This program develops golden nematode (GN)- resistant potato varieties and the necessary cultural practices to help potato growers successfully adopt and market these resistant lines. Resistant potato varieties are the key GN- control strategy utilized by the USDA-APHIS and the New York State Department of Agriculture and Markets (NYSDAM) as it is the most effective, efficient and environmentally sound control measure.

The golden nematode (GN) was first discovered in 1941, but has been successfully confined to nine counties of New York as a consequence of research-based quarantine and nematode management programs. If this pest becomes established in potato, tomato, and eggplant production areas of the United States, it would cause an estimated $5 billion dollars in annual losses of production and marketing of crops. Many states and counties do not wish to risk the importation of this pest into their production areas and so very carefully monitor our control and management activities. In 2006, a GN find was made in Canada, and a different species but similar Potato Cyst Nematode (PCN) was found in Idaho. Within days, international sales from those two locations were halted. In fact, Japan suspended import of all American potatoes and only in February of 2007 did they begin to allow importation from 13 states, not including Idaho. They also require all fields to be tested and certified to be free of PCN. Thus, it is imperative that GN-resistant varieties be developed which will permit New York potato growers to control the spread of the GN, and allow them to continue farming, while at the same time protecting the marketing channels for many American agricultural crops, which could be affected if its control was not effective. Also a new race Ro2 of the GN now threatens the success of the existing quarantine and management programs and will require the development of new potato varieties with Ro2 resistance.

The GN research program has developed and implemented a management plan that has successfully limited the spread of the GN within NYS. This has allowed domestic and international trade to continue uninterrupted. The quarantine has helped to limit the spread of the nematode, but it is the research component of the program that has provided the basis for the effective management of infested areas. An essential part of the GN management program is the development and availability of GN-resistant potato varieties; the GN program has released 18 GN-resistant potato varieties over the past 40 years. Extensive and frequent collaboration with growers, Cornell faculty, NYSDAM, USDA-ARS and USDA-APHIS occurs at technical workgroups, extension meetings, show and tell discussions and field site trials which all have the goal of developing and conducting the best possible GN-management program. The Cornell breeding program has developed germplasm with resistance to both R01 and Ro2 races of the GN and also has material with resistance to the Potato Cyst Nematode (PCN). This material is available for breeding programs in Idaho and Canada (and others) and our field trials will provide important adaptation and utilization characteristics of these lines to facilitate selection of the best lines.

Currently in the United States the only known populations of viable GN cysts are in small areas of land in nine counties in New York State. A combined Federal and NYS quarantine and survey system, along with the GN-resistant variety development program at Cornell, have been very successful in minimizing the potential for spread of the GN. Many states and countries fear the importation of the GN into their soils as it would greatly hinder their ability to market crops from infested soils. Should the GN become widespread, it could impact, possibly stopping, marketing of many crops which are grown on or come into contact with infested soils, easily exceeding a market value of $5 billion dollars. Before resistant varieties were developed, control measures depended upon soil fumigation. However our research has found that GN-resistant potato varieties are the most efficient, effective and environmentally sound control method. Each season that a GN-resistant variety is grown, the nematode population decreases by 90-95 percent, compared to 80-90 percent for soil fumigation and 30-40 percent for a non-host crop rotation. Recently the impact that nematodes can have on potato marketing on an international scale is illustrated by the 2006 GN find in Canada, and a different species but similar Potato Cyst Nematode (PCN) found in Idaho. Within days international sales from those two locations were halted and only 10 months later are the Japanese reopening potato imports from 13 states. Both Idaho and Canada are now looking at our long-standing and very successful GN management program to help build similar programs in their areas.

New York State Potato Industry - Empire State Potato Growers, Inc.

• Walter De Jong (Plant Breeding, Cornell)
• Keith Perry (Plant Pathology, Cornell)
• Tom Zitter (Plant Pathology)
• Eric Sandsted (Horticulture, Cornell)
• Xiaohong Wang (USDA/Plant Pathology, Cornell)