The Effect of the Daily Light Integral and Spectrum on Mesembryanthemum crystallinum L. in an Indoor Plant Production Environment
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsResearch presented in the manuscript although very wide, lacks in research depth, staying mostly descriptive. Most of the reported findings are actually are somehow expected from studies of other authors and there is little novelty. Only studies dedicated to the expression of some genes can be considered as novel and a move forward.
1. The abstract needs to be rewritten for introduction takes up a lot of space
2. It is suggested to supplement the experiment, the photoperiod of the seedling period is inconsistent with that of the treatment, and the more serious is that the photoperiod only uses two long photoperiod
3. Significance mark usage error, please check
4. The design of light quality is confusing, why is it cold white light, warm white light, why do not use green light
5. A set of data is presented 3 times in tables and graphs
6. It was found in this paper that long photoperiod inhibits nitrate absorption, which is very interesting and suggested to focus on discussion
Comments on the Quality of English Languageit needs both a scientific editing (done by a plant physiologist) and good English editing.
The use of abbreviations, first time written in full, then abbreviated, like the use of TAC in line 405 need abbreviated
Author Response
Review 1
Research presented in the manuscript although very wide, lacks in research depth, staying mostly descriptive. Most of the reported findings are actually are somehow expected from studies of other authors and there is little novelty. Only studies dedicated to the expression of some genes can be considered as novel and a move forward.
- The abstract needs to be rewritten for introduction takes up a lot of space.
Answer : Suggestion taken note of and abstract is further summarized.
- It is suggested to supplement the experiment, the photoperiod of the seedling period is inconsistent with that of the treatment, and the more serious is that the photoperiod only uses two long photoperiod.
Answer : The photoperiod of the seedlings before transplanting and subjecting them to light treatment is 14hrs day- light/ 10 hrs dark. The author agrees that 2 photoperiod duration might not be sufficient and there is a need to supplement the experiment with more durations. Due to limited resources, we choose 18 hrs photoperiod as a reference (this seem to be optimum growth for most plants based on past publication), and uses 21 hrs as a guidance to investigate if there is a need to further our research in increasing photoperiod to improve productivity in our future work. There is also plan in line to work on other photo-period concurrently (such as 16 / 18 / 20 hrs) when more resources are available.
- Significance mark usage error, please check
Answer : Amendment to significance mark done.
- The design of light quality is confusing, why is it cold white light, warm white light, why do not use green light
Answer : The light treatment spectra is inherent through the use of a commercial LEDs growth light in our studies, whose current tend is using white light plus a mixture of blue, green and red. Cool white and warm white consists of different proportion of blue, green and red. As shown in figure 1, the contribution of each individual spectra range (PPF-B, PPF-G, and PPF-R) of the light used was tabulated.
- A set of data is presented 3 times in tables and graphs.
Answer : Correlation of both the physical and photochemical contents against light receipts and DLI is further presented in table 2. Scattering plot of morphological data (biomass vs leaf area, leaf are vs leaf width), and chlorophyll a & b are added as figure 6 and figure 12 respectively.
- It was found in this paper that long photoperiod inhibits nitrate absorption, which is very interesting and suggested to focus on discussion.
Answer : Further elaboration in this section is discussed.
Comments on the Quality of English Language
it needs both a scientific editing (done by a plant physiologist) and good English editing.
The use of abbreviations, first time written in full, then abbreviated, like the use of TAC in line 405 need abbreviated.
Answer : Thanks for the suggestion. The above feedback is taken noted of.
Reviewer 2 Report
Comments and Suggestions for AuthorsObservations regarding the drafting:
Line 44: instead of "investigated in cultivars such as", I would propose as investigated in species (or crops) such as. The term "species" was used correctly on line 46.
L. 477: The year of publication does not appear for this cited work.
Author Response
Review 2
Line 44: instead of "investigated in cultivars such as", I would propose as investigated in species (or crops) such as. The term "species" was used correctly on line 46.
Answer : Suggestion is accepted and changes made.
- 477: The year of publication does not appear for this cited work.
Answer : The year of publication (2016) is added.
Reviewer 3 Report
Comments and Suggestions for AuthorsDear editor and author
This is an interesting review article about the investigation of “The effect of daily light integral and spectrum on Mesembryanthemum crystallinum L. in an indoor plant production environment”. I think that it can be useful for the research in the field. The abstract abides by all the editing instructions and presents clear the objectives of the study.
However, there are some minor observations:
1. Is there a change in plant color depending on the LED treatment? Please provide a photo of the plant associated with this.
2. The change in plant color is very important because there are various preliminary studies showing that changes in plastids such as chlorophyll and carotenoid anthocyanin change antioxidant activity through various LED treatments. Since this change in chromaticity is also important in your research, I suggest presenting related pictures.
3. Additionally, we propose to review research in various crops on changes in plastid composition and physiological activity according to various LED treatments.
Author Response
Review 3
This is an interesting review article about the investigation of “The effect of daily light integral and spectrum on Mesembryanthemum crystallinum L. In an indoor plant production environment”. I think that it can be useful for the research in the field. The abstract abides by all the editing instructions and presents clear the objectives of the study.
However, there are some minor observations:
- Is there a change in plant color depending on the LED treatment? Please provide a photo of the plant associated with this.
Answer : There is plan to track the changes in leaves color via NDVI and chromatic measurement (L*a*b) in our next experimental trial. This paper actually presented our first expriment with Mesembryanthemum crystallinum L., and as it is a new plant species to us, we are trying to be familiar with the growth characteristic of this plant.
- The change in plant color is very important because there are various preliminary studies showing that changes in plastids such as chlorophyll and carotenoid anthocyanin change antioxidant activity through various LED treatments. Since this change in chromaticity is also important in your research, I suggest presenting related pictures.
Answer : Suggestion is taken note of, and we will focus it in our next experimental trail.
- Additionally, we propose to review research in various crops on changes in plastid composition and physiological activity according to various LED treatments.
Answer : Current experiment trial is conducted with limited resources (space constraint). We are expanding and improving the existing layout, and there is plan to conduct the next trail concurrently with basil & lettuces (in additional to Mesembryanthemum crystallinum L.).
Reviewer 4 Report
Comments and Suggestions for AuthorsBrief summary: Interesting work that aims to evaluate the effect of different spectra and photoperiods on Mesembryanthemum crystallinum L. Title is not specific and leads to confusion when referring to indoor plant production environment. The knowledge about the productivity conditions of this plant is adapted to the articles of Horticulturae and focused on the SI Controlled Environment Horticulture: Latest Advances and Future Prospects. However, the manuscript has serious flaws, additional explanation of experiments are needed, and the processing of the information was not done correctly.
General concept comments: The final paragraph of the introduction should make the working hypothesis explicit.. An experimental design with two main factors is proposed and a two-way ANOVA should be performed: Spectral bands with 4 levels of action (warm white, cool white, red and blue spectrums), and photoperiod duration (DLI with two levels: 18 and 21 hrs.). However, the effects due to the two main factors are not presented and the data in the tables and figures are presented as if they were nested factors (DLI nested to light receipt). The results present duplicate information that does not provide any new (Fig. 3 represents the data in the first row of Table 1; Fig. 4 the second row, etc.). Discussion boils down for the most part to a repetition of the results without providing solid justifications or arguments. Conclusions are speculative and present conclusions from other authors. Conclusions regarding the effect of light of different colours cannot be drawn from this work.
Specific comments.
Line 17: 18 hours. 18 hrs)
Line 58. wavelength
Line 64. Use the scientific name the first time you use the common species name.
Line 99. Plant growing conditions are not clear, nor their relationship with the indoor plant production environment reflected in the Title.
Line 102. In an indoor growing system, the composition of the fertigation solution should be presented in more detail. The information provided is not enough
Line 109. It does not seem appropriate to refer to light treatments as light recipes or light receipt (1 to 4 in Fig.2.) Could it be more accurate to rename them in a way that refers to light treatments?
Line 113. Why was a low PPFD used? M. Cristalinum is a very radiation demanding CAM plant and the data in the literature recommends PFD between 400 and 1300 μmol.m-2.s-1
Line 130. The axes of the light intensity plot must have their respective units.
Lines 138 et seq. The biomass concept used as a parameter must unify. Fresh weight of the whole plant or weight of the aerial part (shoot)
Line 157. The cited reference does not correspond to the proposed methodology. In any case, reference to a methodology that is not very widespread but local. There are better-established references for determining the dry weight of plants.
Line 167. Reference to this methodology is not attached
Line 181. A prior reference to this methodology would be necessary
Line 204. The reference does not appear in the bibliography
Comments on the Quality of English LanguageExtensive editing of the English language is required; authors are encouraged to use MPDI's English Editing service.
Author Response
General comments:
The final paragraph of the introduction should make the working hypothesis explicit.
Answer: Corrected, on lines 81-84
An experimental design with two main factors is proposed and a two-way ANOVA should be performed: Spectral bands with 4 levels of action (warm white, cool white, red and blue spectrums), and photoperiod duration (DLI with two levels: 18 and 21 hrs.). However, the effects due to the two main factors are not presented and the data in the tables and figures are presented as if they were nested factors (DLI nested to light receipt).
Answer: Completely new statistical analysis was done. Data + methodics (chapter 2.4.1.) are in MS.
Author Response File: 
Author Response.pdf
Reviewer 5 Report
Comments and Suggestions for AuthorsDear Editors and Authors,
I read with interest the manuscript entitled “The effect of daily light integral and spectrum on Mesembryanthemum crystallinum L. in an indoor plant production environment”. This study aimed to establish the most favorable light condition for the growth of M. crystallinum in order to provide sufficient information for high yield and optimized bio-quality production in artificial growing conditions. The subject of the article is important and has great relevance for the scientific environment of the study area. Therefore, the manuscript needs some adjustments so that it can then be forwarded to the publication process. The manuscript has the potential for publication in the journal Horticulturae and needs the following adjustments:
ABSTRACT
- Add excerpts about the Introduction. The Abstract begins with the objective of the work. This needs to be done.
- It is necessary to add a general conclusion about the research. As it stands, these are just results.
- Add the popular name of the species to the keywords.
INTRODUCTION
- At the beginning of the second paragraph it is mentioned what the study will evaluate (objective of the study). This information is mentioned again in the last paragraph. I suggest deleting the first quote and leaving the objective only in the last paragraph.
- The objective needs to be reduced. There is a lot of information in the last paragraph that is confusing. After all, what is the objective of the work?
- Add hypotheses before the objective.
MATERIAL AND METHODS
- Start this section by describing the study location, and inserting the geographic coordinates. This is important because you are working with a species that can withstand low temperatures.
- The description of statistical analysis should be the last subtopic of this section.
- The dry mass of the leaves? It was not mentioned in the growth characteristics. They only mentioned the fresh pasta. Add this information.
- Why was only the width of the sheet measured? And the length?
- There was no way to measure the leaf area? This would be more interesting than just measuring the width.
- Mention the version of the Statistica program.
RESULTS AND DISCUSSION
- Tables and Figures must be inserted after the first citation in the text. Check this throughout the text.
- I didn't understand why they did a correlation analysis separately by treatment. Was it described in the methodology that had this correlation analysis?
- Remove the horizontal lines inside the Figures.
- Add captions within the figures. There is no way of knowing what each bar of a different color means.
- Wouldn't it be more correct to use upper and lower case letters to compare the two factors within the graphs?
CONCLUSIONS
- Does not exist. Create a topic with the conclusions.
Author Response
data and answers in enclosed file
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
Comments and Suggestions for Authorsresearch very easy, but design about light quality and photoperoid must improve
Comments on the Quality of English Language
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Author Response
Comment: research very easy, but design about light quality and photoperoid must improve
Answer:
We understand this view and will include more details to description of methodology to the 2.2 Light treatment chapter.
Spectra with a different R-G-B ratio were used for testing. There were treatments with a ratio of 5-2-1, 6-1-1, 11-2-1 and 78-1-12 RGB, i.e. with different values of the spectrum ratios. At the same time, the fact that the current trend is to cover a wider spectrum (full spectrum) in LED lights was taken into account. Therefore, variants where the white spectrum is represented more significantly and is more suitable for growing areas and workers were included.
Regarding the question of the chosen photoperiod, it can be stated that the reason for choosing 18 h and 21 h was not to test the effect of the photoperiod itself, but whether it is effective to extend the photoperiod beyond the commonly used 18 h in lighted crops and whether it will have a positive effect on growth and other parameters. The evaluation of the influence of short and long photoperiods is generally known, and testing e.g. 12 h would lead to conclusions that can already be stated = extension of cultivation time and thus an uneconomical way for indoor cultivation.
Reviewer 4 Report
Comments and Suggestions for AuthorsDespite being an interesting manuscript and adapted to Horticulturae and the special issue to which it is presented, it still presents serious deficiencies and has serious flaws; the treatment of the information was not carried out correctly.
It still looks like duplicate information in results for tables and figures. The information presented in the tables does not correspond to a multifactorial ANOVA. the effects due to the two main factors (DLI and light receipt) are still lacking. The meaning represented by the letters that follow the means does not differentiate between columns, but between rows. The way the data appears should be restructured so that tables and figures appear as close as possible to the first time they are cited.
The discussion boils down for the most part to a repetition of the results without providing solid justifications or arguments.
Errors in the literature have not been reviewed.
Comments on the Quality of English LanguageDespite being an interesting manuscript and adapted to Horticulturae and the special issue to which it is presented, it still presents serious deficiencies and has serious flaws; the treatment of the information was not carried out correctly.
It still looks like duplicate information in results for tables and figures. The information presented in the tables does not correspond to a multifactorial ANOVA. the effects due to the two main factors (DLI and light receipt) are still lacking. The meaning represented by the letters that follow the means does not differentiate between columns, but between rows. The way the data appears should be restructured so that tables and figures appear as close as possible to the first time they are cited.
The discussion boils down for the most part to a repetition of the results without providing solid justifications or arguments.
Errors in the literature have not been reviewed.
Author Response
It still looks like duplicate information in results for tables and figures. The information presented in the tables does not correspond to a multifactorial ANOVA. the effects due to the two main factors (DLI and light receipt) are still lacking. The meaning represented by the letters that follow the means does not differentiate between columns, but between rows.
Answer: Authors are aware that the results presented in Figures 3, 4, 6, 7, and 8 are summarized in Table 1,2. However, we believe that both the figures and the table have their justification. The table provides a better understanding of the average values including standard deviation for potential reference, whereas the figures visualize the results more effectively.
There is only part of data with this way of presenting, the rest is only in table.
The multifactorial analysis is now added in the tab.1,2.
The way the data appears should be restructured so that tables and figures appear as close as possible to the first time they are cited.
Answer: There were put data of all parameters analysed at the beginning of Results part (Tab. 1 and Tab. 2) to present all relevant results together. We hope that this way of presenting is more efficient according to the space needed as well as according to the fact reader can find all in one place.
Particular figures with data are put in harmony to the particular chapters, eg for morphology data 3.1 are put figs with weight, area, dry matter 3.2 fig. 6 Dry matter ....
The discussion boils down for the most part to a repetition of the results without providing solid justifications or arguments.
Answer: we further worked on this part, too.
Errors in the literature have not been reviewed.
Answer: literature was corrected and used in one format shape.
Reviewer 5 Report
Comments and Suggestions for AuthorsDear,
The authors accepted and implemented many of the previous suggestions.
The last suggestion is to remove the color from the background of Figure 5.
Therefore, the manuscript has the potential for publication in the journal.
Author Response
The authors accepted and implemented many of the previous suggestions.
Answer: thank you for considering further improvement of manuscript
The last suggestion is to remove the color from the background of Figure 5.
Answer: as this is the different type of data to other figures we believe that can be also in different colour mode. If needed by editor, we change also to black-white mode.
Therefore, the manuscript has the potential for publication in the journal.
Round 3
Reviewer 1 Report
Comments and Suggestions for Authors1, experimental treatment should contain 14h/10h
2, check unit of Leaves surface area [mm2]
3, Where is the literature No. 27?
Author Response
1, experimental treatment should contain 14h/10h
Answer: experimental treatmens was used at 18 and 21 h DLI. The only case of using 14h/10h was preparation of young seedlings for experimental purposes as this type of plant seedlings is not accessible by seed/young plants companies. The reason not using 14h/10h for trials is that such short DLI will not bring adequate results in indoor plant production and will lead to the long culture.
2, check unit of Leaves surface area [mm2]
Answer: corrected in MS
3, Where is the literature No. 27?
Answer: corrected, added back - in response to previous reviews was deleted part of sentence incl. this reference in the text
