Abstract
Plant growth regulators (PGRs) are frequently used to adjust cotton growth and development. The objectives of this study were to determine how PGRs affect plant morphology, light distribution and the spatial distribution of leaves and bolls within the cotton canopy. The field experiments were carried out at Shihezi (Xinjiang Uyghur Autonomous Region, China) in 2014 and 2015. The experiment included two PGR treatments: (i) flumetralin (active ingredient (a.i.), N-N-ethyl-2,6-dinitro-4-aniline) and (ii) mepiquat chloride (a.i., 1-dimethyl-piperidiniuchloride) plus flumetralin. No PGR (manual topping) was applied in the control treatment. The chemically-topped plants were taller and had more main stem internodes than the manually-topped plants. Furthermore, the PGRs significantly reduced the length of fruiting branches in the upper canopy, resulting in a more compact canopy. The maximum leaf area index was significantly greater in the chemically-topped treatments than that in the control. In particular, the PGRs increased leaf area index by 25% in the upper canopy. The leaf area duration was also longer in the chemically-topped treatments than in the control. Compared with the control, the chemically-topped treatments increased canopy diffuse non-interceptance by 35.75% in the upper canopy layer, while reducing the fraction of intercepted photosynthetically active radiation by 14.45% in the upper canopy layer. Light transmittance in the upper and middle canopy layers was greater in the chemically-topped treatments than in the control, which increased boll numbers in both the upper canopy and the middle canopy. However, the chemically-topped treatments resulted in less light-leakage through the lower canopy layer during the late growth stages, which had a tendency to increase boll numbers in the whole canopy. In summary, the PGRs optimized canopy shape, light distribution and the spatial distribution of bolls and leaves.
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Claims 11
Claim · model-written summary
Chemical topping produced taller cotton plants and more main stem internodes than manual topping.
- Taxon
- cotton
Gossypium hirsutumt0 - Treatment
- chemically-toppede0
- Outcome
- taller and had more main stem internodese0
- Direction
- tallere0
- Comparator
- manually-topped plantse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The chemically-topped plants were taller and had more main stem internodes than the manually-topped plants”
t0“cotton”
Claim · model-written summary
PGRs shortened upper-canopy fruiting branches.
- Taxon
- cottonGossypium hirsutumt0
- Organ / stage
- upper canopye0
- Treatment
- PGRse0
- Outcome
- length of fruiting branchese0
- Direction
- reducede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the PGRs significantly reduced the length of fruiting branches in the upper canopy”
t0“cotton”
Claim · model-written summary
Chemical topping increased maximum leaf area index relative to control.
- Taxon
- cottonGossypium hirsutumt0
- Treatment
- chemically-topped treatmentse0
- Outcome
- maximum leaf area indexe0
- Direction
- greatere0
- Comparator
- controle0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The maximum leaf area index was significantly greater in the chemically-topped treatments than that in the control”
t0“cotton”
Claim · model-written summary
PGRs increased upper canopy leaf area index by 25%.
- Taxon
- cottonGossypium hirsutumt0
- Organ / stage
- upper canopye0
- Treatment
- PGRse0
- Outcome
- leaf area indexe0
- Direction
- increasede0
- Value
- 25%e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the PGRs increased leaf area index by 25% in the upper canopy”
t0“cotton”
Claim · model-written summary
Chemical topping prolonged leaf area duration relative to control.
- Taxon
- cottonGossypium hirsutumt0
- Treatment
- chemically-topped treatmentse0
- Outcome
- leaf area duratione0
- Direction
- longere0
- Comparator
- controle0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The leaf area duration was also longer in the chemically-topped treatments than in the control”
t0“cotton”
Claim · model-written summary
Chemical topping increased upper canopy diffuse non-interceptance by 35.75%.
- Taxon
- cottonGossypium hirsutumt0
- Organ / stage
- upper canopy layere0
- Treatment
- chemically-topped treatmentse0
- Outcome
- canopy diffuse non-interceptancee0
- Direction
- increasede0
- Value
- 35.75%e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the chemically-topped treatments increased canopy diffuse non-interceptance by 35.75% in the upper canopy layer”
t0“cotton”
Claim · model-written summary
Chemical topping reduced upper canopy intercepted photosynthetically active radiation by 14.45%.
- Taxon
- cottonGossypium hirsutumt0
- Organ / stage
- upper canopy layere0
- Outcome
- fraction of intercepted photosynthetically active radiatione0
- Direction
- reducinge0
- Value
- 14.45%e0
Not reportedTreatmentComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“reducing the fraction of intercepted photosynthetically active radiation by 14.45% in the upper canopy layer”
t0“cotton”
Claim · model-written summary
Chemical topping increased light transmittance in upper and middle canopy layers.
- Taxon
- cottonGossypium hirsutumt0
- Organ / stage
- upper and middle canopy layerse0
- Treatment
- chemically-topped treatmentse0
- Outcome
- Light transmittancee0
- Direction
- greatere0
- Comparator
- controle0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Light transmittance in the upper and middle canopy layers was greater in the chemically-topped treatments than in the control”
t0“cotton”
Claim · model-written summary
Greater light transmittance under chemical topping increased boll numbers in upper and middle canopies.
- Taxon
- cottonGossypium hirsutumt0
- Organ / stage
- upper canopy and the middle canopye0
- Treatment
- chemically-topped treatmentse0
- Outcome
- boll numberse0
- Direction
- increasede0
- Comparator
- controle0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Light transmittance in the upper and middle canopy layers was greater in the chemically-topped treatments than in the control, which increased boll numbers in both the upper canopy and the middle canopy”
t0“cotton”
Claim · model-written summary
Chemical topping reduced lower-canopy light leakage late in growth.
- Taxon
- cottonGossypium hirsutumt0
- Organ / stage
- lower canopy layere0
- Treatment
- chemically-topped treatmentse0
- Outcome
- light-leakagee0
- Direction
- lesse0
- Qualifier
- late growth stagese0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the chemically-topped treatments resulted in less light-leakage through the lower canopy layer during the late growth stages”
t0“cotton”
Claim · model-written summary
Chemical topping tended to increase whole-canopy boll number.
- Taxon
- cottonGossypium hirsutumt0
- Outcome
- boll numberse0
- Direction
- increasee0
- Qualifier
- tendencye0
Not reportedTreatmentComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“which had a tendency to increase boll numbers in the whole canopy”
t0“cotton”
The same questions in other papers
class · growth · Gossypium hirsutum (cotton)Positive and negative results
24 papers in the same direction as this paper · 8 in the opposite direction · 1 reporting no difference from an alternative
- positive
- negative
- negative
30 papers more in this group
See all 34 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.