Abstract
Creeping bentgrass ( Agrostis stolonifera ) is used extensively on temperate zone golf course greens, tees, and fairways, but often performs poorly in shade. Previous research has indicated that sequential applications of gibberellic acid (GA) inhibiting plant growth regulators (PGRs) such as trinexapac-ethyl (TE) increase cool-season turfgrass performance in 70-90% shade. This research was conducted to: 1) confirm appropriate TE application rates and frequencies for maintaining `Penncross' creeping bentgrass in dense shade in the mid-Atlantic region of the U.S.; 2) determine the efficacy of other PGRs, biostimulants, and iron (Fe); and 3) assess whether the addition of a biostimulant with TE would have additive, synergistic, or negative effects. The other compounds tested against TE and the control were: propiconazole (PPC), iron sulfate, CPR (a seaweed and iron containing biostimulant), and a generic seaweed extract (SWE) ( Ascophyllum nodosum ) plus humic acid (HA) combination. These treatments were applied to 88% shaded bentgrass every 14 days from May or June through October in 2001 and 2002, with turf quality, leaf color, root strength, photochemical efficiency, and antioxidant enzyme superoxide dismutase (SOD) activity being determined. While the quality of control plots fell below a commercially acceptable level by the second month of the trial, repeated foliar TE application provided 33% to 44% better quality throughout the experiment. Propiconazole resulted in 13% to 17% better quality through September of each year. Trinexapac-ethyl and PPC resulted in darker leaf color and increased mid-trial root strength by 27% and 29%, respectively. Canopy photochemical efficiency and leaf SOD activity were also increased due to TE in August of both years. Treatment with Fe, CPR, or SWE+HA did not have an effect on quality, root strength, SOD, or photochemical efficiency, but periodic increases in color were observed. The addition of CPR to TE in 2002 provided results that were not different from those of TE-alone. This and previous studies indicate that restricting leaf elongation with anti-GA PGRs is of primary importance for improving shade tolerance, while treatments that increase leaf color or chlorophyll levels without restricting leaf elongation are relatively ineffective.
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Claims 15
Claim · model-written summary
Control turf quality fell below commercial acceptability by month two.
- Taxon
- Creeping bentgrass
Agrostis stoloniferae1 - Outcome
- quality of control plotse0
- Direction
- fell belowe0
- Qualifier
- by the second month of the triale0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the quality of control plots fell below a commercially acceptable level by the second month of the trial”
e1“Creeping bentgrass ( Agrostis stolonifera )”
Claim · model-written summary
Repeated foliar TE improved shaded bentgrass turf quality by 33% to 44%.
- Taxon
- Creeping bentgrassAgrostis stoloniferae1
- Treatment
- repeated foliar TE applicatione0
- Outcome
- qualitye0
- Direction
- bettere0
- Value
- 33% to 44%e0
- Comparator
- control plotse2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“repeated foliar TE application provided 33% to 44% better quality throughout the experiment”
e1“Creeping bentgrass ( Agrostis stolonifera )”
e2“control plots”
Claim · model-written summary
Propiconazole improved turf quality by 13% to 17% through September.
- Taxon
- Creeping bentgrassAgrostis stoloniferae1
- Treatment
- Propiconazolee0
- Outcome
- qualitye0
- Direction
- bettere0
- Value
- 13% to 17%e0
- Comparator
- control plotse2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Propiconazole resulted in 13% to 17% better quality through September of each year.”
e1“Creeping bentgrass ( Agrostis stolonifera )”
e2“control plots”
Claim · model-written summary
Trinexapac-ethyl darkened leaf color.
- Taxon
- Creeping bentgrassAgrostis stoloniferae1
- Treatment
- Trinexapac-ethyle0
- Outcome
- leaf colore0
- Direction
- darkere0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Trinexapac-ethyl and PPC resulted in darker leaf color”
e1“Creeping bentgrass ( Agrostis stolonifera )”
Claim · model-written summary
PPC darkened leaf color.
- Taxon
- Creeping bentgrassAgrostis stoloniferae1
- Treatment
- PPCe0
- Outcome
- leaf colore0
- Direction
- darkere0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Trinexapac-ethyl and PPC resulted in darker leaf color”
e1“Creeping bentgrass ( Agrostis stolonifera )”
Claim · model-written summary
Trinexapac-ethyl increased mid-trial root strength by 27%.
- Taxon
- Creeping bentgrassAgrostis stoloniferae1
- Treatment
- Trinexapac-ethyle0
- Outcome
- root strengthe0
- Direction
- increasede0
- Value
- 27%e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Trinexapac-ethyl and PPC resulted in darker leaf color and increased mid-trial root strength by 27% and 29%, respectively.”
e1“Creeping bentgrass ( Agrostis stolonifera )”
Claim · model-written summary
PPC increased mid-trial root strength by 29%.
- Taxon
- Creeping bentgrassAgrostis stoloniferae1
- Treatment
- PPCe0
- Outcome
- root strengthe0
- Direction
- increasede0
- Value
- 29%e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Trinexapac-ethyl and PPC resulted in darker leaf color and increased mid-trial root strength by 27% and 29%, respectively.”
e1“Creeping bentgrass ( Agrostis stolonifera )”
Claim · model-written summary
TE increased canopy photochemical efficiency in August.
- Taxon
- Creeping bentgrassAgrostis stoloniferae1
- Treatment
- TEe0
- Outcome
- Canopy photochemical efficiencye0
- Direction
- increasede0
- Qualifier
- in August of both yearse0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Canopy photochemical efficiency and leaf SOD activity were also increased due to TE in August of both years.”
e1“Creeping bentgrass ( Agrostis stolonifera )”
Claim · model-written summary
TE increased leaf SOD activity in August.
- Taxon
- Creeping bentgrassAgrostis stoloniferae1
- Treatment
- TEe0
- Outcome
- leaf SOD activitye0
- Direction
- increasede0
- Qualifier
- in August of both yearse0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Canopy photochemical efficiency and leaf SOD activity were also increased due to TE in August of both years.”
e1“Creeping bentgrass ( Agrostis stolonifera )”
Claim · model-written summary
Fe did not affect quality, root strength, SOD, or photochemical efficiency.
- Taxon
- Creeping bentgrassAgrostis stoloniferae1
- Treatment
- Fee0
- Outcome
- quality, root strength, SOD, or photochemical efficiencye0
- Direction
- did not have an effecte0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Treatment with Fe, CPR, or SWE+HA did not have an effect on quality, root strength, SOD, or photochemical efficiency”
e1“Creeping bentgrass ( Agrostis stolonifera )”
Claim · model-written summary
CPR did not affect quality, root strength, SOD, or photochemical efficiency.
- Taxon
- Creeping bentgrassAgrostis stoloniferae1
- Treatment
- CPRe0
- Outcome
- quality, root strength, SOD, or photochemical efficiencye0
- Direction
- did not have an effecte0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Treatment with Fe, CPR, or SWE+HA did not have an effect on quality, root strength, SOD, or photochemical efficiency”
e1“Creeping bentgrass ( Agrostis stolonifera )”
Claim · model-written summary
SWE+HA did not affect quality, root strength, SOD, or photochemical efficiency.
- Taxon
- Creeping bentgrassAgrostis stoloniferae1
- Treatment
- SWE+HAe0
- Outcome
- quality, root strength, SOD, or photochemical efficiencye0
- Direction
- did not have an effecte0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Treatment with Fe, CPR, or SWE+HA did not have an effect on quality, root strength, SOD, or photochemical efficiency”
e1“Creeping bentgrass ( Agrostis stolonifera )”
Claim · model-written summary
These treatments periodically increased turf color.
- Taxon
- Creeping bentgrassAgrostis stoloniferae1
- Treatment
- Fe, CPR, or SWE+HAe0
- Outcome
- colore0
- Direction
- increasese0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Treatment with Fe, CPR, or SWE+HA did not have an effect on quality, root strength, SOD, or photochemical efficiency, but periodic increases in color were observed.”
e1“Creeping bentgrass ( Agrostis stolonifera )”
Claim · model-written summary
CPR added to TE in 2002 produced results no different from TE alone.
- Taxon
- Creeping bentgrassAgrostis stoloniferae1
- Treatment
- addition of CPR to TEe0
- Outcome
- resultse0
- Direction
- not differente0
- Comparator
- TE-alonee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The addition of CPR to TE in 2002 provided results that were not different from those of TE-alone.”
e1“Creeping bentgrass ( Agrostis stolonifera )”
Claim · model-written summary
The authors conclude that restricting leaf elongation with anti-GA PGRs is primary for shade tolerance.
- Taxon
- Creeping bentgrassAgrostis stoloniferae1
- Treatment
- anti-GA PGRse0
- Outcome
- shade tolerancee0
- Qualifier
- restricting leaf elongatione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“restricting leaf elongation with anti-GA PGRs is of primary importance for improving shade tolerance”
e1“Creeping bentgrass ( Agrostis stolonifera )”
The same questions in other papers
propiconazole · quality: general · Agrostis stolonifera (creeping bent grass)Positive and negative results
1 in the opposite direction
- negative
iron atom · physiology: antioxidant enzymes · Agrostis stolonifera (creeping bent grass)Positive and negative results
1 in the opposite direction
- positive
trinexapac-ethyl · quality: postharvest · Agrostis stolonifera (creeping bent grass)Positive and negative results
2 papers in the same direction as this paper · 1 in the opposite direction
- positive
- positive
- negative
iron atom · quality: postharvest · Agrostis stolonifera (creeping bent grass)Results agree
1 paper in the same direction as this paper
- positive
trinexapac-ethyl · physiology: photosynthesis · Agrostis stolonifera (creeping bent grass)Results agree
1 paper in the same direction as this paper
- positive
trinexapac-ethyl · physiology: antioxidant enzymes · Agrostis stolonifera (creeping bent grass)Results agree
1 paper in the same direction as this paper
- positive
trinexapac-ethyl · quality: general · Agrostis stolonifera (creeping bent grass)Results agree
4 papers in the same direction as this paper
- positive
- positive
- positive
1 paper more in this group
See all 5 papers →other · physiology: antioxidant enzymes · Agrostis stolonifera (creeping bent grass)Positive and negative results
2 in the opposite direction
- positive
- positive
8 of 9 groups shown: named compounds and organisms first, then groups whose results differ (checked claim by claim), then those with positive and negative results, then the smaller groups.
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.