Pacific Island Ecosystems at Risk (PIER)
Crotalaria juncea
RISK ASSESSMENT RESULTS: Low risk, score: -3
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Australian/New Zealand Weed Risk Assessment adapted for Hawai‘i. Information on Risk Assessments Original risk assessment |
| Crotalaria juncea (Indian hemp, Madras hemp, sunn-hemp) Family - Leguminoceae/Fabaceae | Answer | Score | |
| 1.01 | Is the species highly domesticated? (If answer is 'no' then go to question 2.01) | n | 0 |
| 1.02 | Has the species become naturalized where grown? | ||
| 1.03 | Does the species have weedy races? | ||
| 2.01 | Species suited to tropical or subtropical climate(s) (0-low; 1-intermediate; 2-high) – If island is primarily wet habitat, then substitute “wet tropical” for “tropical or subtropical” | 2 | |
| 2.02 | Quality of climate match data (0-low; 1-intermediate; 2-high) see appendix 2 | 1 | |
| 2.03 | Broad climate suitability (environmental versatility) | y | 1 |
| 2.04 | Native or naturalized in regions with tropical or subtropical climates | y | 1 |
| 2.05 | Does the species have a history of repeated introductions outside its natural range? y=-2 | y | |
| 3.01 | Naturalized beyond native range y = 1*multiplier (see Append 2), n= question 2.05 | y | 1 |
| 3.02 | Garden/amenity/disturbance weed y = 1*multiplier (see Append 2) | n | 0 |
| 3.03 | Agricultural/forestry/horticultural weed y = 2*multiplier (see Append 2) | n | 0 |
| 3.04 | Environmental weed y = 2*multiplier (see Append 2) | n | 0 |
| 3.05 | Congeneric weed y = 1*multiplier (see Append 2) | n | 0 |
| 4.01 | Produces spines, thorns or burrs | n | 0 |
| 4.02 | Allelopathic | n | 0 |
| 4.03 | Parasitic | n | 0 |
| 4.04 | Unpalatable to grazing animals | n | -1 |
| 4.05 | Toxic to animals | ||
| 4.06 | Host for recognized pests and pathogens | n | 0 |
| 4.07 | Causes allergies or is otherwise toxic to humans | n | 0 |
| 4.08 | Creates a fire hazard in natural ecosystems | n | 0 |
| 4.09 | Is a shade tolerant plant at some stage of its life cycle | n | 0 |
| 4.1 | Tolerates a wide range of soil conditions (or limestone conditions if not a volcanic island) | y | 1 |
| 4.11 | Climbing or smothering growth habit | n | 0 |
| 4.12 | Forms dense thickets | n | 0 |
| 5.01 | Aquatic | n | 0 |
| 5.02 | Grass | n | 0 |
| 5.03 | Nitrogen fixing woody plant | n | 0 |
| 5.04 | Geophyte (herbaceous with underground storage organs -- bulbs, corms, or tubers) | n | 0 |
| 6.01 | Evidence of substantial reproductive failure in native habitat | n | 0 |
| 6.02 | Produces viable seed. | y | 1 |
| 6.03 | Hybridizes naturally | n | -1 |
| 6.04 | Self-compatible or apomictic | y | 1 |
| 6.05 | Requires specialist pollinators | n | 0 |
| 6.06 | Reproduction by vegetative fragmentation | n | -1 |
| 6.07 | Minimum generative time (years) 1 year = 1, 2 or 3 years = 0, 4+ years = -1 | 1 | 1 |
| 7.01 | Propagules likely to be dispersed unintentionally (plants growing in heavily trafficked areas) | n | -1 |
| 7.02 | Propagules dispersed intentionally by people | y | 1 |
| 7.03 | Propagules likely to disperse as a produce contaminant | n | -1 |
| 7.04 | Propagules adapted to wind dispersal | n | -1 |
| 7.05 | Propagules water dispersed | n | -1 |
| 7.06 | Propagules bird dispersed | n | -1 |
| 7.07 | Propagules dispersed by other animals (externally) | n | -1 |
| 7.08 | Propagules survive passage through the gut | n | -1 |
| 8.01 | Prolific seed production (>1000/m2) | n | -1 |
| 8.02 | Evidence that a persistent propagule bank is formed (>1 yr) | ||
| 8.03 | Well controlled by herbicides | ||
| 8.04 | Tolerates, or benefits from, mutilation, cultivation, or fire | ||
| 8.05 | Effective natural enemies present locally (e.g. introduced biocontrol agents) | ||
| Total score: | -3 |
Supporting data:
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Notes |
Reference |
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1.01 |
"Because sun-hemp has been cultivated since antiquity its origins are not known … " [Although widely cultivated there is no evidence that the cultivated plants are ecologically different from the wild ones. Self-compatible Crotalaria are being developed f |
http://www.hort.purdue.edu/newcrop/proceedings1996/ |
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1.02 |
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1.03 |
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2.01 |
"Native: ASIA-TROPICAL Indian Subcontinent: Bangladesh; Bhutan; India - Andhra Pradesh, Arunachal Pradesh, Assam, Bihar, Delhi, Goa, Gujarat, Haryana, Himachal Pradesh, Jammu and Kashmir, Karnataka, Kerala, Madhya Pradesh, Maharashtra, Manipur, Meghalaya |
http://www.ars-grin.gov/cgi-bin/npgs/html/tax_search.pl |
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2.02 |
(1)exact native range in s. Asia obscure (2)"Because sun hemp has been cultivated since antiquity its origins are unknown, but India has been hypothesized as its native homeland." |
(1)http://www.ars-grin.gov/cgi-bin/npgs/html/tax_search.pl
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2.03 |
Specimens collected from established poplations in Colombia above 1000 m (1330 and 1560 m) |
http://mobot.mobot.org/cgi-bin/search_vast |
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2.04 |
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2.05 |
cultivated throughout tropics |
http://www.ars-grin.gov/cgi-bin/npgs/html/tax_search.pl |
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3.01 |
(1)Naturalized in Florida. (2)Naturalized in Hawaii. (3)Naturalized in Madagascar. |
(1)http://plants.usda.gov/java/county?state_name=Florida&statefips=12&symbol=CRJU
(2)http://ravenel.si.edu/botany/pacificislandbiodiversity/ |
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3.02 |
No evidence. |
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3.03 |
No evidence. |
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3.04 |
No evidence. |
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3.05 |
No evidence. |
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4.01 |
No evidence of such structures. |
http://www.worldagroforestrycentre.org/sea/Products/AFDbases/af/asp/SpeciesInfo.asp?SpID=618 |
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4.02 |
Not allelopathic |
http://plants.nrcs.usda.gov/cgi_bin/topics.cgi?earl=plant_attribute.cgi&symbol=CRJU |
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4.03 |
No evidence |
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4.04 |
(1)"Most of the present-day sun hemp production is located in India, Bangladesh, and Brazil, where it is grown as a green manure crop, a fodder crop, or for the bast fibers." (2)Palatability to browsing animals - Low. Palatability to grazing animals - Me |
(1)http://www.hort.purdue.edu/newcrop/proceedings1996/v3-389.html (2)http://plants.nrcs.usda.gov/cgi_bin/topics.cgi?earl=plant_attribute.cgi&symbol=CRJU |
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4.05 |
(1)Vertebrate poisons: mammals (2)"Many species of Crotalaria contain toxic pyrrolizidine al |
(1)http://www.ars-grin.gov/cgi-bin/npgs/html/tax_search.pl (2)http://www.hort.purdue.edu/newcrop/proceedings1996/v3-389.html (3)http://www.fao.org/AG/Agp/agpc/doc/GBASE/DATA/PF000475.HTM (4)http://www.sarep.ucdavis.edu/cgi-bin/CCrop.exe/show_crop_40 |
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4.06 |
"No serious diseases have developed in South Texas and few have been reported for the United States. … Serious diseases of sunn hemp grown in India are anthracnose, caused by Colletotrichum curvatum Briant and Martyn (Mitra 1934; Whiteside 1955) and a wil |
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4.07 |
No evidence. |
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4.08 |
Probably not - a herbaceous plant, not known to occur in groups or in thickets, except when cultivated as a cover crop. |
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4.09 |
Shade intolerant. |
http://plants.nrcs.usda.gov/cgi_bin/topics.cgi?earl=plant_attribute.cgi&symbol=CRJU |
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4.1 |
(1)"Although generally considered to be a tropical or subtropical crop, it is drought resistant and has a wide range of adaptation to soil types. For fiber production, a light loam, moderately rich, well-drained soil is preferred (Montgomery 1954; Kundu 1 |
(1)http://www.hort.purdue.edu/newcrop/proceedings1996/v3-389.html (2)http://plants.nrcs.usda.gov/cgi_bin/topics.cgi?earl=plant_attribute.cgi&symbol=CRJU |
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4.11 |
No evidence. |
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4.12 |
No evidence |
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5.01 |
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5.02 |
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5.03 |
(1)It produced high organic matter yields, was able to fix nitrogen, and could reduce the build-up of root-knot nematode populations (Breitenbach 1958; Dempsey 1975). (2)High nitrogen fixation. [It is a non-woody nitrogen fixing plant]. |
(1)http://www.hort.purdue.edu/newcrop/proceedings1996/v3-389.html (2)http://plants.nrcs.usda.gov/cgi_bin/topics.cgi?earl=plant_attribute.cgi&symbol=CRJU |
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5.04 |
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6.01 |
"Most of the present-day sun hemp production is located in India …" |
http://www.hort.purdue.edu/newcrop/proceedings1996/v3-389.html |
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6.02 |
"Sun hemp is established by seed." |
http://www.fao.org/AG/Agp/agpc/doc/GBASE/DATA/PF000475.HTM |
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6.03 |
Probably not - it is a widely studied species and there is no evidence of hybridization either for C. juncea or in the genus crotalaria. |
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6.04 |
"Sun hemp, 2n = 16, is generally reported to be a self-incompatible plant. Cross-pollination is extensive and self-pollination occurs only after the stigmatic surface has been stimulated by insects or some other means." |
http://www.hort.purdue.edu/newcrop/proceedings1996/v3-389.html |
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6.05 |
Insect pollinated - "Cross-pollination is extensive, and self-pollination occurs only after the stigmatic surface has been stimulated by insects or some other means. The wings and keel of the flower are articulated by a ball-and-socket joint. When large b |
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6.06 |
No evidence of spread by vegetative means. |
http://plants.nrcs.usda.gov/cgi_bin/topics.cgi?earl=plant_attribute.cgi&symbol=CRJU |
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6.07 |
(1)"Sunn hemp is a short-day, erect shrubby annual, generally 1 to 4 m in height. " (2)"This is the fastest-growing species in its genus (Duke, 1981). In tropical areas, maturity may be reached in four months or more (Yost and Evans, 1988). Intervarietal |
(1)http://www.hort.purdue.edu/newcrop/proceedings1996/ |
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7.01 |
Probably not - no evidence that the plants are grown in heavily trafficked areas. |
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7.02 |
Probably yes - It is used as a cover crop, for fiber production as green manure and as fodder. |
http://www.sarep.ucdavis.edu/cgi-bin/CCrop.exe/show_crop_40 |
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7.03 |
"As one of the most widely grown green manure crops throughout the tropics, sun hemp is often grown in rotation with several different crop species." - however seeds are relatively large ( 6 mm in length) and hence not likely to be a contaminant. |
http://www.hort.purdue.edu/newcrop/proceedings1996/v3-389.html and http://www.fao.org/AG/Agp/agpc/doc/GBASE/DATA/PF000475.HTM |
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7.04 |
Probably not - no evidence of adaptation to wind dispersal. |
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7.05 |
No evidence |
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7.06 |
Probably not - a small herbaceous legume - the pods probably open and seeds disperse by gravity - "Pod cylindrical, 3-6 cm x 1-2 cm, tomentose, light brown, containing ca. 6 seeds. Seeds heart-shaped, with narrow end strongly in-curved, up to 6 mm long, |
http://www.fao.org/AG/Agp/agpc/doc/GBASE/DATA/PF000475.HTM |
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7.07 |
Probably not - no evidence that the seeds have any means of attachment. |
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7.08 |
No evidence of spread through animal droppings. Also seeds are known to be poisonous - see question 4.05 above. |
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8.01 |
Probably not - (1)Relatively large seeds - 5 mm in length. (2)"Seeds heart-shaped, with narrow end strongly in-curved, up to 6 mm long, dark brown to black." (3)"Because of the lateness in flowering, with the exception of Texas, very little seed producti |
(1)http://plants.usda.gov/java/profile?symbol=CRJU (2)http:/ |
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8.02 |
"Seed Storage - No information is available on sunnhemp, but for the congeneric C. spectabilis, seeds remain viable for a relatively long time (McLeod, 1982)." |
http://www.sarep.ucdavis.edu/cgi-bin/CCrop.exe/show_crop_40 |
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8.03 |
No evidence that the species is being controlled for. |
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8.04 |
"Crotalaria juncea seedlings are tender and susceptible to mechanical damage. This may restrict its use as a relay intercrop where field operations would occur at this stage." |
http://www.sarep.ucdavis.edu/cgi-bin/CCrop.exe/show_crop_40 |
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8.05 |
Don’t know. |
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