Abstract
Laboratory, greenhouse, and field studies were conducted to determine the allelopathic potential of sunflower ( Helianthus annuus L.) cultivars to suppress weed germination and growth. Germination of wild mustard [ Brassica kaber (DC.) L.C. Wheeler var. pinnatifida (Stokes) L.C. Wheeler] seeds at 25 C in undiluted aqueous extracts of sunflower leaf tissue was inhibited 75%, but was stimulated by up to 150% at 10- and 100-fold dilutions. Stem-tissue extracts at all concentrations stimulated wild mustard seed germination. The germination response of other weed species varied with the sunflower cultivar and concentration of tissue extract. In sand culture, leachates of dried sunflower leaf and stem tissue inhibited broadleaf - weed seedling growth, but had little or no effect on the growth of grass weeds. Sunflower root exudates inhibited seedling growth, but were less effective than leaf and stem tissue leachates. Germination of weed seeds was unaffected by root exudates. Over a 5 -yr period, weed density and percent ground cover increased less in field plots of sunflower than in control plots.
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Claims 10
Claim · model-written summary
Undiluted sunflower leaf extract inhibited wild mustard seed germination by 75%.
- Taxon
- sunflower
Helianthus annuust0 - Treatment
- undiluted aqueous extracts of sunflower leaf tissuee0
- Interactor
- wild mustarde0weed
- Outcome
- Germination of wild mustarde0
- Direction
- inhibitede0
- Value
- 75%e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Germination of wild mustard [ Brassica kaber (DC.) L.C. Wheeler var. pinnatifida (Stokes) L.C. Wheeler] seeds at 25 C in undiluted aqueous extracts of sunflower leaf tissue was inhibited 75%”
t0“Sunflowers”
Claim · model-written summary
Diluted leaf extracts stimulated wild mustard germination by up to 150%.
- Taxon
- sunflowerHelianthus annuust0
- Treatment
- 10- and 100-fold dilutionse0
- Outcome
- stimulatede0
- Direction
- stimulatede0
- Value
- up to 150%e0
Not reportedInteractorInteractor roleComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“but was stimulated by up to 150% at 10- and 100-fold dilutions.”
t0“Sunflowers”
Claim · model-written summary
Stem extracts stimulated wild mustard seed germination at all concentrations.
- Taxon
- sunflowerHelianthus annuust0
- Treatment
- Stem-tissue extractse0
- Interactor
- wild mustarde0weed
- Outcome
- wild mustard seed germinatione0
- Direction
- stimulatede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Stem-tissue extracts at all concentrations stimulated wild mustard seed germination.”
t0“Sunflowers”
Claim · model-written summary
Other weed species varied in germination response by sunflower cultivar and extract concentration.
- Taxon
- sunflowerHelianthus annuust0
- Material
- sunflower cultivare0
- Interactor
- other weed speciese0weed
- Outcome
- germination response of other weed speciese0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The germination response of other weed species varied with the sunflower cultivar and concentration of tissue extract.”
t0“Sunflowers”
Claim · model-written summary
Sunflower leaf and stem leachates inhibited broadleaf weed seedling growth.
- Taxon
- sunflowerHelianthus annuust0
- Treatment
- leachates of dried sunflower leaf and stem tissuee0
- Interactor
- broadleaf - weede0weed
- Outcome
- broadleaf - weed seedling growthe0
- Direction
- inhibitede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“leachates of dried sunflower leaf and stem tissue inhibited broadleaf - weed seedling growth”
t0“Sunflowers”
Claim · model-written summary
Sunflower tissue leachates had little or no effect on grass weed growth.
- Taxon
- sunflowerHelianthus annuust0
- Interactor
- grass weedse0weed
- Outcome
- growth of grass weedse0
- Direction
- little or no effecte0
Not reportedTreatmentComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“but had little or no effect on the growth of grass weeds.”
t0“Sunflowers”
Claim · model-written summary
Sunflower root exudates inhibited weed seedling growth less effectively than tissue leachates.
- Taxon
- sunflowerHelianthus annuust0
- Treatment
- Sunflower root exudatese0
- Outcome
- seedling growthe0
- Direction
- inhibitede0
- Comparator
- leaf and stem tissue leachatese0
Not reportedInteractorInteractor role
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Sunflower root exudates inhibited seedling growth, but were less effective than leaf and stem tissue leachates.”
t0“Sunflowers”
Claim · model-written summary
Root exudates did not affect weed seed germination.
- Taxon
- sunflowerHelianthus annuust0
- Treatment
- root exudatese0
- Interactor
- weede0weed
- Outcome
- Germination of weed seedse0
- Direction
- unaffectede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Germination of weed seeds was unaffected by root exudates.”
t0“Sunflowers”
Claim · model-written summary
Weed density increased less in sunflower plots than controls over five years.
- Taxon
- sunflowerHelianthus annuust0
- Treatment
- field plots of sunflowere0
- Interactor
- weede0weed
- Outcome
- weed densitye0
- Direction
- increased lesse0
- Comparator
- control plotse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Over a 5 -yr period, weed density and percent ground cover increased less in field plots of sunflower than in control plots.”
t0“Sunflowers”
Claim · model-written summary
Weed ground cover increased less in sunflower plots than controls over five years.
- Taxon
- sunflowerHelianthus annuust0
- Treatment
- field plots of sunflowere0
- Interactor
- weede0weed
- Outcome
- percent ground covere0
- Direction
- increased lesse0
- Comparator
- control plotse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Over a 5 -yr period, weed density and percent ground cover increased less in field plots of sunflower than in control plots.”
t0“Sunflowers”
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See all 51 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.