Abstract
In the worldwide search for new strategies in sustainable weed management, the use of plant species able to produce and release phytotoxic compounds into the environment could be an effective alternative to synthetic herbicides. Eucalyptus globulus Labill. is known to be a source of biologically active compounds responsible for its phytotoxic and allelopathic properties. Our previous results demonstrated the bioherbicide potential of eucalyptus leaves incorporated into the soil as a green manure, probably through the release of phytotoxins into the soil solution. Thus, the aims of this study were to understand the phytotoxicity of the eucalyptus leaves aqueous extract applied in pre- and post-emergence, and to identify and quantify its potentially phytotoxic water-soluble compounds. The effects were tested on the germination and early growth of the model target species Lactuca sativa and Agrostis stolonifera, and on physiological parameters of L. sativa adult plants after watering or spraying application. Dose-response curves and ED50 and ED80 values for eucalyptus aqueous extracts revealed pre-emergence inhibitory effects on both target species, effects being comparable to the herbicide metolachlor. While spraying treatment reduced the aerial and root biomass and increased the dry weight/fresh weight ratio of lettuce adult plants, watering application reduced protein contents and chlorophyll concentrations with respect to control, reflecting different modes of action depending on the site of phytotoxin entry. Via HPLC analyses, a total of 8 phenolic compounds (chlorogenic, two ρ-coumaric derivatives, ellagic, hyperoside, rutin, quercitrin, and kaempferol 3-O-glucoside) and other 5 low weight organic acids (citric, malic, shikimic, succinic and fumaric acids) were obtained from aqueous extract, the latter being identified for the first time in E. globulus. Despite some phytotoxic effects were found on lettuce adult plants, the use of eucalyptus aqueous extract would be discarded in post-emergence, whereas it was promising as a pre-emergence bioherbicide.
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Claims 9
Claim · model-written summary
Eucalyptus aqueous extract had pre-emergence inhibitory effects on Lactuca sativa, comparable to the herbicide metolachlor.
- Taxon
- Lactuca sativa
Lactuca sativae0 - Treatment
- eucalyptus aqueous extractse1
- Outcome
- pre-emergence inhibitory effectse1
- Direction
- inhibitorye1
- Comparator
- herbicide metolachlore1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The effects were tested on the germination and early growth of the model target species Lactuca sativa and Agrostis stolonifera”
e1“Dose-response curves and ED50 and ED80 values for eucalyptus aqueous extracts revealed pre-emergence inhibitory effects on both target species, effects being comparable to the herbicide metolachlor”
Claim · model-written summary
Eucalyptus aqueous extract had pre-emergence inhibitory effects on Agrostis stolonifera, comparable to the herbicide metolachlor.
- Taxon
- Agrostis stolonifera
Agrostis stoloniferae0 - Treatment
- eucalyptus aqueous extractse1
- Outcome
- pre-emergence inhibitory effectse1
- Direction
- inhibitorye1
- Comparator
- herbicide metolachlore1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The effects were tested on the germination and early growth of the model target species Lactuca sativa and Agrostis stolonifera”
e1“Dose-response curves and ED50 and ED80 values for eucalyptus aqueous extracts revealed pre-emergence inhibitory effects on both target species, effects being comparable to the herbicide metolachlor”
Claim · model-written summary
Spraying the eucalyptus extract reduced aerial and root biomass of lettuce adult plants.
- Taxon
- lettuceLactuca sativae0
- Treatment
- spraying treatmente0
- Outcome
- aerial and root biomasse0
- Direction
- reducede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“While spraying treatment reduced the aerial and root biomass and increased the dry weight/fresh weight ratio of lettuce adult plants”
Claim · model-written summary
Spraying the eucalyptus extract increased the dry weight/fresh weight ratio of lettuce adult plants.
- Taxon
- lettuceLactuca sativae0
- Treatment
- spraying treatmente0
- Outcome
- dry weight/fresh weight ratioe0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“While spraying treatment reduced the aerial and root biomass and increased the dry weight/fresh weight ratio of lettuce adult plants”
Claim · model-written summary
Watering application of the eucalyptus extract reduced protein contents and chlorophyll concentrations of lettuce adult plants relative to control.
- Taxon
- lettuceLactuca sativae0
- Treatment
- watering applicatione0
- Outcome
- protein contents and chlorophyll concentrationse0
- Direction
- reducede0
- Comparator
- controle0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“lettuce adult plants, watering application reduced protein contents and chlorophyll concentrations with respect to control”
Claim · model-written summary
The differing effects of spraying and watering are interpreted as reflecting different modes of action depending on the site of phytotoxin entry.
- Taxon
- lettuceLactuca sativae0
- Outcome
- different modes of actione0
- Qualifier
- depending on the site of phytotoxin entrye0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“lettuce adult plants, watering application reduced protein contents and chlorophyll concentrations with respect to control, reflecting different modes of action depending on the site of phytotoxin entry”
Claim · model-written summary
HPLC identified 8 phenolic compounds (chlorogenic, two p-coumaric derivatives, ellagic, hyperoside, rutin, quercitrin, kaempferol 3-O-glucoside) in the Eucalyptus globulus aqueous extract.
- Taxon
- Eucalyptus globulus
Eucalyptus globulust0 - Outcome
- phenolic compoundse0
- Value
- 8e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Eucalyptus globulus Labill”
e0“Via HPLC analyses, a total of 8 phenolic compounds (chlorogenic, two ρ-coumaric derivatives, ellagic, hyperoside, rutin, quercitrin, and kaempferol 3-O-glucoside)”
Claim · model-written summary
HPLC identified 5 low weight organic acids (citric, malic, shikimic, succinic and fumaric) in the Eucalyptus globulus aqueous extract, identified for the first time in E. globulus.
- Taxon
- Eucalyptus globulusEucalyptus globulust0
- Outcome
- low weight organic acidse0
- Value
- 5e0
- Qualifier
- identified for the first time in E. globuluse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Eucalyptus globulus Labill”
e0“other 5 low weight organic acids (citric, malic, shikimic, succinic and fumaric acids) were obtained from aqueous extract, the latter being identified for the first time in E. globulus”
Claim · model-written summary
The authors conclude eucalyptus aqueous extract would be discarded for post-emergence use but is promising as a pre-emergence bioherbicide.
- Taxon
- Eucalyptus globulusEucalyptus globulust0
- Outcome
- promising as a pre-emergence bioherbicidee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Eucalyptus globulus Labill”
e0“the use of eucalyptus aqueous extract would be discarded in post-emergence, whereas it was promising as a pre-emergence bioherbicide”
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- negative
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63 papers in the same direction as this paper · 7 in the opposite direction · 1 reporting no difference from an alternative
- negative
- negative
- no effect
68 papers more in this group
See all 72 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.