INFORMATION REQUEST

PRA REQUEST: 2015-08

REVIEW OF PROPOSED LISTING OF FOUR SPECIES AS CLASS 3 SECONDARY NOXIOUS ON THE WEED ORDER OF THE SEEDS REGULATIONS

Bromus tectorum. Photo by K. Allison

Plant and Biotechnology Risk Assessment Unit Health Science Division Ottawa, Ontario March 27, 2015 Review of four Bromus species PRA # 2015-08

INFORMATION REQUEST

BACKGROUND

The purpose of this information request is to determine whether four Bromus species (i.e., , Bromus japonicus, and Bromus tectorum) should be listed as Class 3 secondary seeds on the Weed Seeds Order of the Seeds Regulations. These species have been proposed for addition to the Weed Seeds Order; however, during the consultation process a group of stakeholders presented information stating that the four species should not be listed. As Section moves the revisions of the Weed Seeds Order through the regulatory change process, CFIA is required to address any stakeholder concerns brought forward.

To address these concerns, a thorough and up-to-date review of the four Bromus species as well as a review of the concerns raised by this group of stakeholders is required.

March 27, 2015

1

Review of four Bromus species PRA # 2015-08

SPECIES CATEGORIZATIONS

Identity of organism

Name: Bromus arvensis L. () (USDA-ARS 2015)

Synonym(s): none listed (USDA-ARS 2015)

Common name(s): field brome (USDA-ARS 2015)

French common name(s): brome des champs (USDA-ARS 2015)

Background information: This categorization is an update to a previous categorization of Bromus arvensis in Request #2010-29, Proposed Additions to Class 1 (Prohibited Noxious) of the Federal Weed Seeds Order.

Current regulatory status: Bromus arvensis is not currently regulated as a pest in Canada, either federally or provincially (CanLII 2015). It is not listed as a federal noxious weed in the , nor is it regulated by any U.S. states (USDA-ARS 2015; USDA-NRCS 2015).

Description: Bromus arvensis is an erect annual grass 80-110 cm tall. Lower leaf sheaths are densely, softly hairy and ligules are 1-1.5 mm and hairy. Leaf blades are 10-20 cm long, 2-6 mm wide, coarsely pilose (hairy) on both surfaces. are panicles 11-30 cm long, 4-20 cm wide, open, erect or nodding. Branches are usually longer than the , ascending to widely spreading, slender, slightly curved or straight, with up to 10 spikelets on a branch (Barkworth et al. 2007; Tutin et al. 1980).

Distribution

Current distribution: Bromus arvensis is native to southern and south-central and temperate (Barkworth et al. 2007; USDA-ARS 2015). It is widely naturalized further north in Europe (Oja et al. 2003; Tutin et al. 1980) as well as in the United States, Mexico and Argentina (USDA-ARS 2015). In the U.S., it is found in several states, mostly in the east (Barkworth et al. 2007). Some sources consider Bromus arvensis and Bromus japonicus Thunb. (Japanese brome) to be synonymous (e.g., Howard 1994; Murphy 2011; USDA-NRCS 2015) while other sources consider them separate species (e.g., Barkworth et al. 2007; USDA-ARS 2015). This can lead to some confusion with respect to their reported distribution.

In Canada, Bromus arvensis has been reported from along roadsides in British Columbia, in southern Ontario, and in Quebec (Brouillet et al. 2010+; Dore and McNeill 1980; Scoggan 1979). It is not currently listed in the online flora of British Columbia (Klinkenberg 2013) or in the Flore laurentienne (Marie-

March 27, 2015

2

Review of four Bromus species PRA # 2015-08

Victorin 1995) but it is listed in the flora of Ontario (Newmaster and Ragupathy 2012). Gleason and Cronquist (1991) describe it as sparingly introduced in the northeastern United States and adjacent Canada as well as elsewhere in the United States. Bromus arvensis does not appear to be common in the horticultural trade (Bailey and Bailey 1976) and no evidence was found that it is being sold in Canadian nurseries (e.g., CFIA 2014a; Isaacson and Allen 2007).

Bromus arvensis grows in fields, along forest margins and roadsides, and in waste places (Barkworth et al. 2007; eFloras 2015; Scoggan 1979).

Potential Canadian distribution: Based on its current distribution, Bromus arvensis grows in plant hardiness zones 4-9. It is found in zone 4 in Norway, Sweden and Finland (GBIF 2015). Areas of zones 4 through 9 in Canada include the east and west coasts, much of southern Canada, and scattered coastal areas in the north (Figure 1).

Figure 1. Plant hardiness zones 4 and higher in Canada. Map based on 10-year 2012 NAPPFAST Global Plant Hardiness Map from www.nappfast.org.

Impacts

Bromus arvensis is reported as a weed of arable land, notably winter cereals, in various parts of Europe, including Italy (Viggiani 2007), Germany (Amann 2002), Norway (Hoiland 1993), Poland (Paradowski 2003) and Sweden (Andersson et al. 2002); however, in some cases it is reported as rare, or even (in the case of Norway), endangered. It is also reported as a common weed in the former Soviet Union, and present as a weed in the United States, but not as a principal or serious weed in any country (Holm et al. 1991). In the United States, Bromus arvensis was introduced in the 1920s “where it became adapted to

March 27, 2015

3

Review of four Bromus species PRA # 2015-08

the corn-belt region and eastward” (Williams et al. 2011). It is sometimes planted for control or as a cover crop ( improver) (Wiersema and León 1999). In Ontario, Dore and McNeill (1980) noted that “this versatile and early maturing annual would be difficult to control if it became widely established.” It has persisted as a weed in experimental plots at the University of Guelph since 1933 (Dore and McNeill 1980).

In a Slovenian study, Lesknik (1999) studied the relationship between Bromus arvensis density and winter wheat yield losses in field trials. Bromus arvensis densities of 50-60 m2 resulted in approximately 3-6% winter wheat grain yield loss, densities of 90-110 plants m2 resulted in 9-11% yield loss, and densities of 140-160 plants m2 resulted in 15-27% yield loss. In France, Bromus arvensis was reported among several annual brome species that have been observed to be increasing in agricultural importance in recent decades with the adoption of simplified tillage practices and the lack of effective for these grasses (Cardon and Pierron 2013). Bromus arvensis is also an alternate host for the wheat dwarf virus (Mehner et al. 2003).

Control

Although there is less information available on the control of Bromus arvensis than on the other three Bromus species of interest in this document, the recommended prevention and control measures for annual brome species are similar. Prevention of new infestations is emphasized, by using clean seed, preventing spread in association with vehicles, equipment and livestock, and minimizing soil disturbances. When prevention is no longer an option, control measures for annual bromes should take into account their high seed production and the formation of seed banks that can last several years (Cardon and Pierron 2013; Upadhyaya et al. 1986). Crop rotation, preventing seed production, and the use of effective herbicides are important for control in cropping systems. Herbicides applied prior to seeding annual crops or in broad-leaf crops or can be effective, but control in winter cereals is challenging due to low sensitivity to most grass herbicides and similarities in growth and phenology between the crop and the weed (Lesnik 1999; Viggiani 2007). A study by Cardon and Pierron (2013)in France achieved good control of annual bromes in winter cereals, including Bromus arvensis, with pyroxsulam. In natural ecosystems, maintaining healthy populations of perennial grasses is an effective measure for controlling annual bromes (CABI 2015b).

Conclusion

Bromus arvensis has been reported from Canada but is not widespread or common. Based on reports from the literature, it is more often a minor agricultural weed rather than a major one, and tends to be found in winter cereals. As an agricultural weed, its presence in seed could affect the value and/or intended use of seed lots by increasing costs of control. Although Bromus arvensis is uncommon in Canada, it has been proposed as a secondary noxious weed seed (Class 3) together with three other Bromus species (B. japonicus, B. secalinus, B. tectorum) due to potential impacts and seed identification issues.

March 27, 2015

4

Review of four Bromus species PRA # 2015-08

Identity of organism

Name: Bromus japonicus Houtt. (Poaceae) (USDA-ARS 2015)

Synonym(s): Bromus anatolicus Boiss. & Heldr., Bromus patulus Mert. & W. D. J. Koch, Bromus pendulus Schur, Bromus vestitus Schrad. (USDA-ARS 2015)

Common name(s): Japanese brome, Japanese bromegrass, Japanese chess (Darbyshire 2003)

French common name(s): brome du Japon, brome japonais (Darbyshire 2003)

Background information: This categorization is an update of the categorization provided in Request #2009-52, Weed Seeds Order Revision: Potential Class 2 Primary Noxious Species Information.

Current regulatory status: Bromus japonicus is a designated “noxious” weed in Alberta’s Weed Control Regulation of the Weed Control Act (Province of Alberta 2008; Province of Alberta 2010). There are two categories in the regulation: prohibited noxious and noxious. Noxious weeds are to be controlled on land that people own or occupy and measures are to be taken to prevent their spread. These measures include restrictions on the use or movement of anything that might spread a noxious weed, which can include seed and hay bales (Kimmel 2015).

In Saskatchewan, Bromus japonicus is also listed as a “noxious” weed in the Minister’s Order to The Weed Control Act (Saskatchewan Minister of Agriculture 2010). There are three categories in the order: prohibited, noxious and nuisance. In the case of noxious weeds, isolated infestations are to be eradicated, established infestations are to be contained and controlled, and additional measures are to be taken to prevent their spread (Government of Saskatchewan 2010). Although there are no explicit restrictions in seed, there is a general restriction on “any material” that has noxious weeds “adhering”. There are also disincentives to planting seed contaminated with noxious weed seeds due to the requirement for control, and in some cases crop destruction may be permitted (Brenzil 2015).

Bromus japonicus is also on the “Designated Weed List and Undesirable Plant Species List” of the Alberta Certified Weed Free Hay Program (Alberta Agriculture and Rural Development 2012).

Bromus japonicus is not regulated at the federal level in Canada (CFIA 2014b) or the United States (USDA-APHIS 2012), nor is it listed as a noxious weed in any of the states (USDA-ARS 2015; USDA-NRCS 2015).

Description: Bromus japonicus is an annual grass with erect or ascending culms 30-70 cm tall (Barkworth et al. 2007). It normally behaves as a winter annual, germinating in fall and overwintering in a vegetative state (Beck undated). The leaf sheaths and blades are softly hairy; leaf blades are 10-20 cm long and 1-4

March 27, 2015

5

Review of four Bromus species PRA # 2015-08

mm wide (Barkworth et al. 2007; Looman and Best 1987). Inflorescences are open, nodding panicles 10- 22 cm long (Barkworth et al. 2007). Spikelets are 10-40 cm long, each containing 5-12 florets (Barkworth et al. 2007; Looman and Best 1987). The lemma bears awns that are 8-13 mm long and twisted and flexuous at maturity (Barkworth et al. 2007; Looman and Best 1987). This species is often confused with Bromus tectorum (Whitson et al. 1992).

Distribution

Current distribution: Bromus japonicus is native to northern (Egypt) and much of temperate Eurasia, from France eastward to China, and Korea (USDA-ARS 2015). Bromus japonicus has also naturalized in , , several countries of Europe (Finland, Norway, Sweden, Austria, Germany, Poland, Switzerland), Canada, the United States, Mexico, Argentina and (Holm et al. 1991; USDA-ARS 2015).

In Canada, Bromus japonicus has been reported from the Yukon and all provinces except Prince Edward Island and Newfoundland and Labrador (Brouillet et al. 2010+). It is reported to be expanding its range (Darbyshire 2003). In Ontario, there is an early record of this species from 1912 and additional scattered records until 1948, after which records increased rapidly (Dore and McNeill 1980). By 1980, Bromus japonicus was widely established in the southwestern counties and “threatening to spread throughout southern Ontario” (Dore and McNeill 1980). In western Canada, it was found in a few districts of Alberta but was not yet common in the 1960s (Budd and Best 1964); by 1980, it was described as “abundant in the dry lands of southern Alberta and adjacent British Columbia” (Dore and McNeill 1980). Now Bromus japonicus often occurs in mixed infestations with Bromus tectorum in the southern interior of British Columbia (Gayton and Miller 2012), southwestern Saskatchewan and Alberta, in isolated areas through to the Peace River in Alberta, and in Manitoba, where heavy infestations have been recently identified in isolated fields (Kirkland and Brenzil 2007).

Habitats of Bromus japonicus include cultivated fields (especially winter wheat and annual croplands), old fields, (especially depleted rangelands), , hayfields, gardens, roadsides, industrial sites, and disturbed areas (Barkworth et al. 2007; Darbyshire 2003; Davis 1993; Kirkland and Brenzil 2007; Whitson et al. 1992). Bromus japonicus has been cultivated as an ornamental plant in (Bailey and Bailey 1976), which could account for its occurrence in and around gardens. In North America, it is common in northern mixed grass (Ogle et al. 2003). Bromus japonicus tends to prefer somewhat moister than Bromus tectorum (Kirkland and Brenzil 2007).

Potential Canadian distribution: Based on its current distribution, it is estimated that Bromus japonicus is hardy to plant hardiness zone 3. It is present in zone three in a few areas of British Columbia and Alberta, as well as in Afghanistan (GBIF 2015). There are even a few records from zones 1 and 2 in Afghanistan (GBIF 2015), but not enough evidence to suggest that it is established in those zones. In Canada, zones 3 and above includes most of the provinces, with the exception of much of northern Quebec, and scattered areas across the territories (Figure 2).

March 27, 2015

6

Review of four Bromus species PRA # 2015-08

Figure 2. Plant hardiness zones 3 and higher in Canada. Map based on 10-year 2012 NAPPFAST Global Plant Hardiness Map from www.nappfast.org.

Impacts

Bromus japonicus is listed by Holm et al. (1991) as a common weed in Japan and the United States and a weed of unknown rank in Canada, Iran and Pakistan. In the United States, it occurs as a weed in wheat fields, grass and alfalfa seed fields, pastures and ranges, and many other places (Finnerty and Klingman 1962). It is a serious weed of in the western United States, where along with other invasive annual grasses (i.e., Bromus tectorum, Taeniatherum caput-medusae, Ventenata dubia), millions of hectares have been negatively affected (Howard 1994; Rinella et al. 2014). It invades disturbed and undisturbed sites (Howard 1994), where it contributes to reduced native species richness, abundance, and , livestock carrying capacity, as well as altered nutrient cycling and microbial communities (Rinella et al. 2014; Romo and Eddleman 1987). Outbreaks in native vegetation tend to occur during periods of drought when native species are stressed; they decline again when the competitive strength of native perennial species return (Buckner and Downey 2009). In areas of the central and northern Great Plains, where Bromus japonicus has become naturalized, it is very difficult to eradicate (Harmoney 2007). In Iran, Bromus japonicus is a dominant species in rotations with wheat under arid conditions and is well-adapted to reduced tillage systems for and emergence (Sarani et al. 2014). It has also been reported as one of the most abundant grass weeds of the North China Plain, which is one of the most important winter wheat production areas of the world (Menegat et al. 2012).

Bromus japonicus occurs as a weed in cropland in Canada, and is known to contaminate seed and grain. It has been detected in domestic smooth bromegrass (Bromus inermis), intermediate and pubescent wheatgrass (Thinopyrum intermedium), Russian wildrye (Lolium perenne), tall fescue (

March 27, 2015

7

Review of four Bromus species PRA # 2015-08

arundinacea), and forage mixture seed (CFIA internal data). It is also a common contaminant in Canadian wheat grain (western and eastern), and to a lesser extent, in barley, , canola, flax, lentils and peas (Canadian Grain Commission (CGC) data).

In Canadian rangelands, annual bromes such as Bromus japonicus and Bromus tectorum are often an indicator of poor range condition, and readily infest areas where native vegetation has been disturbed by overgrazing, fire and cultivation (Kirkland and Brenzil 2007). They do not compete well with well- established perennial grasses and are not usually a problem in healthy rangelands (Kirkland and Brenzil 2007). In British Columbia, Bromus japonicus has been noted as one of the leading in mid-seral sites of the BC Southern Interior (Gayton and Miller 2012). In Saskatchewan, Bromus japonicus is problematic in overgrazed pastures and a concern in forage and reclaimed sites (Sask Forage Council).

Control

Prevention, early detection of new populations, and preventing or reducing seed set (e.g., by mowing) are important management objectives for Bromus japonicus (Kirkland and Brenzil 2007). Where the weed has established, chemical control can be effective. A variety of products are registered for use on Bromus japonicus in Canada (Health Canada 2015). Examples include imazamox (in product combination with bentazon or imazapyr) and pyroxsulam (Alberta Council 2014b). Control can be challenging in winter cereals, due to similar growth and phenology, and in grass forages, due to similarity in seed size, which makes them difficult screen out. Resistance of Bromus japonicus to several Group 2 herbicides (imazamox, propoxycarbazone-sodium, pyroxsulam and sulfosulfuron) was reported in winter wheat in 2007 in Kansas (Heap 2015). In pastures and rangelands, maintaining a vigorous cover of perennial grasses is a good prevention measure (Whitson et al. 1992).

Conclusion

Bromus japonicus is relatively common in Canada. It is known to be an agricultural weed that contaminates seed and grain and its presence in seed could potentially affect the value and/or intended use of seed lots. On a practical basis, seed identification of Bromus japonicus can be challenging due to its similarly with other Bromus species. Bromus japonicus has been proposed as a secondary noxious weed seed (Class 3) together with Bromus arvensis, B. secalinus, and B. tectorum due to potential impacts and seed identification issues. This species is also listed as a noxious weed in Alberta and Saskatchewan.

March 27, 2015

8

Review of four Bromus species PRA # 2015-08

Identity of organism

Name: Bromus secalinus L. (Poaceae) (USDA-ARS 2015)

Synonym(s): none listed (USDA-ARS 2015)

Common name(s): cheat, cheat chess, cheat grass, chess, chess brome, ryebrome rye brome (Darbyshire 2003), bronco grass, drooping brome grass, nodding brome grass, six weeks grass (CABI 2015a)

French common name(s): brome des seigles, brome sécalin, coquiole noire, séglin, seigle bâtard, brome faux seigle, seiglin (Darbyshire 2003)

Background information: This categorization is an update of the categorization provided in Request #2009-52, Weed Seeds Order Revision: Potential Class 2 Primary Noxious Species Information.

Current regulatory status: Bromus secalinus is not currently regulated as a pest in Canada, either federally or provincially (CanLII 2015). It is not listed as a federal noxious weed in the United States, but it is listed as a noxious weed in , Arkansas, Delaware, , , Kansas, Louisiana, Mississippi, New Jersey, Oklahoma, , Tennessee and Texas (USDA-ARS 2015). Internationally, Bromus secalinus is regulated in India (Plant Quarantine India 2007).

Description: Bromus secalinus is an annual grass with erect culms, 20-80 cm tall (Barkworth et al. 2007). The leaf blades are 15-30 cm long and 2-4 mm wide (Barkworth et al. 2007). It has open, nodding panicles 5-23 cm long and 2.5-12 cm wide, with branches bearing 1-4 spikelets each (Barkworth et al. 2007; eFloras 2015). The spikelets are ovoid-lanceolate or ovate, laterally compressed, 10-20 mm long, and contain 4-9 florets. The lemma awns are straight or flexuous and 3-6 mm long (Barkworth et al. 2007).

Distribution

Current distribution: Bromus secalinus is native to southern and eastern Europe, northern Africa (Algeria) and temperate Asia (Turkey, Georgia) (USDA-ARS 2015). The Flora of China also includes China, Japan and in its distribution (eFloras 2015). It has naturalized in Australia, North America and South America and is cultivated in the United States (Oregon, Washington) (USDA-ARS 2015). It is common throughout most of the United States (Whitson et al. 1992).

In Canada, Bromus secalinus has been reported from the Yukon, British Columbia, Alberta, Ontario, Quebec, New Brunswick, Nova Scotia, Newfoundland and Prince Edward Island (Brouillet et al. 2010+; CFIA and NRCan/CFS 2011+; Darbyshire 2003). In the Yukon, it has been observed in waste ground at Dawson but has not been observed in recent years (Cody 2000). In British Columbia, it is found along dry

March 27, 2015

9

Review of four Bromus species PRA # 2015-08

roadsides, fields and disturbed areas of lowland, steppe and montane zones but is not common (Klinkenberg, 2014). In Ontario, it is mainly found in cereal crops, but also along roadsides, railways and ports, but is not very common there either (Cowbrough et al. 2007). Although formerly a serious weed of cereal crops, this species is now generally in decline as an agricultural weed and is fairly uncommon (Darbyshire 2003; Dore and McNeill 1980).

Habitats of Bromus secalinus include cultivated fields, especially winter wheat and alfalfa fields, old fields, grassy places, slopes, shores, railway lines, roadsides, and disturbed areas (Darbyshire 2003; Davis 1993; eFloras 2015). Peeper (1984) notes that Bromus secalinus is more common in the eastern portion of the hard red winter wheat and more humid soft red winter wheat regions of the United States, where there are acid sandy or loamy , whereas Bromus tectorum is more common on dry, mostly alkaline, sandy to loamy soils in the western regions.

Potential Canadian distribution: Based on its current distribution, it is estimated that Bromus secalinus is hardy to approximately plant hardiness zone 3. It is present in zone 3 in British Columbia and Finland (GBIF 2015). In Canada, zones 3 and above includes most of the provinces, with the exception much of northern Quebec, and scattered areas across the territories (Figure 2).

Impacts

Economic impacts: Bromus secalinus is listed by Holm et al. (1991) as a common weed of Argentina, Austria, Canada, Finland, Germany, Spain and the United States, and as a weed of unknown rank in Chile, Columbia and the former Soviet Union. It was formerly a serious weed in wheat-growing areas of southwestern Ontario, occurring only temporarily elsewhere in the province along roadsides and on waste ground (Dore and McNeill 1980). Bromus secalinus is thought to have been harvested and re- sown with cereal seed. In the United Kingdom, its decline has been attributed to improved seed cleaning technology which has eliminated the weed seeds from seed lots (Wilson and King 2003).

Despite its decline in some regions, Bromus secalinus is still considered widespread in North America (Barkworth et al. 2007) and a major weed problem in the hard red winter wheat growing areas of the southern Great Plains (Stone et al. 2001). The plants mature simultaneously or slightly later than winter wheat, and its seeds are harvested with the wheat. When grain combines are adjusted to optimum efficiency for harvesting wheat , the majority of the Bromus secalinus seeds move through the combine into the clean grain bin, along with the wheat (Stone et al. 2001).

Bromus secalinus occurs as a seed and grain contaminant in Canada. It has been found in domestic rye (Secale cereale), smooth bromegrass (Bromus inermis), orchardgrass (Dactylis glomeratus), and forage mixture seed (CFIA internal data). It is also found as a contaminant in Canadian wheat grain, more often from eastern wheat than from western wheat (CGC data).

March 27, 2015

10

Review of four Bromus species PRA # 2015-08

Control

As with other annual bromes, Bromus secalinus is similar in its growth and phenology to winter wheat, making control challenging. Although harvesting equipment can be adjusted to discharge a larger proportion of the Bromus secalinus seeds back into the field rather than into the grain bin, the concentration of weed seeds left behind can increase the difficulty of controlling infestations (Stone et al. 2001). In the United States, as a result of recent advances in chemistry, there are now effective herbicides available for Bromus secalinus control in wheat (Armstrong and Peeper undated). Using herbicides with different modes of action is important in control regimes, to prevent herbicide resistance. Resistance of Bromus secalinus biotypes to several Group 2 herbicides (imazamox, propoxycarbazone-sodium, pyrosulam, sulfosulfuron) has been reported in winter wheat in Kansas and wheat in Oklahoma (Heap 2015).

Conclusion

Bromus secalinus has been described as uncommon and declining in Canada. It is an alien weed that has the potential to have an economic impact in parts of Canada. Presence of this species in seed could impact trade due to regulations in India and at the state level in many U.S. states. Although Bromus secalinus is uncommon in Canada, it has been proposed as a secondary noxious weed seed (Class 3) together with three other Bromus species (B. arvensis, B. japonicus, B. tectorum) due to potential impacts and seed identification issues.

March 27, 2015

11

Review of four Bromus species PRA # 2015-08

Identity of organism

Name: Bromus tectorum L. (Poaceae) (USDA-ARS 2015)

Synonym(s): Anisantha tectorum (L.) Nevski, Bromus sericeus Drobow (USDA-ARS 2015), Schedonorus tectorum Fries, Bromus setaceus Buckl., Zerna tectorum Panz. ex Jacks., Zerna tectorum (L.) Lindm, Anisantha pontica C. Koch (Upadhyaya et al. 1986)

Common name(s): downy brome, cheat grass, downy brome grass, downy chess, early chess, drooping brome grass, drooping brome, wall brome, cheatgrass (Darbyshire 2003)

French common name(s): brome des toits, brome des murs (Darbyshire 2003)

Background information: This categorization is an update of the categorization provided in Request #2009-52, Weed Seeds Order Revision: Potential Class 2 Primary Noxious Species Information.

Current regulatory status: Bromus tectorum is a designated “noxious” weed in Alberta’s Weed Control Regulation of the Weed Control Act (Province of Alberta 2008; Province of Alberta 2010). There are two categories in the regulation: prohibited noxious and noxious. Noxious weeds are to be controlled on land that people own or occupy and measures taken to prevent their spread.

In Saskatchewan, Bromus tectorum is listed as a “noxious” weed in the Minister’s Order to The Weed Control Act (Saskatchewan Minister of Agriculture 2010). There are three categories in the order: prohibited, noxious and nuisance. In the case of noxious weeds, isolated infestations are to be eradicated, established infestations are to be contained and controlled, and further measures are required to prevent their spread (Government of Saskatchewan 2010).

Bromus tectorum is a designated “noxious weed” in Manitoba’s The Noxious Weeds Act (Government of Manitoba 2010). The act contains a single category: noxious weed. According to the act, occupants or owners of land are required to destroy noxious weeds and noxious weed seeds on the land as often as necessary to prevent the growth, ripening and scattering of the weeds or weed seeds. Inspectors who find noxious weed seeds in seed or grain may order the screening of the seed or grain to remove the noxious weeds and destruction of the screenings. They may also order the cessation from sowing or using seed that might result in the spread of noxious weeds (Government of Manitoba 2010).

Bromus tectorum is also on the “Designated Weed List and Undesirable Plant Species List” of the Alberta Certified Weed Free Hay Program (Alberta Agriculture and Rural Development 2012).

March 27, 2015

12

Review of four Bromus species PRA # 2015-08

Bromus tectorum is not regulated at the federal level in Canada (CFIA 2014b) or the United States (USDA-APHIS 2012), but it is listed as a noxious weed in Colorado, Connecticut and Wisconsin (USDA- ARS 2015; USDA-NRCS 2015).

Description: Bromus tectorum is a tufted annual, winter annual or biennial grass (Upadhyaya et al. 1986). It most often behaves as a winter annual, germinating in fall and overwintering in a vegetative state (Beck undated). The plants grow from 5-90 cm tall (Barkworth et al. 2007; Upadhyaya et al. 1986). Reproduction is entirely by seeds. The leaf blades are 4-16 cm long and 1-6 mm wide (Barkworth et al. 2007; Upadhyaya et al. 1986). The panicles are 5-20 cm long and rather dense and drooping (CABI 2015a; Upadhyaya et al. 1986). The spikelets, including awns, are 1-4 cm long and include 2-8 florets (Barkworth et al. 2007; Upadhyaya et al. 1986). This species displays considerable variation in characteristics due to genetic differences and responses to local conditions (Upadhyaya et al. 1986).

Distribution

Current distribution: Bromus tectorum has a very broad native distribution which includes northern Africa and temperate Eurasia, from Portugal in the west to China in the east (USDA-ARS 2015). In Europe, it is found as far north as southern Norway and Sweden (USDA-ARS 2015). Bromus tectorum has also naturalized in Canada, the United States (including ), Argentina, Chile, , , Japan, eastern Australia, New Zealand, and South Africa (Upadhyaya et al. 1986; USDA-ARS 2015). It is widely distributed throughout North America (Whitson et al. 1992). In the past, Bromus tectorum was sown as a forage grass and is still used for forage by livestock in spring and fall (Beck undated).

In Canada, Bromus tectorum is found in all provinces and territories except Newfoundland and Labrador, Prince Edward Island and Nunavut (Brouillet et al. 2010+; CFIA and NRCan/CFS 2011+). Valliant et al. (2007) indicated that there are essentially two diffuse ranges of this species in Canada, primarily south of 52ºN and separated by the coniferous forest in western Ontario. It is most extensive in southern British Columbia and southwestern Alberta, with populations in Saskatchewan, Manitoba and eastern Canada mostly restricted to disturbed sites in arid areas with light-textured soils (Valliant et al. 2007).

In southern British Columbia, Bromus tectorum was first detected in an irrigated field in the late 1800s and had spread over much the perennial by about 1930 (Mack 1981; Valliant et al. 2007). Today it is “ubiquitous in all the valleys of the Interior as far north as Williams Lake, and it is plentiful in parts of Vancouver Island” (Gayton 2012).

In the southwest Prairies, Bromus tectorum is thought to have been introduced into Alberta with contaminated alfalfa seed and soil brought from (Valliant et al. 2007). The first herbarium record from Alberta is from Lethbridge in 1915 (Valliant et al. 2007). By 1930, it was well established in both southwestern Alberta and Saskatchewan (Valliant et al. 2007) and by the 1960s it was described as very common and rapidly spreading (Budd and Best 1964). Field crop surveys from the Prairies in the 1970s indicated that Bromus tectorum was found in fields of spring wheat, barley, oats and flax from various ecoregions, including grassland, aspen parkland and boreal transition (Leeson et al. 2005). There were

March 27, 2015

13

Review of four Bromus species PRA # 2015-08

fewer reports of this species in the 1980s and 1990s, although it was still present in spring wheat in mixed grasslands (1980s and 1990s) and aspen parkland (1990s only). In the 2000s, Bromus tectorum was reported from spring wheat, barley and field peas in multiple ecoregions, including various grassland types, aspen parkland and boreal transition (Leeson et al. 2005). Winter wheat, an important host crop for Bromus tectorum, was not included in this series of surveys. In Manitoba, low to medium levels of infestations may be found in some southern areas (Invasive Species Council of Manitoba 2015). However, it has generally been infrequent in southeastern Saskatchewan and southern Manitoba (Valliant et al. 2007).

In eastern Canada, Bromus tectorum was first collected in the late 1880s from southwestern Ontario (Valliant et al. 2007). Almost all early specimens from southwestern Ontario were collected either at ports or along railroads within 50 km of ports (Valliant et al. 2007). This species eventually spread to eastern parts of Ontario (Upadhyaya et al. 1986) and Canada (Quebec, New Brunswick, Nova Scotia) (Valliant et al. 2007), where most records have been collected along railroads. Bromus tectorum is common in southern Ontario but the decline of railroad traffic in recent years may have contributed to a range contraction in some of the eastern parts of its range in Canada (e.g., no Bromus tectorum was found in Quebec in 2005) (Valliant et al. 2007).

Bromus tectorum grows in dry areas, sand dunes, cultivated fields (especially winter wheat, alfalfa and grass fields), pastures, rangelands, grasslands, along railway lines and roadsides, and in disturbed areas (Barkworth et al. 2007; Darbyshire 2003; Morrow and Stahlman 1984; Upadhyaya et al. 1986). In western North America, it dominates large areas of sagebrush (Artemisia sp.) and mixed grass ecosystems (Barkworth et al. 2007; Beck undated; Ogle et al. 2003). It commonly occurs on dry, mostly alkaline, sandy to loamy soils (Peeper 1984).

Potential Canadian distribution: Based on its current distribution, it is estimated that Bromus tectorum is hardy to approximately plant hardiness zone 2. It is present in zone 2 in (GBIF 2015). There are even records from zones 1 in the Yukon and Afghanistan (GBIF 2015), but not enough evidence to suggest that it is fully hardy in those zones. In Canada, zones 2 and above includes most of Canada, with some exceptions in the high arctic (Figure 3).

March 27, 2015

14

Review of four Bromus species PRA # 2015-08

Figure 3. Plant hardiness zones 2 and higher in Canada. Map based on 10-year 2012 NAPPFAST Global Plant Hardiness Map from www.nappfast.org.

Impacts

Bromus tectorum is a principal weed of Turkey, a common weed of Canada, Lebanon, Morocco, the former Soviet Union, and the United States, and as a weed of unknown importance in Iraq and Jordan (Holm et al. 1991). It is a serious weed of rangelands, lands, winter cereals, alfalfa, turf, grass seed fields, and non-crop land (CABI 2015b; Upadhyaya et al. 1986; Uva et al. 1997). It is also reported as a weed of orchards and vineyards (CABI 2015b). Bromus tectorum is “one of the few invasive annual exotic species that is a major weed of rangeland and agronomic fields in North America” (CABI 2015b).

In the western United States, winter wheat growers consider Bromus tectorum to be their worst weed problem (Morrow and Stahlman 1984). Bromus tectorum densities of 108 and 538 plants/m2 have reduced wheat yields 40% to 92% respectively (Morrow and Stahlman 1984). Furthermore, herbicide programs for selective control of Bromus tectorum in winter wheat are limited (Epp 2014; Morrow and Stahlman 1984). It also causes major yield losses in barley and is a spring weed problem in alfalfa hay production (CABI 2015b).

In the grasslands of the western and midwestern United States, Bromus tectorum is the most widespread and damaging invasive annual grass (Finnerty and Klingman 1962; Rinella et al. 2013). On large tracts of overgrazed rangelands, Bromus tectorum has been known to form monocultures (MacNaughton 2012; Upadhyaya et al. 1986). Invasion by Bromus tectorum is enhanced by disturbance such as cultivation and subsequent abandonment, overstory removal, overgrazing and repeated fires;

March 27, 2015

15

Review of four Bromus species PRA # 2015-08

however, it can also establish in undisturbed areas (Beck undated). Its shallow roots extract moisture from the uppermost soil horizon, make it difficult for native perennial grasses to establish (Kirkland and Brenzil 2007; MacNaughton 2012). It is also adapted to drought, producing smaller plants that still set seed under such conditions (Beck undated). Bromus tectorum reduces livestock carrying capacity, native species richness and abundance, and alters structure and function of prairie ecosystems, including biomass production, litter decomposition, nutrient cycling and microbial communities (Knapp 1996; Ogle et al. 2004; Rinella et al. 2014). It is estimated that between 56 to 101 million acres are infested in the United States, spreading at an annual rate of 14% (Beck undated), and costing $350 million USD annually in control efforts (CABI 2015b). Bromus tectorum has also caused a drastic shortening of the normal fire cycle in western rangelands, from approximately every 30 to 100 years to every three to five years (Kirkland and Brenzil 2007; Owen et al. 2011; Westbrooks 1998). fuelled largely by Bromus tectorum cost millions of addition dollars for suppression and emergency restoration events on burnt areas (CABI 2015b).

In addition to its impacts on crops and rangelands, Bromus tectorum also impacts animal health. The long, stiff awns of Bromus tectorum penetrate the skin of the mouth, throat and intestines of grazing livestock, causing discomfort and reduced feed intake (Upadhyaya et al. 1986). Sometimes the injury is serious and death results (Hitchcock 1950). The awns can also contaminate fleece (Kirkland and Brenzil 2007). They can work through clothing and cause discomfort to humans as well (Dore and McNeill 1980). On beaches, Bromus tectorum can be a problem for recreational users (Dore and McNeill 1980).

A number of impacts of Bromus tectorum on wildlife have been documented. The change in native plant community structure by Bromus tectorum, in which shrubs become more and more widely dispersed after fire events, has reduced cover for hiding, nesting and foraging of birds and small mammals (Beck undated). Furthermore, native birds prefer to feed on seeds of native perennial grasses than exotic grasses such as Bromus tectorum, which may potentially allow the exotic grasses to continue to proliferate (Beck undated).

In Canada, Bromus tectorum is a more recent weed problem in the prairies than in the western United States, but causes similar impacts. It has been described as the most serious weed of winter wheat in southern Alberta and Saskatchewan where spread has been exponential and densities of 100 to 200 plants m-2, which can cause high yield losses, are common (Blackshaw 1993). Downy brome is less competitive with fall rye but still has the potential to reduce yields about 15 to 30 percent (Dunn and Blackshaw 2005). Its proliferation in the southern prairies has been associated with fall-seed crops, the adoption of conservation tillage practices, and continuous cropping (Blackshaw 1994; Dunn and Blackshaw 2005). It continues to be a problem in both winter and spring-seeded cereals in Alberta today (R. Blackshaw, pers. comm., 12 March 2015). In Saskatchewan, populations of Bromus tectorum tended to be small and isolated prior to 1960, after which it spread rapidly in subsequent decades in association with increased winter crops (winter wheat, fall rye), zero tillage practices, favorable weather conditions and lack of effective herbicides (Douglas et al. 1990).

Bromus tectorum is also one of the worst rangeland weeds and a fire hazard in British Columbia and Alberta (Dore and McNeill 1980). Frid et al. (2009) estimated the economic damage of Bromus tectorum

March 27, 2015

16

Review of four Bromus species PRA # 2015-08

in British Columbia to be $20.09 per ha due to fire and forage losses on rangeland. MacNaughton (2012) notes that Bromus tectorum and other introduced species are of particular concern on conservation lands and rangelands, both which benefit from the continued presence of intact, functioning grassland ecosystems. Management and restoration efforts in infested areas, which may include acquiring native seeds, are costly undertakings. Studies in the White Lake Basin of British Columbia have also demonstrated that invasion by Bromus tectorum is a factor in decreased native plant diversity (Deane 2010; MacNaughton 2012). In recent surveys in Alberta, Bromus tectorum was identified as a common invader of forage crops and hay (Alberta Agriculture and Rural Development 2014a). It was also identified as a species to watch out for in native rangeland in Alberta (Alberta Agriculture and Rural Development 2014b; Gerling 2007). As well, there is concern in the Saskatchewan forage industry over the introduction of Bromus tectorum into new areas of the province in association with AC Saltlander seed produced in Alberta (Kowalchuk 2015). AC Saltlander green wheatgrass (Elymus hoffmannii Jensen & Asay) is a forage grass and reclamation cultivar developed for improved salinity tolerance and promoted for the semiarid prairies (Steppuhn et al. 2006). In addition to western Canada, Bromus tectorum is also a common and troublesome in southwestern counties of Ontario from where it has spread into eastern counties (Dore and McNeill 1980).

Bromus tectorum is a prolific seed producer and a common seed contaminant. It is very difficult to separate from grass seed (Whitson et al. 1992). It occurs in Canadian forage mixtures, rye (Secale cereale), rough bluegrass (Poa trivialis), tall fescue (Festuca arundinacea), annual ryegrass (), and intermediate wheatgrass (Thinopyrum intermedium) seed (CFIA internal data). It is also found as a contaminant in Canadian grain commodities, including wheat, barley and soybeans (CGC data).

Control

Successful control of Bromus tectorum requires preventing seed production and exhausting the soil seed bank (Government of Saskatchewan 2013). Preventing infestations is considered the best strategy for cultivated land; any seed purchased should be free of Bromus tectorum and care should be taken to clean machinery (Beck undated; Government of Saskatchewan 2013; Invasive Species Council of Manitoba 2015). Mowing just after flowering is effective in preventing seed formation (Weber 2003). Heavy grazing temporarily eliminates plants, but populations recover quickly from the seed bank once grazing pressure is reduced.

There are numerous herbicides that control Bromus tectorum (Health Canada 2015; Upadhyaya et al. 1986). For example, (alone or in product mix with dicamba or 2,4-D) and pyroxsulam are effective against Bromus tectorum (Alberta Invasive Species Council 2014a; Health Canada 2015). Herbicides programs have been developed for crops such as winter wheat, alfalfa, perennial grasses grown for seed, and some rangeland plants (Upadhyaya et al. 1986). As with some of the other annual bromes, control in winter wheat has been difficult because the two species have very similar growth habits and susceptibility to herbicides (Upadhyaya et al. 1986). Currently, pyroxsulam is a good option for control of Bromus tectorum in winter wheat and new options will likely be available in the near future (Barker 2014; Blackshaw 2015; Epp 2014). Crop rotation is a common practice in the Prairies that

March 27, 2015

17

Review of four Bromus species PRA # 2015-08

allows for improved Bromus tectorum control (Blackshaw 2015). Selective control of Bromus tectorum in broad-leaved crops may be achieved during the rotation (Blackshaw 2015). In annual crops, fall tillage to stimulate seed germination or spring tillage and/or glyphosate application are also effective at controlling Bromus tectorum seedlings (Epp 2014; Kirkland and Brenzil 2007). In addition to winter cereals, control of Bromus tectorum in grass forages is also very challenging (Kirkland and Brenzil 2007).

Bromus tectorum herbicide resistance has been reported as early as 1981 in France, where resistance to atrazine (Group 5) was detected in a corn crop (Heap 2015). Since then, resistance to chlorotoluron (Group 7) in wheat and simazine (Group 5) in orchards has been observed in Spain and to several Group 2 herbicides in Kentucky bluegrass and several Group 1 herbicides in grass seed in Oregon (Heap 2015).

Conclusion

Bromus tectorum is relatively common in Canada. It is known to be an agricultural weed that contaminates seed and grain and its presence in seed could potentially affect the value and/or intended use of seed lots. There are fewer seed identification issues with Bromus tectorum than with the other three Bromus species considered in this document; however, separation of this species from its look- alikes can still be challenging on a practical basis. Bromus tectorum has been proposed as a secondary noxious weed seed (Class 3) together with Bromus arvensis, B. japonicus, and B. secalinus due to potential impacts and seed identification issues. This species is also listed as a noxious weed in Alberta, Saskatchewan and Manitoba.

March 27, 2015

18

Review of four Bromus species PRA # 2015-08

SEED IDENTIFICATION

In general, seeds of different Bromus species are not easily separated from each other. The more similar features there are among species, the greater the difficulty in distinguishing them on a practical basis. Partial seeds or seeds lacking awns may be particularly challenging if important diagnostic features are missing.

The following seed description and identification information was provided by the Seed Science and Technology Section, Saskatoon Laboratory, CFIA. A summary table of seed characteristics of the Bromus species considered in this document and their look-alike species is provided in Appendix 2.

Bromus arvensis (Figures 4a, b)

The species that have features most similar to Bromus arvensis are: B. japonicus, B. secalinus and B. hordeaceus. The florets of these four species have a similar boat-shaped profile, length, straw-yellow colour, roughened surface, reddish brown grain, arched rachillas and fine palea teeth.

Upon closer inspection, Bromus secalinus has the most obvious differences with B. arvensis: wider florets, dull brown grains and shorter awns and rachillas that should be visible with further examination. The distinguishing features of B. hordeaceus likely require closer examination and higher magnification to see: a hairy lemma and rachilla, and no hairs on the grain edges.

The differences between B. arvensis and B. japonicus are minor, and may be a challenge to spot without a good reference collection and trained staff. The differences may be further obscured if the awn is broken. Please see below for a more detailed comparison of these species.

Bromus arvensis Bromus japonicus Bromus secalinus 7.0 – 9.0 mm long similar length and wider by up to 1.0 similar length and Size of floret 1.0 – 1.5 mm wide width mm width shorter by up to shorter by up to 6.0 Length of awn 6.0 – 11.0 mm similar length 3.0 mm mm Straw-yellow, similar to B. similar to B. similar to B. Lemma roughened on the arvensis; usually arvensis arvensis upper ½ and margins hairy palea thicker, can Palea Smooth rough surface rough surface be hairy similar to B. Shorter than 1.0 Palea teeth Longer than 1.0 mm similar to B. arvensis arvensis mm similar to B. Reddish-brown, short- similar to B. similar colour; edges Grain arvensis; colour hairs along edges arvensis not hairy can be dull brown similar to B. similar to B. 1.5 – 2.3 mm, rough or similar to B. Rachilla arvensis; can be arvensis; usually hairy arvensis shorter hairy

March 27, 2015

19

Review of four Bromus species PRA # 2015-08

Bromus japonicus (Figures 5a, b)

The species that have features most similar to Bromus japonicus are: B. arvensis and B. hordeaceus. The florets of these three species have a similar boat-shaped profile, dimensions, straw-yellow colour, roughened surface, reddish brown grain, arched rachillas and long palea teeth.

The distinguishing features of the look-alike species require a closer examination and higher magnification: B. arvensis can have a longer rachilla and a lack of long hairs on the floret surface. The differences in B. hordeaceus are subtle: a much shorter awn and lack of hairs on the grain edges. Distinguishing these three species may require a good reference collection and trained staff, especially if the florets are processed. Please see below for a more detailed comparison of these species:

Bromus japonicus Bromus arvensis Bromus hordeaceus 7.0 – 9.0 mm long similar length and similar length and Size of floret 1.0 – 2.0 mm wide width width Length of awn 8.0 – 13.0 mm similar length shorter up to 9.0 mm Straw-yellow, rough or similar colour; similar colour and Lemma long-hairy on the surface not hairy surface upper ½ Palea Rough or hairy smooth similar to B. japonicus similar to B. Palea teeth Longer than 1.0 mm similar to B. japonicus japonicus Reddish-brown, short similar to B. similar colour; edges Grain hairs along edges japonicus not hairy 1.5 mm, linear, similar to B. Rachilla strongly arched, rough japonicus ; can be up similar to B. japonicus or hairy to 1.0 mm longer

March 27, 2015

20

Review of four Bromus species PRA # 2015-08

Bromus secalinus (Figures 6a, b)

The species that have features most similar to Bromus secalinus are: B. arvensis and B. japonicus. The florets of these three species have a similar boat-shaped profile, dimensions, straw-yellow colour, roughened surface, and arched rachillas.

When examining the florets of these three species without magnification, the wider floret, a thicker, more strongly folded brownish grain and the short awn of B. secalinus are notable. However, these features may be variable and all features may not be obvious if the seed is processed.

The distinguishing features of the look-alike species require a closer examination and higher magnification: B. arvensis can have a narrower floret, a longer awn, a hairy rachilla and a reddish grain colour when compared to B. secalinus. The differences between B. secalinus and B. japonicus are very similar to B. arvensis and include a lemma that may be hairy. Distinguishing these three species may require a good reference collection and trained staff, especially if the florets are processed. Please see below for a more detailed comparison of these species:

Bromus secalinus Bromus arvensis Bromus japonicus Size of 6.5 – 8.5 mm long similar length, can be similar length, can be floret 1.8 – 2.5 mm wide narrower narrower Length of can be longer up to can be longer up to 3.0 – 6.0 mm long awn 5.0 mm 10.0 mm Straw-yellow, rough on similar to B. secalinus, Lemma similar to B. secalinus the upper ½ and edges can be hairy Palea Rough smooth rough or hairy Palea teeth Shorter than 1.0 mm longer than B. secalinus longer than B. secalinus Dull brown, short hairs reddish-brown, short reddish-brown, short Grain along edges hairs along edges hairs along edges 1.0 – 2.0 mm, similar to B. secalinus, similar to B. secalinus, Rachilla strongly arched, rough can be hairy can be hairy

March 27, 2015

21

Review of four Bromus species PRA # 2015-08

Bromus tectorum (Figures 7a, b)

Bromus tectorum is the most easily distinguished species among the four in this treatment. Even without magnification the floret is notably narrower and longer than the other three brome species: B. arvensis, B. japonicus and B. secalinus. The distinctive dark purple grain, purplish lemma and straight rachilla of B. tectorum are also evident with a cursory examination of the florets.

The species that have features most similar to Bromus tectorum are B. diandrus and B. madritensis. When examined without magnification the florets of these three species have a similar narrow, arched profile, purplish lemmas, dark grains, roughened surface, and straight rachillas.

Distinguishing the look-alike species from B. tectorum requires a longer examination and higher magnification: B. diandrus has a much longer floret, lack of hairs on the lemma, smooth palea, shorter palea teeth and brown grains. Bromus madritensis florets contain features that are even closer to B. tectorum, and can be distinguished by: a shorter floret, lemma without hairs and the majority of palea teeth shorter when compared to B. tectorum.

Bromus tectorum can be distinguished from B. arvensis, B. japonicus and B. secalinus using low or no magnification. Distinguishing B. tectorum from its look-alike species, specifically B. madritensis, may require a good reference collection and trained staff. Please see below for a more detailed comparison of these species:

Bromus tectorum Bromus diandrus Bromus madritensis longer up to 12.0 mm 9.0 – 12.0 mm long shorter by up to Size of floret and wider up to 1.0 – 2.0 mm wide 4.0 mm 1.0 mm Length of awn 10.0 – 18.0 mm similar to B. tectorum similar to B. tectorum similar to B. Straw-yellow with similar to B. tectorum, Lemma tectorum, not usually purple streaks, hairy not usually hairy hairy Palea Rough or hairy smooth similar to B. tectorum most shorter than Palea teeth Longer than 1.0 mm shorter than 1.0 mm 1.0 mm, a few longer similar to B. Dark purple-red, similar to B. tectorum, tectorum, reddish- Grain arched, short hairs reddish-brown colour brown or dark purple along edges colour 2.5 – 3.0 mm, not Rachilla arched, glabrous to similar to B. tectorum similar to B. tectorum ciliate

March 27, 2015

22

Review of four Bromus species PRA # 2015-08

Figures 4a. Bromus arvensis florets (left); b. floret details (right). National Seed Herbarium, CFIA.

Figures 5a. Bromus japonicus florets (left); b. floret details (right). National Seed Herbarium, CFIA.

Figures 6a. Bromus secalinus caryopsis and florets (left); b. floret details (right). National Seed Herbarium, CFIA.

Figures 7a. Bromus tectorum florets (left); b. floret details (right). National Seed Herbarium, CFIA.

March 27, 2015

23

Review of four Bromus species PRA # 2015-08

CFIA RESPONSE TO STAKEHOLDER COMMENTS

Background

Several stakeholders have responded with concern related to the addition of annual bromes to the Weed Seeds Order. The information they present and the CFIA response are presented here.

Stakeholder Comment:

 Annual bromes (referring to Bromus tectorum, B. japonicus and B. secalinus) have been misclassified as invasive.  The designation of downy brome as ‘invasive’ is an undeserved stigmatism and overplays the potential danger (invasiveness) of the three downy brome species. Downy brome is not invasive.

CFIA Response: The proposed listing of the annual bromes as secondary noxious does not depend upon these species fitting the definition of invasive species. Secondary noxious is defined as: The species is relatively common and widespread in Canada. The species must be a weed whose presence in seed could affect the value and/or intended use of the seed lot. The species must have identifiable seeds that can be visually distinguished from those of other species, or in rare instances, from entire genera. The annual brome species in this proposal meet the criteria for potentially affecting seed lots and being visually distinguishable, and with the exception of Bromus arvensis and Bromus secalinus, are common and widespread in Canada.

The Invasive Alien Species Strategy for Canada defines invasive species as “harmful alien species whose introduction or spread threatens the environment, the economy, or society” (Government of Canada 2004). The annual bromes all fit within this description, as described in detail in this document.

Bromus tectorum, the most prevalent of the annual bromes, is one of the most invasive and widespread exotic plants in North America (Owen et al. 2011). It is well recognized as an invasive plant and a major weed of rangelands and agronomic fields in North America. It is described as a highly invasive exotic grass that has the ability to remain the dominant species in a plant community for a long period of time (CABI 2015b). In the approximately 125 years since introduction into Canada, its range has expanded dramatically on both sides of the country. Further range expansion across Canada is thought possible through the formation of novel genotypes as a result of outcrossing events and adaptive evolution (Valliant et al. 2007).

Stakeholder Comment: In Canada, the ecological range of annual bromes includes the dry interior of British Columbia, the Chinook belt of Southern Alberta, and to a lesser degree Southwestern Saskatchewan and the southern prairies.

March 27, 2015

24

Review of four Bromus species PRA # 2015-08

CFIA Response: Partially agree. Bromus tectorum is most prevalent in the areas described above, and Bromus japonicus is also rather abundant in some of those areas (Frankton and Mulligan 1993). However, the four annual brome species are potentially hardy to much of Canada and, with the exception of Bromus arvensis, which is rare in Canada, are currently found in both western and eastern Canada. Bromus tectorum, and to a lesser extent, Bromus japonicus, are both problem weeds in the east as well (e.g., southern Ontario) (Darbyshire 2003; Dore and McNeill 1980; Uva et al. 1997). Bromus secalinus is more common in Ontario than other provinces, although it is now on the decline (Cowbrough et al. 2007; Dore and McNeill 1980). The annual bromes pose a threat to winter and spring cereals, pastures, rangelands and dry hayfields (Epp 2014; Kirkland and Brenzil 2007).

Stakeholder Comment: A review of the scientific literature brings to light the principle mechanism that allows downy brome to dominate other species in the long, cool, wet winters of its primary , the American Intermountain Region. Downy brome has the capacity to continue root development in soil temperatures as low as 3ºC after winter wheat and desirable perennials have stopped root development at 8º to 10ºC (Upadhyaya et al., 1986). This invasiveness promoting advantage is eliminated in the frozen, snow covered winters of the Canadian Prairies combined with relatively wet spring and summers and rhizomatous native plant communities. More specifically, the topsoil is frozen in the American Intermountain Region generally one to three of the winter months as opposed to five or months in the Canadian Prairies. This is extremely relevant to the Canadian prairies and is at the heart of downy brome’s climatologic containment.

CFIA Response: Bromus tectorum has the ability to germinate in the fall, over winter and mature in the spring, or germinate and mature in the spring. It can grow at very low temperatures and is active before native grassland species have emerged from in the spring and after they have ceased growth in the fall (Gayton 2013; Thill et al. 1984). Although winters are colder and longer in the Canadian Prairies than in the American Intermountain region, Bromus tectorum would still have an advantage over desirable perennials during periods when temperatures are between about 3º and 8ºC.

Stakeholder Comment: These three opportunistic weeds can be successful only in the very short term when there is freshly disturbed soil and an absence of plant . Once the disturbance is healed by vegetation the downy brome quickly recedes.

CFIA Response: We agree that the spread of Bromus tectorum and other annual bromes is enhanced by disturbance. However, disturbance (e.g., livestock grazing, trampling, fire, cultivation activities, road and railroad construction) is common and often repetitive, allowing Bromus tectorum to persist in many cases and/or to spread to other areas. Research has also shown that the presence of Bromus tectorum in a plant community can permanently alter the community or at least interrupt the progress of succession for long periods of time as it does not allow the recruitment of seedlings of native plants species due to competition for water (B.C. Ministry of Agriculture 2002; CABI 2015b). Bromus tectorum uses more water earlier in the growing season than many native plants as it can initiate root and growth at lower temperatures and has greater root and shoot relative growth rates. These attributes all contribute to giving it a competitive advantage over native species in disturbance scenarios (Parkinson et al. 2013). In some areas, Bromus tectorum has also been reported to invade pristine areas and stable

March 27, 2015

25

Review of four Bromus species PRA # 2015-08

native plant communities where it can successfully compete with established native perennial species (Emmerich et al. 1993). Furthermore, Bromus tectorum is difficult to get rid of once established in an area (Gerling 2007).

Stakeholder Comment:

 Escalating the status of downy brome to secondary noxious as proposed in the forthcoming Federal Weed Seeds Order can have a serious and negative long-term effect on grass seed production in Southern Alberta. A significant portion of chaffy grass lots would be ineligible for Certified No. 2 status and some even ineligible for Common No. 2 status due to the presence of downy brome at higher than acceptable levels.  The new classification would definitely penalize growers in an area where it is a problem. Currently the Canadian forage seed market handles downy brome with a simply enforced economic rationale; “if there is any downy brome in a sample, we won’t purchase it.” Changes to its weed status could only serve to disrupt sales of Canadian seed containing downy brome into a market that does not see downy brome as a problem. This would place undue difficulties on any seed business in regions where downy brome grows. While this is a seed related discussion, please do not let any of the groups in favour of changing the status of this weed forget that in relation to downy brome; land mismanagement, hay, straw and feeds are not controlled by anyone and are likely much more important factors in the establishment of downy brome.

CFIA Response: We recognize that including the four annual brome species on the Weed Seeds Order could have negative impacts on prairie forage seed production. Currently, under the Weed Seeds Order, 2005, these four brome species are considered “other weeds” for the purposes of establishing grade. The proposed amendments would result in the brome species being listed as secondary noxious weed seeds. The table below compares the maximum allowable levels of the brome species in Grade Tables XI (single ingredient pasture and turf species) and XII (single ingredient turfgrass species) currently permitted in Canada Certified No. 1 and No. 2 with the allowable levels under the proposed amendments.

Allowable levels of the brome species in Certified Grade Table of seed Schedule I of the Grade Current status (WSO, Seeds Regulations 2005) Proposed amendments Grade Table XI Canada Certified No. 1 50 seeds per 25g 4 seeds per 25g Grade Table XI Canada Certified No. 2 75 seeds per 25g 10 seeds per 25g Grade Table XII Canada Certified No. 1 0.5 % by weight 20 seeds per 25g Grade Table XII Canada Certified No. 2 0.8% by weight 50 seeds per 25g

March 27, 2015

26

Review of four Bromus species PRA # 2015-08

In addition to the forage seed industry, Bromus tectorum also affects forage production, rangeland health and carrying capacity, livestock production, establishment of native species in reclamation sites, and winter cereal quality and yield, as described in this document. It is anticipated that the listing of the brome species as secondary noxious weed seeds on the Weed Seeds Order will have positive impacts in a number of other areas by helping to slow or prevent further spread of these harmful weed species.

Bromus tectorum and Bromus japonicus have also been flagged as problematic weeds by the provincial governments of Alberta, Saskatchewan and Manitoba (B. tectorum only), who have included these species in their weed control acts in order to control their spread.

Stakeholder Comment: No known monoculture infestations of downy brome dominate undisturbed native range in Alberta’s 2.1 million acres of healthy native rangeland. On multiple sites totaling a few hundred acres downy brome is one of two species occupying 20% of the plant canopy in a sandy site Stipa (speargrass) community. After 100 years presence in Alberta, and on the basis of this information, there is no imminent threat of downy brome invading healthy rangeland.

CFIA Response: We agree that Bromus tectorum is not known to be a problem in healthy rangelands of southern Alberta. Its invasion is accelerated by disturbance, including cultivation, land abandonment, excessive grazing pressure by livestock, and repeated fires (Zouhar 2003). Although Bromus tectorum has also been shown to thrive in some areas with little or no history of disturbance, healthy native ranges would not be as susceptible to invasion by Bromus tectorum. However, even if not a significant threat to healthy rangeland in Alberta, Bromus tectorum is still a concern in other sectors and provinces.

Stakeholder Comment: Regarding downy brome as a fire hazard, there may be a severe problem in some parts of the but not in Alberta. Even the most severe disturbance sites I’ve seen would have difficulty carrying a fire. Burning to control downy brome is not an Alberta practice.

CFIA Response: Bromus tectorum range expansion has increased fire frequencies in some ecosystems as it provides a continuous cover of fine fuel that dries early in the growing season. This is a particular concern in big sagebrush (Artemesia tridentata) and pinyon –juniper ecosystems (Pinus-juniperus). Bromus tectorum is able to persist under frequent fires however species such as big sagebrush can be eliminated (Owen et al. 2011). Big sagebrush is native to British Columbia and the southwest corner of Alberta. The intermountain region of British Columbia is a fire dependant ecosystem where the presence of Bromus tectorum and a change in the frequency of fire could result in negative impacts to and range health and carrying capacity.

Stakeholder Comment: If we were to reduce the level of urgency (based on the perception of “invasiveness”) to a more sustainable outlook it is quite possible that we treat downy brome outbreaks on native range with reduced dosages of diquat or dicamba at pollination time to disrupt downy brome seed set while allowing native plants time to reclaim the disturbance.

March 27, 2015

27

Review of four Bromus species PRA # 2015-08

CFIA Response: Restoration of native rangelands dominated by Bromus tectorum can be challenging. Restoration plans need to be site-specific and can include a variety of methods including chemical control, mowing, burning, re-seeding and management of disturbances such as grazing or off-road vehicle use. Successful restoration requires control of the existing Bromus tectorum population and seedbank, along with the establishment of native plants that can compete with future invasive plant incursions. It also requires management actions to limit the re-introduction of invasive annual species and to prevent soil disturbance by livestock grazing and trampling or other activities such as off-highway vehicle traffic (Rosentreter 1998). Herbicides that can control annual species can be a component of the strategy to restore native rangelands but are most effective when combined with other management strategies. Owen et al. (2011) indicate that downy brome has the ability to recover after disturbance, and that disturbances associated with herbicide application and seeding can significantly increase downy brome . Chemical control alone can give short term control but the site is susceptible to re- invasion unless other techniques are used.

It is beyond the scope of the Weed Seeds Order revision to consider the pros and cons of various chemical applications for control of weeds.

March 27, 2015

28

Review of four Bromus species PRA # 2015-08

APPENDIX 1: NOXIOUS WEED SEED CLASS DEFINITIONS

Prohibited Noxious The species is not yet present in Canada, or is present and is under official control as it has not yet reached its full ecological range. Official control is used to prevent further spread of the species and with the goal of eradicating the species. The species must be a weed whose presence in seed could affect the value and/or intended use of the seed lot; and/or could have potential impact on the economy, human health and/or animal health. This determination would be based on a Pest Risk Assessment type process. The species must have identifiable seeds that can be visually distinguished from those of other species, or in rare instances, from entire genera.

Primary Noxious The species is present in Canada and has not reached its full ecological range. The species must be a weed whose presence in seed could affect the value and/or intended use of that seed lot; and/or could have a potential impact on the economy, human health or animal health. This determination would be based on a Pest Risk Assessment type process, when deemed to be necessary. The species must have identifiable seeds that can be visually distinguished from those of other species, or in rare instances, from entire genera.

Secondary Noxious The species is relatively common and widespread in Canada. The species must be a weed whose presence in seed could affect the value and/or intended use of the seed lot. The species must have identifiable seeds that can be visually distinguished from those of other species, or in rare instances, from entire genera.

Other weed seeds Seeds of all plant species that are not included either in the noxious weed seed lists of the Weed seeds Order nor in the Grade Tables of Schedule I to the Seeds Act and Regulations are automatically classified as “other weed seeds”. There is no comprehensive list of “other weed” species.

March 27, 2015

29

Review of four Bromus species PRA # 2015-08

APPENDIX 2: SEED COMPARISON OF BROMUS SPECIES Bromus Bromus Feature Bromus arvensis Bromus japonicus Bromus secalinus Bromus tectorum Bromus diandrus hordeaceus madritensis 16.0 – 21.0 mm 8.0 – 9.0 mm long 7.0 – 9.0 mm long 7.0 – 9.0 mm long 6.5 – 8.5 mm long 9.0 – 12.0 mm long 8.0 – 9.0 mm long Size of floret long 1.5 – 2.0 mm 1.0 – 1.5 mm wide 1.0 – 2.0 mm wide 1.8 – 2.5 mm wide 1.0 – 2.0 mm wide 1.5 – 2.0 mm wide 2.0 – 3.0 mm wide wide

Length of 6.0 – 11.0 mm 8.0 – 13.0 mm 3.0 – 6.0 mm long 10.0 – 18.0 mm up to 4.0 mm 12.0 – 17.0 mm 12.0 – 17.0 mm awn

Straw-yellow, Straw-yellow, scabrous on the Straw-yellow, Straw-yellow with scabrous on the Straw-yellow, Straw-yellow to Straw-yellow to Lemma upper ½ and scabrous or ciliate purple streaks, upper ½ and scabrous or ciliate purple, scabrous purple, scabrous margins, can be on the upper ½ ciliate margins wrinkled

Scabrous to Palea Glabrous Scabrous or ciliate Scabrous Scabrous to ciliate Glabrous to ciliate Glabrous ciliate

Most shorter Longer than 1.0 Longer than 1.0 Shorter than 1.0 Longer than 1.0 Longer than 1.0 Shorter than 1.0 Palea teeth than 1.0 mm, a mm mm mm, thick mm, fine mm, sparse mm few longer Reddish-brown or Reddish-brown, Reddish-brown, Reddish-brown, Dull brown, Dark purple-red, purple, Reddish-brown, pubescent along Grain scabrous along scabrous along scabrous along scabrous along pubescent along thin margins, flares at margins, thick margins, thin margins, thick margins, arched margins, flares at the top, arched the top, arched 1.0 – 2.0 mm, 1.3 – 1.5 mm, 1.5 – 2.3 mm, 1.5 mm, linear, wedge-shaped, wedge-shaped, 2.5 – 3.0 mm, linear, 2.5 – 3.0 mm, 2.5 – 3.0 mm, Rachilla linear, scabrous to strongly arched, strongly arched, strongly arched, glabrous to ciliate linear, scabrous linear, scabrous ciliate scabrous to ciliate expanded at the expanded at the top, scabrous top, ciliate

March 27, 2015

30

Review of four Bromus species PRA # 2015-08

REFERENCES

Alberta Agriculture and Rural Development. 2012. Alberta Certified Weed Free Hay Program. [Online] Available: http://www1.agric.gov.ab.ca/$Department/deptdocs.nsf/All/prm1325 [2015].

Alberta Agriculture and Rural Development. 2014a. Invasive Plants in Alberta: Forages and Hay Land. Government of Alberta, Alberta Agriculture and Rural Development. [Online] Available: http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/agdex14757 [2015].

Alberta Agriculture and Rural Development. 2014b. Invasive Plants in Alberta: Native Rangeland. Government of Alberta, Alberta Agriculture and Rural Development. [Online] Available: http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/agdex15037 [2015].

Alberta Invasive Species Council. 2014a. Downy brome (Bromus tectorum) (aka cheatgrass, cheatgrass brome, drooping brome, downy chess, early chess). [Online] Available: https://www.abinvasives.ca/fact-sheets [2015].

Alberta Invasive Species Council. 2014b. Japanese brome (Bromus japonicus) (aka Japanese chess, Japanese bromegrass). [Online] Available: https://www.abinvasives.ca/fact-sheets [2015].

Amann, A. 2002. Propoxycarbazone-sodium - the chemical cornerstone of integrated brome-grass management in Germany. Pflanzenschutz-Nachrichten Bayer 55(1):87-100.

Andersson, L., Milberg, P., Schültz, W. and Steinmetz, O. 2002. Germination characteristics and emergence time of annual Bromus species of differing weediness in Sweden. Weed Research 42(2):135-147.

Armstrong, J. and Peeper, T. F. undated. Cheat control in Oklahoma winter wheat. Oklahoma Cooperative Extension Service PSS-2774. Oklahoma State University. [Online] Available: http://www.okrangelandswest.okstate.edu/files/invasive%20species%20pdfs/PSS-2774.pdf [2015].

B.C. Ministry of Agriculture. 2002. A Guide to Weeds in British Columbia. Cheatgrass. Bromus tectorum L. [Online] Available: http://www.weedsbc.ca/pdf/cheatgrass.pdf [2015].

Bailey, L. G. and Bailey, E. Z. 1976. Hortus Third: A concise dictionary of plants cultivated in the United States and Canada. McMillan Publishing Co., , New York.

Barker, B. 2014. Controlling Japanese and downy brome: Research looking to expand weed control options in winter wheat. AgAnnex. [Online] Available: http://www.agannex.com/energy/controlling-japanese-and-downy-brome [2015].

Barkworth, M. E., Capels, K. M., Long, S., Anderton, L. K. and Piep, M. B. 2007. Flora of North America, Vol. 24. [Online] Available: http://herbarium.usu.edu/webmanual [2015].

Beck, K. G. undated. Downy brome (Bromus tectorum) and Japanese brome (Bromus japonicus) Biology, , and Management. Literature Review. Colorado State University. [Online] Available: http://mining.state.co.us/SiteCollectionDocuments/DownybromeandJapanesebromeliteraturer eviewColoradoDRMSDec09.pdf [2015].

March 27, 2015

31

Review of four Bromus species PRA # 2015-08

Blackshaw, R. 2015. Information on Bromus tectorum and Bromus japonicus in Alberta. Personal communication to K. Castro on March 12, 2015.

Blackshaw, R. E. 1993. Downy brome (Bromus tectorum) density and relative time of emergence affects interference in winter wheat (Triticum aestivum). Weed Science 41:551-556.

Blackshaw, R. E. 1994. Rotation affects downy brome (Bromus tectorum) in winter wheat (Triticum aestivum). Weed Technology 8(4):728-732.

Brenzil, C. 2015. Information about Saskatchewan's Weed Control Act. Personal communication to K. Castro on March 13, 2015.

Brouillet, L., Coursol, F., Favreau, M. and Anions, M. 2010+. VASCAN, the database vascular plants of Canada. [Online] Available: http://data.canadensys.net/vascan/ [2015].

Buckner, D. L. and Downey, S. 2009. Patterns of annual brome abundance in reclaimed and native rangelands in the Northern Great Plains: A case study from the Big Sky Mine, Southeastern MT. Pages 141-150 26th Annual Meeting of the American Society of Mining and Reclamation and 11th Billings Land Reclamation Symposium 2009.

Budd, A. C. and Best, K. F. 1964. Wild plants of the Canadian Prairies. Research Branch, Canada Department of Agriculture, Ottawa, ON.

CABI. 2015a. Crop Protection Compendium. CAB International, Wallingford, UK. [Online] Available: http://www.cabi.org/cpc/ [2015].

CABI. 2015b. Invasive Species Compendium. CAB International, Wallingford, UK. [Online] Available: www.cabi.org/isc [2015].

CanLII. 2015. The Canadian Legal Information Institute. [Online] Available: http://www.canlii.org/en/index.php [2015].

Cardon, J. L. and Pierron, S. 2013. Interest of pyroxsulam and propyzamide against bromes in the crop rotation. Pages 240-248 22e Conference du COLUMA Journees Internationales sur la Lutte contre les Mauvaises Herbes. Association Française de Protection des Plantes (AFPP), Dijon, France.

CFIA. 2014a. Cultivated Plants in Canada (Internal Database). Canadian Food Inspection Agency and Canadian Ornamental Plants Foundation, Ottawa, ON.

CFIA. 2014b. Pests Regulated by Canada, Ottawa, Ontario. [Online] Available: http://www.inspection.gc.ca/plants/plant-protection/pests/regulated- pests/eng/1363317115207/1363317187811#e [2015].

CFIA and NRCan/CFS. 2011+. Plants of Canada Database. Canadian Food Inspection Agency and Canadian Forest Service. [Online] Available: http://www.plantsofcanada.info.gc.ca/taxa.php?lang=e [2015].

March 27, 2015

32

Review of four Bromus species PRA # 2015-08

Cody, W. J. 2000. Flora of the Yukon Territory. National Research Council of Canada, Ottawa, On. 669 pp.

Cowbrough, M., Darbyshire, S. J., Sikkema, P. and Tardif, F. 2007. Weed Profile: Chess, Bromus secalinus L. Ontario Minitry of Agriculture, Food and Rural Affairs. [Online] Available: http://www.omafra.gov.on.ca/english/crops/facts/info_chess.htm [2015].

Darbyshire, S. J. 2003. Inventory of Canadian Agricultural Weeds. Agriculture and Agri-Food Canada, Research Branch, Ottawa, ON.

Davis, L. W. 1993. Weed Seeds of the Great Plains: A Handbook for Identification. University Press of Kansas, Lawrence, Kansas.

Deane, T. J. 2010. Environmental and biotic influences on the abundance of an introduced grass species: implications for management in the Okanagan Valley, British Colombia Master of Science. University of British Columbia, Vancouver, BC.

Dore, W. G. and McNeill, J. 1980. Grasses of Ontario. Minister of Supply and Services Canada, Hull, Quebec. 566 pp.

Douglas, B. J., Thomas, A. G. and Derksen, D. A. 1990. Downy brome (Bromus tectorum) invasion into southwestern Saskatchewan. canadian Journal of Plant Science 70:1143-1151.

Dunn, R. and Blackshaw, B. 2005. Downy brome control in direct seeding systems. Direct Seeding Agdex 519-14. Alberta Agriculture and Rural Development. [Online] Available: http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/agdex3484/$file/519- 14.pdf?OpenElement. eFloras. 2015. Electronic Floras. Missouri Botanical Garden, St. Louise, MO & Harvard University Herbaria, Cambridge, MA. [Online] Available: http://www.efloras.org [2015].

Emmerich, F. L., Tipton, F. H. and Young, J. A. 1993. Cheatgrass: changing perspectives and management strategies. Rangelands 15:37-40.

Epp, M. 2014. Controlling downy brome. Grainews. [Online] Available: http://www.grainews.ca/2014/05/22/controlling-downy-brome/ [2015].

Finnerty, D. W. and Klingman, D. L. 1962. Life cycles and control studies of some weed bromegrasses. Weeds 10(1):40-47.

Frankton, C. and Mulligan, G. A. 1993. Weeds of Canada. Agriculture Canada, Publication 948.

Frid, L., Knowler, D., Murray, C., Myers, J. and Scott, L. 2009. Economic impacts of invasive plants in British Columbia. Report #12. Prepared for the Invasive Plant Council of BC by ESSA Technologies Ltd., Vancouver, BC. 105 pp.

Gayton, D. 2012. New research on an old weed. BC Journal of Ecosystems and management 13(1):1-2.

March 27, 2015

33

Review of four Bromus species PRA # 2015-08

Gayton, D. 2013. British Columbia's Grassland Resources and Climate Change. Journal of Ecosystems and Management 14(2):104-118.

Gayton, D. and Miller, V. 2012. Impact of biological control on two knapweed species in British Columbia. Journal of Ecosystems and Management 13(3):1-14.

GBIF. 2015. GBIF, Online Database. Global Biodiversity Information Facility (GBIF). [Online] Available: http://data.gbif.org/welcome.htm [2015].

Gerling, H. 2007. Control options for downy brome on prairie reclamation sites. Agri-Facts Agdex 641- 15. Alberta Agriculture and Rural Development. [Online] Available: http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/agdex3472/$file/641- 15.pdf?OpenElement.

Gleason, H. A. and Cronquist, A. 1991. Manual of Vascular Plants of Northeastern United State and Adjacent Canada. The New York Botanical Garden, Bronx, New York.

Government of Canada. 2004. An invasive alien species strategy for Canada. [Online] Available: http://publications.gc.ca/collections/collection_2014/ec/CW66-394-2004-eng.pdf [2015].

Government of Manitoba. 2010. The Noxious Weeds Act, C. C. S. M. c. N110. [Online] Available: http://web2.gov.mb.ca/laws/statutes/ccsm/n110e.php [2015].

Government of Saskatchewan. 2010. The Weed Control Act. Chapter W-11.1 of the Statutes of Saskatchewan, 2010 (effective December 1, 2010) as ammended by the Statutes of Saskatchewan, 2014, c. 19. The Queen's Printer, Regina, Saskachewan.

Government of Saskatchewan. 2013. Weed Identification Guide. Grassy Weed - Downy brome (N). Government of Saskatchewan Agriculture. [Online] Available: http://www.agriculture.gov.sk.ca/Default.aspx?DN=873b2597-ac41-411e-ac00-b9f68bb53fb6 [2015].

Harmoney, K. R. 2007. Grazing and burning Japanese brome (Bromus japonicus) on mixed grass rangelands. Rangeland Ecology & Management 60(5):479-486.

Health Canada. 2015. Consumer Product Safety. Search Product Label service. Pest Management Regulatory Agency. [Online] Available: http://pr-rp.hc-sc.gc.ca/ls-re/index-eng.php [2015].

Heap, I. 2015. The international survey of herbicide resistant weeds. Weed Science Society of America. [Online] Available: www.weedscience.com [2015].

Hitchcock, A. S. 1950. Manual of the grasses of the United States. United States Government Printing Office, Washington, D. C.

Hoiland, K. 1993. Threatened plants in the cultural landscape in Norway: 1. Weeds in arable environments. NINA (Norsk Institutt for Naturforskning) Utredning 0(47):1-44.

Holm, L. G., Pancho, J. V., Herberger, J. P. and Plucknett, D. L. 1991. A Geographical Atlas of World Weeds. Krieger Publishing Company, Malabar, Florida.

March 27, 2015

34

Review of four Bromus species PRA # 2015-08

Howard, J. L. 1994. Bromus japonicus. In: Fire Effects Information System. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). [Online] Available: http://www.fs.fed.us/database/feis/plants/graminoid/brojap/all.html [2015].

Invasive Species Council of Manitoba. 2015. Downy Brome. [Online] Available: http://invasivespeciesmanitoba.com/site/index.php?page=downy-brome [2015].

Isaacson, R. T. and Allen, K. 2007. Plant Information Online. University of Minnesota Libraries, Minnesota, USA. [Online] Available: https://plantinfo.umn.edu/ [2014].

Kimmel, N. 2015. Information on the Alberta Weed Control Act. Personal communication to K. Castro on March 16, 2015.

Kirkland, M. L. and Brenzil, C. 2007. Problem Weeds - A Cattleman's Guide. Government of Saskatchewan, Agriculture. [Online] Available: http://www.agriculture.gov.sk.ca/Problem_Weeds_Cattlemens_Guide [2015].

Klinkenberg, B. 2013. E-Flora BC: Electronic Atlas of the Plants of British Columbia. Lab for Advanced Spatial Analysis, Department of Geography, University of British Columbia, Vancouver. [Online] Available: http://www.geog.ubc.ca/biodiversity/eflora/ [2015].

Knapp, P. A. 1996. Cheatgrass (Bromus tectorum L.) dominance in the Desert. Global Environmental Change 6(1):37-52.

Kowalchuk, T. 2015. Information on the Saskatchewan Forage Industry. Personal communication to K. Castro on March 18, 2015.

Leeson, J. Y., Thomas, A. G., Hall, L. M., Brenzil, C. A., Andrews, T., Brown, K. R. and Van Acker, R. C. 2005. Prairie Weed Surveys of Cereal, Oilseed and Pulse Crops from the 1970s to the 2000s. Weed Survey Series Publication 05-1. Agriculture and Agri-Food Canada, Saskatoon Research Centre, Saskatoon, Saskatchewan. 395 pp.

Lesnik, M. 1999. Possibilities and needs for chemical control of field brome (Bromus arvensis L.) in winter wheat (Triticum aestivum L.). [Slovenian]. Pages 99-107 Zbornik predavanj in referatov 4 Slovenskega Posvetovanja o Varstvu Rastlin v Portorozu od 3 do 4 Marca 1999. Drustvo za varstvo rastlin Slovenije, Slovenia.

Looman, J. and Best, K. F. 1987. Budd's Flora of the Canadian Prairie Provinces. Minister of Supply and Services Canada. Research Branch Agriculture Canada. Publication 1662., Hull, Quebec.

Mack, R. N. 1981. Invasion of Bromus tectorum L. into western North America: An ecological chronicle. Agro-Ecosystems 7:145-165.

MacNaughton, C. J. 2012. Invasive plant influence on the native grass community of the White Lake Basin, British Columbia Master of Science. Royal Roads University.

Marie-Victorin, F. 1995. Flore Laurentienne. Gaëtan Morin Éditeur ltée, Boucherville, Quebec.

March 27, 2015

35

Review of four Bromus species PRA # 2015-08

Mehner, S., Manurung, B., Gruntzig, M., Habekuss, A., Witsack, W. and Fuchs, E. 2003. Investigations into the ecology of the wheat dwarf virus (WDV) in Saxony-Anhalt, Germany. Zeitschrift für Planzenkrankheiten und Pflanzenschultz 110(4):313-323.

Menegat, A., Kaiser, Y., Stephan, A., Hanwen, N. and Gerhards, R. 2012. Chlorophyll fluorescence microscreening as a rapid detection method for herbicide resistance in grass weeds in North China Plain winter wheat production systems and beyond. Pakistan Journal of Weed Science Research 18:409-418.

Morrow, L. A. and Stahlman, P. W. 1984. The history and distribution of downy brome (Bromus tectorum) in North America. Weed Science 32(Supplement 1):2-6.

Murphy, S. D. 2011. Smurphbot 3.0: Vascular Flora Common and Latin names for Northeastern Canada & USA. Last updated September 2011, Waterloo, ON. [Online] Available: https://uwaterloo.ca/environment-resource-studies/sites/ca.environment-resource- studies/files/uploads/files/SmurphBot30.pdf [2015].

Newmaster, S. G. and Ragupathy, S. 2012. Flora Ontario - Integrated Botanical Information System (FOIBIS), Phase I. University of Guelph, Canada. [Online] Available: http://www.uoguelph.ca/foibis/ [2015].

Ogle, S. M., Ojima, D. and Reiners, W. A. 2004. Modeling the impact of exotic annual brome grasses on soil organic carbon storage in a northern mixed-grass prairie. Biological Invasions 6(3):365-377.

Ogle, S. M., Reiners, W. A. and Gerow, K. G. 2003. Impacts of exotic annual brome grasses (Bromus spp.) on ecosystem properties of northern mixed grass prairie. American Midland Naturalist 149(1):46-58.

Oja, T., Jaaska, V. and Vislap, V. 2003. Breeding system, evolution and of Bromus arvensis, B. japonicus and B. squarrosus (Poaceae). Plant Systematics and Evolution 242(1-4):101-117.

Owen, S. M., Sieg, C. H. and Gehring, C. A. 2011. Rehabilitating downy brome (Bromus tectorum) - Invaded shrublands using imazapic and seeding with native shrubs. Invasive Plant Science and Management 4(223-233).

Paradowski, A. 2003. Characteristics and control of weeds occurring locally. Ochrona Roslin 47(5):18-22.

Parkinson, H., Zabinski, C. and Shaw, N. 2013. Impact of native grasses and cheatgrass (Bromus tectorum) on Great Basin Forb Seedling Growth. Rangeland Ecology & Management 66(2):174- 180.

Peeper, T. F. 1984. Chemical and biological control of downy brome (Bromus tectorum) in wheat and alfalfa in North America. Weed Science 31(Supplement 1):18-25.

Plant Quarantine India. 2007. Schedule-VIII [See Clause 3(12)] List of Quarantine Weed Species. [Online] Available: http://plantquarantineindia.nic.in/PQISPub/pdffiles/Schedule-VIII-ason-4th- Oct2007.pdf [2015].

March 27, 2015

36

Review of four Bromus species PRA # 2015-08

Province of Alberta. 2008. Weed Control Act. Statutes of Alberta, 2008. Chapter W-5.1 Current as of October 1, 2011. Alberta Queen's Printer, Edmonton, Alberta.

Province of Alberta. 2010. Weed Control Act. Weed Control Regulation. Alberta Regulation 19/2010. Alberta Queen's Printer, Edmonton, Alberta.

Rinella, M. J., Bellows, S. E. and Roth, A. D. 2014. Aminopyralid constrains seed production of the invasive annual grasses medusahead and ventenata. Rangeland Ecology & Management 67(4):406-4011.

Rinella, M. J., Masters, R. A. and Bellows, S. E. 2013. Effects of growth regulator herbicide on downy brome (Bromus tectorum) seed production. Invasive Plant Science and Management 6(1):60-64.

Romo, J. R. and Eddleman, L. E. 1987. Effects of Japanese brome on growth of bluebunch wheatgrass, Junegrass and squirreltail seedlings. Reclamation and Revegetation Research 6(3):207-218.

Rosentreter, R. 1998. Restoration of Community Structure and Composition in Cheatgrass dominated Rangelands. Pages 92-99 in R. Rose, D. L. Haase, eds. Symposium Proceedings Native plants: Propagating and Planting 9-10 December 1998. Oregon State University College of Forestry.

Sarani, M., Oveisi, M., Mashhadi, H. R. and Alizade, H. 2014. Interactions between the tillage system and crop rotation on the crop yield and weed populations under arid conditions. Weed Biology and Management 14(3):198-208.

Sask Forage Council. Field Guide: Identification of Common Seeded Plants for Forage and Reclamation in Saskatchewan. [Online] Available: http://www.saskforage.ca/publications/Forage%20&%20Reclamation.pdf [2015].

Saskatchewan Minister of Agriculture. 2010. Minister's Order, The Weed Control Act. Designation of Prohibited, Noxious and Nuisance Weeds. The Saskatchewan Gazette 106(49):2397-2399.

Scoggan, H. J. 1979. Flora of Canada. National Museums of Canada, Ottawa.

Steppuhn, H., Jefferson, P. G., Iwaasa, A. D. and McLeod, J. G. 2006. AC Saltlander green wheatgrass. Canadian Journal of Plant Science 86:1161-1164.

Stone, A. E., Peeper, T. F. and Solie, J. B. 2001. Cheat (Bromus secalinus) control with herbicides applied to mature seeds. Weed Technology 15(2):382-386.

Thill, D. C., Beck, K. G. and Callihan, R. H. 1984. The biology of downy brome (Bromus tectorum). Weed Science 32(Supplement 1):7-12.

Tutin, T. G., Heywood, V. H., Burges, N. A., Moore, D. M., Valentine, D. H., Walters, S. M. and Webb, D. A., (eds.) 1980. Flora Europaea. Volume 5 - Alismataceae to Orchidaceae (Monocotyledones). Cambridge University Press, Cambridge, UK.

Upadhyaya, M. K., Turkington, R. and McIlvride, D. 1986. The Biology of Canadian Weeds. 75. Bromus tectorum L. Canadian Journal of Plant Science 66:689-709.

March 27, 2015

37

Review of four Bromus species PRA # 2015-08

USDA-APHIS. 2012. Federal Noxious Weed List. [Online] Available: http://www.aphis.usda.gov/plant_health/plant_pest_info/weeds/index.shtml [2015].

USDA-ARS. 2015. Germplasm Resources Information Network - (GRIN) [Online Database]. National Germplasm Resources Laboratory, Beltsville, Maryland. [Online] Available: http://www.ars- grin.gov/cgi-bin/npgs/html/tax_search.pl [2015].

USDA-NRCS. 2015. The PLANTS Database. National Plant Data Center, Baton Rouge, LA 70874-4490 USA. [Online] Available: http://plants.usda.gov [2015].

Uva, R. H., Neal, J. C. and DiTomaso, J. M. 1997. Weeds of the Northeast. Cornell University Press, Ithaca, New York.

Valliant, M. T., Mack, R. N. and Novak, S. J. 2007. Introduction history and population genetics of the invasive grass Bromus tectorum (Poaceae) in Canada. American Journal of Botany 94(7):1156- 1169.

Viggiani, P. 2007. Identification of weedy bromes (Bromus spp. L.) and their distribution in wheat fields in Italy. Informatore Fitopatologico 57(3):19-24.

Weber, E. 2003. Invasive plant species of the world: A reference guide to environmental weeds. CABI Publishing, Wallingford, UK.

Westbrooks, R. 1998. Invasive plants, changing the landscape of America: Fact book. Federal Interagency Committee for the Management of Noxious and Exotic Weeds (FICMNEW), Washington, D.C.

Whitson, T. D., Burrill, L. C., Dewey, S. A., Cudney, D. W., Nelson, B. E., Lee, R. D. and Parker, R. 1992. Weeds of the West. Western Society of Weed Science, Jackson, Wyoming.

Wiersema, J. H. and León, B. 1999. World Economic Plants: A Standard Reference CRC Press, Boca Raton, Florida.

Williams, W. M., Stewart, A. V. and Williamson, M. L. 2011. Bromus. Pages 15-30 in C. Kole, ed. Wild Crop Relatives: Genomic and Breeding Resources, Millets and Grasses. Springer-Verlag, Berlin Heidelberg.

Wilson, P. and King, M. 2003. Arable Plants: A Field Guide. The Hanway Press, London, UK.

Zouhar, K. 2003. Bromus tectorum. In: Fire Effects Information System. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences (Laboratory). [Online] Available: http://www.fs.fed.us/database/feis/ [2015].

March 27, 2015

38