Analysis of the Vegetative Growth Development and Phenology of Hop Cultivars Grown in the Subtropics Under a Two-Crop-a-Year System

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Major comments

The MS with the title “Analysis of vegetative growth development of hop cultivars grown in subtropics under a two-crop-a-year system” is well written, and the study design is interesting; however, I have some suggestions for the authors that will improve this MS.

Authors are directed to carefully check the whole MS for English corrections. Some sentences need minor corrections, especially in the introduction and discussion sections.

Add the methodology and concluding remarks of the study in the abstract. This information isn’t properly described.

Authors are needed to provide detailed background information about the two-crop-a-year system, especially for hop crops, in the introduction section. Also update the objectives of the study clearly and add the hypothesis.

Authors are advised to make a concluding illustration of the whole study and provide it before the conclusion of the study.

The discussion looks shallow, authors are directed to provide a step-by-step discussion on each result with justification.

The conclusion should be improved based on the results.

Author Response

Dear Editor and Reviewers,

We would like to thank you very much for taking the time to handle our manuscript. 
We are pleased with the points raised by the reviewers and hope to be able to answer any questions that were raised. Below, you will find detailed responses to each comment and the corresponding corrections highlighted at the end of the comment, along with the Word file horticulturae-3592384 with the highlighted changes. 

Warm regards,

The authors

_______
Point-by-point response to Comments and Suggestions for Authors

Reviewer #1:

Comments 1: Add the methodology and concluding remarks of the study in the abstract. This information isn’t properly described.
Response 1: Thanks for pointing this out, we agree with this comment, so the change was made on page 1 between lines 20-25, 26-27 and 31-33.

Comments 2: Authors are needed to provide detailed background information about the two-crop-a-year system, especially for hop crops, in the introduction section. Also update the objectives of the study clearly and add the hypothesis.
Response 2: Thanks for pointing this out, we agree with this comment, so the change was made on page 2 between lines 61-72.

Comments 3: Authors are advised to make a concluding illustration of the whole study and provide it before the conclusion of the study.
Response 3: Thanks for pointing this out, we agree with this comment, so the change was made on page 12 between lines 377-388.

Comments 4: The discussion looks shallow, authors are directed to provide a step-by-step discussion on each result with justification.
Response 4: Thank you for pointing this out, although the article is structured in separate results from the discussion, we have drawn on each result to elaborate the discussion without it becoming repetitive. Changes were made on page 10 between lines 286-307. 

Comments 5: The conclusion should be improved based on the results.
Response 5: Thank you for pointing this out, we agree with this comment, so the change was made on page 12 between lines 394-395.

Response to Comments on the Quality of English Language

Reviewer #1:

Point 1: Authors are directed to carefully check the whole MS for English corrections. Some sentences need minor corrections, especially in the introduction and discussion sections.
Response 1: The manuscript was subjected to an English Editing Service to improve its quality, as requested by the reviewer.

5. Additional clarifications
Some of the requested changes required reformulation of other points in the article and insertion of new references, so to flag the changes in the horticulturae-3592384 file, they were inserted with change tracking turned on.

Reviewer 2 Report

Comments and Suggestions for Authors

The paper describes a two-year field study evaluating production of hops under day extension methods. The paper is well-written and research is novel. There are some questions on methodology that I'd like clarified. Pending those clarifications, the interpretation of results may or may not be valid in my opinion. More detailed comments are below.

Line
1 maybe just semantics here but the project evaluated flowering and cone development which I would not consider strictly vegetative growth
76 sunset varies from day to day - can the authors clarify how controllers were set to come on 30 minutes prior to sunset and if that means start times varied daily to accommodate varying sunset times?
109 this is a confusing bit of information that needs to be more clearly defined. are year 2 data strictly from 1-year old plants or an average across 3-year and 1-year old plants? If the former, then I have doubts this is truly a project that is repeated in time and more justification is needed for why the older plants were scrapped. It clearly shows in the data that 1-year plants are not the same as 3-year plants. If it is averaged across the 1 and 3-year old, then was there any effort to tease out differences between them? I also think the use of CRD in a field study is troubling and should be explained/justified more clearly. Was there any effort to characterize field variability (eg, covariate - but there are more sophisticated ways too).
110 suggest the cut-back method be more clearly defined - were all aerial shoots clipped to the soil?
120 somewhere need to include fertilizer and pesticide programs
154 was there any aggregation of data prior to these analyses? That is, did you average across plants within a rep or use each plant as an observation? Similarly, did you average across reps or use separate reps for each observation?
207 suggest authors use footnotes to define the Growth Stages in this table
259 the decision to prune Mapuche and not Spalter is problematic - I don't see how it is valid to compare these two cultivars in year 2.
264 "consequently"?
267 this comment on the importance of plant maturity is significant - 
286 I don't think "seedlings" is the correct term for these since they presumably came from root cuttings or similar propagation technique - see line 257 too

Author Response

Dear Editor and Reviewers,

We would like to thank you very much for taking the time to handle our manuscript. 
We are pleased with the points raised by the reviewers and hope to be able to answer any questions that were raised. Below, you will find detailed responses to each comment and the corresponding corrections highlighted at the end of the comment, along with the Word file horticulturae-3592384 with the highlighted changes. 

Warm regards,

The authors

Point-by-point response to Comments and Suggestions for Authors
_________________
Reviewer #2:

Comments 6: 1 maybe just semantics here but the project evaluated flowering and cone development which I would not consider strictly vegetative growth.
Response 6: Thanks for pointing this out, we agree with this comment, so the change was made on page 1, line 2.

Comments 7: 76 sunset varies from day to day - can the authors clarify how controllers were set to come on 30 minutes prior to sunset and if that means start times varied daily to accommodate varying sunset times?
Response 7: Thank you for pointing this out, we agree that this information was missing from the text. For clarification, the determination of the daily times for activating and deactivating light supplementation were obtained from the daily sunset and photoperiod times for the latitude of Palotina, PR, using the equation "N="  "2" ⁄"15arcsin"  "(-tan φ × tan δ)"  where N = length of day in hours; φ = geographic latitude (negative values for the southern hemisphere); and δ = solar declination, which was calculated using the equation "δ=23.45 sin [360"  "(284+n)" ⁄"365]" , where n is the Julian day. The sine and tangent values were transformed into radians for sine and tangent. The change was made on page 3 between lines 93-98.

Comments 8: 109 this is a confusing bit of information that needs to be more clearly defined. are year 2 data strictly from 1-year old plants or an average across 3-year and 1-year old plants? If the former, then I have doubts this is truly a project that is repeated in time and more justification is needed for why the older plants were scrapped. It clearly shows in the data that 1-year plants are not the same as 3-year plants. If it is averaged across the 1 and 3-year old, then was there any effort to tease out differences between them? I also think the use of CRD in a field study is troubling and should be explained/justified more clearly. Was there any effort to characterize field variability (eg, covariate - but there are more sophisticated ways too).
Response 8: Thank you for pointing this out, we agree that this information is confusing in the text. For clarification in September 2023, after the end of the fall season, the experimental area underwent a change in the experimental layout to include other experiments, in which the rhizomes of the 3-year-old plants were transplanted to another location within the same area and to complete the experimental design new 1-year-old plants propagated in vitro were used. Therefore, in the summer 2023–2024 and fall 2024 seasons, third- and first-year plants were arranged in a completely randomized design. Despite the divergence between the age of the plants from the second year onwards, no evaluation was performed comparing the 3- and 1-year-old plants, and the average between these was considered for the analyses performed. The replacement of the design adopted between the years extrapolates the results presented in this article. It was necessary to adapt the experimental area to incorporate a greater number of cultivars in the test, and therefore, we chose to distribute the plants in DIC with 10 plants per experimental plot. The change was made on page 4 between lines 120-123.

Comments 9: 110 suggest the cut-back method be more clearly defined - were all aerial shoots clipped to the soil?
Response 9: Thank you for pointing this out, we agree that this information was missing from the text. All of the hops plants were pruned close to the ground to encourage new growth. The change was made on page 4, line 125.

Comments 10: 120 somewhere need to include fertilizer and pesticide programs.
Response 10: Thank you for pointing this out, we agree that this information was missing from the text, so the change was made on page 4 between lines 136-142.

Comments 11: 154 was there any aggregation of data prior to these analyses? That is, did you average across plants within a rep or use each plant as an observation? Similarly, did you average across reps or use separate reps for each observation?
Response 11: The averages between the plants within each repetition were calculated and then the average between the repetitions. Based on these results, the nonlinear regression models of Gompertz for plant height and Gaussian for HGR were applied. 

Comments 12: 207 suggest authors use footnotes to define the Growth Stages in this table.
Response 12: Thank you for pointing this out, we agree with this comment, so the change was made on page 8 with the inclusion of a footnote defining each stage of growth.

Comments 13: 259 the decision to prune Mapuche and not Spalter is problematic - I don't see how it is valid to compare these two cultivars in year 2.
Response 13: Unfortunately, the second pruning had to be carried out in this harvest in Mapuche, because the budding was very uneven, not allowing good selection and conduction of branches. We decided to restart the cycle, because based on previous results from other studies, maintaining the uneven growth of the shoots would harm the performance of the cultivar in terms of the results presented in this article regarding plant growth and phenology, as well as cone production.

Comments 14: 264 "consequently"?
Response 14: Thank you for pointing this out, we agree with this comment, so the change was made on page 10, between lines 278-279.

Comments 15: 267 this comment on the importance of plant maturity is significant - 
Response 15: Thank you for pointing this out, we agree with this comment and the previous ones regarding the change to the layout of the area, so we have reworded the discussion based on the clarification in comment 8. Changes were made on page 10 between lines 295-307.

Comments 16: I don't think "seedlings" is the correct term for these since they presumably came from root cuttings or similar propagation technique - see line 257 too. 
Response 15: Thank you for pointing this out, we agree with this comment, so the change was made on page 10, line 302.

 

 

 

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

No comments 

Author Response

Dear Reviewer, many thanks. As no changed was required, no reply from our side was necessary.

Reviewer 2 Report

Comments and Suggestions for Authors

Thanks to the authors for the quick and thorough response to my comments. My only suggestion further is to define sci nomenclature for "emerald grass" on line 144.

Author Response

Comments: Thanks to the authors for the quick and thorough response to my comments. My only suggestion further is to define sci nomenclature for "emerald grass" on line 144.

Reply: Dear reviewer, thanks for you comment. The scientific name of emerald grass was added to the line 144, as requested.