Regulating invasive plant species

CHANGES UNDER THE PLANT PROTECTION ACT

FOLLOWING RISK ANALYSES and stakeholder consultations, the Canadian Food Inspection Agency (CFIA) has decided to regulate several invasive plant species under the Plant Protection Act. These species are either not yet present in Canada, or present, but not widespread. If they are placed under official control and detected early, efforts at eradication have a good chance of being successful. The potential negative economic impact of these species is high and they are known to have negative impacts on the environment, economy and/or society in the areas they invade.

PHOTO: ALOPECURUS MYOSUROIDES (SLENDER FOXTAIL)

AEGILOPS CYLINDRICA (JOINTED GOATGRASS)
Aegilops cylindrica is native to eastern Europe and western Asia, and is a serious weed in the western United States where it was introduced around the turn of the last century as a contaminant in winter wheat (Triticum aestivum L.) seed from Russia. The weed lowers crop yields through direct competition, reduces harvesting efficiency, and lowers crop quality by contaminating harvested grain. In the US, it infests more than five million acres of winter wheat and 2.5 million acres of fallow land, and costs producers an estimated $150 million a year. In areas where Aegilops cylindrica has established, control in winter wheat is difficult as the two plants have similar growth habits. Similarities in their genetics makes hybridization possible. Herbicide control of Aegilops cylindrica in winter wheat is ineffective, with the exception of herbicide- tolerant winter wheat varieties.

In Canada, it is thought that Aegilops cylindrica will be able to establish anywhere in Canada that winter wheat can survive. Potential pathways of introduction include contaminated grain, used vehicles and farm machinery, and straw.

The only known persistent populations of the weed in Canada are small populations discovered within Ontario in 2006 and 2007 and an isolated area in B.C. in 2012. The Canadian populations are all under official control.

ALOPECURUS MYOSUROIDES (SLENDER FOXTAIL)
Alopecurus myosuroides is a winter annual, tufted grass native to northern Africa, Asia, and Europe.  It is widely naturalized in temperate parts of the world, including the US, Mexico, South America, China, Australia and New Zealand.  Alopecurus myosuroides is considered a serious weed of winter cereals in Europe and the states of Oregon and Washington. It is mostly reported to occur in cultivated fields, but is becoming common in wetter pastures and along roadsides in Oregon and Washington. Its introduction poses an economic risk to cultivated crops, particularly winter cereals. Once established, the weed is difficult to eradicate.

Alopecurus myosuroides is regulated in the State of Washington.  A risk assessment of this species indicated that it could likely survive in coastal and extreme southern British  Columbia, extreme southwestern Ontario and the coasts of Nova Scotia and Newfoundland. 

The main pathway for introduction of Alopecurus myosuroides into Canada is as a contaminant in grass seed lots. Other possible pathways are through imported grain, hay, and straw. The level of risk associated with imports of grass seed, machinery, hay, and straw into Canada is relatively high since they originate primarily from areas where Alopecurus myosuroides is present.

SENECIO INAEQUIDENS (SOUTH AFRICAN RAGWORT)
Senecio inaequidens is a perennial, herbaceous shrub native to southern Africa. It is an introduced species in numerous European countries. It can establish along railway lines, roadsides, in riparian and logging areas, forests, quarries, rocky sites, coastal dunes, and in crops and pasturelands. It contains pyrrolizidine alkaloids that are toxic to both livestock and humans and can contaminate bread, milk, and honey products.
 
It is not reported to occur in Canada. A risk assessment indicated that it could likely survive and establish in Canada in coastal areas of British Columbia and Vancouver Island, in southern Ontario, as well as in coastal areas of Nova Scotia and Newfoundland. Pathways of introduction and spread include ornamental plants, container surfaces, livestock, building materials, tires, hay, and grain.

SOLANUM ELAEAGNIFOLIUM (SILVERLEAF NIGHTSHADE)
Solanum elaeagnifolium is an erect, deep-rooted, shrub-like perennial with silvery-white leaves and bright blue, purple, or white flowers. It is native to the southwestern US and northeastern Mexico and has been introduced to Australia, India, South Africa, the Mediterranean basin, and parts of South America. In North America, Solanum elaeagnifolium is widespread in the US in all but the Great Lakes and New England regions. It is adapted to a wide range of habitats but appears mostly in warm temperate regions in areas of relatively low annual rainfall. It invades cultivated and agricultural land and also occurs along roadsides, railways, riverbanks and canal-sides and in rangeland, livestock corrals, construction sites, and wastelands.

Solanum elaeagnifolium is not currently established in Canada but its introduction poses an economic risk as it is known to reduce yield of cultivated crops. The most serious crop losses have been recorded in alfalfa, cotton, sorghum, corn, wheat, and cultivated pastures. Other affected crops include vegetables (e.g. potato, asparagus, and tomato), grapes, and some fruit trees (e.g. peaches).

It is regulated as a noxious weed and/or noxious weed seed in 19 US, is a quarantine pest in Belarus, Russia, and Ukraine, and is controlled under noxious weed legislation in Australia and South Africa. It is included on the European and Mediterranean Plant Protection Organization list of species recommended for regulation as quarantine pests by member countries. A risk assessment of this species indicates that it could likely survive in parts of British Columbia, southern Ontario, and parts of the Maritimes.

The most likely pathway of entry of Solanum elaeagnifolium into Canada is as a contaminant of crop seed and grain. It may also spread by livestock, agricultural machinery, vehicles, bulldozers, and other earth-moving equipment, as well as in soil, sand, and ornamental plant material.

MORE INFORMATION
The Invasive Plants Directive (D-12-01), “Phytosanitary requirements to prevent the introduction and establishment of plants regulated as pests in Canada”, is now posted on the CFIA website. D-12-01 clarifies the policy to prevent or limit the importation and the domestic spread of plants considered as pests (i.e., weeds). It explains the invasive plants policy, lists the plants considered to be regulated pests, and indicates that these plants are prohibited from entry to Canada. As new invasive plants are assessed, they will also be added to this Directive. It should be noted that all the prohibited invasive plants listed in the Directive have, in fact, been regulated through the Automated Import Reference System (AIRS) on the CFIA website since 2011 and were recently added to the List of Pests Regulated by Canada. Pathway specific directives for relevant species will be developed separately and as appropriate. If you have questions on this Directive please email the Invasive Alien Species and Domestic Programs Section at: CFIA-IAS_ACIA-EEE @inspection.gc.ca.
 
More information can also be found online at: http://www.inspection.gc.ca /plants/plant-rotection/directives/date/d-12-1/eng/1380720513797/1380721302921. •