Applying Biostimulants to Combat Water Deficit in Crop Plants: Research and Debate
, Alba E. Hernándiz 2,3, Sarai Morales-Sierra 4, Ana L. GarcÃa-GarcÃa 1, Francisco J. GarcÃa-Machado 1, Juan C. Luis 4 and Andrés A. Borges 1,*Round 1
Reviewer 1 Report
This article contains interesting research on the use of biostimulants. The analyses conducted in the paper are extensive and sufficient for a research article. The topic of biostimulants is extremely important in the context of the need to adapt crops to climate change. However, I have some minor comments to help improve the manuscript:
The main weakness of the paper is the discussion and conclusion sections. The discussion lacks a broader comparison of the results obtained by the authors to previous world studies. Please expand this significantly. Furthermore, the conclusion chapter is short and does not highlight the main results and conclusions of the authors' research. Please add the main conclusions resulting from your analyses - what and how the use of biostimulants affects.
The abstract lacks the main conclusions of the authors' study.
In the introduction, I suggest a slight expansion of the description regarding Glycine betaine and L-Pyroglutamic acid.
Editorial Notes:
Each word should be capitalized according to the journal guidelines in the title.
In Table 2, please add units of measurement to the parameters described.
Please format all text to journal requirements. Please remember to use superscripts for units such as m3.
Author Response
Dear reviewer 1, many thanks for your comments, we have used them to improve the manuscript.
This article contains interesting research on the use of biostimulants. The analyses conducted in the paper are extensive and sufficient for a research article. The topic of biostimulants is extremely important in the context of the need to adapt crops to climate change. However, I have some minor comments to help improve the manuscript:
The main weakness of the paper is the discussion and conclusion sections. The discussion lacks a broader comparison of the results obtained by the authors to previous world studies. Please expand this significantly. Furthermore, the conclusion chapter is short and does not highlight the main results and conclusions of the authors' research. Please add the main conclusions resulting from your analyses - what and how the use of biostimulants affects.
Discussion and conclusions are improved following your recommendations, see highlighted in yellow
The abstract lacks the main conclusions of the authors' study.
In the introduction, I suggest a slight expansion of the description regarding Glycine betaine and L-Pyroglutamic acid.
We cannot add more information about the Pyroglutamic acid, at the moment only the mentioned manuscript is already published, this is the second proper assay using this compound.
Editorial Notes:
Each word should be capitalized according to the journal guidelines in the title.
Done
In Table 2, please add units of measurement to the parameters described.
Done
Please format all text to journal requirements. Please remember to use superscripts for units such as m3.
Done
Reviewer 2 Report
Article ID: agronomy-1600559-peer-review-v1
Title: Applying biostimulants to combat water deficit in crop plants: Research and debate
Abstract:
This section lacks the results obtained in this study. The introductory sentences are too long relative to the whole abstract.
Materials and Methods:
Table 1: I want to understand... How is the irrigation at 80% of the field capacity is deficit irrigation by 20% compared to the control that has irrigation at 95% of the field capacity. Logically, if the control is 95% of the field capacity, the deficit irrigation at 20% is the irrigation at 76% of the field capacity. is not it?
Discussion:
I do not feel that there is a depth in explaining the optimization mechanisms of the biostimulants used.
General:
There are grammatical errors throughout the manuscript.
Author Response
Dear reviewer 2, thanks for your comments and suggestion after reading our manuscript. We have changed the text following your considerations
Abstract:
This section lacks the results obtained in this study. The introductory sentences are too long relative to the whole abstract.
Fixed follow your comments and now the results are added to abstract see highlighted in yellow
Table 1: I want to understand... How is the irrigation at 80% of the field capacity is deficit irrigation by 20% compared to the control that has irrigation at 95% of the field capacity. Logically, if the control is 95% of the field capacity, the deficit irrigation at 20% is the irrigation at 76% of the field capacity. is not it?
Our treatment was using 100% field capacity, that was a mistake and we change the the numerical details of the irrigation levels in the table and text
Discussion:
I do not feel that there is a depth in explaining the optimization mechanisms of the biostimulants used.
We have added a new paragraph to the Discussion section, following your recommendations
General:
There are grammatical errors throughout the manuscript.
We sent it for text editing by a native speaker.
Reviewer 3 Report
Comments on the manuscript “Applying biostimulants to combat water deficit in crop plants: Research and debate” by David Jiménez-Arias et al.
The abstract describes the rationale reasonably well and the methodology very briefly. But there is no summary of the actual findings. This needs to be included.
General comments: There are occasional typographical errors and formatting inconsistencies throughout the document, including units (e.g. °, m2), inconsistent capitalization, and missing spaces. The authors should review these carefully and correct where needed.
Line 34 – the word “count” should be “account.”
Lines 43-45 – Why were these global regions in particular highlighted while others were left out? For example, why was eastern North America mentioned while the drought-ravaged western part of the continent left out? Eastern North America is actually expected to receive more precipitation as a result of climate change patterns.
Line 55 – Citing a “forthcoming publication” without details is not useful or recommended.
Line 95 – What cultivar of maize, specifically?
Line 108 – Is it necessary to send the reader to another paper to the get methods for this paper? Can the authors at least provide some summary details instead of writing “as previously described” and sending the reader to find the methods elsewhere?
Line 120 – The abbreviation “RGR” has not been defined.
Line 139 – Details? When? Where?
Line 149 – The soil is 27% slime? How about silt?
Line 166 – What is “obs”?
Line 207 – Is the Student’s t-test (please correct this name in the text) the appropriate tool for an experiment that seems to have three main treatments (two biostimulants and a control) and two sub-treatments (the two water regimes)? If repeated t-tests are being used for all comparisons, then a correction to maintain the desired error level is needed. No alpha level for significance is presented.
Line 213 – PEG abbreviation should be capitalized.
Line 215 – “doses dependent” should be “dose-dependent.”
Line 218 – Please review this text and correct: “…to increase the tolerance by a 77%. to the water deficit.”
Line 240 – Should be: “Biostimulants are capable of ameliorating negative effects…”
Line 263 – The word “Length” is misspelled in the table. Also, the authors write that “p<0.05” at the bottom of the table. If this is based on repeated t-tests, then the p value is higher than this. These datasets really should be subjected to ANOVA based on the design that’s been described above.
Line 273 – While most readers would likely know what “WUE” means, all abbreviations should be defined at first mention. Please check all abbreviations in the document to ensure this is the case.
Line 279 – What is “R.W.C”? And why are there periods after the first two of the three letters? Help the reader out by explaining abbreviations and being consistent. Clarity is important!
Line 310 – The word “Flour” is misspelled. And the statistical test is not shown with the p-value. And repeated t-tests would not seem appropriate for this design.
Line 368 – It seems that chemical symbols could be used for minerals (Ca, Mg)
Author Response
Dear reviewer 3, thank you for your comments and your effort in reviewing the paper which we have found very useful to improve it.
Comments on the manuscript “Applying biostimulants to combat water deficit in crop plants: Research and debate” by David Jiménez-Arias et al.
The abstract describes the rationale reasonably well and the methodology very briefly. But there is no summary of the actual findings. This needs to be included.
General comments: There are occasional typographical errors and formatting inconsistencies throughout the document, including units (e.g. °, m2), inconsistent capitalization, and missing spaces. The authors should review these carefully and correct where needed.
Line 34 – the word “count” should be “account.”
Done
Lines 43-45 – Why were these global regions in particular highlighted while others were left out? For example, why was eastern North America mentioned while the drought-ravaged western part of the continent left out? Eastern North America is actually expected to receive more precipitation as a result of climate change patterns.
The reference is about areas with high socioeconomic risk due to climate change, but we think it is better to change it to this sentence:
Drought is considered the greatest threat to farmers growing field crops, the frequency and severity of which has increased worldwide
Reference:
He, Y.; Fang, J.; Xu, W.; Shi, P. Substantial Increase of Compound Droughts and Heatwaves in Wheat Growing Seasons Worldwide. International Journal of Climatology n/a, doi:10.1002/joc.7518.
Line 55 – Citing a “forthcoming publication” without details is not useful or recommended.
Sorry for that, it was a mistake, we put it in the first draft but forgot to change it, we replace it with [8]:
Carson PhD, R.S., ESEP “Not in My Backyard” Is Not Sustainable. INCOSE International Symposium 2017, 27, 1749–1766, doi:10.1002/j.2334-5837.2017.00460.x.
Line 95 – What cultivar of maize, specifically?
A local forage variety of maize from Gran Canaria Island (Zea mays L. c.v. Lechucilla)
Line 108 – Is it necessary to send the reader to another paper to the get methods for this paper? Can the authors at least provide some summary details instead of writing “as previously described” and sending the reader to find the methods elsewhere?
Relative growth rate (RGR) [27], RGR = (ln DW 2-ln DW 1 )/(t2-t1 ), where DW 1 and DW 2 were seedling dry weights at times t1 and t2 (t1 was the beginning of water deficit and t2 the end of the water deficit). Plant water-use efficiency (WUE) considering all the water used over the experiment time-span, WUE = plant biomass/water used [29], and the weight reduction with respect to control, were each calculated using the well-watered untreated plants.
Line 120 – The abbreviation “RGR” has not been defined.
Defined as relative growth rate
Line 139 – Details? When? Where?
We clarify using the following sentence.
average weight of grains per cob and the average number of cobs (Table 2) were used to calculate the total grain mass per ha using as a reference 50,000 maize plants per hectare (Table 3). The result obtained was used to calculate the grain water-use efficiency (WUEg), as the ratio of the mass of grain produced to the water use throughout the growing period [31]
Line 149 – The soil is 27% slime? How about silt?
Changedto silt
Line 166 – What is “obs”?
Fixed by cobs
Line 207 – Is the Student’s t-test (please correct this name in the text) the appropriate tool for an experiment that seems to have three main treatments (two biostimulants and a control) and two sub-treatments (the two water regimes)? If repeated t-tests are being used for all comparisons, then a correction to maintain the desired error level is needed. No alpha level for significance is presented.
As suggested by the reviewer, we performed an ANOVA test:
Statistical analyses for growth experiments were performed by one-way ANOVA (α=0.05). The significance of differences between experimental groups was calculated using a Tamhane post-hoc test.
Line 213 – PEG abbreviation should be capitalized.
Done
Line 215 – “doses dependent” should be “dose-dependent.”
Done
Line 218 – Please review this text and correct: “…to increase the tolerance by a 77%. to the water deficit.”
After the continuous spelling mistakes we decided to have a new text edition by an English native speaker
Line 240 – Should be: “Biostimulants are capable of ameliorating negative effects…”
Done
Line 263 – The word “Length” is misspelled in the table. Also, the authors write that “p<0.05” at the bottom of the table. If this is based on repeated t-tests, then the p value is higher than this. These datasets really should be subjected to ANOVA based on the design that’s been described above.
We perform an ANOVA test as suggested by the reviewer
Line 273 – While most readers would likely know what “WUE” means, all abbreviations should be defined at first mention. Please check all abbreviations in the document to ensure this is the case.
Now this is defined and explained in material and methods, line 107.
. Plant water-use efficiency (WUE) considering all the water used over the experiment time-span, WUE = plant biomass/water used [29], and the weight reduction with respect to control, were each calculated using the well-watered untreated plants.
Line 279 – What is “R.W.C”? And why are there periods after the first two of the three letters? Help the reader out by explaining abbreviations and being consistent. Clarity is important!
Now R.W.C. is defined as relative water content in materials and methods sections line 144
We have changed the axis name in figure 3A to the entire name to be consistent
Line 310 – The word “Flour” is misspelled. And the statistical test is not shown with the p-value. And repeated t-tests would not seem appropriate for this design.
We perform an ANOVA test as suggested by the reviewer
Line 368 – It seems that chemical symbols could be used for minerals (Ca, Mg)
Done
Round 2
Reviewer 2 Report
- For my comment "This section lacks the results obtained in this study. "The introductory sentences are too long relative to the whole abstract". The authors misunderstood. I mean the introductory sentences (lines 20-28) of the abstract (not in the introduction) are too long relative to the whole abstract. Also, authors did not responded to the comment "The abstract lacks the results obtained in this study".
Author Response
Thanks for your comments, we change try to change the abstract following your indications:
Climate change has increased the severity of drought episodes by further reducing precipitation in vulnerable zones. Drought induces a substantial decrease in agricultural water, reducing crops yields. Consequently, addressing water consumption could increase farmers profits. This work describes lab-to-field research in Zea mays, using two biostimulants: glycine betaine (GB) and L-pyroglutamic acid (PG). The biostimulant optimal dosages were selected using a hydroponic system with 20% PEG and nursery experiments under water-deficit irrigation. The established dosages were evaluated in field trials in which irrigation was reduced by 20%. Laboratory biostimulants optimisation showed in stressed treated seedlings (GB 0.1 mM; PG 1 mM) an increased dry weight, RGR and water use efficiency, reducing seedlings growth loss between 65 and 85%, respectively. Field trials using GB optimised dosage showed an increase in plants growth, grain yield and flour Ca content. In addition, grain flour carbohydrate content and protein remain similar to control well-watered plants. Finally, the economic aspects of biostimulant treatments, water consumption, water sources (ground vs desalinated) and grain biomass were addressed. Overall, GB treatment demonstrated to be a valuable tool to reduce water consumption and improve farmers’ earnings.
Reviewer 3 Report
The authors have addressed all issues.
Author Response
Thanks for your comments, the manuscript was revised by a native speaker
