Scientists looking for evidence of potato cyst nematode (PCN) in Idaho today confirmed the presence of the pest in one eastern Idaho field.

The cysts were discovered in soil samples collected by the U.S. Department of Agriculture’s Animal and Plant Health Inspection Service (APHIS) and the Idaho State Department of Agriculture (ISDA). The soil was collected as part of the investigation into the April 19, detection of the pest, which was found in routine samples taken at a potato grading station in Idaho. The nematode does not pose any threat to human health, but can reduce the yield of potatoes and other crops. There is no sign that the quality of tubers grown in Idaho has been affected.

The soil samples that tested positive for PCN were collected from a 45-acre field located in northern Bingham County, south of Idaho Falls. Production in the area is for fresh market and processed potatoes, not seed potatoes. The field is not within an Idaho Seed Potato Crop Management area, where safeguards assuring quality are monitored. As part of the investigation, more than 2,500 samples representing numerous fields associated with the grading station were tested. All other samples collected as part of the investigation have tested negative for PCN. Additionally, more than 3,000 Idaho soil samples taken since last fall as part of the Cooperative Agricultural Pest Survey (CAPS) have been negative for PCN. Based on these survey results, the PCN infestation appears to be isolated, but additional surveillance will continue.

APHIS and ISDA are implementing a regulatory program at the positive site designed to prevent the pest’s spread to other fields. The program will restrict the movement of plants and soil, and require sanitation procedures for equipment used on the regulated field. Aggressive delimiting surveys are being conducted in areas associated with the PCN-positive field. Associated areas include those areas with geographic nearness, common usage of tillage equipment, common seed sources, common irrigation water or other means.

The potato cyst nematode, Globodera pallida, is a major pest of potato crops in cool-temperate areas. It primarily affects plants within the potato family including tomatoes, eggplants and some weeds. Potato cyst nematode infestations may be associated with patches of poor growth. Affected potato plants may exhibit yellowing, wilting or death of foliage–none of which has been observed in Idaho potato fields. If left unmanaged, nematodes can cause significant yield loss. The PCN is widely distributed in many potato-growing regions throughout the world. In North America, the nematode is also known to be present on the island of Newfoundland, Canada.

Early detection of pests minimizes agricultural production costs and enhances product quality and marketability. Crop rotation and the use of certified seed and nematicides (fumigants or granular systemic compounds) are effective and practical means of suppression.

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