Review Reports
- Nelson Ceballos-Aguirre1,
- Alejandro Hurtado-Salazar1,* and
- Gloria M. Restrepo2
- et al.
Reviewer 1: Xiaoyu Wang Reviewer 2: Anonymous Reviewer 3: Anonymous
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsIn this manuscript, authors have assessed the technical and economic viability of a bacterial suspension of Gluconacetobacter diazotrophicus applied to tomato cultivation. In this study, native G. diazotrophicus GIBI025 and GIBI029 isolates were evaluated, with commercial strains of Azotobacter chrococcum and Azospirillium sp. serving as control. Some issues should be addressed before publication. I just noted some instance here, authors should check and amend throughout the manuscript.
1, Authors often cite other studies, e.g., line 38, yet provide no reference. What are these studies?
2, Some sentences are too long and convoluted. For instance, lines 40-43, “Tomato production in Colombia represents a significant opportunity for rural development due to the suitability of the tropics for this agriculture, extensive cultivation knowledge, and the involvement of numerous producers, primarily small-scale farmers, and family-owned operations.”
3, Some abbreviations appeared without their full name, For instance, line 141, What do DYGS and LGI-P stand for?
4, There is only one Figure in this manuscript. Authors should consider to replace some tables, e.g., tables 4 and 5, with figures.
5, Repetition numbers and statistic analysis methods should be described in details in the section of “Methods and Materials”.
6, Results of significance analysis should be presented in tables and Figures. For instance, I can get the significance analysis results in the Table 5.
7, In this study, authors employed the commercial strains of Azotobacter chrococcum and Azospirillium sp. as control. It is fine. But the tomato plants without biofertilization treatment should be included as a negative control.
8, For the biofertilizer concentration, authors only employed one concentration 1×108 CFU·mL-1. Its rational should be explained. What is the situation for the treatment with other concentrations of biofertilizers?
9, Watering conditions for the Macro tunnel should be described.
Comments on the Quality of English LanguageSome sentences are too long and convoluted. For instance, lines 40-43, “Tomato production in Colombia represents a significant opportunity for rural development due to the suitability of the tropics for this agriculture, extensive cultivation knowledge, and the involvement of numerous producers, primarily small-scale farmers, and family-owned operations.”Author should catefully rephrase these sentences.
Author Response
Reviewer 1
- “Authors often cite other studies, e.g., line 38, yet provide no reference. What are these studies?”
Answer: Thanks Reviewer 1 for his/her recommendations. All the first paragraph, including line 38, is based on information from reference [1] (https://www.fao.org/faostat/en/#data/QCL). We have therefore added this reference number at the end of the paragraph. In addition, we have revised the whole manuscript to avoid missing references.
- Some sentences are too long and convoluted. For instance, lines 40-43, “Tomato production in Colombia represents a significant opportunity for rural development due to the suitability of the tropics for this agriculture, extensive cultivation knowledge, and the involvement of numerous producers, primarily small-scale farmers, and family-owned operations.”
Answer: Reviewer 1 is right. Therefore, we have modified this text in order to avoid this long and convoluted sentence (lines 40-43). We have also revised the whole text to identify and simplify this type of complex sentences.
- “Some abbreviations appeared without their full name, For instance, line 141, What do DYGS and LGI-P stand for?”
Answer: These abbreviations were deciphered (see lines 145-146 in the revised version of the manuscript). In particular, the initials of the LG medium come from its author, Dr. Jacob Goodale Lipman. In the case of the LGI medium, the 'I' corresponds to the name of the researcher J. Ivo Baldani, who adapted the medium. Finally, the LGI-P medium was developed from the previous one, where the 'P' corresponds to the state of Pernambuco (Brazil).
- “There is only one Figure in this manuscript. Authors should consider to replace some tables, e.g., tables 4 and 5, with figures.”
Answer: According to Reviewer 1’s suggestion, we have replaced the former Table 4 with the new Figure 2. However, we consider that replacing the former Table 5 (now Table 4) with a figure can lead to a loss of details about the production costs.
- “Repetition numbers and statistic analysis methods should be described in details in the section of “Methods and Materials”.
Answer: We have reorganized and complemented the information about the repetitions numbers and statistical analysis (see lines 154-156 and 214-219). In addition, we have deleted one repeated sentence at the beginning of Section 2.4.
- “Results of significance analysis should be presented in tables and Figures. For instance, I can get the significance analysis results in the Table 5.”
Answer: The results of the significance analysis are now presented in Figure 2 (formerly Table 4). Based on these findings, the economic analysis was conducted by calculating the indicators outlined in Section 2.5. For Table 5, mean tests were not performed due to the substantial weight of the yield variable results, which are sufficient for deriving applicable recommendations regarding economic viability. Consequently, a statistical analysis of the economic parameters was not necessary. Moreover, the biological phenomenon associated with bacterial application can be explained through an analysis of variance and mean tests applied to the yield components throughout the cultivation cycle.
- “In this study, authors employed the commercial strains of Azotobacter chrococcum and Azospirillium sp. as control. It is fine. But the tomato plants without biofertilization treatment should be included as a negative control.”
Answer: In this study, negative control was included. This negative control corresponds to the treatment Farmer-100N (see Table 2 and lines 159-160 and 171-173). Precisely, this treatment represents the conventional fertilization of the farmer when biofertilization is not applied. To improve readability, we replaced or clarified the term “conventional fertilization (farmer’s standard)” with “negative control” in most cases. The last line of Table 2 was also modified to illustrate that this negative control does not involve the addition of any bacteria. We apologize for the lack of clarity regarding this negative control.
- “For the biofertilizer concentration, authors only employed one concentration 1×108 CFU·mL-1. Its rational should be explained. What is the situation for the treatment with other concentrations of biofertilizers?”
Answer: We have used a commercial bacterial inoculant with a concentration of 1×108 UFC/mL. For the native isolates, we have used the same concentration, consistent with the average concentration of bioinputs registered in the Colombian Agricultural Institute, the governmental agency regulating the commercialization of inoculants for agriculture in Colombia. This concentration also matches that of the commercial control, as mentioned above. In previous work using the standard G. diazotrophicus ATCC 49037 strain, a bacterial suspension of this strain with a concentration of 88×106 UFC/mL (about 9×107 UFC/mL, comparable to 1×108 UFC/mL) was applied, resulting in the highest dry weight for tomato seedlings compared to other bacterial concentrations (see reference [30]).
- “Watering conditions for the Macro tunnel should be described.”
Answer: According to this recommendation, the irrigation conditions were described in a more detailed way (see lines 204-209).
“Some sentences are too long and convoluted. For instance, lines 40-43, “Tomato production in Colombia represents a significant opportunity for rural development due to the suitability of the tropics for this agriculture, extensive cultivation knowledge, and the involvement of numerous producers, primarily small-scale farmers, and family-owned operations.”Author should catefully rephrase these sentences.”
Answer: We agreed with Reviewer 1. Therefore, we have modified this text in order to avoid this long and convoluted sentence (lines 40-43). Thus, we have also revised the whole text to identify and simplify this type of complex sentences.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for AuthorsIn the Abstract:
Line 23-25: This is unclear. Conventional control is conventional fertilizer treatment. Merge these two sentences into one, and specify the type/chemical properties of applied N fertilizer.
Line 26: Explain which additional nutrients are applied, or omit this from the abstract.
Line 27-29: More results should be included in the abstract along with a stronger conclusion.
In the Introduction:
Line 82: Which plant species?
Lines 98-101: This is already stated in the lines 86-89.
In the Materials and Methods:
Line 128: Replace “Microorganisms” with “Bacteria”
Line 132: Include chemical properties for MAP; 12% and 61% of what?
Line 141: Replace with “Preparation of bacterial suspensions”
Line 142: Check the incubation time; explain how the commercial inoculum was prepared.
Lines 151-152: Here it is unclear whether the isolates are applied jointly or individually.
Line 159: Amounts and concentrations of bacterial inocula/suspensions are given, but the application method should also be explained in more detail.
Lines 164-166: Include the methods for soil chemical analysis, explain the results of this analysis and specify which nutrients exactly are added based on this analysis.
Line 172: Include the column with other nutrients necessary for balanced fertilization in Table 2.
In the Results:
Figures: Explanation for treatments is missing in Tables 4, 5, and 6. Write full names for applied bacteria, or explain the treatments in table notes.
In the Discussion:
Lines 335-336: Gluconoacetobacter diazotroficus – G. diazotroficus
Line 368: “Azotobacter” – Azotobacter
Lines 382-383: Why this research did not include smaller proportions of N fertilizers in addition to 100% conventional control? At least include in the discussion previous studies related to replacement of mineral N sources with nitrogen-fixing microorganisms.
In the Conclusion:
Line 385: Include the code for isolate code for G. diazotrophicus.
Lines 388-389: “provided that the soil contains sufficient nutrient reserves” – please explain this in more detail
In the References:
Several references (e.g., 13-16, 33, 41, 44) should be updated, if possible.
Author Response
Reviewer 2
“In the Abstract:
Line 23-25: This is unclear. Conventional control is conventional fertilizer treatment. Merge these two sentences into one, and specify the type/chemical properties of applied N fertilizer.
Line 26: Explain which additional nutrients are applied, or omit this from the abstract.
Line 27-29: More results should be included in the abstract along with a stronger conclusion.”
Answer: The abstract was reorganized, and unnecessary sentences were removed. The conventional control was clarified in the abstract text. The nitrogenous fertilizers used were specified. The conclusions in the abstract were strengthened. We hope that the final version of the abstract is clearer, more concise, and with stronger conclusions, considering the limit of 200 words. We apologize for the lack of clarity in the previous abstract.
“In the Introduction:
Line 82: Which plant species?
Lines 98-101: This is already stated in the lines 86-89.”
Answer: The other plant species were specified in lines 90-91. The text of lines 86-69 in the original manuscript was deleted.
“In the Materials and Methods:”
Line 128: Replace “Microorganisms” with “Bacteria”
Answer: The recommendation of Reviewer 2 was taken into account in the revised manuscript (line 133).
“Line 132: Include chemical properties for MAP; 12% and 61% of what?”
Answer: The percentages of ammonium and P2O5 in MAP were specified (lines 174-175).
Line 141: Replace with “Preparation of bacterial suspensions”
Answer: The recommendation of Reviewer 2 was taken into account in the revised manuscript (line 143).
Line 142: Check the incubation time; explain how the commercial inoculum was prepared.
Answer: The incubation time was corrected; we apologize for this error in the original manuscript. In addition, a sentence was added to indicate how the inoculum was prepared (lines 147-148).
Lines 151-152: Here it is unclear whether the isolates are applied jointly or individually.
Answer: The sentence enumerating the four treatments was rewritten to clarify that the isolates were applied individually (lines 157-160).
Line 159: Amounts and concentrations of bacterial inocula/suspensions are given, but the application method should also be explained in more detail.
Answer: The text describing the preparation and application of bacterial suspensions was rewritten and complemented (lines 166-170).
“Lines 164-166: Include the methods for soil chemical analysis, explain the results of this analysis and specify which nutrients exactly are added based on this analysis.
Line 172: Include the column with other nutrients necessary for balanced fertilization in Table 2.”
Answer: The methods for soil chemical analysis were included in lines 178-188. In addition, the usefulness of the results from soil analysis with the indication of the nutrients added based on this analysis was included in lines 191-195 and Table 2, as recommended by Reviewer 2.
“In the Results:
Figures: Explanation for treatments is missing in Tables 4, 5, and 6. Write full names for applied bacteria, or explain the treatments in table notes.”
Answer: The treatments were explained in the caption of Figure 2 (formerly Table 4) and in the notes of Tables 4 and 5 (formerly Tables 5 and 6, respectively).
“In the Discussion:
Lines 335-336: Gluconoacetobacter diazotroficus – G. diazotroficus
Line 368: “Azotobacter” – Azotobacter”
Answer: The italicized abbreviated name of the bacterium was included in lines 396-397, and the correct name of the bacterium cited was presented in line 428. We apologize for these errors.
Lines 382-383: Why this research did not include smaller proportions of N fertilizers in addition to 100% conventional control? At least include in the discussion previous studies related to replacement of mineral N sources with nitrogen-fixing microorganisms.”
Answer: This work corresponds to the first phase of the research on the development of a plant-growth-promoting preparate based on G. diazotrophicus for tomatoes and other vegetables. The utilization of smaller proportions of nitrogen fertilizers in interaction with other factors will be addressed in future work intended for the optimization of bacterial application conditions. Considering Reviewer 2’s recommendations, we have added some comments on previous studies related to the replacement of mineral nitrogen with G. diazotrophicus and other nitrogen-fixing bacteria in the Discussion section (see lines 442-454).
“In the Conclusion:
Line 385: Include the code for isolate code for G. diazotrophicus.”
Lines 388-389: “provided that the soil contains sufficient nutrient reserves” – please explain this in more detail”
Answer: The codes of the isolates were included in line 459. The sentence about the nutrient reserves was deleted because it was confusing. Instead of this sentence, we have added a short text clarifying the conditions for which this conclusion is valid (lines 462-463).
“In the References:
Several references (e.g., 13-16, 33, 41, 44) should be updated, if possible.”
Answer: The references cited, particularly [13-16] and [33], represent foundational studies elucidating the occurrence and characteristics of G. diazotrophicus. Specifically, the Brazilian works are widely recognized as pioneering contributions to the research on this bacterial species.
Author Response File: Author Response.pdf
Reviewer 3 Report
Comments and Suggestions for AuthorsThe article with the title „ Technical and Economic Assessment of Tomato Cultivation through a Macro Tunnel Production System with the Application of Gluconacetobacter diazotrophicus” has the aim to to assess the technical and economic viability of a bacterial suspension of Gluconacetobacter diazotrophicus applied to tomato cultivation.
Some recommendations are highlighted below:
The abstract should be rephrased to be comprehensive especially please see rows 26-29.
In the introduction section you could add some results from the same experimental system macro tunnel.
In the material and methods, it is necessary to write the mean temperature if you tested in controlled conditions?
Rows 178-179: The irrigation duration was adjusted according to the plant’s phenological stage- please insert a table with the water volume applied for each developmental stages.
Provide all details to make the research design replicable by someone else.
Table 4: Please insert the measurement unit for fruits for plant. Also please insert all explanation below table in the table footer to make it standing alone.
Table 5 The economic efficiency should be highlighted in the table
Author Response
Reviewer 3
“The abstract should be rephrased to be comprehensive especially please see rows 26-29.”
Answer: The abstract was reorganized, and unnecessary sentences were removed. The conclusions in the abstract were strengthened. Particularly, we have changed lines 26-29 of the abstract in the original manuscript. We hope that the final version of the abstract is clearer, more concise, and with stronger conclusions, considering the limit of 200 words. We apologize for the lack of clarity in the previous abstract.
“In the introduction section you could add some results from the same experimental system macro tunnel.”
Answer: Reviewer 3 is right. Therefore, we have added a paragraph presenting some results from the macro tunnel system itself in conjunction with the addition of plant-growth-promoting bacteria (see lines 67-75).
“In the material and methods, it is necessary to write the mean temperature if you tested in controlled conditions?”
Answer: We provided the mean temperature of the site in line 131, considering that the temperature was not estrictilly controlled during the cultivation in macro tunnels. For this reason, we stated that the average temperature within the macro tunnel was 3.67°C higher than the ambient temperature (lines 201-202). In fact, our research was conducted under semi-controlled conditions.
“Rows 178-179: The irrigation duration was adjusted according to the plant’s phenological stage- please insert a table with the water volume applied for each developmental stages.”
Answer: According to this recommendation, the irrigation conditions were described in a more detailed way (see lines 204-209). We have decided to provide this additional information in the text to not increase the overall number of tables in the manuscript.
“Provide all details to make the research design replicable by someone else.”
Answer: We have added more information in the Materials and Methods section in order to make the research design replicable by someone else. For this, we have clarified and complemented the information provided in Section 2.4 (see lines 154-160, 166-170, 171-175, 178-188, 191-195, 204-209, 214-219, and the fourth column in Table 2).
“Table 4: Please insert the measurement unit for fruits for plant. Also please insert all explanation below table in the table footer to make it standing alone.”
Answer: Table 4 was replaced with Figure 2 considering the recommendation of other reviewer. To consider and combined suggestions of the two reviewers (Reviewer 3 and Reviewer 1), we have added the explanatory text in the figure caption to make it standing alone (see lines 259-267). This same approach was applied in the footers of Tables 4 and 5 (formerly, Tables 5 and 6). For the variable “fruits per plant”, the measurement unit is the tomato fruit itself, i.e., the amount of tomato fruits produced during the production cycle. We have added the “tomato” word in line 257 in an attempt to clarify this type of units.
“Table 5 The economic efficiency should be highlighted in the table”
Answer: The economic efficiency is referred in this work to the economic indicators calculated for the macro tunnel production system. Table 5 in the original manuscript (now renamed Table 4) is intended to show the total production costs per hectare corresponding to each one of the treatments assessed. From this table, the total production costs were extracted (see last row in Table 4) and transferred into the third column of Table 5 (formerly, Table 6). In this last table, the main economic indexes calculated as indicators of economic efficiency were presented: net income, unit value of production, benefit/cost ratio, and rate of return.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
Comments and Suggestions for AuthorsAuthors have addressed my concerns in the revision.
Reviewer 2 Report
Comments and Suggestions for AuthorsThe authors acknowledged all suggestions and made corrections to the manuscript. The new version of the manuscript is acceptable for publication.