What are potato cyst nematodes?
Potato cyst nematodes (PCN) are soil-dwelling, worm-like organisms, less than 1mm in length (Figure 1). PCN feeds on the roots of potatoes, tomatoes, eggplant, and other plants in the Solanaceae family.
There are two closely related PCN species - the pale cyst nematode, Globodera pallida, and the golden nematode, Globodera rostochiensis. After a female is fertilized, her body swells with up to 400 developing eggs, then she dies and her exterior body wall hardens into a cyst to protect the eggs (Figures 2, 3).
Why are potato cyst nematodes important?
High populations of PCN can reduce potato yield up to 80% (Figure 4). In the absence of host plants, the cysts remain dormant but alive in the soil for 20 years or more. Cysts are spread by seed tubers, farm machinery, and roots or bulbs of other plants grown in infested fields. Cysts are also moved by wind and flood water. Fields of all types of potatoes (those for processing, those for baking whole, etc.) can have significant yield losses, but the risk of spreading PCN to new fields is greatest for seed potatoes. PCN is also important because seed potatoes from PCN-infested fields may not be sold to Canada, and trade with other countries would be seriously impacted as well.
Where are potato cyst nematodes found? Do we have them in Minnesota?
Potato cyst nematodes are not known to be present in the state at this time. They are not native to Minnesota, having originated in the Andes Mountains of South America. In North America, the pale cyst nematode is present in Newfoundland, Canada, and in 2006, was found in Idaho. The golden nematode is present in Canada in Newfoundland, Vancouver Island, Quebec, and in 2007, was found in Alberta. In the United States, strict quarantine measures have kept the golden nematode confined to 9 counties in New York since 1941.
How are potato cyst nematodes managed?
Once a field is infested, management includes sanitation, crop rotation, use of resistant varieties, and chemicals.
What is being done to protect Minnesota potato growers from PCN infestations?
The Minnesota Department of Agriculture (MDA) has been conducting surveys for PCN since 2006. The survey involves collecting (Figures 5-7), drying (Figure 8) and analyzing (Figures 9-12) soils samples from numerous locations throughout the field. So far, the survey has been voluntary except for growers who ship seed potatoes to Canada. However, the MDA encourages all seed potato growers to participate.
What happens if PCN is found in Minnesota?
The MDA would coordinate with Minnesota potato growers and the USDA Animal and Plant Health Inspection Service, Plant Protection and Quarantine (APHIS PPQ) to determine the extent of the infestation and limit its spread.
Exclusion and early detection of PCN are critical to protecting our potato industry!
More about our surveys:
Survey of 2006 potato fields - More than 1700 5-pound soil samples were collected from 6400 acres of fields planted to potatoes in 2006. The survey included both seed and commercial fields. Analysis of the samples was carried out at the MDA East Grand Forks Laboratory. PCN was not detected.
Golden nematode trace forward in 2007 - Two Minnesota growers planted seed potatoes that had been produced in Alberta, Canada, on farms where golden nematode cysts were detected in 2007. These growers entered into compliance agreements with the MDA and were restricted in their movement of tubers and equipment from these sites until surveys of those fields were completed. Almost 700 soil samples were collected from those fields in spring 2008 and analyzed. No PCN was found and the growers were released from the agreements.
Survey of 2008 potato fields - About 4500 acres planted to seed potatoes in 2008 and over 21,000 2008 commercial acres were surveyed in the fall of 2008 and spring of 2009. No PCN has been found to date.
Survey of 2009 potato fields - Fields that were planted to potatoes in 2009 were surveyed in the fall of 2009 with the priority being fields planted to seed for shipment to Canada. Seed potatoes that are exported to Canada require a phytosanitary certificate stating that the fields of origin were surveyed for PCN according to USA/Canada Guidelines of June 2009. Approximately 1100 five-pound samples were collected and processed. No PCN were detected.
Survey of 2010 potato fields - Soil sample collection from fields that will be planted to seed potatoes in 2010 began April 21, 2010, starting in Wadena County. Sampling will continue through May and resume in September with a total collection of about 1500 samples from 1500 seed potato acres in several counties. As in previous surveys, priority is given to those fields that are planted to seed for shipment to Canada.
For more information on PCN:
For more information on Minnesota potato growers:
For information on soybean cyst nematodes in Minnesota:
For Further questions contact
Kathryn Kromroy
651-201-6343
Kathryn.Kromroy@state.mn.us
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