United States 

Department of 

Agriculture 

Animal and Plant 

Health Inspection 

Service 

December 1, 2014 

Version 1 

Weed Risk Assessment for Brassica 

carinata A. Braun (Brassicaceae) – 

Ethiopian mustard

. Brassica carinata plants in a field trial in northern Florida [source: David Wright (2014)]. 

Agency Contact: 

Plant Epidemiology and Risk Analysis Laboratory 

Center for Plant Health Science and Technology 

Plant Protection and Quarantine 

Animal and Plant Health Inspection Service 

United States Department of Agriculture 

1730 Varsity Drive, Suite 300 

Raleigh, NC 27606 
Weed Risk Assessment for Brassica carinata

Ver. 1 December 1, 2014 1

Introduction Plant Protection and Quarantine (PPQ) regulates noxious weeds under the authority 

of the Plant Protection Act (7 U.S.C. § 7701-7786, 2000) and the Federal Seed Act 

(7 U.S.C. § 1581-1610, 1939). A noxious weed is defined as “any plant or plant 

product that can directly or indirectly injure or cause damage to crops (including 

nursery stock or plant products), livestock, poultry, or other interests of agriculture, 

irrigation, navigation, the natural resources of the United States, the public health, 

or the environment” (7 U.S.C. § 7701-7786, 2000). We use weed risk assessment 

(WRA)—specifically, the PPQ WRA model (Koop et al., 2012)—to evaluate the 

risk potential of plants, including those newly detected in the United States, those 

proposed for import, and those emerging as weeds elsewhere in the world. 

Because the PPQ WRA model is geographically and climatically neutral, it can be 

used to evaluate the baseline invasive/weed potential of any plant species for the 

entire United States or for any area within it. As part of this analysis, we use a 

stochastic simulation to evaluate how much the uncertainty associated with the 

analysis affects the model outcomes. We also use GIS overlays to evaluate those 

areas of the United States that may be suitable for the establishment of the plant. 

For more information on the PPQ WRA process, please refer to the document, 

Background information on the PPQ Weed Risk Assessment, which is available 

upon request. 

Brassica carinata A. Braun – Ethiopian mustard 

Species Family: Brassicaceae 

Information Synonyms: B. integrifolia var. carinata (A. Braun) O. Schulz. (Clement and Foster, 

1994); B. integrifolia auct. non (H. West) Rupr. (Stace, 2010); Sinapsis

integrifolia H. West (MBG, 2014). Other synonyms listed on The Plant List 

(2014). 

Common names: Abyssinian cabbage, Abyssinian mustard, Ethiopian kale, 

Ethiopian mustard, Ethiopian rape, and mustard collard (NGRP, 2014). Also 

African mustard (Rana, 2006). 

Botanical description: Brassica carinata is an erect, annual herb growing from 30 

to 200 cm tall (Alemayehu and Becker, 2002; APD, 2014; Mnzava and 

Schippers, 2007). It is usually branched with leaves arranged alternately on 

stems (Mnzava and Schippers, 2007). Brassica carinata (2N=34) is an 

amphidiploid (an allopolyploid behaving as a diploid) derived from an ancient 

cross between B. oleracea (2N=18) and B. nigra (2N=16) (Mabberley, 2008; 

NGRP, 2014; Stace, 2010). Hybridization occurred at least a few thousand years 

ago, since it has been cultivated in Ethiopia for at least that long (Alemayehu 

and Becker, 2002; Mnzava and Schippers, 2007). 

Initiation: On August 4, 2014, the Environmental Protection Agency (EPA) 

contacted Jonathan Jones, USDA Biofuel Team Leader, with questions about the 

weed status of B. carinata (Lie, 2014). Later, we understood that EPA wanted to 

know whether or not this species should be regulated under their Renewable 

Fuel Standard as a potential invasive species (Lie, 2014). On October 6, the PPQ 

Weeds Cross-Functional Working Group requested that the PERAL Weed Team 

conduct a WRA of this species. Over the last 20 years, considerable interest has 

been shown in cultivating B. carinata as an oilseed crop for biofuel production 

and other uses (Babu et al., 2013; Getinet et al., 1996; Guerrero-Diaz et al., 

2013; Newson et al., 2013; Pan, 2009; Warwick et al., 2006). This species has 
Weed Risk Assessment for Brassica carinata

Ver. 1 December 1, 2014 2

great potential as a commercial crop due to increased drought and disease 

resistance, reduced shattering, and increased ability to compete with weeds 

relative to other oilseed brassicas (Marillia et al., 2014). 

Taxonomic Scope of the analysis: For practical reasons, we are restricting our 

analysis to the original or wild form of B. carinata (genome BBCC) and the 

cultivars that have been developed or selected within the species. Numerous 

cultivars of this species are available (Mnzava and Schippers, 2007), and more 

biotypes are being selected in ongoing develop improved lines (e.g., Marillia et 

al., 2014; Taylor et al., 2010). Breeding efforts also include hybridization and 

backcrossing with B. rapa (Sheikh et al., 2014; Taylor et al., 2010), production 

of trigenomic hexaploids with B. carinata and B. rapa (e.g., Malek et al., 2013) 

and genetic engineering to introduce specific genes into the genome of B. 

carinata (Taylor et al., 2010). It is beyond the scope of this assessment to 

evaluate the weed risk associated with B. carinata cultivars derived from 

interspecific crossing, polyploidization, or with genetic engineering since we 

don’t have enough information at the moment to evaluate how these changes 

may affect the weed potential of the plant. 

Foreign distribution: Researchers believe that B. carinata originated in Ethiopia 

(Warwick et al., 2006). It has been introduced into and field-tested for biofuel 

production in Canada (Marillia et al., 2014), India (Malik, 1990), Italy (Bozzini 

et al., 2007), Pakistan (Zada et al., 2013b), and Spain (Velasco et al., 2003). It 

has also been introduced into Australia (Gunasinghe et al., 2013) and Pakistan 

(Zada et al., 2013a). Because of widespread interest in oilseed brassicas 

(Downey and Röbbelen, 1989), additional countries have also likely introduced 

it for biochemical analysis and/or breeding (e.g., Bangladesh: Malek et al., 

2013). 

 U.S. distribution and status: Brassica carinata is already present in the United 

States but is not known to be naturalized here (Kartesz, 2014; NRCS, 2014) or in 

Canada (Brouillet et al., 2014). It was brought from Ethiopia in 1957 for leafy 

vegetable production (Stephens, 2009). In 1972, the Texas Agricultural 

Experiment Station released the cultivar TAMU Tex Sel, which never became 

popular (Stephens, 2009). Brassica carinata has been field tested in North 

Dakota, Montana, Florida, and Mississippi (Harrison, 2013; Marillia et al., 

2014). 

 WRA area1

: Entire United States, including territories. 

 

 1. Brassica carinata analysis 

Establishment/Spread 

Potential 

We found no evidence that Brassica carinata naturalizes and spreads where it has 

been introduced. However, this species is able to germinate and grow as a 

contaminant from discarded bird seed and bird-seed screenings (Clement and 

Foster, 1994; Hanson and Mason, 1985). It also reportedly can “often escape” from 

cultivation in Africa (Mnzava and Schippers, 2007). Despite decades of some 

breeding and cultivation in the United States, and a longer history elsewhere, 

relatively little biological and ecological information has been published about this 

species. We did not find many traits contributing to invasive potential. Brassica 

 

1

 “WRA area” is the area in relation to which the weed risk assessment is conducted [definition modified from that for “PRA 

area”] (IPPC, 2012). 
Weed Risk Assessment for Brassica carinata

Ver. 1 December 1, 2014 3

carinata is self-compatible (PFAF, 2014; Séguin-Swartz et al., 2013), produces 

viable seeds (Cohen and Knowles, 1984; Séguin-Swartz et al., 2013) and is likely 

to disperse unintentionally via both agricultural activities (Gulden et al., 2003; 

Marillia et al., 2014; Wright, 2014) and as a contaminant in bird food (Clement and 

Foster, 1994; Hanson and Mason, 1985). We had a high amount of uncertainty for 

this risk element due to incomplete knowledge about its traits. We answered five 

questions in this risk element as unknown. 

Risk score = 5 Uncertainty index = 0.24 

Impact Potential We found no evidence that B. carinata affects natural and anthropogenic systems, 

although we did find one comment on an herbarium sheet that it is a garden weed 

(GBIF, 2014). We found no direct evidence of impacts in agricultural systems, 

although this species might harm animals. Brassica carinata seeds generally have a 

large amount of glucosinolate compounds (Getinet et al., 1996; Marillia et al., 

2014) that could be problematic if animals are exposed to it in large quantities. 

Depending on the concentration and specific types of these compounds, 

glucosinolates can be toxic or anti-nutritional and can directly affect the thyroid 

(Assayed and Abd El-Aty, 2009). Those compounds have allelopathic effects on 

plants (reviewed in Earlywine et al., 2010; Gulden et al., 2008) and are being 

investigated as biofumigants against plant pests (Guerrero-Diaz et al., 2013). We 

had a very high amount of uncertainty for this risk element. 

Risk score = 1.2 Uncertainty index = 0.26 

Geographic Potential Based on three climatic variables, we estimate that about 13 percent of the United 

States is suitable for the establishment of B. carinata (Fig. 1). This predicted 

distribution is based on the species’ known distribution elsewhere in the world and 

includes point-referenced localities and areas of occurrence. The map for B. 

carinata represents the joint distribution of Plant Hardiness Zones 9-12, areas with 

0-100 inches of annual precipitation, and the following Köppen-Geiger climate 

classes: tropical savanna, steppe, desert, Mediterranean, humid subtropical and 

marine west coast. Although we answered yes, we had high uncertainty about 

whether or not this species can grow without human assistance in desert areas or 

areas with 0-10 inches of annual precipitation. Some of the geo-referenced 

occurrences obtained from the Global Biodiversity Information Facility (GBIF, 

2014) may have been derived from cultivated plants. Two researchers report that 

"[t]ruly wild types are not known” (Mnzava and Schippers, 2007). If seeds of B. 

carinata can withstand temperatures colder than those seen in hardiness zone 9, 

then it could establish further north than indicated in Fig. 1. 

The area shown in Fig. 1 is an estimate as it only uses three climatic variables. 

Other environmental variables, such as soil and habitat type, may further limit the 

areas in which this species is likely to establish (i.e., naturalize). However, if it is 

cultivated as an annual and given suitable moisture, nutrients, light, and other 

growing requirements, it can likely be grown anywhere in the United States. 
Weed Risk Assessment for Brassica carinata

Ver. 1 December 1, 2014 4

Entry Potential We did not assess the entry potential of B. carinata because it is already present in 

the United States. It was imported into the United States from Ethiopia in 1957 for 

leafy vegetable production (Stephens, 2009), has undergone cultivar development 

in Canada and presumably the United States (Taylor et al., 2010), and has been 

field tested in multiple states (see above) (Harrison, 2013; Marillia et al., 2014). 

Figure 1. Predicted distribution of Brassica carinata in the United States. Map 

insets for Alaska, Hawaii, and Puerto Rico are not to scale. 

 2. Results 

Model Probabilities: P(Major Invader) = 9.7% 

 P(Minor Invader) = 68.3% 

 P(Non-Invader) = 22.0% 

Risk Result = Evaluate Further 

Secondary Screening = Evaluate Further

 
Weed Risk Assessment for Brassica carinata

Ver. 1 December 1, 2014 5

.

Figure 2. Brassica carinata risk score (black box) relative to the risk scores of 

species used to develop and validate the PPQ WRA model(other symbols). See 

Appendix A for the complete assessment. 

. 

. 

Figure 3. Model simulation results (N=5,000) for uncertainty around the risk score 

for Brassica carinata. The blue “+” symbol represents the medians of the simulated 

outcomes. The smallest box contains 50 percent of the outcomes, the second 95 

percent, and the largest 99 percent. 
Weed Risk Assessment for Brassica carinata

Ver. 1 December 1, 2014 6

 3. Discussion 

The result of the weed risk assessment for B. carinata is Evaluate Further (Fig. 2). 

Due to the limited amount of biological and ecological information available for 

this species, we had a high level of uncertainty with the analysis. Our uncertainty 

analysis resulted in high risk outcomes about 20 percent of the time, while very few 

were low risk and 80.5 percent of the outcomes were Evaluate Further (Fig. 3). 

Additional information addressing unanswered questions would very likely shift 

the risk score, as well as reduce our uncertainty (Fig. 3). Overall, our analysis 

indicates that B. carinata poses a moderate weed risk potential. Its attributes are 

similar to other U.S. minor invaders (Fig. 2). Both of its parents, B. oleracea and B. 

nigra, are naturalized in the United States (Warwick, 1993+). 

In this assessment we did not find any strong evidence that B. carinata is likely to 

become a major invader or weed. In Africa, "[t]ruly wild types are not known, but 

Brassica carinata often escapes from cultivation" (Mnzava and Schippers, 2007). 

Despite that, one breeder commented that it volunteers no more than canola, B. 

napus (Mayles, 2014). Another researcher indicated zero issues with it in northern 

Florida during three years of field trials (Wright, 2014). In Canadian field trials, 

volunteers were noted but not considered invasive (Mendenhall, 2013). It is not 

clear how this species will behave in the United States or if it will behave similarly 

in different regions. It is also not clear how continued breeding might affect its 

weed potential. Relative to other Brassica species, B. carinata has reduced seed 

pod shattering (Wright, 2014), which reduces its risk. However, relative to other 

oilseed brassicas, increased disease and drought resistance (Fredua-Agyeman et al., 

2014; Warwick et al., 2006) and increased competitiveness with crop weeds 

(Mayles, 2014) increase its risk potential. 

 

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Johnson, and K. C. Falk. 2013. Pollen-mediated gene flow between 

glyphosate-resistant Brassica napus canola and B. juncea and B. carinata 

mustard crops under large-scale field conditions in Saskatchewan. 

Canadian Journal of Plant Science 93(6):1083-1087. 

Sharma, D., D. P. Abrol, M. Kumar, S. K. Singh, and P. K. Singh. 2013. Pollinator 

diversity and its impact on cauliflower (Brassica campestris var. botrytis) 

pollination. Annals of Agri Bio Research 18(3):383-385. 

Sheikh, F. A., S. Bangha, and S. S. Banga. 2014. Broadening the genetic base of 

abbysinian mustard (Brassica carinata A. Braun) through introgression of 

genes from related allotetraploid species. Spanish Journal of Agricultural 

Research 12(3):742-752. 

Stace, C. 2010. New Flora of the British Isles (3rd ed.). Cambridge University 

Press, Cambridge, United Kingdom. 1130 pp. 

Stanley, D. A., D. Gunning, and J. C. Stout. 2013. Pollinators and pollination of 

oilseed rape crops (Brassica napus L.) in Ireland: Ecological and economic 

incentives for pollinator conservation. Journal of Insect Conservation 

17(6):1181-1189. 

Stanton, R., J. Pratley, and D. Hudson. 2003. Sheep are potential vectors for the 

spread of canola (Brassica napus) seed. Australian Journal of Experimental 

Agriculture 43:535-538. 

Stephens, J. M. 2009. Mustard Collard — Brassica carinata. University of Florida, 

Institute of Food and Agricultural Sciences, Gainseville, Florida. 1 pp. 

Taylor, D. C., K. C. Falk, C. D. Palmer, J. Hammerlindl, V. Babic, E. Mietkiewska, 

A. Jadhav, E. F. Marillia, T. Francis, T. Hoffman, E. M. Giblin, V. Katavic, 

and W. A. Keller. 2010. Brassica carinata - A new molecular farming 
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Ver. 1 December 1, 2014 11

platform for delivering bio-industrial oil feedstocks: Case studies of genetic 

modifications to improve very long-chain fatty acid and oil content in 

seeds. Biofuels, Bioproducts and Biorefining 4(5):538-561. 

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Missouri Botanical Garden. http://www.theplantlist.org/. (Archived at 

PERAL). 

Tokumasu, S., I. Kanada, and M. Kato. 1985. The change of dormancy and mustard 

oil content in seeds of Brassica juncea and B. carinata. Journal of the 

Japanese Society for Horticultural Science 54:75-81. 

Velasco, L., A. Nabloussi, A. De Haro, and J. M. Fernández-Martínez. 2003. 

Development of high-oleic, low-linolenic acid Ethiopian-mustard (Brassica 

carinata) germplasm. Theoretical and Applied Genetics 107(5):823-830. 

Warwick, S. I. 1993+. Brassica. Vol. 7, Pages 419-423 in Flora of North America 

Editorial Committee, (ed.). Flora of North America North of Mexico. 18+ 

vols. New York and Oxford. 

Warwick, S. I., R. K. Gugel, T. McDonald, and K. C. Falk. 2006. Genetic variation 

of Ethiopian mustard (Brassica carinata A. Braun) germplasm in western 

Canada. Genetic Resources and Crop Evolution 53(2):297-312. 

Weber, E. 2003. Invasive Plant Species of the World: A Reference Guide to 

Environmental Weeds. CABI Publishing, Wallingford, UK. 548 pp. 

Wright, D. 2014. Some questions about the biology of Brassica carinata. Personal 

communication to A. Koop on Wednesday 29, 2014, from David L. 

Wright, Professor of Agronomy, University of Florida, North Florida 

Research and Education Center. 

Zada, M., Z. K. Shinwari, N. Zakir, and M. A. Rabbani. 2013a. Study of total seed 

storage proteins in ethiopian mustard (Brassica carinata A. Braun) 

germplasm [Abstract]. Pakistan Journal of Botany 45(2):443-448. 

Zada, M., N. Zakir, M. Ashiq Rabbani, and Z. K. Shinwari. 2013b. Assessment of 

genetic variation in ethiopian mustard (Brassica carinata A. Braun) 

germplasm using multivariate techniques. Pakistan Journal of Botany 

45(SPL.ISS):583-593. 

 

 
Weed Risk Assessment for Brassica carinata

Ver. 1 December 1, 2014 12

Appendix A. Weed risk assessment for Brassica carinata A. Braun (Brassicaceae). The following 

information came from the original risk assessment, which is available upon request (full responses and 

all guidance). We modified the information to fit on the page. 

Question ID Answer - 

Uncertainty 

Score Notes (and references) 

ESTABLISHMENT/SPREAD POTENTIAL

ES-1 (Status/invasiveness 

outside its native range) 

d - mod 0 Brassica carinata likely originated in Ethiopia a few thousand 

years ago (Mnzava and Schippers, 2007; Warwick et al., 2006). 

Its exact native distribution is not well understood because it has 

been cultivated for a long time in Africa; furthermore, it is often 

confused with B. juncea (Mnzava and Schippers, 2007). It is 

currently cultivated, native, and/or escaping from cultivation in 

many countries in Africa (Mnzava and Schippers, 2007). "Truly 

wild types are not known...” (Mnzava and Schippers, 2007). The 

NGRP (2014) reports B. carinata as naturalized in Ethiopia, but 

because this is where the species is believed to have originated 

(Warwick et al., 2006), we did not consider that evidence here. 

Brassica carinata is a casual species in the United Kingdom 

(Hanson and Mason, 1985; Stace, 2010), "sometimes appearing to 

be persistent, but probably repeatedly introduced" (Clement and 

Foster, 1994). It is reported as naturalized in Madagascar (Kull et 

al., 2012). This species has been grown since at least 1984 in 

Canada (Rakow and Getinet, 1998) and 1957 in the United States 

(Stephens, 2009) without evidence of naturalization in either 

country (Brouillet et al., 2014; Kartesz, 2014; Mendenhall, 2013; 

NRCS, 2014). One researcher stated that B. carinata does not 

volunteer any more than B. napus (Mayles, 2014), which without 

disturbance usually goes extinct in about three years (Hall et al., 

2005). Third party evaluation of Canadian farms growing B. 

carinata stated that while the species may not be invasive in 

Canada, it does volunteer on site (Mendenhall, 2013). Based on 

the weight of this evidence, we answered "d" for casual/escaped 

with moderate uncertainty. Because the reference reporting it to 

be naturalized in Madagascar is merely a list of categorized 

species without any substantive description of behavior, we are 

unsure of its status in Madagascar. The alternate answers for the 

Monte Carlo simulation were both set as "e," which reflects a 

possible naturalized status in that country. 

ES-2 (Is the species highly 

domesticated) 

n - low 0 Brassica carinata (2N=34) is an amphidiploid (an allopolyploid 

behaving as a diploid) derived from an ancient cross between B. 

oleracea (2N=18 ) and B. nigra (2N=16 ) (Mabberley, 2008; 

Stace, 2010). Throughout most of Africa, where it is cultivated, it 

is used as leafy vegetable, but in Ethiopia, it is also grown for its 

seed oil (Mnzava and Schippers, 2007; NGRP, 2014; Taylor et al., 

2010; Warwick et al., 2006). Grown as game-cover in England 

(Stace, 2010). Wild forms of B. carinata have not been reported 

but there are diverse ecotypes (Alemayehu and Becker, 2002). 

The species is currently being bred to improve a variety of traits 

including maturation time, yield, oil composition, disease 

resistance, etc. (e.g., Marillia et al., 2014; Taylor et al., 2010). 

Some breeding programs are crossing B. carinata with other 

oilseed brassicas to introduce desirable traits into B. carinata

(Sheikh et al., 2014; Taylor et al., 2010). Because this evaluation 

is based on the species as a whole and not on any one cultivar, we 
Weed Risk Assessment for Brassica carinata

Ver. 1 December 1, 2014 13

Question ID Answer - 

Uncertainty 

Score Notes (and references) 

answered no with low uncertainty. Furthermore, breeding 

programs are focusing on crop improvement and not reduced 

weed potential. 

ES-3 (Weedy congeners) y - negl 1 Brassica is a relatively small genus with about 40 species 

(Mabberley, 2008). Seventeen of these have been reported as 

weeds, but five of them have been reported at least 55 or more 

times as weedy: Brassica juncea, B. napus, B. nigra, B. oleracea, 

and B. rapa (Randall, 2012). Brassica rapa subsp. oleifera

(reported as B. campestris) is a serious or principal weed in 16 

countries, including Canada and Mexico (Holm et al., 1979). 

Brassica juncea and B. rapa are principal weeds in Canada and 

Brazil, respectively (Holm et al., 1979). Brassica kaber competes 

with crops for water and nutrients, reducing yield in wheat by 16 

percent and yield in spring rapeseed by 66 percent (Holm et al., 

1997). Brassica tournefortii “forms dense stands, accumulates 

large quantities of dried plant material and thus increases fire 

hazard” (Weber, 2003). 

ES-4 (Shade tolerant at 

some stage of its life cycle) 

n - mod 0 We did not find any strong evidence that B. carinata is shade 

tolerant. An online factsheet states it can grow in partial shade or 

no shade but provided no supportive evidence (PFAF, 2014). One 

greenhouse study showed that plants lit from the sides, in addition 

to being lit from above, grew faster and produced more biomass 

than those lit from just above (Monti et al., 2009), suggesting that 

plants respond well to increasing light levels. Although none of 

this evidence is very conclusive, because this species is grown in 

open fields as an annual crop (Pan, 2009) like other Brassica

species, we suspect it is not shade tolerant. It is noteworthy that B. 

carinata’s diploid parents, B. oleracea and B. nigra, occur in open 

habitats in the United States (Warwick, 1993+). 

ES-5 (Climbing or 

smothering growth form) 

n - negl 0 This species is an erect herbaceous annual, sometimes biennial or 

perennial, growing from about 30 to 200 cm in height (APD, 

2014; Marillia et al., 2014; Mnzava and Schippers, 2007; Pan, 

2009); it is not a vine and does not have a smothering growth 

form. 

ES-6 (Forms dense thickets) ? - max 0 Unknown. We did not find very much information about this 

species' behavior outside of cultivation. 

ES-7 (Aquatic) n - negl 0 Not an aquatic plant; this species is a terrestrial herb (Getinet et 

al., 1996; Marillia et al., 2014; Mnzava and Schippers, 2007). 

ES-8 (Grass) n - negl 0 This species is not a grass; it is a mustard (NGRP, 2014). 

ES-9 (Nitrogen-fixing 

woody plant) 

n - negl 0 We found no evidence that B. carinata fixes nitrogen. It is not a 

member of one of the plant families known to fix nitrogen (Martin 

and Dowd, 1990). Also, it is not a woody plant. 

ES-10 (Does it produce 

viable seeds or spores) 

y - negl 1 Propagated through seed production (Cohen and Knowles, 1984). 

In one field study, 98.5 percent of the seeds were viable (SéguinSwartz et al., 2013). 

ES-11 (Self-compatible or 

apomictic) 

y - negl 1 Brassica carinata is autogamous (i.e., self-compatible; PFAF, 

2014; Séguin-Swartz et al., 2013). It readily self-pollinates 

(Mnzava and Schippers, 2007). In a breeding program to 

introduce disease resistance from B. carinata to B. napus, hybrids 

of these two taxa were backcrossed twice to B. napus and the 

resulting progenies were self-pollinated for three generations 

(Fredua-Agyeman et al., 2014). 

ES-12 (Requires special n - negl 0 It readily self-pollinates without insect pollinators (Mnzava and 
Weed Risk Assessment for Brassica carinata

Ver. 1 December 1, 2014 14

Question ID Answer - 

Uncertainty 

Score Notes (and references) 

pollinators) Schippers, 2007). Pollinated by bees (PFAF, 2014). We expect 

that pollinators for B. carinata will be similar to the species that 

pollinate its close relatives. Brassica nigra, B. rapa, B. napus, and 

B. oleracea are pollinated by flies and bees, including honeybees 

(Bruinsma et al., 2008; Manning and Boland, 2000; Rader et al., 

2013; Sharma et al., 2013; Stanley et al., 2013). Brassica napus is 

also probably pollinated to some degree by wind (Gulden et al., 

2008; McCartney and Lacey, 1991). Brassica rapa and B. napus

can be pollinated by bees and other non-specialist pollinators 

(Hall et al., 2005). 

ES-13 (Minimum 

generation time) 

b - negl 1 An annual plant, sometimes biennial or perennial (Babu et al., 

2013; Mnzava and Schippers, 2007; Pan, 2009). Plants up to four 

years old have been recorded, but this is due to continual harvest 

of leaves under cultivation (Mnzava and Schippers, 2007). Under 

agronomic conditions plants are ready for harvest 148 to 172 days 

after planting (Alemayehu and Becker, 2002). In a Canadian 

agronomic study, B. carinata matured seeds in 101 to 111 days 

from planting (Getinet et al., 1996). In another study, plants 

matured in 94-110 days after planting (Warwick et al., 2006). In 

Africa, seed oil biotypes produce seeds in dry regions in about 4 

months, whereas vegetable types produce seeds in about 5-6 

months (Mnzava and Schippers, 2007). Alternate answers for the 

Monte Carlo simulation were "c" and "a." 

ES-14 (Prolific 

reproduction) 

? - max 0 We found no information on seed production in natural 

populations, but there was some information on agronomic yield. 

In a study of plant traits under agronomic conditions, plants 

produced an average of 270 pods (range = 179 to 352) and 3300 

seeds (range = 1900 to 5200) per plant (Alemayehu and Becker, 

2002). Assuming at least two plants per square meter and 98 

percent seed viability (Séguin-Swartz et al., 2013), two plants 

alone would be sufficient to meet the threshold of 5000 seeds per 

square meter. In another study, seed yield was 597 and 1267 

kg/ha in 1984 and 1985, respectively (Getinet et al., 1996), with 

thousand-seed weights ranging from 3.7 g to 4.6 g in 1984 and 

from 4.9 g to 5.7 g in 1985 (Getinet et al., 1996). Using the 

heaviest estimates of seed weight, this yield converts to 13,000 

and 22,000 seeds per square meter. Other studies reported similar 

thousand-seed weights: 3.48 g (Alemayehu and Becker, 2002) and 

2.0 to 3.9 g (Warwick et al., 2006). Therefore, under field 

production where water, herbicides, and fertilizers may be used to 

maximize yield, B. carinata is a prolific reproducer. However, 

because there is no information about seed production outside of 

cultivation, we answered unknown. Naturalized B. rapa produces 

fewer seeds than cultivated plants (Hall et al., 2005). 

ES-15 (Propagules likely to 

be dispersed unintentionally 

by people) 

y - low 1 We found no direct evidence of unintentional dispersal by people 

for B. carinata. However, based on information from its close 

relative, B. napus (canola), we and another weed scientist 

(Johnson, 2014) believe unintentional dispersal is very likely to 

occur through regular agricultural activities. For example, in one 

study of yield loss due to unharvested seeds of canola (B. napus), 

the authors estimated that on average 3000 viable seeds per square 

meter were being added to the soil seed bank (Gulden et al., 

2003). Even though B. carinata is the most shatter-resistant of all 

the brassicas (Marillia et al., 2014; Wright, 2014), some seeds are 
Weed Risk Assessment for Brassica carinata

Ver. 1 December 1, 2014 15

Question ID Answer - 

Uncertainty 

Score Notes (and references) 

still likely to be incorporated back into the soil (Wright, 2014). 

Combine harvesters may increase the spread of B. napus in fields 

(Gulden et al., 2008). Long-distance dispersal of volunteer B. 

napus to non-agricultural habitats such as railroads, roadways, 

and seaports is believed to occur through commercial seed 

movement (Gulden et al., 2008; Mizuguti et al., 2011). Seeds of 

B. rapa and B. napus are dispersed long distances through 

transport (Hall et al., 2005; Légère, 2005). 

ES-16 (Propagules likely to 

disperse in trade as 

contaminants or hitchhikers) 

y - negl 2 In a study that germinated seeds in bird food and screenings from 

imported bird food, the authors found B. carinata as a 

contaminant (impurity) (Hanson and Mason, 1985). A bird-seed 

or oilseed alien (Clement and Foster, 1994). Bird-seed alien 

(Stace, 2010). 

ES-17 (Number of natural 

dispersal vectors) 

0 -4 Fruit and seed characters for ES-17a through ES-17e: Fruit 2.5 to 

6 cm long (Stace, 2010). Brassica carinata’s fruit type is a 

silique, a long pod (less than 5 cm long) composed of two valves, 

with seeds in one row under each valve (Pan, 2009; Stace, 2010). 

Seeds are roughly spherical in shape (Fig. 2 in Marillia et al., 

2014) and about 2 mm thick (Pan, 2009). Brassica carinata is 

relatively more resistant to seed shattering than B. napus

(Alemayehu and Becker, 2002; Wright, 2014). 

 ES-17a (Wind dispersal) n - negl Brassica carinata does not possess adaptive features to aid in 

wind dispersal (Johnson, 2014). This statement is consistent with 

its biology. We found no information on seed dispersal of B. 

carinata. However, we suspect seed dispersal via wind is unlikely 

given fruit and seed morphology. 

 ES-17b (Water dispersal) n - negl Brassica carinata does not possess any adaptive features to aid in 

water dispersal (Johnson, 2014). An unpublished study found that 

only 5.5 percent of 1000 seeds floated, and that after 4 hours with 

periodic stirring every 30 minutes, only 0.2 percent of the seeds 

remained floating (Johnson, 2014). Given this evidence and the 

fact that this species grows in dry regions and is not restricted to 

riparian environments (Warwick et al., 2006), we answered no 

with negligible uncertainty. 

 ES-17c (Bird dispersal) ? - max Unknown. 

 ES-17d (Animal external 

dispersal) 

n - low We found no evidence. Because fruit and seeds don’t possess any 

obvious adaptations for attachment to animals, external dispersal 

seems unlikely. 

 ES-17e (Animal internal 

dispersal) 

? - max We found no information on seed dispersal of B. carinata. Sheep 

fed a diet including B. napus seeds were shown to pass 

germinable seeds up to five days after ingesting seeds (Stanton et 

al., 2003). Because internal animal dispersal may be occurring for 

a closely related congener, we answered unknown. 

ES-18 (Evidence that a 

persistent (>1yr) propagule 

bank (seed bank) is formed) 

? - max 0 Little is known about seed dormancy and soil seed bank 

persistence of B. carinata (Johnson, 2014). One study found that 

seeds exhibit some primary dormancy for a few weeks after they 

mature (Tokumasu et al., 1985). But it is not clear how readily 

seeds may enter secondary dormancy, which is environmentally 

induced (e.g., seed burial, dry conditions), or how long they may 

persist in the soil. Through secondary dormancy, B. rapa and B. 

napus can survive for several years in the soil, but their seedbank 

declines very rapidly in agroecosystems (Hall et al., 2005). Seeds 

of B. nigra can survive in the soil for up to 40 years (Loewer, 
Weed Risk Assessment for Brassica carinata

Ver. 1 December 1, 2014 16

Question ID Answer - 

Uncertainty 

Score Notes (and references) 

2001). Brassica kaber seeds survive up to 26 years (Holm et al., 

1997). 

ES-19 (Tolerates/benefits 

from mutilation, cultivation 

or fire) 

n - high -1 We found no evidence of this, nor evidence of traits that would 

contribute to this kind of tolerance. 

ES-20 (Is resistant to some 

herbicides or has the 

potential to become 

resistant) 

n - high 0 We found no evidence that B. carinata is resistant to herbicides 

(e.g., Heap, 2014), but it may be able to acquire resistance 

through gene flow. Brassica carinata has been successfully 

hybridized with nine other related species, including B. napus

(FitzJohn et al., 2007), which has been engineered for herbicide 

resistance (Schafer et al., 2011). A field study with four hectare 

plots of B. carinata and glyphosate-resistant B. napus planted 

next to each other demonstrated these species can cross with each 

other under field conditions, albeit at a low rate (0.002 percent 

and 0.005 of sampled B. carinata seeds; Séguin-Swartz et al., 

2013). Hybrids were detected as far away as 150 meters from the 

common border (Séguin-Swartz et al., 2013). Pollen viability of 

hybrid plants was 14 percent and 8 percent for the two sites, and 

average seed set was 1.5 and 3.8 seeds per plant (Séguin-Swartz 

et al., 2013). Laboratory studies reported that B. carinata can 

cross with B. napus, but the resulting progeny are highly sterile 

(reviewed in Séguin-Swartz et al., 2013). A review of B. carinata

concluded that while hybridization is possible, it is not likely to 

act as a vector for gene exchange (Taylor et al., 2010). Based on 

this evidence, we answered no with high uncertainty. 

ES-21 (Number of cold 

hardiness zones suitable for 

its survival) 

4 0 

ES-22 (Number of climate 

types suitable for its 

survival) 

5 2 

ES-23 (Number of 

precipitation bands suitable 

for its survival) 

9 1 

IMPACT POTENTIAL 

General Impacts 

Imp-G1 (Allelopathic) y - high 0.1 Brassica napus and B. rapa produce allelopathic compounds with 

detrimental effects on crop yield, and seed germination of crops 

and other weeds (reviewed in Gulden et al., 2008). Brassica

species in general can suppress weeds due to the presence of 

compounds known as glucosinolates (reviewed in Earlywine et 

al., 2010). Brassica carinata has a high glucosinolate 

concentration in oils extracted from its seeds (Getinet et al., 

1996). One researcher commented that B. carinata competes well 

against weed species (Mayles, 2014), but did not clarify if this 

was due to plant morphology or allelopathy. This species has also 

shown some promise for use as a biofumigant against a common 

nematode species (Guerrero-Diaz et al., 2013). Consequently, we 

answered yes with high uncertainty. 

Imp-G2 (Parasitic) n - negl 0 We found no evidence. This species does not belong to a plant 

family known to contain parasitic species (Heide-Jorgensen, 

2008; Nickrent, 2009). 
Weed Risk Assessment for Brassica carinata

Ver. 1 December 1, 2014 17

Question ID Answer - 

Uncertainty 

Score Notes (and references) 

Impacts to Natural Systems

Imp-N1 (Change ecosystem 

processes and parameters 

that affect other species) 

n - low 0 We found no evidence of this impact. Because this species has not 

been reported to be weedy in natural areas, and because the 

closely related B. napus and B. rapa are only a concern in 

agricultural fields (Gulden et al., 2008), we used low uncertainty 

for this question and the others in this subelement. 

Imp-N2 (Change 

community structure) 

n - low 0 We found no evidence. 

Imp-N3 (Change 

community composition) 

n - low 0 We found no evidence. 

Imp-N4 (Is it likely to affect 

federal Threatened and 

Endangered species) 

n - low 0 We found no evidence. 

Imp-N5 (Is it likely to affect 

any globally outstanding 

ecoregions) 

n - low 0 We found no evidence. 

Imp-N6 (Weed status in 

natural systems) 

a - low 0 We found no evidence that this species is a weed of natural 

systems. Alternate answers for the Monte Carlo simulation were 

both "b." 

Impact to Anthropogenic Systems (cities, suburbs, roadways) 

Imp-A1 (Impacts human 

property, processes, 

civilization, or safety) 

n - low 0 We found no evidence. Because it has not been recorded as an 

anthropogenic weed, we used low uncertainty for this question, as 

well as Imp-A2 and Imp-A3. 

Imp-A2 (Changes or limits 

recreational use of an area) 

n - low 0 We found no evidence. 

Imp-A3 (Outcompetes, 

replaces, or otherwise 

affects desirable plants and 

vegetation) 

n - low 0 We found no evidence. 

Imp-A4 (Weed status in 

anthropogenic systems) 

a - high 0 This species occurs on trash dumps and waste ground in the 

London area (Clement and Foster, 1994) and elsewhere in the 

United Kingdom (Hanson and Mason, 1985). One herbarium 

record classified it as a garden weed (GBIF, 2014). Because one 

report of it behaving as a garden weed is not very strong evidence, 

particularly when the herbarium label provided no additional 

description, we answered no with high uncertainty. Alternate 

answers for the Monte Carlo simulation were both "b." 

Impact to Production Systems (agriculture, nurseries, forest plantations, orchards, etc.)

Imp-P1 (Reduces 

crop/product yield) 

n - high 0 We found no evidence of this impact for B. carinata. Brassica 

napus and B. rapa, which are also grown as oilseed crops, are 

only a weed concern in agricultural fields (Gulden et al., 2008). 

"Herbicide-resistance and the stacking of genes in volunteer 

populations conferring resistance to multiple herbicides have 

contributed to increased difficulties in controlling volunteer B. 

napus in some crops. However, yield loss resulting from 

volunteer populations is not well documented in Canada" (Gulden 

et al., 2008). Because B. carinata’s closely related congeners may 

be problematic as volunteers, we used high uncertainty instead of 

moderate. 

Imp-P2 (Lowers commodity 

value) 

? - max 0 We found no direct evidence that B. carinata lowers commodity 

value. However, glucosinolate compounds (see Imp-P5) and their 

hydrolyzed products produce off-flavors in eggs from poultry fed 

Brassica seeds (Burrows and Tyrl, 2013). Similar off-flavors 
Weed Risk Assessment for Brassica carinata

Ver. 1 December 1, 2014 18

Question ID Answer - 

Uncertainty 

Score Notes (and references) 

develop in meat and milk from cattle fed Brassicaceae plants 

(Burrows and Tyrl, 2013). Because B. carinata seeds generally 

have a large amount of glucosinolate compounds (Getinet et al., 

1996; Marillia et al., 2014), it is possible it may have a similar 

impact. Consequently, we answered unknown. 

Imp-P3 (Is it likely to 

impact trade) 

n - mod 0 We found no evidence of this impact for B. carinata. We note that 

European importers of Canadian mustard (B. juncea) require that 

shipments of seed be free of transgenes and that there is no 

outcrossing between genetically engineered canola (B. napus) and 

mustard (Séguin-Swartz et al., 2013). 

Imp-P4 (Reduces the quality 

or availability of irrigation, 

or strongly competes with 

plants for water) 

n - mod 0 We found no evidence. 

Imp-P5 (Toxic to animals, 

including livestock/range 

animals and poultry) 

y - low Brassicaceae plants produce a group of compounds known as 

glucosinolates (GSLs), which, when broken down, yield 

isothiocyanates, nitriles, and other products (Assayed and Abd ElAty, 2009; Halkier and Gershenzon, 2006). "Depending on the 

concentration and structural types of these compounds, their 

biological effects can be toxic, antinutritional or beneficial to 

health. Most serious economic problems in livestock seem to 

result from rapeseed meal; arising from GSLs or their breakdown 

products. In contrast, GSLs and their isothiocyanate (ITC) 

hydrolysis products are reportedly well-known protectors against 

carcinogenesis" (Assayed and Abd El-Aty, 2009). "One of the 

predominant rapeseed glucosinolates ... forms a oxazolidine-2-

thione upon hydrolysis that causes goiter and has other harmful 

effects on animal nutrition" (Halkier and Gershenzon, 2006). 

Burrows and Tyrl (2013) review the harmful effects of these 

compounds, which include thyroid enlargement, embryonal death, 

growth retardation, liver hemorrhage, and digestive disturbances. 

Brassica carinata seeds generally have a large amount of 

glucosinolate compounds (Getinet et al., 1996; Marillia et al., 

2014). "The goitrogenic nature of this glucosinolate poses a 

serious constraint to the commercial use of B. carinata meal in 

animal feed capacity" (Marillia et al., 2014). Although we found 

no direct evidence of toxicity resulting from consumption of B. 

carinata, we answered yes because the impact of these toxins at 

the genus and family level are well known (Burrows and Tyrl, 

2013). We also note that breeders are aware of this problem and 

are trying to breed biotypes of B. carinata that have lower levels 

of glucosinolates so that animal meal can be made from seeds 

after the seed soil has been extracted (Getinet et al., 1996). 

Imp-P6 (Weed status in 

production systems) 

a - high 0 We found only one source stating B. carinata is a weed in 

agricultural systems, and that source only stated that it was a 

"weed of cultivation" (APD, 2014). This species has been present 

in the United States for about 40 years (Stephens, 2009) without 

demonstrating any weedy behavior. Furthermore, in the last 20 to 

30 years it has been introduced to several countries for field trials 

as a potential biofuel plant (Bozzini et al., 2007; Gunasinghe et 

al., 2013; Malik, 1990; Velasco et al., 2003; Zada et al., 2013a; 

Zada et al., 2013b), and we found no evidence of weedy behavior. 

Without additional evidence or a more detailed explanation of 

why this species is a "weed of cultivation," we answered "a" with 
Weed Risk Assessment for Brassica carinata

Ver. 1 December 1, 2014 19

Question ID Answer - 

Uncertainty 

Score Notes (and references) 

high uncertainty. Alternate answers for the Monte Carlo 

simulation were both "b." 

GEOGRAPHIC 

POTENTIAL 

 Unless otherwise indicated, the following evidence represents 

geographically referenced points obtained from the Global 

Biodiversity Information Facility (GBIF, 2014). 

Plant hardiness zones 

Geo-Z1 (Zone 1) n - negl N/A We found no evidence that it can establish in this zone. 

Geo-Z2 (Zone 2) n - negl N/A We found no evidence that it can establish in this zone. 

Geo-Z3 (Zone 3) n - negl N/A We found no evidence that it can establish in this zone. 

Geo-Z4 (Zone 4) n - negl N/A We found no evidence that it can establish in this zone. 

Geo-Z5 (Zone 5) n - negl N/A We found no evidence that it can establish in this zone. 

Geo-Z6 (Zone 6) n - negl N/A We found no evidence that it can establish in this zone. 

Geo-Z7 (Zone 7) n - negl N/A We found no evidence that it can establish in this zone. 

Geo-Z8 (Zone 8) n - high N/A Grown over the winter in Osimo, Italy (Raccuia et al., 2013), but 

an exact location was not given; Osimo encompasses both Zone 9 

(coastal) and Zone 8 (inland). Because seedlings are not resistant 

to frost (Anonymous, 2014), we answered no with high 

uncertainty. 

Geo-Z9 (Zone 9) y - low N/A A few points in Ethiopia. Overwintered in Catania and Palozzola 

dello Stella, Italy (Raccuia et al., 2013). Several points around 

London and the southern United Kingdom (GBIF, 2014), but 

these are likely due to repeated introductions and not persistent 

populations (Clement and Foster, 1994). 

Geo-Z10 (Zone 10) y - negl N/A Many points in Ethiopia. 

Geo-Z11 (Zone 11) y - negl N/A Many points in Ethiopia. Also a few points in Eritrea, Tanzania, 

and Zambia. 

Geo-Z12 (Zone 12) y - high N/A Ethiopia. 

Geo-Z13 (Zone 13) n - high N/A One point near edge of this zone in Ethiopia. 

Köppen -Geiger climate classes

Geo-C1 (Tropical 

rainforest) 

n - low N/A We found no evidence that it can establish in this climate class. 

Geo-C2 (Tropical savanna) y - low N/A Ethiopia. Two points in Tanzania. 

Geo-C3 (Steppe) y - negl N/A Many points in Ethiopia. Also Eritrea. 

Geo-C4 (Desert) y - high N/A Three accessions from the Bale province of Ethiopia that appear 

to be in desert (occurrence data; Alemayehu and Becker, 2002). 

We used high uncertainty as these may be under cultivation. 

Geo-C5 (Mediterranean) y - low N/A Some points in Ethiopia. 

Geo-C6 (Humid 

subtropical) 

y - low N/A Two points in Zambia. Also reported to be grown in this country 

(Mnzava and Schippers, 2007). Grown in Osimo and Palozzola 

dello Stella, Italy (Raccuia et al., 2013). 

Geo-C7 (Marine west coast) y - mod N/A Ethiopia. Several points in the southern portion of the United 

Kingdom, but these are likely due to repeated introductions and 

not persistent populations (Clement and Foster, 1994). 

Geo-C8 (Humid cont. warm 

sum.) 

n - mod N/A We found no evidence that it can establish in this climate class. 

Geo-C9 (Humid cont. cool 

sum.) 

n - low N/A We found no evidence that it can establish in this climate class. 

Geo-C10 (Subarctic) n - negl N/A We found no evidence that it can establish in this climate class. 

Geo-C11 (Tundra) n - negl N/A We found no evidence that it can establish in this climate class. 

Geo-C12 (Icecap) n - negl N/A We found no evidence that it can establish in this climate class. 
Weed Risk Assessment for Brassica carinata

Ver. 1 December 1, 2014 20

Question ID Answer - 

Uncertainty 

Score Notes (and references) 

10-inch precipitation bands

Geo-R1 (0-10 inches; 0-25 

cm) 

y - high N/A One point in Ethiopia. Three accessions from the Bale province of 

Ethiopia that appear to be in this precipitation band (occurrence 

data; Alemayehu and Becker, 2002). We used high uncertainty as 

these may be under cultivation. 

Geo-R2 (10-20 inches; 25-

51 cm) 

y - low N/A Ethiopia. Grown in Tanzania, Zimbabwe, Zambia, and Malawi as 

a market crop (Mnzava and Schippers, 2007); this region receives 

from 10 to 70 inches of mean annual precipitation, but it is 

unknown whether these plants are irrigated or not. 

Geo-R3 (20-30 inches; 51-

76 cm) 

y - negl N/A Ethiopia. Grown in Tanzania, Zimbabwe, Zambia, and Malawi as 

a market crop (Mnzava and Schippers, 2007); this region receives 

from 10 to 70 inches of mean annual precipitation, but it is 

unknown whether these plants are irrigated or not. Grown in 

Catania, Italy (Raccuia et al., 2013). 

Geo-R4 (30-40 inches; 76-

102 cm) 

y - negl N/A Ethiopia. Grown in Tanzania, Zimbabwe, Zambia, and Malawi as 

a market crop (Mnzava and Schippers, 2007); this region receives 

from 10 to 70 inches of mean annual precipitation, but it is 

unknown whether these plants are irrigated or not. Grown in 

Osimo, Italy (Raccuia et al., 2013). Found in waste dumps in the 

United Kingdom (Clement and Foster, 1994). 

Geo-R5 (40-50 inches; 102-

127 cm) 

y - negl N/A Ethiopia. Grown in Tanzania, Zimbabwe, Zambia, and Malawi as 

a market crop (Mnzava and Schippers, 2007); this region receives 

from 10 to 70 inches of mean annual precipitation, but it is 

unknown whether these plants are irrigated or not. Grown in 

Palozzola dello Stella, Italy (Raccuia et al., 2013). 

Geo-R6 (50-60 inches; 127-

152 cm) 

y - negl N/A Ethiopia. Grown in Tanzania, Zimbabwe, Zambia, and Malawi as 

a market crop (Mnzava and Schippers, 2007); this region receives 

from 10 to 70 inches of mean annual precipitation, but it is 

unknown whether these plants are irrigated or not. 

Geo-R7 (60-70 inches; 152-

178 cm) 

y - negl N/A Ethiopia. Grown in Tanzania, Zimbabwe, Zambia, and Malawi as 

a market crop (Mnzava and Schippers, 2007); this region receives 

from 10 to 70 inches of mean annual precipitation, but it is 

unknown whether these plants are irrigated or not. 

Geo-R8 (70-80 inches; 178-

203 cm) 

y - low N/A Ethiopia. 

Geo-R9 (80-90 inches; 203-

229 cm) 

y - mod N/A Ethiopia. 

Geo-R10 (90-100 inches; 

229-254 cm) 

y - high N/A One point in Ethiopia. 

Geo-R11 (100+ inches; 

254+ cm) 

n - high N/A We found no evidence that it can establish in this climate class. 

ENTRY POTENTIAL 

Ent-1 (Plant already here) y - negl 1 This species is already present in the United States. It was 

imported from Ethiopia in 1957 for leafy vegetable production 

(Stephens, 2009). In 1972, Texas Agricultural Experiment Station 

released the cultivar TAMU Tex Sel, which has never become 

very popular (Stephens, 2009). It has been field tested in North 

Dakota, Montana, Florida, and Mississippi (Harrison, 2013; 

Marillia et al., 2014). 

Ent-2 (Plant proposed for 

entry, or entry is imminent ) 

 - N/A 

Ent-3 (Human value & 

cultivation/trade status) 

 - N/A Sold on the internet at Amazon.co.uk (Amazon, 2014). Now 

commonly planted as a game-cover crop in the United Kingdom 
Weed Risk Assessment for Brassica carinata

Ver. 1 December 1, 2014 21

Question ID Answer - 

Uncertainty 

Score Notes (and references) 

(PFAF, 2014). 

Ent-4 (Entry as a 

contaminant) 

 

 Ent-4a (Plant present in 

Canada, Mexico, Central 

America, the Caribbean or 

China ) 

 - N/A 

 Ent-4b (Contaminant of 

plant propagative material 

(except seeds)) 

 - N/A 

 Ent-4c (Contaminant of 

seeds for planting) 

 - N/A 

 Ent-4d (Contaminant of 

ballast water) 

 - N/A 

 Ent-4e (Contaminant of 

aquarium plants or other 

aquarium products) 

 - N/A 

 Ent-4f (Contaminant of 

landscape products) 

 - N/A A bird-seed or oil-seed alien (Clement and Foster, 1994). Birdseed alien (Stace, 2010). A contaminant of imported bird seed 

(Hanson and Mason, 1985). 

 Ent-4g (Contaminant of 

containers, packing 

materials, trade goods, 

equipment or conveyances) 

 - N/A 

 Ent-4h (Contaminants of 

fruit, vegetables, or other 

products for consumption or 

processing) 

 - N/A 

 Ent-4i (Contaminant of 

some other pathway) 

 - N/A 

Ent-5 (Likely to enter 

through natural dispersal) 

 - N/A