RMD-13-04: Consolidated Pest Risk Management Document for pest plants regulated by Canada
Appendix 1B: Risk Management Considerations for Aegilops cylindrica (jointed goat grass)

This page is part of the Guidance Document Repository (GDR).

Looking for related documents?
Search for related documents in the Guidance Document Repository

Existing Programs

In the United States the National Jointed Goatgrass Research Program was established in 1994 to guide research across the United States towards developing management systems based on cultural tactics and population dynamics.

The Government of Alberta, Agriculture and Rural Development, administers the Alberta Certified Weed Free Hay Program. The objective of the program is to provide a premium product that is recognized as marketable and transportable, to prevent the spread of restricted and noxious weeds, and to protect private and public lands from non-native, invasive plant species. Aegilops cylindrica is listed on their "Designated Weed List and Undesirable Plant Species List". Currently, this is the only existing weed free forage program in Canada.

Detection Surveys in Canada

Aegilops cylindrica is not known to occur in Canada outside of local incursions in the Regional Municipality of Niagara in Ontario (CFIA 2007). Field surveys for Aegilops cylindrica have focussed on potential points of introduction such as rail yards, ports, grain elevators, disturbed urban habitats and agricultural areas. Aegilops cylindrica was not found at any of the sites surveyed in Ontario or elsewhere in Canada.

Agriculture and Agri-Food Canada (AAFC) have been conducting weed surveys of the Prairie Provinces since the 1970s (Thomas and Leeson 2007). All weed species encountered in these surveys are identified and documented. Aegilops cylindrica is included in this general survey and has not been detected (J. Leeson per. comm. June 2009). An Inventory of Canadian Agricultural Weeds published by Darbyshire in 2002, also reported that Aegilops cylindrica was absent in Canada.

Hybridization with Wheat

The grass tribe Triticeae is known for inter-specific and inter-generic hybridization (S. Darbyshire, 2006, pers. comm). The genus Aegilops is capable of hybridizing with many species of Triticum, including T. aestivum (wheat) and producing fertile offspring, although fertility rates are low. Germination rates of Aegilops cylindrical/ wheat hybrid spikelets in an Okalahoma study ranged between 0.42 and 1.10% (Stone and Peeper 2004).

Hybridization needs to be considered in a determination of risk management as it could reduce the effectiveness of control methods if a herbicide-tolerant trait in wheat has the potential to be transferred to Aegilops cylindrica, potentially reducing the effectiveness of current control options.

The CFIA Plant Biosafety Office has reviewed the safety of herbicide-tolerant Clearfield wheat which is tolerant to the herbicide imidazolinone. The review examined the potential for gene flow of the imidazolinone-tolerant genes to wild relatives, including Aegilops cylindrica. These documents conclude "that there is no increased risk of consequences of gene flow between imidazolinone-tolerant wheat and Aegilops cylindrica, given the non-persistent nature of the introduction in British Columbia" and "the non-agricultural nature of the Ontario site" (CFIA 2007).

Although hybridization is currently unlikely the risks should not be underestimated if population of Aegliops cylindrica are allowed to expand into Canadian agricultural systems.

The large area occupied by both winter wheat and Aegilops cylindrica in the United States could lead to a significant number of hybridization events and, subsequently, the transfer of the herbicide resistance gene (Guadagnuolo et al. 2001). The weediness of Aegilops cylindrica could increase while control options decrease. It is possible that herbicide-tolerant Aegilops cylindrica populations evolved in the United States may be introduced into Canada via the pathways previously discussed.

Host for Pests that attack Winter Wheat

Aegilops cylindrica is considered an over-wintering host for some pests of winter wheat. The species has been shown to act as an alternate host for Russian wheat aphid (Diuraphis noxia Mordvilko) (Hammon et al. 1989). Aegilops cylindrica also acts as an over-wintering host for a number of fungal pathogens, such as those that cause pink mold, foot rot, root browning, damping off, dwarf bunt and karnal bunt (Donald and Ogg 1991).

Wheat Production Areas of Canada at Risk

During 2008-2009, Canada's wheat production was estimated at 27.3 million metric tons, an increase of 36% from 2007 (USDA 2008). Farm cash receipts indicated that the value of all wheat production in Canada was $4.2 and $5.7 million dollars in 2007 and 2008 respectively (Statistics Canada 2009). Wheat production areas at risk from Aegilops cylindrica include Alberta, Saskatchewan, Manitoba, Ontario, Quebec and the Atlantic provinces (Figure 2 & Figure 3). The majority of Canadian winter wheat is sown in southern Ontario and in the southern Prairie provinces.

Figure 3: Average wheat yields in Canada 1997-2001

Figure 3. Description follows.
Description for Figure 3:

This image shows the average wheat yields in Canada for the years of 1997 through 2001. The wheat yields can be predominantly found in the Prairie region consisting of lower to mid Manitoba, Saskatewan and Alberta the average wheat yield ranging from greater than 2.00 and less than 3.01 within that region. High wheat yields averaging more than 3.01 can also be found in the Atlantic Provinces as well.

Source: USDA 2004.

Canada is one of the world's largest wheat exporters with more than 95% of Canada's wheat produced in western Canada. According to the 2006 Census of Agriculture, wheat was Canada's largest field crop. Canada produces an average of over 25 million tonnes and exports approximately 19 million tonnes of wheat annually. As production significantly exceeds requirements for domestic consumption, the Canadian wheat industry is export-oriented.

If Aegilops cylindrica becomes established in export-oriented agricultural systems in Canada, exports of Canada's major crops and agricultural commodities could potentially be subject to phytosanitary measures by countries where Aegilops cylindrica is a regulated pest. For example, Aegilops cylindrica appears on the published regulated pest lists of China and Mexico; both countries have imported Canadian wheat in the past (Industry Canada 2009). While Aegilops cylindrica has the greatest impact on the production of winter wheat, phytosanitary measures could be applied by NPPOs of importing country to all wheat shipments; regardless of planting time or variety.

Previous imports

Intentional Introduction Pathways

Unintentional Introduction Pathways

Grains and Field Crops

The total value of grain and field crop commodities Footnote 1 imported into Canada in 2008 was approximately $368 million. Of this amount, 3% of imports consisted of wheat from the United States, where Aegilops cylindrica is present. A small percentage of wheat was imported from other countries where Aegilops cylindrica is present, namely Lebanon, Russia, Turkey, Bosnia, Italy, and Mexico. This represents less than 1% of the remaining imports of wheat in 2008 (Industry Canada 2009).

Seed

Canada imported approximately $1 million worth of wheat seed in 2007/2008, the majority of that from the United States (Canadian Seed Trade Association 2008).

Hay and Straw

The total value of hay and straw imported into Canada was approximately $13 million in 2008; 98% of this value came from states in the United States where Aegilops cylindrica is present (Industry Canada 2009).

Washington State was the greatest exporter of hay and straw to Canada with an average value of approximately $10 million per year in the last 5 years (Industry Canada 2009).

Used Vehicles and Farm Machinery

Used farm machinery moves across the United States-Canada border every year. Information is not available on the volume of imports of used farm machinery.

Recommended Risk Mitigation Measures

Natural Means of Dispersal

Natural range expansion could occur from infested counties in the United States along the U.S.-Canada border (USDA, NRCS 2006). It is recommended that risk mitigation include regular surveys targeting high risk areas along the Canada-United States border where the adjacent United States County is infested.

Education and outreach programs will also work to limit establishment in Canada, through early detection of new incursions.

Intentional and Unintentional Means of Introduction

Regulatory measures under the Plant Protection Act

Regulatory measures under the Seeds Act

Continue to regulate Aegilops cylindrica as a prohibited noxious weed under the Weed Seeds Order of the Seeds ActFootnote 2. The importation of Aegilops cylindrica seed is prohibited under the Seeds Act and the Seeds Regulations have specific information requirements (CFIA 2009) to verify that seed imported into Canada is free of prohibited noxious weeds and meets the minimum standards for purity and germination for the crop kind in question. A certificate of analysis is required to demonstrate freedom from all prohibited noxious weeds.

Non regulatory measures

Education and outreach programs can assist in preventing and detecting new populations of Aegilops cylindrica. This can include providing information on identifying Aegilops cylindrica in the field, as well as educating people using custom combines and moving used farm machinery to clean all plant debris and soil that could contain seeds or spikelets of Aegilops cylindrica prior to moving the machines.

Trade Implications

Cost effectiveness and feasibility

Date modified: