A Multifaceted Approach to Optimizing Processed Tomato Production: Investigating the Combined Effects of Biostimulants and Reduced Nitrogen Fertilization

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

This study focuses on the use of biostimulants, recently noted as an alternative strategy to curb the use of synthetic chemicals in crop production. Authors did a sterling work; however, there are a few aspects to be majorly considered before the manuscript can be considered, for instances: 

 

The affiliation is from the same institution, it may only be suitable to add superscript 1 when there is another different address; authors are to compare with the authors' guidelines.

There seems to be an inconsistency with the initials in the affiliation with the correspondences. Please verify. 

In line 29, write the leaf with a small letter instead of a capital.

Some common symbols, like nitrogen, are really necessary as they are commonly known across science, but I would discourage this in science. 

Lines 16 - 20 are over information in the abstract; this section should only provide the study design and layout, and partially the treatment; there is space for this in the Materials and Methods.

Lines 53 and 70 have nitrogen (N) redefined twice; this can always be done only once and maintain the abbreviation; maybe all abbreviations other than N, verify this across the manuscript. 

Combine - morphological, physiological, to ''morphophysiological parameters'', across the document.

Results from lines 20 - 31 in the abstract are found to be overly emphasised; authors should seek a golden thread to report the key findings in brief. 

Keywords: Remove the dash - morpho-physiological traits.

Basic things like the authority should only be mentioned once for the plant and then a common name, then used; however, taxa with authority were repeated more than three times across. Maybe language editing is required. 

Define the Factorial Design clearly, i.e. 4 x 2...

Is there IP for this "(not commercial prod- 128 uct, developed by Fomet Spa, Verona, Italy)"?

No pest control was necessary during the growing cycle, and hand-weeding thoroughly controlled weeds. - Does it mean no pesticides were applied for preventative measures? Yet authors say, "All cultural practices have been consistent with local 150commercial crop management using integrated pest management."

If the experiment was repeated, were the soil properties checked only once or in both seasons? Because the pH and other minerals will not be the same. Provide a realistic time when this analysis was done.

 In Table 1, describe what Ntot is.

What is the SI unit for pH? %? Check and correct.

In line 125, describe clearly what the design is that led to 36 treatment combinations, i.e. 4x3 replicated…

In line 126, write the biostimulant with a small letter instead of a capital.

In the fertiliser treatments, remove, i.e, it sounds like an estimation and not a precise application.

In line 140, provide details of the row spacing.

Line 150 needs a reference to corroborate repetition of this; and there seems to be a contradiction with line 135…

Only provide the abbreviation once, i.e. LAI and DAT were repeated so many times.

Line 196, is it 5 leaves randomly per plant or plot?

ANOVA is common, remove full meaning and just leave the abbreviation. Again, correct the issue of acronyms.

With your results, line 228, maybe start with the parameters not significant and signpost to the table concerned, then give us the important information regarding the actual findings.

Line 230, if you say as expected, maybe capture such in the introduction to relate more easily, yes, it is common, but provide evidence for this.

With the results, it would have been nice to analyse for the year effect, where you use the season as an extra factor or analyse for the homoscedasticity; I believe this is the reason why you repeated the study for validation; this can always be reported much better when both years are combined.

Tables 3, 4, 5 and 6 show that the biostimulant was not effective, so what is the novelty in this study? N is known to affect the yield and quality of most plants; there is a lot of data around this. Are you reporting negative results? Suggestion: shorten the study, focusing your study on Table 7, and refer to the rest as extra information. Starting with Table 7 will make the study appealing. I do not have any problem with how you interpreted the results.

Once the above comment is addressed, the discussion and conclusion will also slightly change.

Consistency in the list of references: i.e. Ref 1 – year is not bolded; remove the DOIs just before the link; With abbreviated references, put a full stop at the end, i.e. Ref 34, etc.

Author Response

Responses to Reviewer 1

This study focuses on the use of biostimulants, recently noted as an alternative strategy to curb the use of synthetic chemicals in crop production. Authors did a sterling work; however, there are a few aspects to be majorly considered before the manuscript can be considered, for instances: 

Response: We sincerely thank the reviewer for their positive evaluation of our work and for acknowledging our efforts in exploring biostimulants as an alternative to synthetic chemicals in crop production. We appreciate the recognition of the potential relevance of our study.

We also acknowledge about the comments regarding the aspects that require further improvement, as kindly pointed out. Below, we provide detailed responses to each of the specific concerns raised and describe the corresponding revisions made to the manuscript to address them. We hope that these changes enhance the clarity, scientific rigor, and overall quality of the manuscript.

1. The affiliation is from the same institution, it may only be suitable to add superscript 1 when there is another different address; authors are to compare with the authors' guidelines.

Response: We thank the reviewer for this observation. We have revised the author affiliation section by removing the superscript numbering, as all authors are affiliated with the same institution. The formatting now complies with the journal’s author guidelines. See lines 5-6.

2. There seems to be an inconsistency with the initials in the affiliation with the correspondences. Please verify. 

Response: We thank the reviewer for highlighting this issue. We have carefully reviewed the author names, initials, and corresponding author details throughout the manuscript. All initials and affiliations have now been verified to ensure consistency across the author list, affiliation, and correspondence section.

3. In line 29, write the leaf with a small letter instead of a capital.

Response: Thank you for pointing this out. We have corrected the word “Leaf” to lowercase “leaf” in line 29, as suggested. See line 36.

4. Some common symbols, like nitrogen, are really necessary as they are commonly known across science, but I would discourage this in science. 

Response: We appreciate the reviewer’s suggestion. We agree that while commonly recognized symbols such as “N” for nitrogen are appropriate, excessive or unnecessary abbreviations can hinder readability. We have reviewed the manuscript and ensured that only standard, widely recognized symbols are used, and non-essential abbreviations have been minimized or removed to improve clarity.

5. Lines 16 - 20 are over information in the abstract; this section should only provide the study design and layout, and partially the treatment; there is space for this in the Materials and Methods.

Response: Thank you for this helpful observation. In response, we have revised lines 16–20 (in previous version) of the abstract to provide a more concise description of the study design and treatments, limiting the level of detail as suggested. Full experimental details have been retained and are now clearly described in the Materials and Methods section. See lines 16-19.

6. Lines 53 and 70 have nitrogen (N) redefined twice; this can always be done only once and maintain the abbreviation; maybe all abbreviations other than N, verify this across the manuscript. 

Response: We thank the reviewer for pointing this out. We have revised the manuscript to ensure that "nitrogen (N)" is defined only once at its first appearance, and the abbreviation “N” is consistently used thereafter. We have also reviewed the manuscript for other abbreviations and ensured they are introduced only once and used consistently throughout.

7. Combine - morphological, physiological, to ''morphophysiological parameters'', across the document.

Response: We appreciate the reviewer’s suggestion. As recommended, we have combined "morphological" and "physiological" into "morphophysiological parameters" throughout the manuscript to improve clarity and conciseness.

8. Results from lines 20 - 31 in the abstract are found to be overly emphasised; authors should seek a golden thread to report the key findings in brief. 

Response: We thank the reviewer for this valuable suggestion. In response, we have revised the abstract to present the key findings in a more concise and focused manner. We have removed excessive detail and emphasized only the most relevant results to maintain clarity and alignment with the abstract’s purpose. See lines 25-40.

9. Keywords: Remove the dash - morpho-physiological traits.

Response: Thank you for the suggestion. We have removed the dash and now use “morphophysiological traits” consistently throughout the manuscript.

10. Basic things like the authority should only be mentioned once for the plant and then a common name, then used; however, taxa with authority were repeated more than three times across. Maybe language editing is required. 

Response: We thank the reviewer for this helpful comment. We have carefully revised the manuscript so that the scientific name with authority is mentioned only once in the Abstract and at the first occurrence in Materials and Methods. Subsequent mentions within the same section use only the species or common name. This approach is consistent with standard scientific writing, given that each section can be read independently. Additionally, we have arranged for professional language editing to improve overall clarity and consistency.

11. Define the Factorial Design clearly, i.e. 4 x 2...

Response: We appreciate the reviewer’s suggestion. We have revised the section to clearly define the factorial design used in the study i.e., factorial randomized complete block design, specifying the number of levels for each factor (e.g., 4 biostimulants × 3 nitrogen regimes × 3 replications) to improve clarity in the experimental layout description. See line 145-155.

12. Is there IP for this "(not commercial prod- 128 uct, developed by Fomet Spa, Verona, Italy)"?

Response: Thank you for this question. The biostimulant BIOS2 was provided by Fomet Spa (Verona, Italy) is currently a research-grade product not yet commercialized. To the best of our knowledge, it is not covered by any active patents or intellectual property restrictions, and it is provided for experimental use under agreement with Fomet Spa.

13. No pest control was necessary during the growing cycle, and hand-weeding thoroughly controlled weeds. - Does it mean no pesticides were applied for preventative measures? Yet authors say, "All cultural practices have been consistent with local 150commercial crop management using integrated pest management."

Response: Thank you for highlighting this point. We followed integrated pest management (IPM) protocols aligned with local commercial practices, which include regular monitoring and preventive strategies. However, during the experimental period, pest incidence was low, and therefore, no pesticide applications were required. Weed control was successfully managed through hand-weeding. We have revised the manuscript to clarify this and avoid any potential misunderstanding. See line 186-189.

14. If the experiment was repeated, were the soil properties checked only once or in both seasons? Because the pH and other minerals will not be the same. Provide a realistic time when this analysis was done.

Response: Thank you for the comment. Soil samples were collected and analyzed at the beginning of each growing season, before treatment application. As the soil properties were similar in both years, we reported the average values in Table X to represent the initial conditions.

15. In Table 1, describe what Ntot is.

Response: We thank the reviewer for this observation. We have added a clear description of “Ntot” as total nitrogen content in the soil in the table. Additionally, we have ensured that all other soil property abbreviations in Table 1 are clearly defined for reader clarity. See Table 1.

16. What is the SI unit for pH? %? Check and correct.

Response: We appreciate the reviewer pointing this out. We acknowledge the mistake of using “%” as the unit for soil pH. The pH is a unitless measure and does not have a percentage or SI unit. We have corrected this error. See table 1.

17. In line 125, describe clearly what the design is that led to 36 treatment combinations, i.e. 4x3 replicated…

Response: Thank you for the suggestion. We have clarified the experimental design as follows: “The experiment consisted of 4 biostimulant treatments (including the control) × 3 nitrogen levels × 3 replications, resulting in a total of 36 experimental units per year. See line 154-156.

18. In line 126, write the biostimulant with a small letter instead of a capital.

Response: Thank you for pointing this out. We have corrected the capitalization and now write “biostimulant” with a lowercase letter as per the reviewer’s suggestion. See line 146.

19. In the fertiliser treatments, remove, i.e, it sounds like an estimation and not a precise application.

Response: Thank you for your comment. We have removed “i.e.” from the fertilizer treatment descriptions and now present the application rates as exact values to avoid any ambiguity. See line 152-154.

20. In line 140, provide details of the row spacing.

Response: Thank you for the suggestion. We have added details of plant spacing in the manuscript: plants were spaced 0.3 m apart within rows, and rows were spaced 1 m apart. See line 174-175.

21. Line 150 needs a reference to corroborate repetition of this; and there seems to be a contradiction with line 135…

Response: Thank you for pointing this out. We have updated the contradictory statement in line 135 to ensure consistency and updated line 150 accordingly. Additionally, we have added a relevant reference to support the information. See line 188.

22. Only provide the abbreviation once, i.e. LAI and DAT were repeated so many times.

Response: Thank you for the observation. We have revised the manuscript to ensure that each abbreviation (e.g., LAI, DAT) is defined only once upon first use and then used consistently throughout. We also reviewed and corrected other repeated abbreviations across the manuscript to maintain clarity and avoid redundancy.

23. Line 196, is it 5 leaves randomly per plant or plot?

Response: We thank the reviewer for this question. We confirm that it was 5 leaves randomly selected per plot, and we have clarified this in the manuscript to avoid any confusion.

24. ANOVA is common, remove full meaning and just leave the abbreviation. Again, correct the issue of acronyms.

Response: Thank you for the helpful comment. We have removed the full form of ANOVA and retained only the abbreviation, as it is widely recognized in scientific literature. Additionally, we have reviewed and corrected the use of other acronyms throughout the manuscript to ensure consistency and proper formatting. See line 267.

25. With your results, line 228, maybe start with the parameters not significant and signpost to the table concerned, then give us the important information regarding the actual findings.

Response: Thank you for the insightful suggestion. While we acknowledge the value of highlighting non-significant parameters early on, we have chosen to maintain the current structure of the Results section to preserve the logical flow of our analysis—beginning with year effects, followed by nitrogen, biostimulants, and then their two-way interactions. This sequence aligns with the experimental design and ensures a coherent and progressive presentation of findings. Non-significant results are still reported and clearly indicated in the relevant tables for transparency.

26. Line 230, if you say as expected, maybe capture such in the introduction to relate more easily, yes, it is common, but provide evidence for this.

Response: Thank you for the comment. To maintain objectivity and avoid unsupported assumptions, we have removed the phrase “as expected” from line 230. The result is now presented in a neutral and evidence-based manner. See line 276.

27. With the results, it would have been nice to analyse for the year effect, where you use the season as an extra factor or analyse for the homoscedasticity; I believe this is the reason why you repeated the study for validation; this can always be reported much better when both years are combined.

Response: We thank the reviewer for this valuable suggestion. We agree that including “year” as a factor in a combined statistical model can provide additional insights into seasonal effects and help test for homoscedasticity. However, the two growing seasons (2023 and 2024) in our study were characterized by markedly different agro-climatic conditions, particularly in terms of rainfall distribution and temperature patterns. Moreover, statistical analyses revealed that the effect of “year” was not consistently significant across all measured parameters. This variability further supported our decision to present the data separately by year, rather than including “year” as a fixed factor in a combined model. Combining the data under such conditions could obscure meaningful treatment-specific responses and lead to misleading interpretations.

Analysing the years independently allowed us to better capture the interaction between biostimulant application, nitrogen input, and specific seasonal stressors. This approach aligns with established practices in agronomic field research, especially when the assumption of inter-annual homogeneity does not hold.

We believe this strategy enhances the ecological validity and clarity of our findings, without compromising statistical rigor. We will clarify this rationale more explicitly in the revised manuscript.

28. Tables 3, 4, 5 and 6 show that the biostimulant was not effective, so what is the novelty in this study? N is known to affect the yield and quality of most plants; there is a lot of data around this. Are you reporting negative results? Suggestion: shorten the study, focusing your study on Table 7, and refer to the rest as extra information. Starting with Table 7 will make the study appealing. I do not have any problem with how you interpreted the results.

Response: We sincerely thank the reviewer for this constructive and thoughtful comment. While it is true that nitrogen effects on plant productivity are well-documented, the novelty of our study lies in evaluating the interactive role of biostimulants under both optimal and reduced nitrogen conditions, particularly in open-field tomato production over two climatically distinct years.

Although some of the main effects of biostimulants did not reach statistical significance in Tables 3–6, we believe that statistical insignificance does not necessarily equate to biological irrelevance. As noted in Table 7 and across the data, biostimulants exhibited important interaction effects with nitrogen treatments, particularly under low nitrogen input, where synergistic responses were observed in traits such as chlorophyll content, N-uptake, and anatomical adaptation, highlighting their functional potential under nutrient-limited conditions.

We respectfully argue that reporting such nuanced and context-dependent findings — including those that may be statistically modest — is valuable in agronomic research. It reflects real-world variability and guides more site-specific, resource-efficient recommendations. In this context, our work does not simply report "negative results" but rather highlights the conditional and integrative nature of biostimulant performance, which is increasingly recognized in the scientific literature.

We also appreciate the suggestion to focus on Table 7 and have considered emphasizing its content more prominently in the Results and Discussion sections. However, we have retained the full dataset as presented, as it contributes to a comprehensive understanding of the biological response and treatment dynamics across morphological, physiological, biochemical, and anatomical traits. We support the philosophy that "biology is beyond the statistics", and in this case, the interaction trends, environmental dependency, and adaptive responses captured by our study contribute to the evolving understanding of sustainable nutrient management.

29. Once the above comment is addressed, the discussion and conclusion will also slightly change.

Response: We appreciate the reviewer’s insightful guidance. We agree that the discussion and conclusion should accurately reflect the emphasis and interpretations aligned with the presentation of key findings. Following the previous response and our approach to highlighting the nuanced and interaction-based effects of biostimulants under varying nitrogen regimes, we have carefully reviewed and revised the discussion and conclusion sections to better emphasize these aspects.

These revisions ensure that the narrative clearly conveys the biological relevance of our findings beyond mere statistical significance, providing a balanced and comprehensive synthesis of the results in the context of sustainable crop management.

30. Consistency in the list of references: i.e. Ref 1 – year is not bolded; remove the DOIs just before the link; With abbreviated references, put a full stop at the end, i.e. Ref 34, etc.

Response: We thank the reviewer for pointing out these important formatting inconsistencies. We have thoroughly reviewed the reference list and made the necessary corrections to ensure uniformity, including bolding the year in all references where required, removing DOIs preceding the links as per journal guidelines, and adding full stops at the end of abbreviated references. We appreciate the reviewer’s attention to detail, which has helped improve the manuscript’s overall presentation and professionalism.

 

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

This manuscript presents a well-designed two-year field study investigating the synergistic effects of biostimulants and reduced nitrogen (N) fertilization on processing tomato production. The research addresses critical gaps in sustainable agriculture by exploring strategies to enhance nitrogen use efficiency (NUE) while maintaining yield and quality, which aligns with global efforts to mitigate environmental impacts of excessive fertilization. Here are some concerns and suggestions for improvement:

1. Clarity in Biostimulant Characterization:

Table 2 provides limited details on BIOS1 (seaweed extract), such as active compounds or application rates, hindering comparability with other biostimulants (BIOS2 and BIOS3). Standardizing descriptions (e.g., concentration, mode of action) should be provided.

The source of BIOS2 (protein hydrolysates) is noted as a "by-product from agri-food industry" but lacks specifics (e.g., raw material, hydrolysis method), which could influence its efficacy and interpretation of results.

2. Methods of Measurements：

  The detailed methods to measure above-ground dry matter, total yield, marketable yield and leaf area index (LAI) should be provided.  

3. Statistical and Interpretive Consistency:

While the manuscript acknowledges that biostimulant effects were "not consistently significant," it occasionally emphasizes trends (e.g., BIOS2 and BIOS3 outperforming BIOS1) without statistical support. Stricter distinction between significant results and anecdotal trends is needed to avoid overinterpretation.

4. Environmental Contextualization:

Weather data (Figure 1) are critical for explaining interannual variability (e.g., stronger biostimulant effects in 2023), but the manuscript does not explicitly link specific climatic factors (e.g., rainfall patterns, temperature stress) to observed differences in plant performance. It’s suggest to link Climate to Results: Explicitly correlate 2023-2024 weather differences (e.g., rainfall post-transplantation) to observed phenotypic responses, explaining why biostimulants performed better under stress. Besides, quantifying stress indices (e.g., drought severity) would strengthen this connection.

Soil properties (Table 1) include pH as "8%" (likely a typo; should be 8.0), which may affect nutrient availability and biostimulant activity. Correcting this and discussing potential interactions between soil pH and N/biostimulant uptake would improve accuracy.

5. Mechanistic Depth:

The discussion attributes biostimulant efficacy to "physiological efficiency" and "anatomical adaptation" but lacks mechanistic explanations (e.g., hormonal regulation, microbial community shifts). Incorporating hypotheses on how BIOS2 (protein hydrolysates) and BIOS3 (N-fixing bacteria) specifically enhance N uptake under low N could elevate the manuscript’s impact.

Anatomical findings (e.g., thicker leaves in BIOS3_RED) are intriguing but not linked to functional outcomes (e.g., photosynthetic capacity or water use efficiency). Connecting structural traits to physiological performance would strengthen their relevance.

It’s suggest to deepen Mechanistic Discussions by integrating literature on biostimulant-induced molecular pathways (e.g., N transporters, chlorophyll biosynthesis) to explain observed trends.

6. Fruit Quality Analysis:

Table 5 on fruit quality appears incomplete (e.g., truncated data for "Colour" and inconsistent formatting). The key processing traits (e.g., firmness, acidity, lycopene content, that are critical for processing tomatoes) should be analyzed to better assess the impact of treatments on marketability.

Author Response

Responses to Reviewer 2

This manuscript presents a well-designed two-year field study investigating the synergistic effects of biostimulants and reduced nitrogen (N) fertilization on processing tomato production. The research addresses critical gaps in sustainable agriculture by exploring strategies to enhance nitrogen use efficiency (NUE) while maintaining yield and quality, which aligns with global efforts to mitigate environmental impacts of excessive fertilization. Here are some concerns and suggestions for improvement:

Response: We sincerely thank the reviewer for the positive assessment of our research and the recognition of its relevance to sustainable agricultural practices. We appreciate the reviewer’s constructive feedback and valuable suggestions, which have helped us improve the clarity, depth, and presentation of the manuscript. Below, we address each point raised in detail.

1. Clarity in Biostimulant Characterization:

Table 2 provides limited details on BIOS1 (seaweed extract), such as active compounds or application rates, hindering comparability with other biostimulants (BIOS2 and BIOS3). Standardizing descriptions (e.g., concentration, mode of action) should be provided.

Response: Thank you for the observation. We have added the additional details for each biostimulant like its composition, concentration, and application rate, to ensure consistency and comparability. This standardization has also been reflected in the relevant text of the Materials and Methods section.

The source of BIOS2 (protein hydrolysates) is noted as a "by-product from agri-food industry" but lacks specifics (e.g., raw material, hydrolysis method), which could influence its efficacy and interpretation of results.

Response: We thank the reviewer for highlighting this important point. We agree that such information is essential for fully understanding and comparing the efficacy of biostimulants. However, the specific details regarding the raw material and hydrolysis method of BIOS2 were not disclosed by the supplying company. The product was provided solely for efficacy evaluation under experimental conditions, and the manufacturer did not authorize the release of further technical information. That is why we put in the manuscript that this is not a commercial product.  

1. Methods of Measurements：

The detailed methods to measure above-ground dry matter, total yield, marketable yield and leaf area index (LAI) should be provided.  

Response: Thank you very much for your valuable comment. We appreciate your suggestion and have accordingly included detailed descriptions of the procedures used to measure above-ground dry matter, total yield, marketable yield, and leaf area index (LAI) to enhance the clarity and reproducibility of the methodology. See section 2.2.1. Plant sampling line number 192.

1. Statistical and Interpretive Consistency:

While the manuscript acknowledges that biostimulant effects were "not consistently significant," it occasionally emphasizes trends (e.g., BIOS2 and BIOS3 outperforming BIOS1) without statistical support. Stricter distinction between significant results and anecdotal trends is needed to avoid overinterpretation.

Response: Thank you for your valuable observation. While we acknowledge that some biostimulant responses were not statistically significant, our intention was to highlight potential trends in their efficacy. We agree that it is important not to overinterpret such findings, and we have revised at some points in the manuscript to ensure that any mention of biostimulant performance is framed as a biological tendency rather than a statistically proven effect. We believe that, in certain cases, meaningful physiological or agronomic improvements may not always be captured by statistical tests but can still provide insight into the potential utility of biostimulants under reduced nitrogen conditions.

1. Environmental Contextualization:

Weather data (Figure 1) are critical for explaining interannual variability (e.g., stronger biostimulant effects in 2023), but the manuscript does not explicitly link specific climatic factors (e.g., rainfall patterns, temperature stress) to observed differences in plant performance. It’s suggest to link Climate to Results: Explicitly correlate 2023-2024 weather differences (e.g., rainfall post-transplantation) to observed phenotypic responses, explaining why biostimulants performed better under stress. Besides, quantifying stress indices (e.g., drought severity) would strengthen this connection.

Response: Thank you for this valuable suggestion. We have incorporated a discussion linking the climatic differences between the two growing seasons—particularly variations in rainfall and temperature—with the observed variability in biostimulant effectiveness. We acknowledge that while specific stress indices were not measured in this study, future research including such quantifications would enhance understanding of how environmental stress influences biostimulant performance. See lines 456-469.

Soil properties (Table 1) include pH as "8%" (likely a typo; should be 8.0), which may affect nutrient availability and biostimulant activity. Correcting this and discussing potential interactions between soil pH and N/biostimulant uptake would improve accuracy.

Response: Thank you for the valuable observation. We acknowledge the typographical error in Table 1, where pH was incorrectly reported as "8%". It has now been corrected to the appropriate unitless value of 8.0. We have also addressed the potential implications of soil pH on nutrient availability and biostimulant performance in the discussion section, as suggested. See lines 498-505.

1. Mechanistic Depth:

The discussion attributes biostimulant efficacy to "physiological efficiency" and "anatomical adaptation" but lacks mechanistic explanations (e.g., hormonal regulation, microbial community shifts). Incorporating hypotheses on how BIOS2 (protein hydrolysates) and BIOS3 (N-fixing bacteria) specifically enhance N uptake under low N could elevate the manuscript’s impact.

Response: Thank you for this insightful comment. We acknowledge the importance of including mechanistic insights to support the observed effects of the biostimulants. In response, we have expanded the discussion to include plausible hypotheses regarding how BIOS2 and BIOS3 may enhance nitrogen uptake under limited N conditions, drawing on known mechanisms such as hormonal modulation and microbial contributions. We believe this strengthens the manuscript’s scientific depth and relevance. See lines 516-529.

Anatomical findings (e.g., thicker leaves in BIOS3_RED) are intriguing but not linked to functional outcomes (e.g., photosynthetic capacity or water use efficiency). Connecting structural traits to physiological performance would strengthen their relevance.

Response: Thank you for your valuable suggestion. We have incorporated this point into the revised discussion section to strengthen the relevance of the anatomical findings. See lines 564-570.

It’s suggest to deepen Mechanistic Discussions by integrating literature on biostimulant-induced molecular pathways (e.g., N transporters, chlorophyll biosynthesis) to explain observed trends.

Response: Thank you for the valuable suggestion. We have deepened the mechanistic discussion by integrating relevant literature on biostimulant-induced molecular pathways, including key nitrogen transporters and enzymes involved in nitrogen uptake and chlorophyll biosynthesis, and linked these to the observed anatomical changes such as increased leaf thickness. This enhances the understanding of how biostimulants may improve physiological performance under reduced nitrogen conditions. See lines 578-586.

1. Fruit Quality Analysis:

Table 5 on fruit quality appears incomplete (e.g., truncated data for "Colour" and inconsistent formatting). The key processing traits (e.g., firmness, acidity, lycopene content, that are critical for processing tomatoes) should be analyzed to better assess the impact of treatments on marketability.

Response: Thank you for the insightful comment. Table 5 includes the key parameters measured in our study, specifically Brix, color, and fruit pH, which are important indicators of processing tomato quality. While data on additional traits such as firmness, acidity, and lycopene content were not collected in this experiment, we acknowledge their relevance and suggest including them in future studies to provide a more comprehensive assessment of fruit marketability.

 

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

All comments were captured to my satisfactory. 

Reviewer 2 Report

Comments and Suggestions for Authors

The manuscript has been extensively revised in response to the reviewers' suggestions. All issues raised have been thoroughly addressed, and there is no further comment at this momment.