Abstract
The phytotoxicity of aqueous foliar extracts and ground dried residues of sunn hemp ( Crotalaria juncea L.), cowpea [ Vigna unguiculata (L.) Walp. cv. Iron Clay], and velvetbean [ Mucuna deeringiana (Bort) Merr.] to crop and weed germination and growth was evaluated to compare the allelopathic potential of the cover crops. By 14 days after treatment (DAT), goosegrass [ Eleusine indica (L.) Gaertn.] germination with 5% aqueous extracts of all cover crops (w/v fresh weight basis) was similar and greater than 75% of control. However, with the 10% extracts, goosegrass germination was lowest with cowpea extract, intermediate with velvetbean extract, and highest with sunn hemp extract. Livid amaranth ( Amaranthus lividus L.) germination declined to ≈50% with cowpea and sunn hemp extracts and even lower to 22% with velvetbean extract. The suppression of livid amaranth germination was greater with the 10% extracts than the 5% extracts. Bell pepper ( Capsicum annuum L.) germination was unaffected by velvetbean extract, inhibited more by the 5% cowpea extract than the 10% extract, and was also sensitive to the 10% sunn hemp extract. All cover crop extracts resulted in an initial delay in tomato ( Lycopersicon esculentum Mill.) germination, but by 14 DAT, inhibition of germination was apparent only with cowpea extract. The phytotoxicity of ground dried residues of the three cover crops on germination, plant height, and dry weight of goosegrass, smooth amaranth ( A. hybridus L.), bell pepper, and tomato was evaluated in greenhouse studies. Goosegrass germination was inhibited in a similar manner by residues of the three cover crops to 80% or less of control. Smooth amaranth germination, plant height, and dry biomass were more sensitive to sunn hemp residues than to cowpea and velvetbean residues. Bell pepper germination, plant height, and dry weight were greater than 90% of control except for dry weight with cowpea residue, which was only 78% of control. The greatest effect of cover crop residue on tomato occurred with dry weight, because dry weights with cowpea and sunn hemp were only 76% and 69% of control, respectively, and lower than with velvetbean. There was more evidence of cover crop phytotoxicity with the weed species than with the crop species and cowpea extracts and residue affected all species more consistently than those of sunn hemp and velvetbean.
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Claims 20
Claim · model-written summary
At 14 days, goosegrass germination with 5% extracts of all three cover crops exceeded 75% of control.
Verbatim
e0“By 14 days after treatment (DAT), goosegrass [ Eleusine indica (L.) Gaertn.] germination with 5% aqueous extracts of all cover crops (w/v fresh weight basis) was similar and greater than 75% of control.”
Claim · model-written summary
Goosegrass germination with 10% cowpea extract was lowest among the three extracts.
Verbatim
e0“However, with the 10% extracts, goosegrass germination was lowest with cowpea extract, intermediate with velvetbean extract, and highest with sunn hemp extract.”
Claim · model-written summary
Goosegrass germination with 10% velvetbean extract was intermediate among the three extracts.
Verbatim
e0“However, with the 10% extracts, goosegrass germination was lowest with cowpea extract, intermediate with velvetbean extract, and highest with sunn hemp extract.”
Claim · model-written summary
Goosegrass germination with 10% sunn hemp extract was highest among the three extracts.
Verbatim
e0“However, with the 10% extracts, goosegrass germination was lowest with cowpea extract, intermediate with velvetbean extract, and highest with sunn hemp extract.”
Claim · model-written summary
Livid amaranth germination declined to ≈50% with cowpea extract.
Not reportedComparator
Verbatim
e0“Livid amaranth ( Amaranthus lividus L.) germination declined to ≈50% with cowpea and sunn hemp extracts and even lower to 22% with velvetbean extract.”
Claim · model-written summary
Livid amaranth germination declined to ≈50% with sunn hemp extract.
Not reportedComparator
Verbatim
e0“Livid amaranth ( Amaranthus lividus L.) germination declined to ≈50% with cowpea and sunn hemp extracts and even lower to 22% with velvetbean extract.”
Claim · model-written summary
Livid amaranth germination was lower at 22% with velvetbean extract.
Not reportedComparator
Verbatim
e0“Livid amaranth ( Amaranthus lividus L.) germination declined to ≈50% with cowpea and sunn hemp extracts and even lower to 22% with velvetbean extract.”
Claim · model-written summary
The 10% extracts suppressed livid amaranth germination more than 5% extracts.
Verbatim
e0“The suppression of livid amaranth germination was greater with the 10% extracts than the 5% extracts.”
Claim · model-written summary
Bell pepper germination was unaffected by velvetbean extract.
Not reportedComparator
Verbatim
e0“Bell pepper ( Capsicum annuum L.) germination was unaffected by velvetbean extract, inhibited more by the 5% cowpea extract than the 10% extract, and was also sensitive to the 10% sunn hemp extract.”
Claim · model-written summary
Bell pepper germination was inhibited more by 5% cowpea extract.
Verbatim
e0“Bell pepper ( Capsicum annuum L.) germination was unaffected by velvetbean extract, inhibited more by the 5% cowpea extract than the 10% extract, and was also sensitive to the 10% sunn hemp extract.”
Claim · model-written summary
Bell pepper germination was sensitive by 10% sunn hemp extract.
Not reportedComparator
Verbatim
e0“Bell pepper ( Capsicum annuum L.) germination was unaffected by velvetbean extract, inhibited more by the 5% cowpea extract than the 10% extract, and was also sensitive to the 10% sunn hemp extract.”
Claim · model-written summary
All cover crop extracts initially delayed tomato germination.
- Taxon
- tomato
Solanum lycopersicume0 - Treatment
- All cover crop extractse0
- Outcome
- germinatione0
- Direction
- delaye0
- Qualifier
- initiale0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“All cover crop extracts resulted in an initial delay in tomato ( Lycopersicon esculentum Mill.) germination, but by 14 DAT, inhibition of germination was apparent only with cowpea extract.”
Claim · model-written summary
Only cowpea extract still inhibited tomato germination by 14 DAT.
- Taxon
- tomatoSolanum lycopersicume0
- Treatment
- cowpea extracte0
- Outcome
- germinatione0
- Direction
- inhibitione0
- Qualifier
- 14 DATe0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“All cover crop extracts resulted in an initial delay in tomato ( Lycopersicon esculentum Mill.) germination, but by 14 DAT, inhibition of germination was apparent only with cowpea extract.”
Claim · model-written summary
Residues of all three cover crops similarly inhibited goosegrass germination to at most 80% of control.
Verbatim
e0“Goosegrass germination was inhibited in a similar manner by residues of the three cover crops to 80% or less of control.”
Claim · model-written summary
Smooth amaranth germination, height and dry biomass were more sensitive to sunn hemp residue than cowpea or velvetbean residue.
Verbatim
e0“Smooth amaranth germination, plant height, and dry biomass were more sensitive to sunn hemp residues than to cowpea and velvetbean residues.”
Claim · model-written summary
Bell pepper germination, height and dry weight under cover crop residues generally exceeded 90% of control.
- Taxon
- Bell peppere0
- Outcome
- germination, plant height, and dry weighte0
- Direction
- greater thane0
- Value
- 90%e0
- Comparator
- controle0
Not reportedTreatment
Verbatim
e0“Bell pepper germination, plant height, and dry weight were greater than 90% of control except for dry weight with cowpea residue, which was only 78% of control.”
Claim · model-written summary
Bell pepper dry weight with cowpea residue was only 78% of control.
Verbatim
e0“Bell pepper germination, plant height, and dry weight were greater than 90% of control except for dry weight with cowpea residue, which was only 78% of control.”
Claim · model-written summary
Tomato dry weight with cowpea residue was 76% of control and lower than with velvetbean.
- Taxon
- tomatoSolanum lycopersicume0
- Treatment
- cowpeae0
- Outcome
- dry weightse0
- Direction
- lowere0
- Value
- 76%e0
- Qualifier
- velvetbeane0
- Comparator
- controle0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The greatest effect of cover crop residue on tomato occurred with dry weight, because dry weights with cowpea and sunn hemp were only 76% and 69% of control, respectively, and lower than with velvetbean.”
Claim · model-written summary
Tomato dry weight with sunn hemp residue was 69% of control and lower than with velvetbean.
- Taxon
- tomatoSolanum lycopersicume0
- Treatment
- sunn hempe0
- Outcome
- dry weightse0
- Direction
- lowere0
- Value
- 69%e0
- Qualifier
- velvetbeane0
- Comparator
- controle0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The greatest effect of cover crop residue on tomato occurred with dry weight, because dry weights with cowpea and sunn hemp were only 76% and 69% of control, respectively, and lower than with velvetbean.”
Claim · model-written summary
The authors found more cover-crop phytotoxicity in weeds than crops, with cowpea material affecting species most consistently.
Verbatim
e0“There was more evidence of cover crop phytotoxicity with the weed species than with the crop species and cowpea extracts and residue affected all species more consistently than those of sunn hemp and velvetbean.”
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See all 291 papers →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.