National Potato Wart Response Plan

Effective date: March 7, 2025

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Overview

Synchytrium endobioticum is a fungal pathogen and causal agent of potato wart or potato canker disease. It can survive in soil for more than 40 years and no chemical treatments are available to control the fungus. Potato (Solanum tuberosum) is the primary cultivated host. In Canada, it is a regulated and reportable disease and known to be present in Newfoundland and Labrador and Prince Edward Island.

Potato wart is recognized as a regulated pest by most of Canada's trading partners, including the United States (where it has been declared eradicated), and by many European countries (where it is present and under official control). Worldwide, spread has largely been controlled through strict quarantine measures, including the prohibition of susceptible host plant production in fields where potato wart has been detected and the development and extensive use of resistant potato cultivars.

In 2020, the Canadian Food Inspection Agency (CFIA) initiated a full review of its approach to help contain, control and prevent the spread of potato wart based on current science, international standards and available technologies. The review included the development of a pest risk assessment and a pathway risk assessment document, and a review of investigation procedures and the Potato Wart Domestic Long-Term Management Plan (2009 management plan). In 2021, the CFIA also implemented a national survey for potato wart based on soil sampling and analysis.

This National Potato Wart Response Plan outlines phytosanitary measures to improve the processes used to help contain, control, and prevent the spread of potato wart in Canada (excluding Newfoundland and Labrador). The measures described in this plan, including the requirement for an implemented farm-based preventive control plan, increased soil analysis and the addition of equipment cleanliness requirements, are applied to fields following the detection and confirmation of potato wart (via symptomatic tubers or detection of S. endobioticum spores) and an investigation procedure (see Appendix A) to delimit potential spread. This response plan supersedes the 2009 management plan.

Fields in Prince Edward Island already under restrictions for potato wart at the date of publication of this response plan will be evaluated to determine their equivalent step toward lifting of specific phytosanitary measures for potato wart based on the steps completed under the 2009 management plan.

Introduction

Synchytrium endobioticum, the causal agent of potato wart disease, is a fungal pathogen that has been reported in Canada, most European countries and many other countries around the world. The pathogen has been declared eradicated in the United States. Dormant potato wart spores can survive extreme environmental conditions in the soil for more than 40 years. To grow, S. endobioticum requires cool, moist conditions during the growing season, particularly in the spring, and generally does not survive in areas with low annual precipitation. Climate suitability modeling suggests that most of Canada's potato-producing regions are a good climatic match for this pathogen and the risk of new introductions establishing in other regions of Canada is high.

In Canada, potato wart is a regulated and reportable disease. It is present in Newfoundland and Labrador (NL), where it was first reported in 1909, and Prince Edward Island (PEI), where it was first reported in 2000. Potato wart has not been detected in other provinces in Canada as supported by official surveys. In NL, potato wart is regulated under Schedule II of the Plant Protection Regulations and is considered widespread geographically, but at low levels of incidence. Potato wart is not widely distributed in PEI and with mitigation measures in place, including the Potato Wart Order, is under official control. In November 2021, the Potato Wart Order was issued and established restricted and unrestricted areas within the province of PEI. It also included restrictions on the movement of soil, seed, table and processing potatoes and other regulated things (farm machinery, sod, root crops etc.). In PEI, potato wart has been managed under plant protection programs since 2000. In 2005, the management plan was implemented in PEI, and last updated in 2009, to outline the minimum testing and surveillance and risk mitigation activities (phytosanitary measures) required for any field associated with a potato wart detection. The steps required for a change in a field's potato wart classification and release from certain phytosanitary measures, and the investigation criteria for fields associated with new detections of potato wart were included.

The 2009 management plan was a field-based risk management strategy, based on analysis of scientific evidence related to the plant health risk of individual fields. It included 5 basic land categories: index fields (where the pest has been detected); fields adjacent to the index field (within 15 metres); primary contact fields (related to an index field through movement of soil or seed potatoes); other contact fields (for example, secondary contact); and new or new portions of fields entering potato production for the first time. The last two categories were considered lower risk for exposure to potato wart. Each field category was required to undergo specific steps to verify its freedom from potato wart.

Existing phytosanitary import and domestic requirements to prevent the introduction and spread of the pathogen are outlined in the CFIA's automated import reference system (AIRS) and CFIA plant health directives. Canada applies strict import control measures on soil and only allows the import of field grown potato tubers for seed, table and processing from the United States to mitigate the risk of entry of S. endobioticum and other regulated pests into Canada.

The primary human-mediated pathways for S. endobioticum spread are movement of seed potato tubers, movement of soil and soil associated with plant products (including potato tubers for consumption and plants and plant parts for propagation), movement of soil adhering to machinery, equipment, and conveyances or movement of contaminated organic solid or liquid waste materials originating from potato processing and packing facilities. Contaminated animal manure is also a risk pathway as the pest can survive the digestive tracts of livestock fed on infested potato culls or other infested organic waste. The pest has a limited ability to spread naturally through the movement of wind-blown soil or waterways. The movement of infected seed potato tubers is the most likely pathway for long distance introduction and establishment of the pest.

In summer 2022, in support of its program review, the CFIA established an independent panel of international experts and requested it review and assess the potato wart situation in PEI and provide a report of expert opinions and recommendations. The report was completed in December 2022 and provided recommendations to the CFIA to improve the management of potato wart disease in PEI, and considerations for the establishment of pest free areas.

In 2022, the CFIA also established an Industry-Government Technical Working Group focussed on revisions to the 2009 management plan. The objective of this working group was to provide a technical forum to exchange information from key industry stakeholders, to collaborate and to coordinate efforts to obtain input and feedback to improve the 2009 management plan. The working group provided its recommendations to the CFIA in April 2023.

The international panel report, the recommendations from the Industry-Government Technical Working Group, and feedback received during public consultations informed the development of this response plan. Improvements to risk mitigation, including restrictions on seed potato production in restricted fields, increased soil sampling and analysis and the addition of equipment cleanliness requirements, are a result of this feedback. This plan will be reviewed and updated as new scientific information becomes available.

Scope

This National Potato Wart Response Plan (response plan) provides detailed information to the CFIA, potato industry stakeholders, provincial and territorial government stakeholders and other national plant protection organizations on phytosanitary measures to improve processes to help contain, control, and prevent the spread of potato wart from any regulated areas in Canada, except for NL. It also supports the long-term sustainability of the potato sector in Canada. This response plan supersedes the 2009 management plan.

For PEI, the prohibitions and requirements specified in the Potato Wart Order remain in place and are in addition to the risk mitigation measures outlined in this response plan.

Definitions

Definitions of terms used in this document can be found in the International Standard for Phytosanitary Measures 5: Glossary of phytosanitary terms (PDF), and the definitions in the Potato Wart Order, except for the following terms.

Compliance agreement

An audit-based quality management system approach used to mitigate the phytosanitary risks associated with the handling of the regulated things throughout the activities of a receiving facility as outlined in QSM-09: Quality Management System Requirements for Facilities Receiving and Handling Regulated Non-Propagative Potatoes and Related Potato Articles, Including Associated Soil.

Detection

An official CFIA confirmation of a symptomatic tuber or spores of S. endobioticum as determined by morphological identification followed by a molecular method confirmation.

Equipment cleanliness

The removal of all loose adhering soil from all machinery, equipment, and conveyances before exiting the field / farm unit as per the requirements of the farm unit's preventive control plan.

Field

A distinct plot of land distinguished from neighbouring plots of land by physical boundaries including a:

  • tree line
  • fence line
  • permanent waterway
  • ditch
  • road or permanent lane
  • berm
  • permanent irrigation track
  • transition to non-agricultural area (fallow, lawn, wetland)

Freedom from soil

The cleanliness standard for regulated things (for example, machinery, equipment, and conveyances) as outlined in PI-016: Procedure for inspection regulated articles for freedom from soil, plants, plant parts and related matter.

Laboratory bioassay

A method used for the purposes of detecting potato wart (S. endobioticum) in field-collected soil, using susceptible potato varieties grown under conducive growing conditions with appropriate positive and negative controls to confirm proper environmental conditions for development of the disease.

Pathotypes

S. endobioticum has over 40 pathotypes, defined as groups of isolates with a similar response to a set of differential potato varieties. For example, pathotypes 2, 6, and 8 have been reported from Canada.

Potato culls

Potatoes that are deemed surplus or otherwise unsuitable for the intended use and are considered waste, including whole or parts of tubers, or tubers with defects related to size, disease, physiology or any other defect.

Preventive Control Plan (PCP)

A written document that describes how risks to plant health are identified and controlled. It includes a combination of control measures that, when taken as a whole, provide for a science-based approach to managing risks posed by hazards, such as plant diseases, and contributes to achieving compliance with phytosanitary measures and regulatory requirements. A PCP can be built off existing farm plans including on-farm biosecurity plans and may also be referred to as a 'systems approach' to mitigate pest risk(s).

Regulated things

Means any of the following:

  • S. endobioticum, in all its life stages
  • potato plants (Solanum tuberosum), including tubers or parts thereof
  • soil
  • plants or parts thereof including root crops, nursery stock, greenhouse plants, bedding plants, vegetable transplants and sod
  • machinery, implements and conveyances
  • manure

Restricted field

Field in which S. endobioticum has been detected as well as land that by reason of its agricultural history, or its location, is associated with land in which S. endobioticum has been detected. Restricted fields are classified as index, adjacent, primary contact, secondary contact or field of concern.

Resistant varieties

Potato varieties which have been accepted by the CFIA as being considered resistant to infection by specified pathotypes of S. endobioticum, using criteria defined by the CFIA.

Susceptible varieties

Potato varieties which have been accepted by the CFIA as being considered susceptible to infection by specified pathotypes of S. endobioticum, using criteria defined by the CFIA.

Tare soil

Soil that falls from tubers as they move into storage or during storage and subsequent handling processes. It can accumulate beneath handling equipment at potato storages, processing facilities or other locations where the potatoes are being stored or handled.

Human-mediated pathways for potato wart introduction and spread

S. endobioticum spores can spread from one field to another through human-mediated pathways, including:

  • movement of infested planting material, such as infected seed potato tubers or soil adhering to non-host plants and plant parts for propagation (for example, nursery stock or sod)
  • movement of potato wart contaminated tare soil or soil adhering to machinery, equipment, and conveyances
  • improper disposal of potato packing or processing waste products including wastewater effluent, soil sediment or sludge and organic waste (for example, culls, peels, etc.)
  • application of contaminated manure (from livestock fed infected tubers) to fields

Regulated pests

Synchytrium endobioticum, in all its life stages.

Classification of restricted fields or land

Following the detection of S. endobioticum (in other words, via symptomatic tuber or 2 or more S. endobioticum spores), the CFIA will immediately:

  • place phytosanitary measures on the field and initiate an investigation to identify the possible source(s) of the pathogen, and
  • assess the risk relationships between associated fields based on location (adjacent) and past and present human-mediated activities (primary and secondary contact)

These relationships are important and help determine the pathogen risk exposure of associated fields based on the field classification system described below. Find details on the investigation and tracing of associated fields in Appendix A.

During an investigation, the CFIA will delimit the extent of the infestation through soil sampling and analysis of all associated fields and implement phytosanitary measures to help mitigate risk and facilitate long-term control of the index field or field of concern and all identified associated fields.

Index field

A field where 2 or more spores of S. endobioticum or symptomatic tuber(s) have been detected and confirmed by the CFIA.

Index – viability confirmed

An index field where 2 or more S. endobioticum spores have been detected and where symptomatic tuber(s) or plant parts have been observed either directly from the field or in laboratory bioassays for fields with direct linkages to the index field (for example, common equipment, soil movement, seed potato movement)

Index – viability not confirmed

An index field where 2 or more spores of S. endobioticum have been detected but where there is no confirmed symptomatic tuber(s) or plant parts for the index field or any fields with direct linkages to the index field (for example, common equipment, soil movement, seed potato movement).

Assessment of index field – viability not confirmed

An "index field – viability not confirmed" will be subject to the phytosanitary measures for index fields. A full trace-out will occur and all field categories will be regulated as an "index field – viability confirmed."

Soil collected from the "index – viability not confirmed" field will undergo laboratory bioassay in an effort to generate potato wart symptoms to confirm viability and to multiply inoculum for use in determining the potato wart pathotype present in the field. Up to 5 rounds of consecutive bioassay will be conducted on the original soil samples using protocols based on European and Mediterranean Plant Protection Organization OEPP / EPPO Bulletin 47. Potato wart symptoms on any growing part of the potato (in other words, seed tuber, mother plant or progeny tubers) will be considered evidence of a viable S. endobioticum population and the field status will be changed to "index- viability confirmed'. If, following 5 rounds of bioassay, there are no observed potato wart symptoms, the soil from the bioassay pots will be analysed to confirm if S. endobioticum spores were present in areas of the field where it was not detected during the original analysis. Spores collected from the analysis will be used for a final (6th) round of bioassay. If there are detectable potato wart symptoms on tubers or plant parts it will be considered evidence of a viable S. endobioticum population and the field status will be changed to 'index – viability confirmed'. Detection of potato wart symptoms on potato tubers or plant parts in any field with direct linkages to the index field will also result in an 'index – viability confirmed' status.

Following this process, should no confirmation of spore viability be demonstrated (in the original index field or in fields with direct linkages to the index field via common equipment, soil movement, or seed potato movement), the field will be reclassified as a "primary contact" field and will follow the process for release of phytosanitary measures for primary contact fields. All associated fields that were categorized during the trace-out will be released from all phytosanitary measures (unless associated with another "index field – viability confirmed").

Adjacent field

A field directly bordering an index field and not separated from the index field by a physical barrier of more than 15 metres in width, such as a:

  • tree line
  • fence line
  • permanent waterway
  • ditch
  • road or permanent lane
  • berm or permanent irrigation track

and where, during investigation soil sample analysis, no S. endobioticum spores were detected.

Primary contact field

A field where, during investigation soil sampling analysis, no S. endobioticum spores are detected but where there may have been exposure to S. endobioticum spores via at least one of the following pathways:

  • Direct movement of machinery, equipment, and conveyances after use in an index field without a documented freedom from soil activity as described in an on-farm preventive control plan (PCP) and documented in associated records
  • Planting of propagative host material (for example, seed potatoes) originating from an index field
  • Transfer of tare soil originating from an index field
  • Application of potato waste materials, including wastewater effluent, sludge and solid organic materials, originating from an index field
  • Secondary contact fields with connections to multiple potato wart investigations as determined following case-by-case evaluations
    • only the equipment cleanliness standard will be required for secondary contact fields
  • A former "index-viability not confirmed" field where neither symptomatic tubers nor plant parts were detected as described above.

Secondary contact field

A field exposed to an index field through indirect movement (after initial movement to a primary contact field) of common machinery, equipment, and conveyances without a documented freedom from soil activity as described in an on-farm PCP and documented in associated records. During investigation soil sample analysis, no potato wart spores were detected.

Field of concern

A field where only one spore of S. endobioticum has been detected and confirmed via both morphological and molecular analyses.

Quarantine disposal site

A parcel of land designated for disposal of tare soil or liquid or solid waste material that originated from potato wart restricted field(s). These sites will be under official control and may be used for official disposal of regulated material.

Farm biosecurity, phytosanitary measures and restricted field use

The purpose of establishing phytosanitary measures on the index field and all associated fields is to help contain and control the pest and prevent further spread of the pest to other fields. These controls and movement restrictions will remain in place until a field has been released from phytosanitary measures, following the land release protocols described in this response plan.

The standard for farm-level preventive control plans (PCP) is based on the principles included in the National Farm-Level Biosecurity Standard for Potato Growers. PCP plans will be developed and implemented by individual farm units and be tailored to address their needs. Consult Appendix B for more information.

The PCP must detail:

  • farm-level risk reduction (in other words, biosecurity) practices implemented to help contain, control and prevent the risk of spread of potato wart from restricted fields that are part of the farm unit
    • records should be maintained to document these biosecurity practices
  • procedures for informing the CFIA of critical information including changes in ownership or land users and annual cropping information
  • traceability records related to host crop production (for example, source of seed potatoes, shipment details) and equipment movement.

An implemented PCP will facilitate the issuance of a written authorization to permit the movement of regulated things, including machinery, equipment, conveyances, and potatoes.

To obtain written authorization from the CFIA to move regulated things, and further mitigate against the spread of S. endobioticum spores from a restricted field (including fields of concern), land users must develop and implement a PCP for their farm unit. For more information, consult Appendix B.

The PCP must be tailored to meet the needs of each farm unit and incorporate biosecurity measures that include traceability, segregation of restricted products and things, movement of product, machinery, implements, and conveyances, and waste disposal elements.

Phytosanitary measures and restricted field use: Fields with host crop production included in the rotation

Index field

A written authorization is required to move all regulated things from the index field. Conditions must be met to obtain the required written authorization.

A person in care and control of an index field also requires an implemented PCP as described in Appendix B that incorporates biosecurity, traceability, product and equipment movement, and waste disposal elements for their farm unit.

Production requirements and end uses

The production of all potatoes, root crops and plants, and plant parts for propagation other than botanical seed is prohibited for a minimum of 20 calendar years from the year of potato wart detection.

The production of other above-ground crops (for example, corn, wheat, and hay) is permitted, but the commodity and all machinery, equipment, and conveyances must be free from soil when leaving the index field.

Equipment cleaning requirements

A cleaning area separated from the field soil (for example, gravel or similar product) is required at the entrance/ exit of an index field to facilitate equipment cleaning. Run-off from the cleaning area must not contaminate other fields.

All machinery, equipment, and conveyances must be cleaned free from soil and plant debris and authorized to move by the CFIA prior to exiting the field. See PI-016: Procedure for inspecting regulated articles for freedom from soil, plants, plant parts and related matter for details on freedom from soil requirements for more information.

Soil and waste disposal requirements

All plant material that is contaminated with soil can only be moved from the field if a written authorization is obtained from the CFIA. Waste material including soil and potato waste must be returned to the field of origin or disposed of in an approved manner as described in the farm unit PCP.

While it is acknowledged that disposal of soil and waste material back onto an index field may be the only feasible option, it may re-introduce potato wart spores to the field and therefore is not recommended when other options are available.

Tuber movement

If there are potato tubers associated with the index field in the year that potato wart is detected, including harvested tubers already in storage or mixed with tubers from other fields, they must be handled and processed or disposed of in a manner approved by the CFIA.

Release from phytosanitary measures

Release of adjacent fields from the response plan's phytosanitary measures requires a minimum of 4 potato crops and the 4th potato crop must be a susceptible potato variety.

Host plant production is prohibited for 20 calendar years from the year of potato wart detection. Following this period, the index field may be assessed at landowner request or land user request with landowner consent using the following procedure:

20 calendar years after the initial detection of potato wart in the field

Soil will be collected and undergo:

  • laboratory analysis for S. endobioticum spores
  • laboratory bioassay for tuber symptom development if S. endobioticum spore counts in the soil are less than 5 spores/gram of soil.

If no detection of potato wart symptoms on potato tubers or plant parts is observed in the laboratory bioassay, the phytosanitary measures on the field will be amended to permit production of potato varieties designated as resistant to the pathotype of S. endobioticum that was detected/confirmed in the index field (or to all known Canadian pathotypes).

If S. endobioticum spore counts of 5 spores/gram of soil or more or potato wart symptoms are detected following bioassay, all phytosanitary measures will remain in place including the prohibition of host crop production. If requested by the landowner or land user with landowner consent, the field will be reassessed in no less than 5 calendar years.

Freedom from soil requirements remain in place.

All potato crops authorized for production in an index field must be processed and handled in a facility with a valid compliance agreement to mitigate risks associated with identified waste streams. Consult QSM-09: Quality Management System Requirements for Facilities Receiving and Handling Regulated Non-Propagative Potatoes and Related Potato Articles, Including Associated Soil for guidance on establishing a compliance agreement.

Soil will be collected following each authorized potato crop and laboratory analysis for S. endobioticum spores will be conducted.

  • If S. endobioticum spore counts of 5 spores/gram or more are detected, the phytosanitary measures on the field will be amended to include prohibition of potato production. The field will be eligible for re-assessment in not less than 5 years calendar years.
27 calendar years (minimum) after the initial detection of potato wart

A minimum of 27 calendar years after the initial detection of potato wart, and after a minimum of 3 resistant potato crops with post-harvest soil sampling and analysis with no potato wart spores detected on the third or subsequent soil analysis and a laboratory bioassay with no observed potato wart symptoms, an index field may be considered for additional assessment on a case-by-case basis.

If supported by the case-by-base assessment and available scientific information, the phytosanitary measures on the field will be amended to:

  • remove the requirement for freedom from soil
  • permit production of non-host plants and plant parts for propagation
  • permit production of non-host root crops
  • continue to permit the production of resistant potato varieties for processing end use in the province of origin
  • implementation of a PCP continues to be required.
40 calendar years (minimum) after the initial detection of potato wart

A minimum of 40 calendar years after the initial detection of potato wart, a final soil sample and analysis followed by laboratory bioassay will be completed. If there is no further evidence of potato wart spores in the field, the production of potato wart resistant varieties for direct human consumption (table stock) may be permitted.

The index field will remain a restricted field indefinitely and the following restrictions will remain in place:

  • potato production is limited to potato varieties designated as resistant to the pathotype of S. endobioticum that was detected / confirmed in the index field (or to all known Canadian pathotypes)
  • seed potato production is prohibited
  • implementation of a PCP continues to be required
  • equipment cleanliness is recommended
  • potatoes produced in the field will continue to be considered "restricted' for the purposes of domestic movement and export.

Adjacent field

A written authorization is required to move all regulated things from the adjacent field. Conditions must be met to obtain the required written authorization.

A person in care and control of an adjacent field also requires an implemented PCP as described in Appendix B which incorporates biosecurity, traceability, product and equipment movement, and waste disposal elements for their farm unit.

Initial production requirements and end-uses
  • The production of seed potatoes is prohibited indefinitely.
  • Potatoes or root crops produced in adjacent fields must only be used for processing or table stock / direct consumption end uses. Planting resistant potato varieties is recommended.
  • All potato crops or root crops produced in the adjacent field must be processed and/ or handled in a facility with a valid compliance agreement to control identified waste streams. Consult QSM-09: Quality Management System Requirements for Facilities Receiving and Handling Regulated Non-Propagative Potatoes and Related Potato Articles, Including Associated Soil for guidance on establishing a compliance agreement.
  • The movement of plants and plant parts for propagation except botanical seed is prohibited until the associated index field has been released from all phytosanitary measures outlined in the response plan (except those related to the indefinite prohibition on seed potato production).
  • The production of other above-ground crop kinds (for example, corn, wheat, hay) is permitted, but the commodity must be free of soil when leaving the field.
Equipment cleaning requirements

A cleaning area separated from the field soil (gravel or similar product) is required at the entrance/exit of an adjacent field to facilitate equipment cleaning while freedom from soil requirements are in place. Run-off from the cleaning area must not contaminate other fields.

All machinery, equipment, and conveyances must be cleaned free from soil and plant debris and authorized to move by the CFIA prior to exiting the field. See PI-016: Procedure for inspection regulated articles for freedom from soil, plants, plant parts and related matter for more information.

Soil and waste disposal requirements

All plant material that is contaminated with soil can only be moved from the field if a written authorization is obtained from the CFIA. Waste material including soil and potato waste must be returned to the field of origin or disposed of in an approved manner as described in the farm unit's PCP.

Release from phytosanitary measures

Release of primary contact fields from the response plan's phytosanitary measures requires a minimum of potato crops and the fourth potato crop must be a potato wart susceptible potato variety.

Adjacent field will be assessed for risk of natural spread of potato wart (for example, via natural water flow) from the neighbouring index field to confirm that lifting of phytosanitary measures is possible.

If the risk of natural spread is deemed low, adjacent fields may be assessed at the written request of the landowner or land user with the consent of the landowner, using the following procedure:

  • Production of one crop of potatoes (following the investigation soil sampling and analysis) followed by:
    • soil sampling and laboratory analysis for S. endobioticum spores
    • tuber visual inspection (if the potato variety planted is not considered resistant to the pathotype of S. endobioticum that was detected in the associated index field)
  • If potato wart is not detected, the phytosanitary measures on the field will be amended to the following:
    • Remove the freedom from soil requirement.
    • All machinery, equipment, and conveyances must meet the equipment cleanliness definition for soil prior to exiting the field as per the procedures described in the farm unit's PCP.
      • A farm unit's PCP may include additional details on risk mitigation associated with soil movement and may include moving equipment from lowest to highest risk fields within the farm unit with a more thorough cleaning step before the equipment returns to lower risk fields.
    • Potatoes leaving the farm must be sent to a facility with a compliance agreement. Product may move directly to a facility without a compliance agreement in place if it has been dry-brushed on farm and sent directly to a facility within the province of origin.
    • Implementation of a PCP continues to be required.
  • Production of 2 additional potato crops.
  • Production of one crop of a potato variety designated as susceptible to the pathotype of S. endobioticum that was detected / confirmed in the associated index field (or to all known Canadian pathotypes). This will be followed by:
    • soil sampling and laboratory analysis for S. endobioticum spores
    • tuber visual inspection

Following the assessment procedures, if S. endobioticum spores have not been detected, all phytosanitary measures outlined in the response plan will be removed from the field, except for the prohibition on seed potato production which will remain on the field indefinitely. An implemented PCP is recommended.

The final host crop produced while the field is restricted as an adjacent field must meet the same phytosanitary requirements as the previous 2 crops:

  • processing or tablestock use only
  • must be sent to a facility with a compliance agreement compliance agreement or dry-brushed on farm and sent directly to facility within the province of origin

The subsequent crop will be considered produced in an "unrestricted field' for the purposes of domestic movement and export.

Primary contact field

A written authorization is required to move all regulated things from the primary contact field. Conditions must be met to obtain the required written authorization.

A person in care and control of a primary contact field is also required to have an implemented PCP as described in Appendix B which incorporates biosecurity, traceability, product and equipment movement, and waste disposal elements for their farm unit.

Initial production requirements and end-use
  • Seed potatoes will not be certified on primary contact fields until all specific phytosanitary measures have been removed from the field. Potatoes and root crops produced in the primary contact field must only be used for processing or table stock / direct consumption purposes. Planting of resistant varieties is recommended.
  • All potato crops or root crops produced in the primary contact field must be processed and / or and handled in a facility with a valid compliance agreement to control identified waste streams. Consult QSM-09: Quality Management System Requirements for Facilities Receiving and Handling Regulated Non-Propagative Potatoes and Related Potato Articles, Including Associated Soil for guidance on establishing a compliance agreement.
  • The movement of plants and plant parts for propagation except botanical seed is prohibited until the field is released from all phytosanitary measures outlined in the response plan.
  • The production of other above-ground crop kinds (for example, corn, wheat, hay) is permitted, but the commodity must be free of soil when leaving the field.
Equipment cleaning requirements

A cleaning area separated from the field soil (gravel or similar product) is required at the entrance/exit of a primary contact field to facilitate equipment cleaning while freedom from soil requirements are in place. Run-off from the cleaning area must not contaminate other fields.

All machinery, equipment, and conveyances must be cleaned free from soil and plant debris, and authorized to move prior to exiting the field See PI-016: Procedure for inspection regulated articles for freedom from soil, plants, plant parts and related matter for more information.

Soil and waste disposal requirements

All plant material that is contaminated with soil can only be moved from the field if a written authorization is obtained from the CFIA. Waste material including soil and potato waste must be returned to the field of origin or disposed of in an approved manner as described in the farm unit's PCP.

Release from phytosanitary measures

Primary contact fields may be assessed at the written request of the landowner or land user with consent of the landowner, using the following procedure:

  • Production of one crop of a potatoes (after the investigation soil sampling and analysis) followed by:
    • Soil sampling and laboratory analysis for S. endobioticum spores.
    • Tuber visual inspection (if the potato variety planted is not considered resistant to the pathotype of S. endobioticum that was detected in the associated index field).
  • If potato wart is not detected the phytosanitary measures on the field will be amended as follows:
    • Remove the requirement for freedom from soil.
    • All machinery, equipment, and conveyances must meet the equipment cleanliness definition for soil prior to exiting the field as per the procedures described in the farm unit's PCP.
      • A farm unit's PCP may include additional details on risk mitigation associated with soil movement and may include moving equipment from lowest to highest risk fields within the farm unit with a more thorough cleaning step before the equipment returns to lower risk fields.
    • Potatoes leaving the farm must be sent to a facility with a compliance agreement. Product may move directly to a facility without a compliance agreement in place if it has been dry-brushed on farm and sent directly to a facility within the province of origin.
    • Implementation of a PCP continues to be required.
  • Production of 2 additional potato crops
  • Production of one crop of a potato variety designated as susceptible to the pathotype of S. endobioticum that was detected / confirmed in the associated index field (or to all known Canadian pathotypes). This will be followed by:
    • soil sampling and laboratory analysis for S. endobioticum spores
    • tuber visual inspection

Following the assessment procedures, if S. endobioticum has not been detected, all phytosanitary measures outlined in the response plan will be removed from the field.

The final host crop produced while the field is restricted as a primary contact field must meet the same phytosanitary measures as the previous 2 crops

  • processing or tablestock use only
  • must be sent to a facility with a compliance agreement or dry-brushed on farm and sent directly to a facility within the province of origin.

The subsequent crop will be considered produced in an "unrestricted field' for the purposes of domestic movement and export.

Secondary contact fields that have been elevated to primary contact status

Requirements specific to secondary contact fields that have been elevated to primary contact status due to connections to multiple potato wart investigations:

  • Freedom from soil is not required.
  • All machinery, equipment, and conveyances must meet the equipment cleanliness definition for soil prior to exiting the field as per the procedures described in the farm unit's PCP.
  • Potatoes leaving the farm unit must be sent to a facility with a compliance agreement. Product may move directly to a facility without a compliance agreement in place if it has been dry-brushed on farm and sent directly to a facility within the province of origin.
  • Following categorization of the field as a primary contact field, the field may be assessed at the written request of the landowner or land user with the consent of the landowner, using the following procedure:
  • Production of one crop of potatoes (after the investigation soil sampling and analysis) followed by:
    • Soil sampling and analysis for S. endobioticum spores.
    • Tuber visual inspection (if the variety planted is not considered resistant to the pathotype of S. endobioticum that was detected in the associated index fields).
  • Production of two additional potato crops.
  • Production of one crop of a potato variety designated as susceptible to the pathotype of S. endobioticum that was detected / confirmed in the associated index field (or to all known Canadian pathotypes). This will be followed by:
    • Soil sampling and laboratory analysis for S. endobioticum spores.
    • Tuber visual inspection.
  • Following the assessment procedures, if S. endobioticum has not been detected, all phytosanitary measures outlined in the response plan will be removed from the field.

The final host crop produced while the field is restricted as a primary contact field must meet the same phytosanitary measures as the previous 2 crops:

  • processing or tablestock use only
  • must be sent to a facility with a compliance agreement or dry-brushed on farm and sent directly to facility within the province of origin).

The subsequent crop will be considered produced in an "unrestricted field' for the purposes of domestic movement and export.

Secondary contact field

A written authorization is required to move all regulated things from the secondary contact field. Conditions must be met to obtain the required written authorization.

A person in care and control of a secondary contact field also requires a PCP as described in Appendix B which incorporates biosecurity, traceability, product and equipment movement, and waste disposal elements for their farm unit.

Initial production requirements and end-use

Seed potatoes will not be certified on secondary contact fields until all specific phytosanitary measures have been removed from the field.

Potatoes or root crops must only be used for processing or table stock/ direct consumption purposes. Planting of resistant varieties is recommended.

The potatoes or root crops originating from a secondary contact field must be sent to a facility with a compliance agreement. Product may move directly to a facility without a compliance agreement in place if it has been dry-brushed on farm and sent directly to a facility within the province of origin. The movement of plants and plant parts for propagation except botanical seed will not be authorized for movement from the secondary contact field until the field is released from all phytosanitary measures outlined in the response plan.

Equipment cleaning requirements

All machinery, equipment and conveyances must meet the equipment cleanliness definition for soil prior to exiting the field as per the procedures described in the farm unit's PCP.

  • A farm unit's PCP may include additional details on risk mitigation associated with soil movement and may include moving equipment from lowest to highest risk fields within the farm unit with a more thorough cleaning step before the equipment returns to lower risk fields.
Soil and waste disposal requirements

All plant material that is contaminated with soil can only be moved from the field if a written authorization is obtained from the CFIA. Soil and waste must be handled and disposed of as described in the PCP.

Release from phytosanitary measures

Release of secondary contact fields from the response plan's phytosanitary measures requires a minimum of 2 potato crops.

Secondary contact fields may be assessed at the written request of the landowner or land user with the consent of the landowner, using the following procedure:

  • Production of 2 crops of potatoes (after the investigation soil sampling and analysis.) The second crop will be followed by:
    • Soil sampling and laboratory analysis for S. endobioticum spores.
    • Tuber visual inspection (if the potato variety planted is not considered resistant to the pathotype of S. endobioticum that was detected in the associated field).

Following the assessment procedures, if S. endobioticum has not been detected all phytosanitary measures outlined in the response plan will be removed from the field.

The final host crop produced while the field is restricted as a secondary contact field must meet the same phytosanitary measures as the previous 2 crops:

  • processing or tablestock use only
  • must be sent to a facility with a compliance agreement or dry-brushed on farm and sent directly to facility within the province of origin

The subsequent crop will be considered produced in an "unrestricted field' for the purposes of domestic movement and export.

Field of concern

A field where only one S. endobioticum spore is detected and confirmed, via morphology and molecular analysis, will be designated a "field of concern".

If a field of concern is not already classified as a primary contact field, equivalent risk mitigation measures will be applied, including the requirement for freedom from soil and restrictions on potato crop usage. A farm unit PCP is required and potato production will not be permitted while the field is classified as a field of concern.

  • Intensified soil sampling (in other words, higher rate than original sampling method) of the field of concern will be prioritized. The method of soil sampling will be determined based on the method of collection of the original sample in other words, tare or grid. If one or more additional spores is detected, the field will be classified as an "index – viability not confirmed" field.
    • If the detection threshold (symptomatic tuber(s) and/or 2 spores confirmed via 2 methods) is not met following laboratory analysis of the soil from the intensified sampling the field will remain under restrictions equivalent to a primary contact field and will follow the process from release for phytosanitary measures for primary contact fields described above including freedom from soil and 2 additional rounds of sampling, one of which must follow a susceptible potato crop.

Phytosanitary measures and restricted field use: Fields with no host crop production included in the rotation

Quarantine disposal site

A quarantine disposal site is designated for disposal of soil and liquid and solid waste originating from restricted fields and crops. All machinery, equipment and conveyances must be cleaned free from soil and plant debris and authorized to move by the CFIA prior to exiting these sites. See PI-016: Procedure for inspection regulated articles for freedom from soil, plants, plant parts and related matter for more information.

Quarantine disposal sites will not be considered for release from phytosanitary measures outlined in the response plan until a minimum of 20 years after the last exposure to potato wart waste from any restricted field. Sites will be assessed on a case-by-case basis to determine whether release from phytosanitary measures is possible and what specific steps must be followed.

Restricted non-agricultural land

Restricted non-agricultural land is land that is regulated for potato wart but has subsequently been altered, or based on its inherent characteristics, been permanently removed from agricultural use (for example, paved roads, recreational areas or commercial and residential development).

To have the restricted non-agricultural land considered for release from phytosanitary measures outlined in the response plan, the landowner (or land user, with consent of the landowner) must apply to the CFIA. Soil cannot be removed from the site without written permission and freedom from soil requirements may be applied to equipment leaving the site.

This land will be assessed on a case-by-case basis to determine whether release from phytosanitary measures is possible and to ensure the process of converting the land to other uses is completed in a way that does not pose a risk of pest spread.

The CFIA must have confirmation that the field has been permanently removed from agricultural production.

Restricted agricultural fields

Partial release of index fields

Index fields no longer in host crop, root crop or plants and plant parts for propagation production (except botanical seed) may be assessed for partial release from phytosanitary measures outlined in the response plan at the written request of the landowner or land user with consent of the landowner following a minimum of 50 years of documented non-host crop production.

Partial release of adjacent and primary contact fields

Adjacent and primary contact fields no longer in host crop, root crop or plants and plant parts for propagation (except botanical seed) production may be assessed for partial release from phytosanitary measures at the written request of the landowner or land user with consent of the landowner.

Fields will be assessed on a case-by-case basis to determine whether release from phytosanitary measures outlined in the response plan is possible (including the risk of natural spread of potato wart into adjacent fields).

These fields may be assessed using the following procedure.

Soil sampling followed by:

  • laboratory analysis for S. endobioticum spores
  • laboratory bioassay

If potato wart is not detected, then phytosanitary measures on the field may be amended to:

  • remove the requirement for freedom from soil.
    • All machinery, equipment, and conveyances must meet the equipment cleanliness definition for soil prior to exiting the field as per the procedures described in the farm unit's PCP.
  • host crop, root crop and plants and plant parts for propagation (except botanical seed) production is not permitted until the field has been out of host crop production for a minimum of 50 years.
  • implementation of a PCP continues to be required until the field is released from all phytosanitary measures.
  • if host crop, root crop or plants and plant parts for propagation (except botanical seed) are planted in the field after the field has been released from phytosanitary measures including freedom from soil, the initial production requirements outlined above for adjacent and primary contact fields will immediately be re-instated on the field.
Release of secondary contact fields

Secondary contact fields no longer in host crop, root crop or plants and plant parts for propagation (except botanical seed) production may be assessed for release from phytosanitary measures at the written request of the landowner or land user with the consent of the landowner.

Fields that have not produced host crops for a minimum of 25 years may be assessed on a case-by-case basis to determine whether release from phytosanitary measures outlined in the response plan is possible.

These fields may be assessed using the following procedure:

  • soil sampling followed by:
    • laboratory analysis for S. endobioticum spores.
    • following the assessment procedures, if S. endobioticum has not been detected all phytosanitary measures outlined in the response plan will be removed from the field.

Appendix A: Investigation and trace-out procedures of associated fields following a detection

Consult Appendix A: Investigation and trace-out procedures of associated fields following a potato wart detection.

Appendix B: Preventative control plan

Consult Appendix B: How to build a preventative control plan for a potato wart restricted field.

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