Abstract
Greenhouse studies were initiated to determine the duration of time after herbicide treatment required to render johnsongrass physiologically noncompetitive. Nicosulfuron, imazapic, clethodim, and glyphosate were applied to rhizomatous johnsongrass at 35, 70, 140, and 840 g ai ha−1, respectively. Net carbon assimilation, stomatal conductance, chlorophyll meter readings, and maximum (dark adapted) efficiency of photosystem II were measured. Net carbon assimilation (AN) was assumed to be the best indicator of johnsongrass competitiveness. Johnsongrass was considered to be physiologically noncompetitive when AN declined below 50% of that of nontreated check. From these data, it was concluded that glyphosate rendered johnsongrass noncompetitive most readily, 4.3 d after treatment, whereas no differences were detected between nicosulfuron, imazapic, or clethodim throughout the experiment. Stomatal conductance (gs) was highly correlated to AN and was determined to be an adequate substitute for AN when determining johnsongrass competitiveness. It was concluded that chlorophyll meter readings and photosystem II efficiency were poor indicators of johnsongrass competitiveness.
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Claims 4
Claim · model-written summary
Glyphosate rendered johnsongrass noncompetitive after 4.3 days.
- Taxon
- johnsongrass
.jpg?width=60)
Sorghum halepensee0 - Treatment
- glyphosatee0
- Outcome
- johnsongrass noncompetitivee0
- Value
- 4.3 de0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
.jpg?width=500)
Verbatim
e0“glyphosate rendered johnsongrass noncompetitive most readily, 4.3 d after treatment”
Claim · model-written summary
Nicosulfuron, imazapic and clethodim did not differ in time to johnsongrass noncompetitiveness.
- Taxon
- johnsongrassSorghum halepenset0
- Treatment
- nicosulfuron, imazapic, or clethodime0
- Outcome
- no differencese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“johnsongrass”
e0“no differences were detected between nicosulfuron, imazapic, or clethodim throughout the experiment”
Claim · model-written summary
Stomatal conductance was highly correlated with net carbon assimilation and could substitute for it in determining competitiveness.
- Taxon
- johnsongrassSorghum halepenset0
- Outcome
- Stomatal conductancee0
- Comparator
- ANe0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“johnsongrass”
e0“Stomatal conductance (gs) was highly correlated to AN and was determined to be an adequate substitute for AN when determining johnsongrass competitiveness”
Claim · model-written summary
Chlorophyll meter readings and photosystem II efficiency were poor indicators of johnsongrass competitiveness.
- Taxon
- johnsongrassSorghum halepenset0
- Outcome
- poor indicators of johnsongrass competitivenesse0
- Comparator
- chlorophyll meter readings and photosystem II efficiencye0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“johnsongrass”
e0“chlorophyll meter readings and photosystem II efficiency were poor indicators of johnsongrass competitiveness”
The same questions in other papers
glyphosate · organism · Sorghum halepense (Johnson grass)Results agree
1 paper in the same direction as this paper
- positive
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.