Use of Ethephon and Calcium Acetate to Manipulate the Foliage Retention Rates of Camphor and Golden Shower Trees

Round 1

Reviewer 1 Report (New Reviewer)

This paper describes the defoliation effect of ethephon and calcium acetate on two tree species with the aim of reducing transpiration during transplantation. The results are interesting but a more rigorous analysis of the data is required. Further information is required in the Methods and the Discussion needs reconsideration.

Experimental design requires more information, was this a completely randomised design or were the trees blocked in some way?

How were the sprays applied, how much product per plant and what water rates etc.

Retention categories are very broad.

Results section contains both methodology and discussion. There are several instances where there is no difference between treatments but the authors have stated that there are differences. For example, in Line 159: the statement The higher doses of ethephon resulted in lower LRRs is not correct. Yes ethephon did lower LRR but there was no significant difference between the 1K, 2K and 3K rates.

Figure 1 and 2: there is no indication of significant differences between the treatments or the degree of variation, at the very least SE bars should be added.

Captions for Figure 1 and 2 – lines 216-221 and 236-243 should be in the text not the captions.

Choosing to separate the ethephon and ethephon + CA into two separate graphs is not valid as these treatments were not separate trials.

There is some concern in relation to the decision to undertake one-way ANOVA for each species after the two-way ANOVA showed no significant difference between the two species. Was this two separate trials or one trial? You can’t have it both ways.

Lines 295-297 discuss dieback in camphor trees, but there are no results relating to dieback.

Author Response

Please see attachment

Author Response File: Author Response.docx

Reviewer 2 Report (New Reviewer)

The manuscript Use of Ethephon and Calcium Acetate to Manipulate the Foliage Retention Rates of Camphor and Golden Shower Trees by Nelson Li, Yu-sen Chang deals with the important practical issue of using defoliants in works related to replanting trees and shrubs, especially large ones. Unfortunately, although the work was done, probably taking into account all the necessary repetitions and the proper number of controls, its evaluation is rather problematic. The point is that the article lacks several important elements to demonstrate the results obtained. No availability of graphs and statistics makes it possible to evaluate and confirm the real state of affairs in the experiment. This requires photographic confirmation. Qualitative characteristics can be reflected in tables and histograms and contain different types of statistical processing, but this does not make it possible to understand what the authors mean in qualitative descriptions.

It is necessary to reflect and demonstrate the qualitative effects of processing, accompanying such statements with photographic materials.

In addition, the article requires deep author's editing.

The abstract contains a lot of material, which is redundant and not required. It should be indicated briefly and clearly why they studied, why it is necessary, what is the result, what problem it allowed to solve, in this case, the authors selected the best option for preserving the quality of the crown after processing. Is it so?

In the introduction, the goal should be highlighted in a separate paragraph.

In the materials and methods section, it is required to single out the growing conditions as a separate item, a description of the plant material (including the name of the plants in accordance with the rules: Cinnamomum camphora (L.) J.Presl .; Cassia fistula L.) The description should be detailed.

The next section describes the growing conditions and substrate. It is required to indicate what kind of soil you used, what was the pH level, mechanical composition.

The next section should include a description of the experiment.

After that, the features of collecting and recording data and the statistical analysis of the hotel are described.

Corrections of this kind are purely technical and require some additions for clarity.

The main data of the work are presented in figures 1 and 2. These figures have a low degree of resolution. They should be redone, become more clear, colored, transcripts should be easy to read. Photos about the features and consequences of the state of plants after treatments should be placed accordingly in this section.

I recommend removing the link from the conclusion section to the discussion section. If the authors want to emphasize that they are familiar with these works, then this is not required in the conclusion. Specify the description of your data, and place the link above.

I think that the work has a technical focus, but it can be useful for many people involved in the improvement of cities, landscaping and laying nurseries and plantations. After making additions, the manuscript can be accepted.

Author Response

Please see attachment

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report (New Reviewer)

This paper describes the defoliation effect of ethephon and calcium acetate on two tree species with the aim of reducing transpiration during transplantation. The revision following the 1^st review round has improved the manuscript however there are still some area that require addressing.

1.       The query relating to how the sprays were applied has not been addressed what equipment was used and how much spray was applied to each tree?

2.       Figure 3 – use the same scale on the y-axis for both graphs

3.       Figure 4 – use the same scale on the y-axis for both graphs

4.       Keywords – remove ‘calcium acetate’ as it is in the title

5.       The paper requires editing by a native English speaker as the grammar and flow are very poor

Author Response

Reviewer #1 comment:

1. The query relating to how the sprays were applied has not been addressed what equipment was used and how much spray was applied to each tree?

Answer: Thank you for the alert. The sprays were conducted by using a 1.5 L hand sprayer which we usually use for indoor plant irrigation. The amount of spray had thoroughly wetted the top and bottom side of the leaves until the liquid dripped down to the potting soil. 

2. Figure 3 – use the same scale on the y-axis for both graphs

Answer: Thank you for the alert. We have revised accordingly.

3. Figure 4 – use the same scale on the y-axis for both graphs

Answer: Thanks. We have revised accordingly.

4. Keywords – remove ‘calcium acetate’ as it is in the title

Answer: Thanks. We have revised accordingly.

5. The paper requires editing by a native English speaker as the grammar and flow are very poor.

Answer: Answer: Thanks. We have improved our grammar and flow of the paper with outside help. 

Reviewer 2 Report (New Reviewer)

The manuscript "Use of Ethephon and Calcium Acetate to Manipulate the Foliage Retention Rates of Camphor and Golden Shower Trees" by Nelson Li and Yu-Sen Chang has been greatly improved. It can be accepted in this form.

Author Response

The paper has been reviewed with the grammar and flow improved.

This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.

Round 1

Reviewer 1 Report

Tittle. The title conveys the main message of the paper — the issues addressed and the relationships among the issues.

Abstract. The abstract is concise, provides a clear overview, and includes essential facts for the paper. However, it’s necessary to include the date the experiment started.

Keywords. These are enough for the topic.

Introduction. The introduction includes background to provide an appreciation for the context of the work presented but it is not enough.

The first and second paragraphs provide the background necessary to see the particular topic of the research and understand the study.

In the third paragraph (lines 43–45) authors talk about the defoliation chemicals used in crops, but not in tree species. It’s necessary to review the write a background about it.  

The fourth and fifth paragraphs provide more information and describe an important problem.

The sixth and seventh paragraphs examine the previous literature and highlight the important aspect of the research area.

The eighth paragraph states the specific objective of the research, the authors statement correctly the purpose.

Material and methods.  In this section, the authors describe the correct steps that followed during conducting their study, but there are some aspects that must be corrected or complemented.

Line 107 — In this statement, it’s necessary to write the number of trees by treatment (n) and the number total of the trees (N). It’s necessary to write the experimental design used.

Lines 120-121 — It’s necessary to indicate the test statistic (t, F, x², other) used during the analysis.

Lines 120-124 — In order to support that the statistical test is appropriate for the data, I recommend checking (and reporting) the statistical assumptions.

Results. This section was well written. The results say about the objective that motivates the research. However, there are some comments that authors must attend to.

Lines 139-143 — It’s necessary to write the Table(s) where we can see the results.

Lines 152-166 — It’s necessary to write the Table(s) where we can see the results.

 Lines 161-163 — Were these variations observed for both species? Clarify.

Lines 176-183 — It’s necessary to write the Table(s) where we can see the results.

Lines 189-198 — It’s necessary to write the Table(s) where we can see the results.

Lines 220-221 — Where are the movement curves on the article?

Discussion. In this section, the authors take a broad look at their findings and examine the work in the larger context of the field.

Lines 264-268 — Explain whether or not the result supports the research objective. Is this result according to another work? Why couldn’t irrigation (every 2 days) be appropriate?

Lines 271-275 — What are the defoliations (%) reported by Dozier et al, and Sterrett et al? Write them.

Lines 279-280 — What is the higher defoliation (%) reported by Dozier et al?

In this section, it’s necessary to write the limitations of the study.

Conclusion. This section included the major conclusions, which were briefly written.

Reviewer 2 Report

This study used Ethephon sprays to reduce foliage in the nursery stocks to reduce transpiration and stress. They also use Calcium Acetate to mitigate the side effects of ethephon. Both ethephon and calcium acetate are frequently used in the horticulture industry.  The authors used eight different treatments with ethephon alone or in combination with Calcium acetate.

Major comment:

1) The data on effect of sprays on foliage retention was assessed visually (percent). These types of data recording are prone to bias and depend on observer’s ability to spot and discern the foliage. Hence repeatability of experiment may not easy.   How many observers were involved in recording data throughout the experiment? Please explain under methods.

2) The variation in leaf area among the treatment groups would also influence the visual observation.  How was such bias was accounted ? Please explain

3) The arrangement of pots may also obstruct the visual observations? What designs in arranging pots were followed to avoid such bias. ? Please explain.

4) Usually the percent data may not be  normal distribution hence may not satisfy the assumption for ANOVA. The study do not report any data transformation done before ANOVA. 

Minor comment:

4) Line 97-98 Avoid using quotes (“) and please use “inch”

5) Please edit and rephrase the results or figure legend  statement. Avoid repeating sentences in both results and figure legends. For example: Line 236-237 (results) and Line 256-257 (Fig. 2 legend) are identical.