Abstract
The allelopathic effect of Sphenoclea zeylanica Gaertn., a broadleaf paddy weed that hinders rice production in Thailand, was investigated. Different parts of S. zeylanica were used to determine their inhibitory effect on seed germination, and shoot and root length of rice in a laboratory. Aqueous extracts of leaves and stems had an inhibitory effect on rice germination and seedling growth more than 50% that of control at concentrations higher than 50 g L-1, whereas all concentrations of root extracts had no effect on rice seeds. At the concentration of 100 g L-1, leaf and stem extracts completely (100%) inhibited rice seed germination. The inhibitory effect was increased with increasing concentrations. Additionally, leaf extracts contained higher total phenolics (7.36 mg GE g-1 DW) and total flavonoids (254.19 µg QE g-1 DW) than extracts of other parts. In glasshouse conditions, soil incorporation with dried whole plant residue had a significant inhibitory effect on rice emergence, seedling height, and dry weight when compared with extracted residue at an equal concentration. The decomposition of S. zeylanica in the soil was also evaluated regarding rice seedling growth. The maximum inhibition was achieved 1-3 days after the application of plant residues. At the 30th day, the inhibition disappeared, suggesting that residue decomposition in the soil has been finished. These results support that S. zeylanica has an allelopathic effect on paddy fields, which may cause a reduction in rice growth and yield.
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Claims 11
Claim · model-written summary
Leaf extract above 50 g L-1 inhibited rice germination and seedling growth by over 50% versus control.
- Taxon
- rice
Oryza sativat0 - Treatment
- Aqueous extracts of leavese0
- Interactor
- Sphenoclea zeylanica
Sphenoclea zeylanicat1weede0 - Outcome
- rice germination and seedling growthe0
- Direction
- inhibitorye0
- Value
- more than 50%e0
- Comparator
- controle0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Aqueous extracts of leaves and stems had an inhibitory effect on rice germination and seedling growth more than 50% that of control at concentrations higher than 50 g L-1”
t0“rice”
t1“Sphenoclea zeylanica”
Claim · model-written summary
Stem extract above 50 g L-1 inhibited rice germination and seedling growth by over 50% versus control.
- Taxon
- riceOryza sativat0
- Treatment
- stemse0
- Outcome
- rice germination and seedling growthe0
- Direction
- inhibitorye0
- Value
- more than 50%e0
- Comparator
- controle0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Aqueous extracts of leaves and stems had an inhibitory effect on rice germination and seedling growth more than 50% that of control at concentrations higher than 50 g L-1”
t0“rice”
Claim · model-written summary
Root extracts had no effect on rice seeds at any tested concentration.
- Taxon
- riceOryza sativat0
- Treatment
- root extractse0
- Outcome
- rice seedse0
- Direction
- no effecte0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“all concentrations of root extracts had no effect on rice seeds”
t0“rice”
Claim · model-written summary
Leaf extract at 100 g L-1 completely inhibited rice germination.
- Taxon
- riceOryza sativat0
- Treatment
- leaf extractse1
- Outcome
- rice seed germinatione0
- Direction
- inhibitede0
- Value
- 100%e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“At the concentration of 100 g L-1, leaf and stem extracts completely (100%) inhibited rice seed germination”
t0“rice”
e1“leaf extracts contained higher total phenolics”
Claim · model-written summary
Stem extract at 100 g L-1 completely inhibited rice germination.
- Taxon
- riceOryza sativat0
- Treatment
- stem extractse0
- Outcome
- rice seed germinatione0
- Direction
- inhibitede0
- Value
- 100%e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“At the concentration of 100 g L-1, leaf and stem extracts completely (100%) inhibited rice seed germination”
t0“rice”
Claim · model-written summary
Inhibition increased with extract concentration.
- Taxon
- riceOryza sativat0
- Treatment
- concentrationse0
- Outcome
- inhibitory effecte0
- Direction
- increasede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The inhibitory effect was increased with increasing concentrations”
t0“rice”
Claim · model-written summary
Leaf extracts had higher total phenolics than other plant-part extracts, at 7.36 mg GE g-1 DW.
- Taxon
- S. zeylanicaSphenoclea zeylanicae1
- Outcome
- total phenolicse0
- Direction
- highere0
- Value
- 7.36 mg GE g-1 DWe0
- Comparator
- extracts of other partse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“leaf extracts contained higher total phenolics (7.36 mg GE g-1 DW) and total flavonoids (254.19 µg QE g-1 DW) than extracts of other parts”
e1“The decomposition of S. zeylanica in the soil was also evaluated regarding rice seedling growth”
Claim · model-written summary
Leaf extracts had higher total flavonoids than other plant-part extracts, at 254.19 µg QE g-1 DW.
- Taxon
- S. zeylanicaSphenoclea zeylanicae1
- Outcome
- total flavonoidse0
- Direction
- highere0
- Value
- 254.19 µg QE g-1 DWe0
- Comparator
- extracts of other partse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“leaf extracts contained higher total phenolics (7.36 mg GE g-1 DW) and total flavonoids (254.19 µg QE g-1 DW) than extracts of other parts”
e1“The decomposition of S. zeylanica in the soil was also evaluated regarding rice seedling growth”
Claim · model-written summary
Whole dried weed residue suppressed rice emergence, height and dry weight versus extracted residue.
- Taxon
- riceOryza sativat0
- Treatment
- dried whole plant residuee0
- Outcome
- rice emergence, seedling height, and dry weighte0
- Direction
- inhibitorye0
- Comparator
- extracted residuee0
- Setting
- glasshouse conditionse1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“soil incorporation with dried whole plant residue had a significant inhibitory effect on rice emergence, seedling height, and dry weight when compared with extracted residue at an equal concentration”
t0“rice”
e1“In glasshouse conditions”
Claim · model-written summary
Residue inhibition of rice seedlings was greatest one to three days after application.
- Taxon
- riceOryza sativat0
- Outcome
- inhibitione0
- Direction
- maximume0
- Qualifier
- 1-3 dayse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The maximum inhibition was achieved 1-3 days after the application of plant residues”
t0“rice”
Claim · model-written summary
Residue inhibition disappeared by day 30.
- Taxon
- riceOryza sativat0
- Outcome
- inhibitione0
- Direction
- disappearede0
- Qualifier
- 30th daye0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“At the 30th day, the inhibition disappeared”
t0“rice”
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See all 211 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.