Influence of Supplementary Blue and Far-Red Light on the Morphology and Texture of Ocimum basilicum L. Grown in Controlled Environments

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Manuscript is very well written and prepared and I have no suggestions concerning the text and presentation of the study. Also the equipment and work organization described for the research facility are impressive, therefore this manuscript should be published in MDPI Horticulturae, providing example to wider scientific audience what they need to acquire in their own facilities in order to maintain necessary competitiveness. Unfortunately most of us (other scientist) need constantly to reach for some makeshift solutions.

Presented results are in total contrast to the research output level which could be expected from the facility and research team. A brief inspection of previous research done on basil (presented in reference 5) shows that Oehler et al made little progress, mostly repeating findings of other groups. You could have used more than just two basil genotypes/ cultivars (there are over 60 recognized species) and the light treatments provided to plants except the supplemental light colors could also contain treatments in which some wavebands could be removed or significantly decreased. Like in the approach of B. Seabrook using yellow filters in her potato studies. Having so much white light in all treatments is indeed optimization but of limited range. With all of the bang described in material and methods authors could provide much more, perhaps even some hints on secondary metabolite content, as in some parts of the world, basil (O. basilicum L.) is primarily considered as a medicinal plant of tremendous importance for folk medicine.

Manuscript should be accepted for publication, but authors should be aware that although bombastic, manuscript it is rather thin when evaluated for the importance of presented findings. It is possible that you had limitations in making decisions regarding the data presentation, but anyhow you have very good basis for future work.    

 

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The article “Supplemental Blue and Far-Red Light Regulate the Morphology and Texture of Ocimum basilicum L. Grown in Controlled Environments” provides valuable insights into how different light spectra influence the morphology and texture of basil in controlled environments. The topic is highly relevant to controlled environment agriculture (CEA), a rapidly advancing field in horticultural science. The study follows a well-structured methodology, and its findings contribute significantly to optimizing basil production. However, several aspects could be improved to enhance clarity, coherence, and scientific rigor.

Abstract

Please specify the total duration (in days) for which the plants were exposed to LED light treatments.

Materials and Methods

Table 1: Including a more detailed legend with an explanation of all treatments would improve clarity.

Light Treatments: Clearly defining the abbreviations BL and FR would enhance reader understanding.

The manuscript should maintain an impersonal tone throughout.

Results and Discussion

Some significant differences, such as variations in leaf toughness, are not thoroughly explained. Providing potential physiological mechanisms behind these findings would strengthen the discussion.

The frequent mention of "statistical differences" without reporting specific p-values or standard deviations makes it difficult to assess the robustness of the results. Including these details would improve transparency.

While the study references multiple prior works, a more critical comparison of its findings with existing literature would add scientific depth.

Additional citations are needed for claims related to photoreceptor responses and consumer preferences for leaf texture.

Figures and Tables

Some figures and tables lack detailed captions explaining their significance. For example, the color analysis results (Lab values) are not sufficiently elaborated in the text. Providing more details in the table legends would improve clarity.

Including representative images of basil under each treatment would enhance the impact of the findings.

 

Overall, this study provides important insights into light spectrum manipulation in basil cultivation, with implications for CEA and LED-based plant production. However, improvements in clarity, justification of experimental choices, statistical rigor, and depth of discussion would further enhance the manuscript’s impact.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

Dear Collegues

I have read with great interest the manuscript of Oehler N et al entitled “Supplemental Blue and Far-Red Light Regulate the Morphology and Texture of Ocimum basilicum L. Grown in Controlled Environments Madison”.

First of all, the theme corresponds to the profile of the journal. The direction of research is quite relevant. There is quite a large literature on the effect on plants of additional light of different quality to the usual illumination. There are some works performed in this field and on basil plants (Ocimum basilicum L.). This allowed the authors to easily formulate not only the aim and objectives of the study, but also the working hypothesis, which was quite predictable. The data obtained are mainly practical in nature and do not contain much fundamental novelty.

The authors obtained evidence that supplemental BL (blue), FR (far red) light and their combination (BL+FR) significantly affect the growth, morphology, texture and leaf color of two basil cultivars (Prospera and Amethyst) grown in a controlled environment. Interestingly, FR increased plant biomass and leaf strength, while the response of plants to BL+FR supplemental light was almost identical to the response of plants to FL alone supplementation. In contrast to FR, BL enhanced leaf dark pigmentation and leaf thickness. On this basis, the authors concluded that (1) the addition of light of different quality can regulate leaf morphology, mechanical properties, and leaf marketability; (2) each plant variety requires optimization of the light regime to obtain the desired results.

From my point of view, the technology of the experiment is described in detail and clearly. I do not have any claims of methodological plan. The material in the manuscript is presented logically. The conclusion made by the authors is confirmed by the obtained experimental data.

I believe that the manuscript can be accepted for printing with a very small reservation. The authors used the LED technique. Unfortunately, the manuscript lacks the emission spectra of the light sources used, which makes it difficult to evaluate the results obtained. For this reason, I would recommend that the authors provide emission spectra of all the light sources used.

Kind regards

 

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 4 Report

Comments and Suggestions for Authors

The manuscript “Supplemental Blue and Far-Red Light Regulate the Morphology and Texture of Ocimum basilicm L. Grown in Controlled Environments” has value from a practical point of view, but in order to appreciate the scientific component, the design of the experiment needs to be revised. I mean that the authors need to reconsider the very concept of presenting the material, given that the control variant differs from the experimental ones by at least 2 parameters (spectrum and irradiation intensity), so it is impossible to draw conclusions about the influence of individual spectrum components. In addition, as I understand it, the percentage ratio of %BL:%R:%FR:%W was specified not by spectrum components (which should be presented as %B:%R:%FR:%G:%UV), but by the ratio of the LEDs used, which is generally incorrect. I recommend that the authors reconsider the control variant of the experiment (use negative control LW and positive control HW), remeasure the spectra with a spectrocolorimeter, and rewrite the corresponding sections of the manuscript (Materials and Methods, Discussion, Conclusion). Please also pay attention and correct the following points:

Lines 12-25 Check the format.

Line 19 Blue is designated as B, not BL

Line 26 Check and change “keyword 1…  2; hydroponics 3; basil 4;” (Remove numbering and parts of the Template)

Lines 38-40 This statement is very controversial: “Basil is traditionally grown outdoors or in greenhouses; however, Sipos et al. [5] noted that basil cultivated in controlled-environment agriculture (CEA) systems tend to develop richer flavors compared to those grown in traditional open-field settings”. The fact is that it has been proven that when growing basil in CEA, the accumulation of essential oil can be 10 times less than grown outdoors [https://doi.org/10.3390/app12147190, https://doi.org/10.3390/horticulturae3020036]. Therefore, UV radiation is added to the lighting spectrum, increasing the content of aromatic substances, or elicitors are used, creating stress to stimulate the production of secondary metabolites. Please complete this section.

Subsection 2.1. Please provide description of the variety (growing period, standard morphological parameters, features).

Lines 117-119 It is incorrect to describe the emission spectrum by the LEDs used. You need to break down the full spectrum as Red, Blue, Far Red, Green, Ultraviolet. It was necessary to use a spectrocolorimeter and provide data from the obtained spectra.

Line 119 Why did you use photoperiod of 20 h? Provide references.

Table 1 The design of the experiment is incorrect. In the control, the PPFD is 60 lower than in the other variants of the experiment, so it differs in the intensity of illumination and spectrum, which excludes the possibility of comparing the variants.

Lines 144-154 Check the format (Line spacing)

Line 155 Please divide subsection 2.3 into 2 ones (Determination of Biometric Indicators, Fluorescence Measurement)

Figures 2, 3 should be designed differently. Ideally, it would be necessary to present a photo of the plants with a ruler attached. Ideally, it was necessary to present a photo of the plants with a ruler attached. It is better to put the presented figures in supplemental materials.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 5 Report

Comments and Suggestions for Authors

Dear authors,

Your work has practical significance and will be of interest to farmers growing basil under controlled conditions in a hydroponic system.

You have shown that a combination of white light with added blue and infrared has a noticeable effect on the basil biomass, its color, and leaf density.

The design of the study is clear and generally meets the objectives. However, the methods you used do not always seem objective. The relevance of your study is obvious, but its novelty is not sufficiently substantiated.

There are points that should be clarified:

1. It is unclear why it was necessary to count the number of microorganisms. These data are beyond the objectives of the study and are practically not discussed.

2. Why is the ρf index equal to 1? Wouldn't it be easier to measure the leaf thickness microscopically on the leaf cross-sections?

3. Visual assessments of leaf color may be suitable in agricultural practice, but in biological studies it is better to provide the pigment content. It gives more objective information. For basil, it could be at least chlorophylls and anthocyanins.

4. To better understand how the leaf structure changes with the light conditions, it would be better  to provide data on SLA and the correlation between SLA and leaf thickness. It would be good to demonstrate a cross-section of leaves. This would help explain such indicators as peak force and toughness and make the discussion more convincing.

5. In my opinion, the Methods section is excessively detailed. It can be corrected.

6. Please correct the keywords.

Author Response

Please see the attchment.

Author Response File: Author Response.pdf

Round 2

Reviewer 4 Report

Comments and Suggestions for Authors

The authors of the manuscript "Supplemental Blue and Far-Red Light Regulate the Morphology and Texture of Ocimum basilicm L. Grown in Controlled Environments " have done a great job of improving the work, describing the experimental variants in more detail in the Materials and Methods section, and supplementing the Results and Discussion sections. All comments were taken into account, and the manuscript was improved. I believe that the manuscript is worth publication and recommend that the authors make the following minor adjustments:

Reduce the percent match (16%).

Please write the name of the varieties in quotation marks  - 'Prospera'...

Figure 2 Do you mean "Leaf surface area" when use "specific leaf area"? Also add the method for determining this indicator in Materials and Methods.

Lines 847-850 Please do not repeat yourself. This information is presented in the next subsection.

Author Response

We have uploaded our responses in a word document. Thank you.

Author Response File: Author Response.pdf

Reviewer 5 Report

Comments and Suggestions for Authors

I thank the authors for their great work on improving the manuscript. It has become much more interesting in terms of discussion. However, there are still many comments.
1. The responses to questions 2 and 3 did not convince me.
2. Lines 743-745 - the phrase is not supported by the data on the content of chlorophylls. It should be deleted.
3. Lines 813-818, 743-744, 845-850, etc. need to be rephrase, since the same words are repeated at least twice.
4. Lines 816-817 - the same reference is given twice in the same sentence. It needs to be rephrased.
Thus, the article is still not ready for publication.

Comments on the Quality of English Language

Lines 812-816, 830-831 (mechanism is not the role), 852-855 -should be refrased for better understanding.

Author Response

We have uploaded our responses in the form of a word document. Thank you.

Author Response File: Author Response.pdf