Abstract
Sunnhemp ( Crotalaria juncea L.) is a tropical legume that could be an important summer cover crop in the southeastern United States, but it has the potential for suppressing both crops and weeds. Allelopathic effects of sunnhemp on weeds, vegetable crops, and cover crops were evaluated in greenhouse and growth chamber experiments. In the greenhouse, ground dried sunnhemp residues (applied mixed with the soil at 1.6% w/w) reduced percent germination of lettuce ( Lactuca sativa L.) and smooth pigweed ( Amaranthus hybridus L.) to a similar degree as that caused by cereal rye ( Secale cereale L. subsp. cereale ) residues (applied at 1.5% w/w). The allelopathic activity of sunnhemp was greater in the leaves than in the roots or stems. In growth chamber studies, the mean reduction in germination (relative to the control) caused by sunnhemp leaf aqueous extracts was: bell pepper (100%), tomato (100%), onion (95%), turnip (69%), okra (49%), cowpea (39%), collard (34%), cereal rye (22%), sweet corn (14%), Austrian winter pea (10%), crimson clover (8%), cucumber (2%), and winter wheat (2%). In lettuce, carrot, smooth pigweed, and annual ryegrass, sunnhemp aqueous leaf extract reduced seedling length to a degree similar as that produced by rye aqueous leaf extract. Sicklepod [S enna obtusifoli a (L.) H.S. Irwin & Barneby CA] germination was not inhibited by any of the sunnhemp or rye aqueous extracts. In conclusion, sunnhemp reduced the germination percentage and seedling growth of various crop species. The allelochemical activity in sunnhemp was primarily in the leaves and remained active at least 16 d after harvest under dry conditions. Sunnhemp's allelochemical effect may be a useful attribute for weed management in sustainable production systems. However, plant growth in the field in crops such as bell pepper, tomato, onion, and turnip may be impacted as a result of allelopathic activity of sunnhemp residues. Thus, weed management may be more effective when sunnhemp is grown in rotation with crops that tolerate the allelochemicals from sunnhemp, resulting in optimization of the rotation effects.
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Claims 20
Claim · model-written summary
Sunnhemp residues reduced lettuce germination comparably to cereal rye residues.
- Taxon
- lettuce
Lactuca sativae0 - Treatment
- ground dried sunnhemp residues (applied mixed with the soil at 1.6% w/w)e0
- Interactor
- sunnhemp
Crotalaria junceae0weed - Outcome
- percent germination of lettucee0
- Direction
- reducede0
- Comparator
- cereal rye ( Secale cereale L. subsp. cereale ) residues (applied at 1.5% w/w)e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“ground dried sunnhemp residues (applied mixed with the soil at 1.6% w/w) reduced percent germination of lettuce ( Lactuca sativa L.) and smooth pigweed ( Amaranthus hybridus L.) to a similar degree as that caused by cereal rye ( Secale cereale L. subsp. cereale ) residues (applied at 1.5% w/w)”
Claim · model-written summary
Sunnhemp residues reduced smooth pigweed germination comparably to rye residues.
- Taxon
- smooth pigweed
Amaranthus hybriduse0 - Treatment
- ground dried sunnhemp residues (applied mixed with the soil at 1.6% w/w)e0
- Interactor
- sunnhempCrotalaria junceae0weed
- Outcome
- percent germinatione0
- Direction
- reducede0
- Comparator
- cereal rye ( Secale cereale L. subsp. cereale ) residues (applied at 1.5% w/w)e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“ground dried sunnhemp residues (applied mixed with the soil at 1.6% w/w) reduced percent germination of lettuce ( Lactuca sativa L.) and smooth pigweed ( Amaranthus hybridus L.) to a similar degree as that caused by cereal rye ( Secale cereale L. subsp. cereale ) residues (applied at 1.5% w/w)”
Claim · model-written summary
Sunnhemp leaf allelopathic activity exceeded that of roots and stems.
- Taxon
- sunnhempCrotalaria junceae0
- Organ / stage
- leavese0
- Outcome
- allelopathic activitye0
- Direction
- greatere0
- Comparator
- roots or stemse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The allelopathic activity of sunnhemp was greater in the leaves than in the roots or stems.”
Claim · model-written summary
bell pepper germination was reduced by 100% by sunnhemp leaf extract.
- Taxon
- bell peppere0
- Treatment
- sunnhemp leaf aqueous extractse0
- Interactor
- sunnhempCrotalaria junceae0weed
- Outcome
- germinatione0
- Direction
- reductione0
- Value
- 100%e0
- Comparator
- the controle0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the mean reduction in germination (relative to the control) caused by sunnhemp leaf aqueous extracts was: bell pepper (100%), tomato (100%), onion (95%), turnip (69%), okra (49%), cowpea (39%), collard (34%), cereal rye (22%), sweet corn (14%), Austrian winter pea (10%), crimson clover (8%), cucumber (2%), and winter wheat (2%)”
Claim · model-written summary
tomato germination was reduced by 100% by sunnhemp leaf extract.
- Taxon
- tomato
Solanum lycopersicume0 - Treatment
- sunnhemp leaf aqueous extractse0
- Interactor
- sunnhempCrotalaria junceae0weed
- Outcome
- germinatione0
- Direction
- reductione0
- Value
- 100%e0
- Comparator
- the controle0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the mean reduction in germination (relative to the control) caused by sunnhemp leaf aqueous extracts was: bell pepper (100%), tomato (100%), onion (95%), turnip (69%), okra (49%), cowpea (39%), collard (34%), cereal rye (22%), sweet corn (14%), Austrian winter pea (10%), crimson clover (8%), cucumber (2%), and winter wheat (2%)”
Claim · model-written summary
onion germination was reduced by 95% by sunnhemp leaf extract.
- Taxon
- onion
Allium cepae0 - Treatment
- sunnhemp leaf aqueous extractse0
- Interactor
- sunnhempCrotalaria junceae0weed
- Outcome
- germinatione0
- Direction
- reductione0
- Value
- 95%e0
- Comparator
- the controle0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the mean reduction in germination (relative to the control) caused by sunnhemp leaf aqueous extracts was: bell pepper (100%), tomato (100%), onion (95%), turnip (69%), okra (49%), cowpea (39%), collard (34%), cereal rye (22%), sweet corn (14%), Austrian winter pea (10%), crimson clover (8%), cucumber (2%), and winter wheat (2%)”
Claim · model-written summary
turnip germination was reduced by 69% by sunnhemp leaf extract.
- Taxon
- turnip
.jpg?width=60)
Brassica rapa subsp. rapae0 - Treatment
- sunnhemp leaf aqueous extractse0
- Interactor
- sunnhempCrotalaria junceae0weed
- Outcome
- germinatione0
- Direction
- reductione0
- Value
- 69%e0
- Comparator
- the controle0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
.jpg?width=500)
Verbatim
e0“the mean reduction in germination (relative to the control) caused by sunnhemp leaf aqueous extracts was: bell pepper (100%), tomato (100%), onion (95%), turnip (69%), okra (49%), cowpea (39%), collard (34%), cereal rye (22%), sweet corn (14%), Austrian winter pea (10%), crimson clover (8%), cucumber (2%), and winter wheat (2%)”
Claim · model-written summary
okra germination was reduced by 49% by sunnhemp leaf extract.
- Taxon
- okra
.jpg?width=60)
Abelmoschus esculentuse0 - Treatment
- sunnhemp leaf aqueous extractse0
- Interactor
- sunnhempCrotalaria junceae0weed
- Outcome
- germinatione0
- Direction
- reductione0
- Value
- 49%e0
- Comparator
- the controle0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
.jpg?width=500)
Verbatim
e0“the mean reduction in germination (relative to the control) caused by sunnhemp leaf aqueous extracts was: bell pepper (100%), tomato (100%), onion (95%), turnip (69%), okra (49%), cowpea (39%), collard (34%), cereal rye (22%), sweet corn (14%), Austrian winter pea (10%), crimson clover (8%), cucumber (2%), and winter wheat (2%)”
Claim · model-written summary
cowpea germination was reduced by 39% by sunnhemp leaf extract.
- Taxon
- cowpea
Vigna unguiculatae0 - Treatment
- sunnhemp leaf aqueous extractse0
- Interactor
- sunnhempCrotalaria junceae0weed
- Outcome
- germinatione0
- Direction
- reductione0
- Value
- 39%e0
- Comparator
- the controle0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the mean reduction in germination (relative to the control) caused by sunnhemp leaf aqueous extracts was: bell pepper (100%), tomato (100%), onion (95%), turnip (69%), okra (49%), cowpea (39%), collard (34%), cereal rye (22%), sweet corn (14%), Austrian winter pea (10%), crimson clover (8%), cucumber (2%), and winter wheat (2%)”
Claim · model-written summary
collard germination was reduced by 34% by sunnhemp leaf extract.
- Taxon
- collarde0
- Treatment
- sunnhemp leaf aqueous extractse0
- Interactor
- sunnhempCrotalaria junceae0weed
- Outcome
- germinatione0
- Direction
- reductione0
- Value
- 34%e0
- Comparator
- the controle0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the mean reduction in germination (relative to the control) caused by sunnhemp leaf aqueous extracts was: bell pepper (100%), tomato (100%), onion (95%), turnip (69%), okra (49%), cowpea (39%), collard (34%), cereal rye (22%), sweet corn (14%), Austrian winter pea (10%), crimson clover (8%), cucumber (2%), and winter wheat (2%)”
Claim · model-written summary
cereal rye germination was reduced by 22% by sunnhemp leaf extract.
- Taxon
- cereal ryee0
- Treatment
- sunnhemp leaf aqueous extractse0
- Interactor
- sunnhempCrotalaria junceae0weed
- Outcome
- germinatione0
- Direction
- reductione0
- Value
- 22%e0
- Comparator
- the controle0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the mean reduction in germination (relative to the control) caused by sunnhemp leaf aqueous extracts was: bell pepper (100%), tomato (100%), onion (95%), turnip (69%), okra (49%), cowpea (39%), collard (34%), cereal rye (22%), sweet corn (14%), Austrian winter pea (10%), crimson clover (8%), cucumber (2%), and winter wheat (2%)”
Claim · model-written summary
sweet corn germination was reduced by 14% by sunnhemp leaf extract.
- Taxon
- sweet corne0
- Treatment
- sunnhemp leaf aqueous extractse0
- Interactor
- sunnhempCrotalaria junceae0weed
- Outcome
- germinatione0
- Direction
- reductione0
- Value
- 14%e0
- Comparator
- the controle0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the mean reduction in germination (relative to the control) caused by sunnhemp leaf aqueous extracts was: bell pepper (100%), tomato (100%), onion (95%), turnip (69%), okra (49%), cowpea (39%), collard (34%), cereal rye (22%), sweet corn (14%), Austrian winter pea (10%), crimson clover (8%), cucumber (2%), and winter wheat (2%)”
Claim · model-written summary
Austrian winter pea germination was reduced by 10% by sunnhemp leaf extract.
- Taxon
- Austrian winter peae0
- Treatment
- sunnhemp leaf aqueous extractse0
- Interactor
- sunnhempCrotalaria junceae0weed
- Outcome
- germinatione0
- Direction
- reductione0
- Value
- 10%e0
- Comparator
- the controle0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the mean reduction in germination (relative to the control) caused by sunnhemp leaf aqueous extracts was: bell pepper (100%), tomato (100%), onion (95%), turnip (69%), okra (49%), cowpea (39%), collard (34%), cereal rye (22%), sweet corn (14%), Austrian winter pea (10%), crimson clover (8%), cucumber (2%), and winter wheat (2%)”
Claim · model-written summary
crimson clover germination was reduced by 8% by sunnhemp leaf extract.
- Taxon
- crimson clovere0
- Treatment
- sunnhemp leaf aqueous extractse0
- Interactor
- sunnhempCrotalaria junceae0weed
- Outcome
- germinatione0
- Direction
- reductione0
- Value
- 8%e0
- Comparator
- the controle0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the mean reduction in germination (relative to the control) caused by sunnhemp leaf aqueous extracts was: bell pepper (100%), tomato (100%), onion (95%), turnip (69%), okra (49%), cowpea (39%), collard (34%), cereal rye (22%), sweet corn (14%), Austrian winter pea (10%), crimson clover (8%), cucumber (2%), and winter wheat (2%)”
Claim · model-written summary
cucumber germination was reduced by 2% by sunnhemp leaf extract.
- Taxon
- cucumber
Cucumis sativuse0 - Treatment
- sunnhemp leaf aqueous extractse0
- Interactor
- sunnhempCrotalaria junceae0weed
- Outcome
- germinatione0
- Direction
- reductione0
- Value
- 2%e0
- Comparator
- the controle0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the mean reduction in germination (relative to the control) caused by sunnhemp leaf aqueous extracts was: bell pepper (100%), tomato (100%), onion (95%), turnip (69%), okra (49%), cowpea (39%), collard (34%), cereal rye (22%), sweet corn (14%), Austrian winter pea (10%), crimson clover (8%), cucumber (2%), and winter wheat (2%)”
Claim · model-written summary
winter wheat germination was reduced by 2% by sunnhemp leaf extract.
- Taxon
- winter wheat
Triticum aestivume0 - Treatment
- sunnhemp leaf aqueous extractse0
- Interactor
- sunnhempCrotalaria junceae0weed
- Outcome
- germinatione0
- Direction
- reductione0
- Value
- 2%e0
- Comparator
- the controle0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the mean reduction in germination (relative to the control) caused by sunnhemp leaf aqueous extracts was: bell pepper (100%), tomato (100%), onion (95%), turnip (69%), okra (49%), cowpea (39%), collard (34%), cereal rye (22%), sweet corn (14%), Austrian winter pea (10%), crimson clover (8%), cucumber (2%), and winter wheat (2%)”
Claim · model-written summary
Sunnhemp leaf extract reduced seedling length similarly to rye extract in lettuce, carrot, smooth pigweed, and annual ryegrass.
- Taxon
- lettuce, carrot, smooth pigweed, and annual ryegrasse0
- Treatment
- sunnhemp aqueous leaf extracte0
- Interactor
- sunnhempCrotalaria junceae0weed
- Outcome
- seedling lengthe0
- Direction
- reducede0
- Comparator
- rye aqueous leaf extracte0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“In lettuce, carrot, smooth pigweed, and annual ryegrass, sunnhemp aqueous leaf extract reduced seedling length to a degree similar as that produced by rye aqueous leaf extract.”
Claim · model-written summary
Sicklepod germination was not inhibited by sunnhemp or rye extracts.
- Taxon
- Sicklepode0
- Treatment
- sunnhemp or rye aqueous extractse0
- Interactor
- sunnhempCrotalaria junceae0weed
- Outcome
- germinatione0
- Direction
- not inhibitede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Sicklepod [S enna obtusifoli a (L.) H.S. Irwin & Barneby CA] germination was not inhibited by any of the sunnhemp or rye aqueous extracts.”
Claim · model-written summary
Sunnhemp allelochemical activity remained active for at least 16 days after dry harvest.
- Taxon
- sunnhempCrotalaria junceae0
- Organ / stage
- leavese0
- Outcome
- allelochemical activitye0
- Qualifier
- at least 16 d after harvest under dry conditionse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The allelochemical activity in sunnhemp was primarily in the leaves and remained active at least 16 d after harvest under dry conditions.”
Claim · model-written summary
The authors suggest rotating sunnhemp with crops tolerant of its allelochemicals for weed management.
- Taxon
- sunnhempCrotalaria junceae0
- Treatment
- grown in rotation with crops that tolerate the allelochemicals from sunnhempe0
- Outcome
- weed management may be more effectivee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“weed management may be more effective when sunnhemp is grown in rotation with crops that tolerate the allelochemicals from sunnhemp”
The same questions in other papers
Crotalaria juncea · growth · Triticum aestivum (wheat)Positive and negative results
1 in the opposite direction
- positive
Crotalaria juncea · growth · Capsicum annuum (sweet pepper)Positive and negative results
1 paper in the same direction as this paper · 1 in the opposite direction
- positive
- negative
Crotalaria juncea · growth · Vigna unguiculata (cowpea)Positive and negative results
1 paper in the same direction as this paper · 1 in the opposite direction
- positive
- negative
Crotalaria juncea · growth · Solanum lycopersicum (tomato)Positive and negative results
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- no effect
Crotalaria juncea · growth · Zea mays (maize)Positive and negative results
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See all 9 papers →processing · growth · Lactuca sativa (garden lettuce)Positive and negative results
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See all 34 papers →botanical · growth · Abelmoschus esculentus (okra)Positive and negative results
7 papers in the same direction as this paper · 49 in the opposite direction
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See all 57 papers →8 of 15 groups shown: named compounds and organisms first, then groups whose results differ (checked claim by claim), then those with positive and negative results, then the smaller groups.
Claims are grouped by organism, treatment and what was measured or targeted. A paper counts as positive when any of its claims in the group is positive.