The Qualitative and Quantitative Relationship of Lettuce Grown in Soilless Systems in a Mediterranean Greenhouse

Round 1

Reviewer 1 Report

There was no data available on temperatures of outdoor and greenhouse and precipitation during the experimental period, making it impossible to objectively compare the differences among treatments. At least, temperature data should have been included to support the discussion. Additionally, as the authors themselves mentioned, the absence of data on energy by light wavelength prevents an objective explanation of the relationship between light quality, growth, and antioxidant activity. It is therefore necessary to conduct a deeper analysis using existing literature, particularly in relation to the previously mentioned temperature effects.

 

Abstruct

The abstruct merely presents the results and lacks a clear conclusion.

 

Results

L280. Refference number [3]?

L289. The term 'PH' should be written in full as 'plant height' to ensure clarity.

L327. ‘able 3’ >>> ‘Table 3’

L359. Refference number [41]?

 

Discussion

L455. Refference number [51]?

L494. ‘high temperature’ >>> There was no data available on temperatures.

L537. The heading should be removed. And, the order of the references appears to be incorrect, possibly due to changes in the order of the sections.

Author Response

^{Major comments}

^{There was no data available on temperatures of outdoor and greenhouse and precipitation during the experimental period, making it impossible to objectively compare the differences among treatments. At least, temperature data should have been included to support the discussion. Additionally, as the authors themselves mentioned, the absence of data on energy by light wavelength prevents an objective explanation of the relationship between light quality, growth, and antioxidant activity. It is therefore necessary to conduct a deeper analysis using existing literature, particularly in relation to the previously mentioned temperature effects.}

^{Response: Thanks for your comments. In the new version of the manuscript the data “on temperatures of outdoor” as well as on light wavelength were included and commented in the discussion. Finally, a comparation using existing literature was conducted. The paragraph “3.3 Total irradiance, e-PAR and Temperature” (L358 revised version) includes the data on the temperature and also in Supplementary material (Figure S3). Furthermore, in the discussion section we reported our data about temperatures (L501-L506) and we corroborated our results with existing literature (reference 55, L508-L512).}

^{Minor comments}

^Abstract

^{The abstract merely presents the results and lacks a clear conclusion.}

^{Response: Thanks for your suggestions, and in the revised version the abstract was modified as suggested.}

^Results

^{L280. Reference number [3]?}

^{Response: Thanks – we changed it. In L280 the reference is [4].}

^{L289. The term 'PH' should be written in full as 'plant height' to ensure clarity.}

^{Response: thanks for your suggestion, we changed it (L294 in revised version)}

^{L327. ‘able 3’ >>> ‘Table 3’}

^{Response: Thanks – we changed it.(L330 revised)..}

^{L359. Reference number [41]?}

^{Response: Thanks – we changed it, the same reference can be found in L112 with [23] (revised version). As suggested by reviewer 2, we defined the e-PAR, moving the L356-L359 (previous version) in L112-L114 (revised version).} 

^Discussion

^{L455. Reference number [51]?}

^{Response: Thanks – we changed it. In the revised version (L461) the same reference is cited as “Thomas et al., [47]”}

 

^{L494. ‘high temperature’ >>> There was no data available on temperatures.}

^{Response: In the revised version we added data on temperatures, paragraph “ 3.3 Total irradiance, e-PAR and Temperature” (L358 revised version). Furthermore, we added another graph on the monthly air temperature in outdoor and indoor environment for the growing period (21 days) in the supplementary material.}

^{L537. The heading should be removed. And, the order of the references appears to be incorrect, possibly due to changes in the order of the sections.}

^{Response: In the revised version (L551), the heading was removed and the citation were completely ordered. Thank you for your suggestions}

Author Response File: Author Response.pdf

Reviewer 2 Report

The manuscript named “Qualitative and quantitative relationship of lettuce grown in soilless- systems in a Mediterranean green-house”, and addressed a critical gap in controlled environment agriculture by comparing different cultivation systems for lettuce production in a Mediterranean greenhouse. The integration of soilless systems with innovative light-modifying materials is timely, given global challenges such as climate change.

Suggestions:

1.Expand the introduction to contrast photoluminescent bands with other spectral-shifting materials. The abstract should be revised to more effectively summarize the study’s objectives, methods, results, and conclusions.

2.The key details of experimental setup were missing, with six replicates per system and comprehensive measurements.

The study notes a 19.58% reduction in e-PAR indoors but omits spectral composition. photoluminescent bands presumably shift light quality, which directly affects chlorophyll synthesis. Quantifying it would link light modifications to observed differences of lettuce growth.

The inorganic (PLANTAFOL® 20-20-20) and organic (Terra Aquatica 3-1-5) solutions differ in NPK ratios. This confounds comparisons between HSN and HSO, as yield disparities may stem from nutrient imbalances rather than system efficacy.

3. Error Bars of Table 1 was missing.

Organic Hydroponics’ Underperformance: HSO’s low yield (11.19 g FW) is attributed to nutrient uptake issues, but this study lacks root morphology data (e.g., root hair density, root length of weight density) to support this.

4. Please added light-related variables to PCA .
5. Please introduced and defined technical terms “e-PAR” (line 356) earlier.

6.The complex sentences should be broken down for better readability.

1. The abstract should be revised to more effectively summarize the study’s objectives, methods, results, and conclusions.
2. Please introduced and defined technical terms “e-PAR” (line 356) earlier.
3. Error Bars of Table 1 was missing (line 293).

Author Response

The manuscript named “Qualitative and quantitative relationship of lettuce grown in soilless- systems in a Mediterranean green-house”, and addressed a critical gap in controlled environment agriculture by comparing different cultivation systems for lettuce production in a Mediterranean greenhouse. The integration of soilless systems with innovative light-modifying materials is timely, given global challenges such as climate change.

 

Suggestions:

1.Expand the introduction to contrast photoluminescent bands with other spectral-shifting materials.

Response: Thanks for your suggestions. The Introduction was expanded as suggested thereby including “contrast photoluminescent bands with other spectral-shifting materials”.

The abstract should be revised to more effectively summarize the study’s objectives, methods, results, and conclusions.

Response: Thanks for your suggestion. The abstract in the new version was revised as suggested.

2.The key details of experimental setup were missing, with six replicates per system and comprehensive measurements.

Response: Thanks for your comment. In the new version of the manuscript some details about statistical analysis were added.

The study notes a 19.58% reduction in e-PAR indoors but omits spectral composition. photoluminescent bands presumably shift light quality, which directly affects chlorophyll synthesis. Quantifying it would link light modifications to observed differences of lettuce growth.

Response: Thanks for your comments. In the new version, we focused on the intensity of the photon flux and the high exposure found in outdoor environments compared to indoor environment. Our focus in this case was to focus more on how high exposure to sunlight could presumably alter plant growth. The effect of light on the quality of lettuce was not part of our purpose.

The inorganic (PLANTAFOL® 20-20-20) and organic (Terra Aquatica 3-1-5) solutions differ in NPK ratios. This confounds comparisons between HSN and HSO, as yield disparities may stem from nutrient imbalances rather than system efficacy.

Response: We thank the reviewer for this insightful observation. Indeed, the inorganic (PLANTAFOL® 20-20-20) and organic (Terra Aquatica 3-1-5) nutrient solutions used in our study differ in NPK composition. This choice was intentional, as our aim was to assess the performance of two commercially available fertilization approaches commonly used in hydroponic systems (inorganic vs. organic), rather than to compare equalized nutrient formulations. Our primary objective was to evaluate system-level efficacy under realistic cultivation conditions, where nutrient solutions are typically applied as commercial products with distinct formulations. While we acknowledge that differences in nutrient composition may influence yield and quality, this reflects real-world application and user experience.

 

3. Error Bars of Table 1 was missing.

Response: Thanks for your comment. Perhaps you intended figure 1, but we added it in the revised version.

Organic Hydroponics’ Underperformance: HSO’s low yield (11.19 g FW) is attributed to nutrient uptake issues, but this study lacks root morphology data (e.g., root hair density, root length of weight density) to support this.

Response: Thank you very much for your insightful comments and suggestions on our manuscript. In the revised version, we have included data on root fresh weight, which may provide a stronger indication of the factors contributing to the underperformance observed in the Organic Hydroponics system (Discussion section-L473-L474, Supplementary Figure S2). These data offer additional insight into root morphology and help to better support the hypothesis regarding nutrient uptake limitations.

4. Please added light-related variables to PCA .

Response: Thanks for your suggestion. However, adding light-related variables to the PCA would not significantly alter the current PCA results. Statistically, the plants across many systems were exposed to similar light conditions, except for the outdoor system. Therefore, the variation explained by existing factors in the PCA model is robust and not influenced by light conditions.

5. Please introduced and defined technical terms “e-PAR” (line 356) earlier.

Response: Thanks, we added it in the revised version. We defined the e-PAR, moving the L356-L359 (previous version) in L112-L114 (revised version). 

 

6.The complex sentences should be broken down for better readability.

Response: We thank the reviewer for this helpful suggestion. We have revised the manuscript by breaking down several complex sentences to improve clarity and readability throughout the text.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

The manuscript is deemed to have been appropriately revised and is therefore accepted.

There is no detailed comments.

Reviewer 2 Report

The current version of manuscript has already adequately addressed the concerns proposed by the reviewer. It is recommended to accept this manuscript for publication in the journal.

The current version of manuscript has already adequately addressed the concerns proposed by the reviewer. It is recommended to accept this manuscript for publication in the journal.