Abstract
Ethephon (2-chloroethylphosphonic acid) is frequently used for flush management in order to maximize flowering in litchi. However, the optimal dosage of ethephon, which balances between flush control effect and the detrimental effect on leaves, is unknown. This study aimed to identify the optimal ethephon dosage and test more efficient ethephon application methods, using a drone for flush control and flowering promotion in litchi. The effects of a single manual full-tree spray of 250, 500 or 1000 mg/L of ethephon in early November on the bud break rate, leaf drop rate, net photosynthetic rate, LcFT1 expression and floral induction (panicle emergence rate and panicle number) in ‘Jingganghongnuo’ litchi were examined in the season of 2021–2022. In the season of 2022–2023, the effects of drone application of 1000 mg/L of ethephon in early November on bud growth and floral induction were observed. The results showed that the manual ethephon treatments were effective at enforcing bud dormancy and elongating the dormancy period and that the effects were positively dependent on dosage. One manual spray of 1000 mg/L of ethephon in late autumn enabled a dormancy period of 6 weeks. The treatments advanced seasonal abscission of old leaves in winter and caused short-term suppression on photosynthesis within 2 weeks after treatment. Ethephon treatments, especially at 1000 mg/L, enhanced the expression of LcFT1 in the mature leaves and promoted floral induction reflected by earlier panicle emergence and increased panicle emergence rate and number in the terminal shoot. The floral promotion effect was also positively dosage dependent. The cumulative chilling hours below 15 °C from the date of treatment to the occurrence of a 20% panicle emergence rate were lowered in ethephon treatments. A drone spray of 1000 mg/L of ethephon solution consumed a sixth of the manual spray solution volume and was two thirds less effective in suppressing bud break compared with manual spraying. However, it achieved a significant flowering promotion effect comparable to traditional manual spraying. The results suggest that ethephon application enhanced flowering responsiveness to chilling as well as enforced bud dormancy. The application of ethephon with a drone proved to be an efficient method for flush control and flower promotion.
Abstract from the paper’s OpenAlex record; open copy licensed cc-by. Read at the source ↗
The text the model read, with the source record’s inline markup (italics, sub- and superscripts) rendered and its character entities decoded; quote offsets refer to the raw text.
Claims 11
Claim · model-written summary
Manual ethephon enforced bud dormancy and lengthened its duration in a dose-dependent manner.
- Treatment
- manual ethephon treatmentse0
- Outcome
- bud dormancy and elongating the dormancy periode0
- Direction
- elongatinge0
LitchiNot reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the manual ethephon treatments were effective at enforcing bud dormancy and elongating the dormancy period and that the effects were positively dependent on dosage”
t0“Litchi (Litchi chinensis Sonn.)”
Claim · model-written summary
One 1000 mg/L manual spray gave six weeks of dormancy.
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“One manual spray of 1000 mg/L of ethephon in late autumn enabled a dormancy period of 6 weeks”
t0“Litchi (Litchi chinensis Sonn.)”
Claim · model-written summary
Ethephon advanced old-leaf abscission.
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The treatments advanced seasonal abscission of old leaves in winter”
t0“Litchi (Litchi chinensis Sonn.)”
Claim · model-written summary
Ethephon briefly suppressed photosynthesis within two weeks.
- Treatment
- treatmente0
- Outcome
- photosynthesise0
- Direction
- suppressione0
- Qualifier
- within 2 weeks after treatmente0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“caused short-term suppression on photosynthesis within 2 weeks after treatment”
t0“Litchi (Litchi chinensis Sonn.)”
Claim · model-written summary
Ethephon, especially at 1000 mg/L, enhanced LcFT1 expression in mature leaves.
- Organ / stage
- mature leavese0
- Treatment
- Ethephon treatments, especially at 1000 mg/Le0
- Gene
- LcFT1e0
- Outcome
- expression of LcFT1e0
- Direction
- enhancede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Ethephon treatments, especially at 1000 mg/L, enhanced the expression of LcFT1 in the mature leaves”
t0“Litchi (Litchi chinensis Sonn.)”
Claim · model-written summary
Ethephon advanced panicle emergence.
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“promoted floral induction reflected by earlier panicle emergence”
e1“Ethephon treatments, especially at 1000 mg/L, enhanced the expression of LcFT1 in the mature leaves”
t0“Litchi (Litchi chinensis Sonn.)”
Claim · model-written summary
Ethephon increased panicle emergence rate and number, with a positive dose response.
Not reportedTreatmentComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“increased panicle emergence rate and number in the terminal shoot. The floral promotion effect was also positively dosage dependent”
t0“Litchi (Litchi chinensis Sonn.)”
Claim · model-written summary
Ethephon lowered chilling hours needed to reach 20% panicle emergence.
- Treatment
- ethephon treatmentse0
- Outcome
- cumulative chilling hourse0
- Direction
- lowerede0
- Qualifier
- below 15 °C from the date of treatment to the occurrence of a 20% panicle emergence ratee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The cumulative chilling hours below 15 °C from the date of treatment to the occurrence of a 20% panicle emergence rate were lowered in ethephon treatments”
t0“Litchi (Litchi chinensis Sonn.)”
Claim · model-written summary
Drone spraying used one sixth of the solution volume of manual spraying.
- Treatment
- A drone spray of 1000 mg/L of ethephon solutione0
- Outcome
- solution volumee0
- Direction
- a sixthe0
- Value
- a sixthe0
- Comparator
- manual spraye0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“A drone spray of 1000 mg/L of ethephon solution consumed a sixth of the manual spray solution volume”
t0“Litchi (Litchi chinensis Sonn.)”
Claim · model-written summary
Drone spraying was two thirds less effective at suppressing bud break than manual spraying.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“was two thirds less effective in suppressing bud break compared with manual spraying”
e1“A drone spray of 1000 mg/L of ethephon solution consumed a sixth of the manual spray solution volume”
t0“Litchi (Litchi chinensis Sonn.)”
Claim · model-written summary
Drone spraying significantly promoted flowering comparably to manual spraying.
Not reportedTreatment
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“it achieved a significant flowering promotion effect comparable to traditional manual spraying”
t0“Litchi (Litchi chinensis Sonn.)”
The same questions in other papers
(2-chloroethyl)phosphonic acid · growth · LitchiPositive and negative results
2 papers in the same direction as this paper · 1 in the opposite direction
- no effect
- positive
- positive
(2-chloroethyl)phosphonic acid · yield · LitchiPositive and negative results
2 papers in the same direction as this paper · 1 in the opposite direction
- negative
- positive
- positive
(2-chloroethyl)phosphonic acid · molecular: expression · LitchiResults agree
1 paper in the same direction as this paper
- positive
application · growth · LitchiPositive and negative results
5 papers in the same direction as this paper · 1 in the opposite direction
- no effect
- 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.