RMD-13-04: Consolidated Pest Risk Management Document for pest plants regulated by Canada
Appendix 8B: Risk Management Considerations for Microstegium vimineum (Japanese stiltgrass)
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- Values at Risk
- Potential Mitigation Measures for Natural Means of Dispersal
- Potential Mitigation Measures for Intentional Introduction Pathways
- Potential Mitigation Measures for Non-intentional Introduction Pathways
Values at Risk
Microstegium vimineum prefers wetlands and forested areas. It is difficult to assign a value to the biodiversity of our Canadian landscape
Potential Mitigation Measures for Natural Means of Dispersal
No potential mitigation measures for natural means of dispersal are highlighted herein for Microstegium vimineum. Microstegium vimineum has disturbed many areas of the New England States and is approaching the Canadian border. Regulating the dispersal by surface water runoff and the migration of wild animals is nearly impossible to control.
Potential Mitigation Measures for Intentional Introduction Pathways
No intentional pathways were identified
Potential Mitigation Measures for Non-intentional Introduction Pathways
Field Crops Not Intended for Propagation
Previous imports
- Based on the information available in the CFIA's Import Permit System, Import Retrieval System, and information compiled at the CFIA's Import Service Centres, Microstegium vimineum has not been recently imported into Canada.
- Birdfeed has been reported in EPPO (2008) as a possible pathway for the introduction of Microstegium vimineum, although no such North American references were found. Birdseed can be imported as mixes or as lots of pure grain. Lots of pure grain are imported to Canada, then mixed, packaged and sold on the domestic retail market. Lots for domestic or wild birds are generally composed of several kinds of grains, whole or broken. More than 30 crop species are used for birdseed mixes, some of the major birdseed component crops include millet, sorghum and niger.
Potential risk mitigation measures
Regulate Microstegium vimineum as a quarantine pest under the Plant Protection Act. Add this species to the List of Pests Regulated by Canada (CFIA 2009) in order to:
- prevent the importation, movement, and cultivation of this species in Canada.
- enable inspectors to take appropriate action for the purposes of eradicating the pest or preventing its spread Footnote 1.
Regulatory actions under the Plant Protection Act could include one or more of the following:
- Exporters could be required to provide a Phytosanitary Certificate with or without an Additional Declaration stating freedom from Microstegium vimineum.
- Recognition of Pest Free Areas – if Microstegium vimineum can be shown to be absent in the country/state/region from which the field crop product was propagated, then risk is negligible and additional phytosanitary requirements may be waived.
- A Permit to Import indicating specific import requirements and conditions for the pest status, handling and use of the commodity could be required. It is the importer's responsibility to apply for and obtain the permit.
- Provisions for importation of grain contaminated with Microstegium vimineum for research, processing, industrial or educational uses under a section 43 permit on a case-by-case basis.
- Phytosanitary measures may be waived for those commodities that have been treated or processed such that the risk of introduction of Microstegium vimineum has been reduced to an acceptable level. End uses impact risk and may therefore impact required risk mitigation measures. For example, field crop commodities containing Microstegium vimineum imported for milling (grinding) into flour would have lower risk than that coming in for direct use as pastured/rangeland animal feed. For milling, risk mitigation measures would include: the milling itself and proper disposal (incineration, grinding or deep burial) of anything removed from the commodity prior to the milling process. The same is true of field crop commodities imported for processing into feed (pelleting, crushing, etc.). Commodities imported for human consumption or direct feeding to livestock would have greater risk and could require treatment to render the grain unviable. Treatments, where applicable, such as heat (i.e. where heat would not compromise quality of grain for intended end use), grinding, pelletizing could be used prior to import or post-entry.
- All risk mitigation measures for field crop commodities containing Microstegium vimineum must be taken with consideration for requirements/measures for pests other than plants (e.g. pathogens and insects).
- Combine harvesting equipment will likely remove the majority of weed seeds out of the grain during harvest. The seeds are unlikely to enter Canada in field crops not intended for propagation.
Trade implications
- Exporting countries may have to devote resources towards inspection and issuance of phytosanitary certificates. Laboratories in exporting countries will need to be able to identify seeds of Microstegium vimineum. Exporters will need to ensure freedom of Microstegium vimineum in field crop shipments, otherwise CFIA can refuse import.
- Potential for reduction and/or loss of some import markets for Canada should exporting countries be unable to meet proposed phytosanitary requirements.
- Not controlling import and spread of the species may result in infestations of field crops for export; if the importing country prohibits that species, market access for Canadian commodities could be compromised.
Cost-effectiveness and Feasibility
- Only a low proportion of imported grain is likely to contain Microstegium vimineum seeds, which reduces the impact of regulating this pathway. This measure is already in place for other pests regulated by Canada. Minor costs will be incurred for identification training for inspectors.
- Microstegium vimineum is easily confused with Leersia virginica Willd., a native grass species. Confusion arises in the field as these two species often are found growing together, have similar leaf sizes and shapes and are similar in overall appearances.
- The seeds of these two species are readily distinguishable as the plants belong to different tribes with very different floral morphologies. This mitigation measure should be feasible and minor costs will be incurred for identification training for inspectors.
Hay and Straw
Previous imports
- The total value of hay and straw imports was approximately $13 million in 2008 for "Swedes, Mangolds, Fodder Roots, Hay, Clover, Sainfoin, Forage Kale, Pellets" (HS 121490) and "Cereal Straw and Husks, Unprepared" (HS 121300). Ninety-seven percent of this value originated from the United States (Industry Canada 2009).
- Between 2006 and 2008 and using the above HS codes, the approximate value of hay and straw imports was $2.2 million from the United States, India, China and Japan, where Microstegium vimineum is present (Industry Canada 2009).
- Between 2004 and 2008 and using the above HS codes, the majority of hay and straw (approximate total of $44 million) was imported from Washington where Microstegium vimineum is not present. This represents the majority of hay and straw imported into Canada (Industry Canada, 2009).
- The level of risk associated with imports of hay and straw into Canada is relatively low since they originate primarily from areas where Microstegium vimineum is not present (i.e., Washington state).
Potential risk mitigation measures
Regulate Microstegium vimineum under the Plant Protection Act as a quarantine pest by placing it on the List of Pests Regulated by Canada. This will:
- Enable inspectors to take appropriate action for the purposes of eradicating the pest or preventing its spread Footnote 2.
- Require importers to obtain a Phytosanitary Certificate with or without an Additional Declaration stating freedom from Microstegium vimineum.
- A Permit to Import indicating specific import requirements and conditions for the pest status, handling and use of the commodity could be required. It is the mporter's responsibility to apply for and obtain the permit.
- For hay or straw intended for use as a biofuel stock, heat treatment or pelletization could be required.
Trade implications
Exporting countries will need to devote resources towards inspection of hay and straw commodities and issuance of phytosanitary certificates. Inspectors in exporting countries need to be able to identify seeds of Microstegium vimineum that could be associated with hay and straw. Exporters need to ensure freedom of Microstegium vimineum in hay and straw, otherwise CFIA can refuse import.
Cost-effectiveness and Feasibility
This measure will facilitate trade of hay and straw with the State of Alabama, Connecticut and Massachusetts, where Microstegium vimineum is regulated. This measure is already in place for other pests regulated by Canada. Minor costs will be incurred for training of inspectors
Vehicles and Used Farm Machinery
Previous imports
- A considerable volume of vehicles cross the U.S.-Canada border every year.
- Information is not available on the volume of imports of used farm machinery.
Potential Risk mitigation measures
Enforcement of Directive 95-26: "Phytosanitary requirements for soil and related matter, alone or in association with plants" (CFIA 2008).
In 2003, the Canada Border Services Agency (CBSA) assumed responsibility for the initial import inspection services in respect to the Acts and Regulations administered by the CFIA to the extent that they are applicable at Canadian border points. The inspection of goods that may be contaminated with soil are among the responsibilities that were transferred to the CBSA in 2003. The Food, Plant and Animals Programs Product of the CBSA is currently finalizing its Standard Operating Procedures (SOP) concerning the "Inspection of Imported Goods Potentially Contaminated with Soil." This SOP provides the CBSA's Border Services Officers with formal procedures for the inspection and disposition of goods that may be contaminated with soil, including used agricultural machinery and vehicles.
Nursery Stock with soil
Previous imports
The total value of imports of nursery stock was $173 million in 2008 (Industry Canada 2009) with approximately 80% of that value originating from the United States (Industry Canada, 2009; based on data using HS 0602 – Other Live Plants (incl. Roots), Cuttings and Slips; Mushroom Spawn). Approximately 40% of the imports from the United States originate from states where Microstegium vimineum is present (e.g., Florida, Pennsylvania, Tennessee, New York, Ohio)
Potential Risk mitigation measures
- Phytosanitary measures, such as nursery certification programs and "pest-free places of production" may be considered if warranted.
- Revision of D-95-26 (CFIA 2008b)to include Microstegium vimineum within its scope (i.e., sections 3.0 and 6.0).
Trade implications
- Soil and related matter is already a highly regulated commodity, and as such trade implications should be relatively minimal. However, the addition of a requirement for declaration of freedom from Microstegium vimineum from those states where it is present would increase the requirements already in place.
Cost-effectiveness and Feasibility
Nursery Stock from infested areas where Microstegium vimineum is present may be imported under the condition that the plants are bare root. Alternatively, using soil free growing media may be a condition of entry imposed on these imports. This mitigation measure should be feasible and minor costs will be incurred.
Used Recreational Equipment and Clothing
Previous imports
- Numerous travelers cross the U.S.-Canada border all year round or fly into Canada from various countries, but foreign travelers usually bring clean clothes with them into Canada. Only Canadians coming back into Canada from a site where Microstegium vimineum is prevalent could potentially carry seed or propagules attached on their clothes. The risk depends on the species' habitats and if these sites at risk are usually visited by travelers.
- Travelers entering Canada by land are more likely to travel with their pet and recreational equipment. The risk will depend on the presence of the species along the Canadian border.
Risk mitigation measures
Increase public awareness of the regulation and the risk posed by this plant and distribute awareness material at border crossings to the public
- Not considered effective by itself if the risk is high, but is a viable action if the level of risk is low.
- Monitor for the presence of Microstegium vimineum in Canada where there are suitable conditions for its establishment.
Trade implications
There are no trade implications anticipated.
Cost-effectiveness and Feasibility
- The most likely pathway for entry for Microstegium vimineum is via attachment to the fur of animals or on human clothes or in mud on tires or hiking boots. The insidious nature of these main pathways could undermine phytosanitary measures that would be put in place to prevent the entry of the species through other pathways.
- Certain states in which Microstegium vimineum is found are adjacent to the Canadian border, in particular Ohio, Pennsylvania and New York. However, with the exception of presence noted in Pennsylvania in a county proximate to Lake Erie, reports from the said states are from counties not adjacent to the border (USDA Plants Database).
- Given the challenge in determining movement of individuals and wildlife from the United States, then within Canada, monitoring for Microstegium vimineum would need to be conducted at key locations not necessarily restricted to border locations. Some training of survey staff would be required.
- A combination of public awareness campaigns and monitoring efforts could serve, respectively, to lower the risk that Microstegium vimineum is introduced through these pathways in question, and to verify the effectiveness of any phytosanitary measures that would be put in place.
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