management procedures had been followed and 2) measure plot size.

From 2008-2010, a subset of the varieties made available to growers was included in a trial on ground under organic management on the Cornell Freeville Farm. Plot size was 10.9 x 2.8 ft, and each treatment (variety) was replicated twice.

Workshops and field days were held to 1) acquaint growers with varieties (including their taste), 2) discuss best management practices, 3) provide growers with training in identification and management of foliar and tuber-borne diseases, and 4) disseminate project results. To facilitate the development of a potato seed-sharing network, several grower meetings also focused on assessing risk in planting either their own saved seed or that shared by other growers. A handout and a presentation by a certified potato seed producer were used to disseminate information on requirements for becoming a state-certified potato seed producer.

At the end of the final year of trialing, all growers who sent in trialing reports were surveyed to document adoption of varieties and assess project impact (see Methods Attachment3).


Hildebrand, P.E., and J.T. Russell. 1996. Adaptability analysis: A method for the design, analysis and interpretation of on-farm research-extension. Iowa State University Press, Ames, IA.

Research results and discussion:

Milestone 1. In a three-year cycle, at least 60 heirloom/new, disease-tested potato varieties per year (180 total) are grown at Cornell. Thirty to 40 grower-selected varieties are increased (year 2). Twenty final selections are distributed as seed (year 3).

Over the course of this project, a total of 310 heirloom and new, disease-tested potato varieties were grown and evaluated at Cornell by growers and project members. The majority of these varieties came from the USDA germplasm repository in Sturgeon Bay, WI. Other sources included state potato programs, Seed Savers Exchange, other potato growers, and the Uihlein Farm of Cornell University. Of these varieties, 32 were made available to growers for trialing in 2008, 25 in 2009, 20 in 2010, and 25 in 2011.

Milestone 2. Each year 40 growers trial 20 heirloom/new, disease-tested potato varieties identified in milestone 1.
Milestone 3. Each year, replicated yield trials are conducted at Cornell organic farm, using 10 of the heirloom and new varieties planted and under evaluation by growers.

There was strong grower interest in trialing potato varieties in each year of the project. Due to seed increase at both the Uihlein and Freeville Farms, the project was able to supply varieties to far more than the target number of 40 growers per year. At growers’ request, an additional trialing season was undertaken in 2011.

Result Table 1 summarizes the number of trialers receiving tubers per year, the number of trialers who sent back potato reports, and their geographic distribution. Over the four trialing seasons, the number of growers returning potato reports averaged 77%. Table 1 also breaks out the number of trialers who grow potatoes for sale: Each year trialers were relatively evenly split between commercial growers and gardeners.

In their reports, growers recorded marketable yield. For 21 varieties, only one year of yield data was obtained (Result Table 2). Yields of 27 varieties were obtained for two or more growing seasons (Result Table 3). Average varietal yields determined from single-replicate, free-choice grower trialing can be problematic for a couple of reasons. First, substantial error can be introduced if the grower does not measure the planting area accurately. Second, because different subsets of growers report on each variety, yield comparisons between varieties may not be valid. For these reasons, the yield potential under organic growing conditions of the varieties that were trialed for a single year (Result Table 2) needs further study.

However, the project did generate evidence that free-choice trialing when done over multiple growing seasons with large numbers of growers can provide a useful indication of relative yield potential. In 2009, the subset of growers that trialed the same four varieties allowed for replication across environments (farms). Multi-year averages of yields of the same four varieties obtained from free-choice trialing (Result Table 3) are comparable to the yields obtained through the replicated grower trial (Result Table 4), especially in terms of relative yield. Relative yields are also generally comparable between the results of multi-year, free-choice trialing (Result Table 3) and results of replicated varietal trialing at the Cornell Freeville Research Farm (Result Table 5).

The collection of varietal yield data also allowed an assessment of grower yields. Across all varieties and years, growers’ yield averaged 210 Cwt/A (Result Table 6). This is a low yield when compared to conventional potato yields, which in the U.S. average around 300 Cwt/A, with 400 Cwt/A considered a good yield (Maynard and Hochmuth, 2007). However, a small subset of trialers consistently reported much higher average yields, e.g., of 350 Cwt/A or above. Project staff visits to these operations corroborated these higher yields. Although further research is needed, analysis of these “high-yielders’” management practices suggest that high inputs of organic matter during the rotation (either as manure/compost and/or green manure) may be a key factor in boosting potato yield.

In addition to yield, growers also provided qualitative data on the varieties. Grower ratings generally failed to identify high-performing varieties, with one exception: A question added to the rating section in 2010 that asked growers whether they would grow the variety again was a good predictor of varietal adoption. Grower written comments on the varieties tended to be extensive. Analysis of these comments often showed consensus on varietal traits and helped to explain the adoption of specific varieties (see Milestone 6 below).

Milestone 4. A grower seed-sharing network of 20 members produces & distributes seed (years 1, 2, 3). Two new double certified potato seed growers begin operating in year three.

In a questionnaire distributed to 2008 trialers, 25 growers expressed strong interest in developing a seed-sharing network. However, a severe outbreak of late blight during the 2009 season completely halted development of a network. Primary prevention strategies for late blight include not saving seed for planting and buying certified seed. Sporadic incidence of late blight in 2010 continued to dampen grower interest in seed sharing. However, a fledgling sharing network was begun in 2011 with four growers sharing seed of several varieties. 2011 grower reports indicated no quality or disease issues with this shared seed. Communications from growers after the end of the project indicate a resurgence of interest in a seed sharing network focusing on those varieties introduced by the project that have not yet found a commercial outlet.

One additional double certified seed grower started production in 2009, bringing the total double-certified seed producers in NY state to two. However, in 2010, the original NY state double-certified grower ceased production. Project staff continue to work with growers who are interested in developing seed potato enterprises.

Milestone 5. Twenty growers from three different geographic & cropping regions attend educational meetings (3 per year, 9 total) focused on potato varieties, seed production, pests, diseases, and marketing. A total of 120 growers/year also attend two yearly workshops - the NOFA-NY annual winter conference and a Cornell potato program showcasing varieties.

Result Table 7 summarizes the grower meetings held by the project.

Milestone 6. Forty growers adopt at least one of the project-trialed potato varieties, resulting in ten additional varieties available to consumers in markets in the northeast.

Trialer reports and final survey results indicate that the following ten varieties introduced by the project have been adopted by growers. The first six varieties have been adopted by between 11-28 growers, and the remaining four varieties, by three to eight growers.

Red Maria (formerly NY 129) is a red-skinned, white-fleshed potato bred by Cornell that averaged 220 cwt/A in grower trialing from 2008-2011 and 333 Cwt/A over two seasons at the Freeville Farm. Growers like this potato for its attractive tubers (nice red color, round shape, uniform size), reliable yield, and good taste. A negative characteristic for some is its rough skin. Red Maria is often referred to as a “favorite” and by grower demand became the control variety for 2010 and 2011 trialing.

Papa Cacho, a landrace from Peru, produces long, skinny tubers that have pink-red skin and pinkish to white flesh. Its foliage grows well into the fall until a hard frost. Its foliage was also noted by growers to be resistant to late blight, although further research is needed to confirm this. Its yield averaged 205 cwt/A in growers’ trials from 2009-2011, a relatively high yield for a fingerling. Growers prize this variety for its unique (“fun”) appearance and note its appeal to consumers and chefs.

Daisy Gold has oval-shaped tubers with tan to yellow skin and deep yellow flesh. In grower trials from 2008-2011, its yield averaged 207 cwt/A. Over three seasons at the Freeville Farm, it averaged 235 Cwt/A. Growers repeatedly mention Daisy Gold’s good taste, appearance, and yield and compare it favorably to Yukon Gold.

Magic Molly is a purple-skinned and purple-fleshed variety bred in Alaska that averaged 151 cwt/A over 2008-2011 in grower trials. Its striking color, which is retained even after boiling, makes it appealing to consumers. In addition to its relatively low yield, some growers complain of difficulty in harvesting because the dark-colored tubers are hard to spot in the soil.

Early Ohio is an heirloom variety with round to oval, slightly flattened tubers that have tan to whitish skin and very white flesh. Its yield averaged 234 cwt/A in grower trials from 2008-2011 and 261 Cwt/A over three seasons at the Freeville Farm. Growers often referred to this as a “nice white” potato, noting its consistently high yield and good taste, texture, and appearance. Its early maturity was also seen as an advantage. Conversely, some growers found its white color unappealing and a more difficult sell at market.

Bernadette, a variety developed in Germany, has tubers with yellow skin and flesh that are oval to oblong in shape; one grower described them as almost conical in shape. Over four growing seasons (2008-2011), yield averaged 234 Cwt/A among growers. Bernadette is valued for its good yield, yellow flesh, smooth skin, and creamy and smooth texture. A minority of trialers found its unusual shape unattractive.

Peter Wilcox (B1816-5) was bred in MD and named for a professor there. Its round to oblong tubers have purple skin and yellow flesh. Grower yields from 2008-2011 averaged 185 Cwt/A, while the three-year average at the Cornell Freeville Farm was 201 Cwt/A. Growers rated Peter Wilcox as exceptional in taste and appearance. It was repeatedly mentioned as a good boiled potato. Its relatively low yield in comparison to other standard-size potato varieties has limited its adoption by growers.

Purple Finger produces fingerling tubers that are deep purple, inside and out. The color is retained after cooking. Purple Finger’s foliage persists until a hard frost; its tubers remain firmly attached to plant vines. Growers’ yields over four years averaged 122 Cwt/A. Growers were divided in their assessment of this variety. Enthusiasts mentioned its spectacular appearance that drew customers, along with its good taste and firm texture after cooking. Detractors found its tubers to be too small, difficult to harvest, and to store poorly.

Aeggeblomme produces small “B “size tubers that have tan to yellow skin, light yellow flesh, and deep eyes. Grower yields from the 2008 and 2011 growing season averaged 283 Cwt/A. Average tuber weight was 1.3 oz. Growers consider this an excellent novelty potato, appealing to consumers who like small potatoes that can be cooked quickly in their skins. Other attributes are its heavy yield and good taste and texture. It was also noted, however, that the abundance of small tubers made harvesting time-consuming.

Spunta is a variety from the Netherlands with elongated tubers that have buff skin and white to yellow flesh. Growers’ yields from 2009-2010 averaged 253 Cwt/A. Although fewer than 20 growers trialed this variety, it made a strong impression chiefly due to its large, uniform tubers: Average tuber weight across seasons was 4.8 oz.

Maynard, D.N., and G.J. Hochmuth. 2007. Knott's handbook for vegetable growers, 5th ed. John Wiley & Sons, Hoboken, NJ, p. 421.

Participation Summary


Educational approach:

Webpages dedicated to the project were established on the OGRIN website
Resources available to growers on the webpages include a potato photo gallery, a workshop report with photos on identifying common potato diseases, and a fact sheet on late blight prevention and management. Under development are individual webpages for potato varieties trialed during the project and a four-page fact sheet on organic potato production. An article containing partial project results can be found at
A paper is in preparation that will analyze the methodology used in the project and its implications for on-farm research.

Outreach events included three hands-on trainings in pest identification and management, including a field day training on virus identification and roguing, 27 farm visits to train growers in leafhopper damage identification, and a “bring out your problem tubers” workshop on identification and management of tuber diseases. Four workshops on potato varieties and organic management that included potato tasting were held in western and northern NY, in the Hudson Valley and on Long Island. The final grower workshop (held at the NOFA-NY Annual Winter Conference in 2011), in which four growers shared their trialing results and experiences, got excellent evaluations from attendees. Typical comments included “very informative,” “really great information about variety choice, yield, availability,” and “great presenters!” A complete summary of project workshops and conference presentations can be found in Results Table 7.

No milestones

Additional Project Outcomes

Project outcomes:

Impacts of Results/Outcomes

A major indicator of beneficiary response to the project was the number of grower trialers who completed and returned a lengthy annual potato report (see Methods Attachment 2). As documented in Results Table 1, in each project year, the goal of 40 participating trialers was exceeded by 20 or more growers. Grower feedback at the end of scheduled trialing (end of the 2010 growing season) led to an additional year of trialing in 2011. The number of trialers in the 2011 season was constrained only by variety/tuber availability and project funds. As documented in Results Table 7, grower interest as evidenced by attendance at project outreach events remained strong throughout the project.

Another major verification tool was a grower survey undertaken after project completion in December 2011 (see Methods Attachment 3). Of the 104 trialers reached by the project through email or regular mail, 70 completed a 2-page survey, a response rate of 67%. The survey’s findings on variety adoption, a major component of the project’s performance target, are discussed in Section 9 below (Farmer Adoption). However, the survey also elicited information on project impact. In answer to the question whether participation in the project had resulted in a change in potato management practices, 51 respondents (73%) detailed one or more changes. Almost half of these responses (45%) involved adoption of practices to improve pest management (e.g., lengthened rotation, change in row spacing to increase air flow around plants, rigorous roguing of volunteer potatoes, use of clean seed and resistant varieties, etc.), which had been stressed in multiple project outreach events.

A possible future impact of the project is the adoption of certain aspects of its methodology. Researchers and extension personnel in New York and Wisconsin have contacted project staff for information on methods used to manage large numbers of cooperating growers and have requested copies of the project’s trialing instructions and trialer reporting forms. After a seminar on collaborative research with farmers at Cornell University that focused on the benefits of making germplasm widely available for grower experimentation, project staff were contacted for several weeks after the event by plant breeders and graduate students inquiring further about the project’s methodology.

Economic Analysis

Not applicable, per the instructions.

Farmer Adoption

The project’s final survey (see Methods Attachment 3) was an integral tool in assessing farmer adoption of potato varieties introduced by the project—a key component of the project’s performance target. In answer to the question asking growers to list any varieties they are growing as a result of the project, 46 growers listed one or more of ten varieties introduced into the region by the project. In addition, five or more growers credited the project with their adoption of one or more of five varieties that have previously been commercially available in the region. Answers to a question asking which varieties they planned to plant in 2012 corroborated the adoption of these varieties. In answer to a question rating interest in sharing or swapping tubers with other growers, 24 (34%) respondents indicated that they were either interested or highly interested in continuing this activity.

In response to a survey question on what aspects of the project should continue, 62% of respondents specifically mentioned variety trialing. The next largest response category was information-sharing on potato production between growers (12%). In an answer to a question on how the project could be improved, the most frequent response (after “no improvements needed”) was request for more opportunities for communication between trialers, particularly during the growing season (e.g., through on-farm field days, a listserv, and multiple workshops/meetings in each growing region).

When asked for other comments on the project, 53 of those surveyed (78%) appended comments. These comments ranged from thank yous to explanations of what aspects of the trialing were most informative/enjoyable to specific requests for more information. Suggestions for further research included potato hoophouse production and documentation of varietal maturity and best preparation method. Farmer Adoption Attachment 4 lists examples of substantive comments from the final survey.

Assessment of Project Approach and Areas of Further Study:

Areas needing additional study

Project results and outcomes suggest two areas that should be prioritized for further research.
First, there is a disconnect between stated grower need for local access to organically grown, high-quality seed of specialty potatoes and the continued scarcity of double-certified seed potato enterprises in New York State and most of the Northeast. One constraining factor may be economic—growers interested in seed production raise the point that the current price for seed tubers is lower than that for potatoes sold for consumption. An economic analysis, including development of an enterprise budget, marketing surveys, and case studies of profitable operations, could identify the needed components for sustainable double-certified seed potato production in our region.

Second, research is needed into the production practices of the consistently high-yielding organic potato growers identified in this study. A boost in yield from the current average for organic producers (~200 Cwt/A) to the yield levels of these growers (over 300 Cwt/A) would substantially increase profitability per unit land area. High profitability per acre would seem crucial to the sustainability of Northeast diversified vegetable producers—the majority of whom, as documented by this project, are growing on 5 acres or less of land.

Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.