Abstract
Variation in kochia {Kochia scoparia (L.) Schrader} response to triazine herbicides was investigated in the greenhouse and laboratory. Kochia plants from railroad rights-of-way with a 13-year history of annual triazine applications were not controlled by 20 kg/ha atrazine {2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine} (atrazine resistant). These plants were considered resistant because they could no longer be controlled by atrazine dosages that were economically feasible. Kochia plants from fields nearby with no triazine history were destroyed with 2 kg/ha atrazine (atrazine susceptible). Atrazine-resistant and susceptible kochia biotypes were treated with common use rates of chloro-, methoxy-, and methylthio- substituted symmetrical triazines, an asymmetrical triazine, a substituted urea and a phenoxy herbicide. All triazines controlled atrazine-susceptible kochia but they did not control atrazine-resistant kochia. Diuron {3-(3,4-dichlorophenyl)-1,1-dimethylurea} controlled atrazine-resistant and susceptible kochia. Susceptibility to 2,4-D ester {(2,4-dichlorophenoxy)acetic acid} was greater in atrazine-resistant than in atrazine-susceptible kochia. Leaf disk and leaf infusion laboratory techniques were modified to detect atrazine resistance or susceptibility in kochia non-destructively. Only atrazine and deethylated atrazine {2-chloro-4-(amino)-6-(isopropylamino)-s-triazine} were toxic to atrazine-susceptible kochia chloroplasts. There were no significant differences in atrazine translocation to shoots or in metabolism to non-phytotoxic compounds in atrazine-resistant or susceptible kochia biotypes. Electron transport in atrazine-resistant isolated chloroplasts was not inhibited by 10('-4) M atrazine. Electron transport in atrazine-susceptible chloroplasts was stopped at 10('-5) M atrazine indicating that at least part of the mechanism of atrazine resistance in kochia is at the chloroplast level. Triazine-resistance had no effect on kochia germination or seedling vigor. When competing for light and nutrients, greenhouse-grown atrazine-resistant kochia accumulated 24% less dry matter than the suscetible biotypes. Under atrazine-free conditions this competitive disadvantage would slowly decrease the frequency of triazine resistance in this kochia population.
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Claims 15
Claim · model-written summary
Kochia plants from railroad rights-of-way with a 13-year history of annual triazine applications were not controlled by 20 kg/ha atrazine.
- Treatment
- 20 kg/ha atrazinee0
- Outcome
- controllede0
- Direction
- not controllede0
- Setting
- railroad rights-of-waye0
BassiaNot reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Kochia plants from railroad rights-of-way with a 13-year history of annual triazine applications were not controlled by 20 kg/ha atrazine”
Claim · model-written summary
Kochia plants from nearby fields with no triazine history were destroyed by 2 kg/ha atrazine (atrazine susceptible).
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Kochia plants from fields nearby with no triazine history were destroyed with 2 kg/ha atrazine (atrazine susceptible)”
Claim · model-written summary
All tested triazines controlled atrazine-susceptible kochia.
- Material
- atrazine-susceptible kochiae0
- Treatment
- All triazinese0
- Outcome
- controllede0
- Direction
- controllede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“All triazines controlled atrazine-susceptible kochia but they did not control atrazine-resistant kochia”
Claim · model-written summary
All tested triazines did not control atrazine-resistant kochia.
- Material
- atrazine-resistant kochiae0
- Treatment
- All triazinese0
- Outcome
- controle0
- Direction
- did not controle0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“All triazines controlled atrazine-susceptible kochia but they did not control atrazine-resistant kochia”
Claim · model-written summary
Diuron controlled both atrazine-resistant and susceptible kochia.
- Material
- atrazine-resistant and susceptible kochiae0
- Treatment
- Diurone0
- Outcome
- controllede0
- Direction
- controllede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Diuron {3-(3,4-dichlorophenyl)-1,1-dimethylurea} controlled atrazine-resistant and susceptible kochia”
Claim · model-written summary
Susceptibility to 2,4-D ester was greater in atrazine-resistant than in atrazine-susceptible kochia.
- Material
- atrazine-resistante0
- Treatment
- 2,4-D estere0
- Outcome
- Susceptibilitye0
- Direction
- greatere0
- Comparator
- atrazine-susceptible kochiae0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Susceptibility to 2,4-D ester {(2,4-dichlorophenoxy)acetic acid} was greater in atrazine-resistant than in atrazine-susceptible kochia”
Claim · model-written summary
Only atrazine and deethylated atrazine were toxic to chloroplasts of atrazine-susceptible kochia.
- Material
- atrazine-susceptible kochiae0
- Organ / stage
- chloroplastse0
- Treatment
- Only atrazine and deethylated atrazinee1
- Outcome
- toxice0
- Direction
- toxice0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“were toxic to atrazine-susceptible kochia chloroplasts”
e1“Only atrazine and deethylated atrazine”
Claim · model-written summary
There was no significant difference in atrazine translocation to shoots between atrazine-resistant and susceptible kochia biotypes.
- Outcome
- atrazine translocation to shootse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“There were no significant differences in atrazine translocation to shoots or in metabolism to non-phytotoxic compounds in atrazine-resistant or susceptible kochia biotypes”
Claim · model-written summary
There was no significant difference in metabolism of atrazine to non-phytotoxic compounds between atrazine-resistant and susceptible kochia biotypes.
- Outcome
- metabolism to non-phytotoxic compoundse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“There were no significant differences in atrazine translocation to shoots or in metabolism to non-phytotoxic compounds in atrazine-resistant or susceptible kochia biotypes”
Claim · model-written summary
Electron transport in isolated chloroplasts of atrazine-resistant kochia was not inhibited by 10-4 M atrazine.
- Taxon
- KOCHIA SCOPARIA
Bassia scopariat0 - Material
- atrazine-resistante0
- Organ / stage
- chloroplastse0
- Treatment
- 10('-4) M atrazinee0
- Outcome
- Electron transporte0
- Direction
- not inhibitede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Electron transport in atrazine-resistant isolated chloroplasts was not inhibited by 10('-4) M atrazine”
t0“KOCHIA SCOPARIA”
Claim · model-written summary
Electron transport in isolated chloroplasts of atrazine-susceptible kochia was stopped by 10-5 M atrazine.
- Taxon
- KOCHIA SCOPARIABassia scopariat0
- Material
- atrazine-susceptiblee0
- Organ / stage
- chloroplastse0
- Treatment
- 10('-5) M atrazinee0
- Outcome
- Electron transporte0
- Direction
- stoppede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Electron transport in atrazine-susceptible chloroplasts was stopped at 10('-5) M atrazine”
t0“KOCHIA SCOPARIA”
Claim · model-written summary
At least part of the mechanism of atrazine resistance in kochia is at the chloroplast level.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“at least part of the mechanism of atrazine resistance in kochia is at the chloroplast level”
Claim · model-written summary
Triazine resistance had no effect on germination or seedling vigor of kochia.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Triazine-resistance had no effect on kochia germination or seedling vigor”
Claim · model-written summary
When competing for light and nutrients in the greenhouse, atrazine-resistant kochia accumulated 24% less dry matter than the susceptible biotypes.
- Material
- atrazine-resistant kochiae0
- Outcome
- dry mattere0
- Direction
- lesse0
- Value
- 24%e0
- Qualifier
- competing for light and nutrientse0
- Comparator
- the suscetible biotypese0
- Setting
- greenhouse-growne0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“When competing for light and nutrients, greenhouse-grown atrazine-resistant kochia accumulated 24% less dry matter than the suscetible biotypes”
Claim · model-written summary
Under atrazine-free conditions the competitive disadvantage of resistant kochia would slowly decrease the frequency of triazine resistance in the population.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“this competitive disadvantage would slowly decrease the frequency of triazine resistance in this kochia population”
The same questions in other papers
atrazine · control · BassiaPositive and negative results
6 in the opposite direction
- positive
- positive
- positive
3 papers more in this group
See all 7 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.