Potato Virus and Virus-Like Disease Management

WERA-089 (2006-2011): This project identified and characterized new potato disease problems; standardized testing methods for potato  viruses; shared information with the U.S. and Canadian potato industries; strengthened relationships with state certification programs; and
developed cooperative strategies to obtain funding for potato virus and virus-like disease management.

Potatos infected with zebra chip develop unsightly dark lines that resemble the stripes of a zebra.

Who cares and why?

Virus and virus-like diseases in potatoes in the western U.S. create a costly situation requiring limited-generation seed programs and the  use of multiple pesticides to minimize yield and quality losses in commercial crops. Substantial yield losses and rejections of seed lots for  certification have resulted in tremendous dollar losses to growers. Public and environmental concerns surround the use of pesticides on  potatoes. In addition, potato growers face potential registration cancellation of key pesticides and the difficulties of developing new  information for re-registration or development of new pesticides. Pest resistance to current pesticides is always of concern. Loss of  pesticides or pesticide effectiveness will increase yield and quality losses if alternative solutions are not developed. This group provides a  regional forum for collaboration among potato virus disease researchers and the dissemination of information on control strategies. The  group also advises regional and national organizations, evaluating concerns, recommending policies, and reviewing quarantine and seed  certification issues with the goal to improve plant health and crop sustainability.

The potato plant leaf on the left shows symptoms of potato virus Y infection compared to the healthy leaf on the right. Photo courtesy of Southern IPM Center.

What has the project done so far?

  • Members have organized annual meetings to discuss current concerns regarding virus and virus-like diseases occurring in potato crops.  This forum has also included presentations of ongoing research on potato viruses and virus-like diseases, their vectors, and alternate hosts.  In addition, participants have considered research priorities for upcoming years. Sub-groups have been formed to work on specific projects  throughout the year, including development of educational materials, presentations, and reference sheets.
  • Impact Statements:
  • Helped to prevent disease spread and serious damage by responding to reported findings of viruses (including new and uncommon strains)  in potato fields, quickly diagnosing the problem, and implementing the appropriate control tactics.
  • Characterized new strains of  potato virus Y (PVY) and assessed the impact of infection by these different strains of PVY on the yield and quality of potato varieties.
  • Identified the components of the tuber necrotic complex and developed new diagnostic tools that allow heightened confidence that potato  seed with internal necrosis due to PVY will not be used for planting commercial potatoes. The PVY survey and the Canadian quality  assurance survey have provided additional information about the health status of potato seed.
  • Found that hairy nightshade is a significant source of potato virus and the aphids which can transmit the disease, leading to new potato disease control strategies that include  managing the various hosts and vectors of PVY.
  • Determined that younger plants are more susceptible to the potato purple top disease,  giving potato growers in the Pacific Northwest much-needed information for using timely and appropriate insecticide applications to  control the beet leafhopper insect that carries the disease, thereby preventing yield losses and reductions in potato processing quality.
  • Discovered that zebra chip, a new and damaging potato disease in the southwestern and central U.S., Mexico, Central America, and New  Zealand, is associated with a previously undescribed species of the bacterium Liberibacter and is transmitted by potato psyllid insects. Development of effective management strategies for the potato psyllid is under way to minimize damage caused by this potato disease.

Potato plants showing symptoms of potato virus Y infection. Photo by Nina Zidack/Montana State University.

What research is needed?

To improve long-term plant health and crop sustainability, scientists must continue to provide a regional forum for the exchange of ideas  and collaborative research on potato virus and viruslike diseases. Scientists need to continue to assist with the implementation of  knowledge, methods, and resources that control potato virus and viruslike diseases. Furthermore, scientists need to share research results  and advise regional and national organizations and help them evaluate concerns, review quarantine and seed certification issues, and develop policies that relate to potato viruses or virus-like organisms and their control.

Want to know more?

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Administrative Advisor: Donn Thill, dthill@uidaho.edu

This project was supported by the Multistate Research Fund (MRF) established in 1998 by the Agricultural Research, Extension, and Education Reform Act (an amendment to the Hatch Act of 1888) to encourage and enhance multistate, multidisciplinary research on critical issues that have a national or regional priority. For more information, visit http://www.waaesd.org/.