Abstract
Ethephon (2-chloroethylphosphonic acid) is a plant growth regulator widely used in horticultural and agronomic crop production to control stem elongation, increase lateral branching, and manipulate flowering. While substrate drench applications of ethephon can inhibit the growth of containerized annual bedding plants, research has been limited to fewer than 30 taxa despite the hundreds of species grown in floriculture production. Therefore, our objective was to evaluate and quantify the efficacy of ethephon substrate drenches on the growth of 20 taxa of containerized annual bedding plants. Plants were transplanted into 12-cm, 12.7-cm, or 16.5-cm containers filled with a soilless peat-based substrate. After 10 d, eight single-plant replicates received a substrate drench of 90-mL or 150-mL aliquots of solution, based on container size, containing 0, 25, 50, 75, 100, or 200 mg·L −1 ethephon. Plants were grown in a glass-glazed greenhouse for 3 to 6 weeks after drench before growth and morphological data, including plant height, plant diameter, shoot dry weight (SDW), and root dry weight (RDW) were determined. The magnitude of growth control varied among annual bedding plant taxa with increasing ethephon substrate drench concentrations. For most taxa, drenches of 25 to 100 mg·L −1 ethephon were determined to be effective at controlling plant height and plant diameter without negatively impacting visual ornamental plant quality. For example, when drenched with 100 mg·L −1 ethephon, interspecific geranium ( Pelargonium interspecific ‘Calliope ® Large Dark Red’) and zonal geranium [ Pelargonium zonale (L.) L’Hér. ‘Americana ® Dark Red’] were 27% (8.0 cm) and 29% (8.1 cm) shorter, respectively, than untreated plants. We observed 1.5% (0.34 cm) and 18.1% (3.2 cm) smaller plant diameters for coleus [ Coleus scutellarioides (L.) Benth. ‘Main Street TM Ocean Drive’] and heliotropium ( Heliotropium arborescens L. ‘Scentropia TM Dark Blue’), respectively, as concentrations increased from 0 to 25 mg·L −1 ethephon. The SDW and RDW were also influenced by increasing ethephon substrate concentrations. For instance, SDW of New Guinea impatiens ( Impatiens hawkeri R.W. Baker & Corner ‘Magnum Fire’) and calibrachoa [ Calibrachoa × hybrida (Llave and Lex.) M. Martens and L. Westra. ‘Callie ® Dark Red’] drenched with 25 mg·L −1 ethephon were 24% (2.1 g) and 33% (0.9 g) smaller, respectively, compared with untreated plants. The RDWs of lantana ( Lantana camara L. ‘Bandolista TM Red Chili’) and portulaca ( Portulaca oleracea L. ‘Flame Red’) were 62% (1.42 g) and 55% (0.8 g) less, respectively, as concentrations increased from 0 to 200 mg·L −1 ethephon. While responses varied across taxa, this research expands the scope of annual bedding plants and further demonstrates the effectiveness of ethephon applied as a substrate drench.
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Claims 10
Claim · model-written summary
Growth control varied across taxa with increasing ethephon drench concentration.
- Taxon
- annual bedding plant taxae0
- Treatment
- increasing ethephon substrate drench concentrationse0
- Outcome
- magnitude of growth controle0
Not reportedComparatorDirection
Verbatim
e0“The magnitude of growth control varied among annual bedding plant taxa with increasing ethephon substrate drench concentrations”
Claim · model-written summary
For most taxa, 25 to 100 mg·L −1 ethephon controlled height and diameter without reducing ornamental quality.
- Taxon
- annual bedding plantst0
- Treatment
- 25 to 100 mg·L −1 ethephone0
- Outcome
- plant height and plant diametere0
- Direction
- controllinge0
Not reportedComparator
Verbatim
e0“For most taxa, drenches of 25 to 100 mg·L −1 ethephon were determined to be effective at controlling plant height and plant diameter without negatively impacting visual ornamental plant quality”
t0“annual bedding plants”
Claim · model-written summary
Geranium height was 27% shorter with 100 mg·L −1 ethephon than without treatment.
Verbatim
e0“interspecific geranium ( Pelargonium interspecific ‘Calliope ® Large Dark Red’) and zonal geranium [ Pelargonium zonale (L.) L’Hér. ‘Americana ® Dark Red’] were 27% (8.0 cm) and 29% (8.1 cm) shorter, respectively, than untreated plants”
e1“when drenched with 100 mg·L −1 ethephon”
Claim · model-written summary
Zonal geranium height was 29% shorter with 100 mg·L −1 ethephon than without treatment.
- Taxon
- zonal geranium
Pelargonium ×hortorume0 - Material
- Americana ® Dark Rede0
- Treatment
- 100 mg·L −1 ethephone1
- Outcome
- shortere0
- Direction
- shortere0
- Value
- 29%e0
- Comparator
- untreated plantse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“zonal geranium [ Pelargonium zonale (L.) L’Hér. ‘Americana ® Dark Red’] were 27% (8.0 cm) and 29% (8.1 cm) shorter, respectively, than untreated plants”
e1“when drenched with 100 mg·L −1 ethephon”
Claim · model-written summary
Coleus diameter was 1.5% smaller at 25 than 0 mg·L −1 ethephon.
ColeusOrganisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“1.5% (0.34 cm) and 18.1% (3.2 cm) smaller plant diameters for coleus [ Coleus scutellarioides (L.) Benth. ‘Main Street TM Ocean Drive’] and heliotropium ( Heliotropium arborescens L. ‘Scentropia TM Dark Blue’), respectively, as concentrations increased from 0 to 25 mg·L −1 ethephon”
Claim · model-written summary
Heliotropium diameter was 18.1% smaller at 25 than 0 mg·L −1 ethephon.
- Taxon
- heliotropium
Heliotropiume0 - Treatment
- 25 mg·L −1 ethephone0
- Outcome
- plant diameterse0
- Direction
- smallere0
- Value
- 18.1%e0
- Comparator
- 0e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“1.5% (0.34 cm) and 18.1% (3.2 cm) smaller plant diameters for coleus [ Coleus scutellarioides (L.) Benth. ‘Main Street TM Ocean Drive’] and heliotropium ( Heliotropium arborescens L. ‘Scentropia TM Dark Blue’), respectively, as concentrations increased from 0 to 25 mg·L −1 ethephon”
Claim · model-written summary
New Guinea impatiens shoot dry weight was 24% smaller at 25 mg·L −1 ethephon.
Verbatim
e0“SDW of New Guinea impatiens ( Impatiens hawkeri R.W. Baker & Corner ‘Magnum Fire’) and calibrachoa [ Calibrachoa × hybrida (Llave and Lex.) M. Martens and L. Westra. ‘Callie ® Dark Red’] drenched with 25 mg·L −1 ethephon were 24% (2.1 g) and 33% (0.9 g) smaller, respectively, compared with untreated plants”
Claim · model-written summary
Calibrachoa shoot dry weight was 33% smaller at 25 mg·L −1 ethephon.
- Taxon
- calibrachoa
Calibrachoae0 - Treatment
- 25 mg·L −1 ethephone0
- Outcome
- SDWe0
- Direction
- smallere0
- Value
- 33%e0
- Comparator
- untreated plantse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“SDW of New Guinea impatiens ( Impatiens hawkeri R.W. Baker & Corner ‘Magnum Fire’) and calibrachoa [ Calibrachoa × hybrida (Llave and Lex.) M. Martens and L. Westra. ‘Callie ® Dark Red’] drenched with 25 mg·L −1 ethephon were 24% (2.1 g) and 33% (0.9 g) smaller, respectively, compared with untreated plants”
Claim · model-written summary
Lantana root dry weight was 62% less at 200 than 0 mg·L −1 ethephon.
LantanaOrganisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The RDWs of lantana ( Lantana camara L. ‘Bandolista TM Red Chili’) and portulaca ( Portulaca oleracea L. ‘Flame Red’) were 62% (1.42 g) and 55% (0.8 g) less, respectively, as concentrations increased from 0 to 200 mg·L −1 ethephon”
Claim · model-written summary
Portulaca root dry weight was 55% less at 200 than 0 mg·L −1 ethephon.
PortulacaOrganisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The RDWs of lantana ( Lantana camara L. ‘Bandolista TM Red Chili’) and portulaca ( Portulaca oleracea L. ‘Flame Red’) were 62% (1.42 g) and 55% (0.8 g) less, respectively, as concentrations increased from 0 to 200 mg·L −1 ethephon”
The same questions in other papers
(2-chloroethyl)phosphonic acid · growth · Pelargonium x hortorum (zonal geranium)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.