Variation of Grain Yield, Grain Protein Content and Nitrogen Use Efficiency Components under Different Nitrogen Rates in Mediterranean Durum Wheat Genotypes

Round 1

Reviewer 1 Report

Dear authors

The following are limitations to this manuscript:

1- The article has errors that are noted in the text of the manuscript.

2- The materials and methods section contains insufficient information, including:

- This research contains two experimental factors, genotype, and nitrogen fertilizer use levels (a two-factor experimental design); thus, given the state of the treatments, it should be conducted as a split-plot based on a randomized complete block design which is not described in the manuscript.

- A two-year experiment was conducted, and a two-year analysis of combined data was performed. It should thus be explained in the materials and methods section.

- Is have been done the significant or non-significant source of changes (S.O.V) based on mathematical expectations? There is no explanation for it.

- How much of each plot's area was harvested to measure grain yield?

- The soil analysis results are reported for one of the years, but there is no information for the other year.

3- The errors in the tables and figures in the results and discussion section are described in the manuscript, and these problems should be corrected.

4- In the article's content, references to figures and tables include mistakes.

5- There are errors in the list of references, and references should be formatted according to the journal's guidelines.

Comments for author File: Comments.pdf

Author Response

Dear Reviewer, we answered in the attached file. Corrections and answers are in blue.

Author Response File: Author Response.docx

Reviewer 2 Report

Comments for author File: Comments.pdf

Author Response

Dear Reviewer, we answered in the attached file. Please see the attachment, corrections and answers are in blue.

Author Response File: Author Response.docx

Reviewer 3 Report

General comments

1.       Why use upper case for certain terms? E.g., L-25: use text in lower case e.g., “grain Yield”, “grain Protein Content”; L-29 “Crop N Supply” etc throughout the manuscript.

2.       Carefully check spelling and grammar to avoid mistakes e.g., L-58: “shown to ehibit”

3.       Delete the botanical name of wheat i.e., Triticum durum in L-77, as already defined in L-58.

4.       Thorough English revision is required to improve English Language.

5.       Rewrite the aim of study.

6.       Throughout the manuscript better use "experimental year", as the experiment was conducted from June-November for two consecutive years (2010 & 2011). This manuscript performed an inter-annual comparison, but not inter-seasonal comparison.

Specific Comments

L-60: define GY

“Beneficial effects on GY” of what?

L-63: add this text "higher nitrogen rate will extend the grain filling period and potentially increase the chances of abiotic stresses like drought and heat, increasing its vulnerability to changing climatic conditions

L-70:  kernel number per spike is under strict Genetic Control, however grain weight is significantly influenced by prevailing environmental conditions like temperature, moisture etc.

L-72, revise the text

L-77, is that staple food?

L-82: Rewrite the purpose of study. What is main growth?

L-83-84: closing bracket is missing.

L-84-88: “These varieties have been previously reported to exhibit significant differences in those enzymes involved in N metabolism, namely nitrate reductase (NR), glutamine synthetase (GS), glutamine oxoglutarate aminotransferase (GOGAT) and glutamate dehydrogenase (GDH), showing interesting performance upon N deprivation condition [23]. Shift to the Materials and Methods section, with cultivar description.

L-100-101: Please provide the complete address of the Lab, and mention institute/university, city and country.

L-101 and throughout the manuscript: “table” use first letter capital “Table”

L-102: Revise the text.

L-110: replace “fractions” with “splits”

L-112-113: what were the dimensions of experimental plot? (Length × Width) and how many total rows in each experimental unit?

L-13-14: Revise text as “Seed were manually sown…”

L-159-160: Revise the text.

L-157: remove duplication “TN = total nitrogen of soil“

Figure 2: add lettering to indicate statistical differences among the treatments                                                                                                                                       

L-220: is that experiment year or season? Better use experimental year throughout the manuscript, as the experiment was conducted from June-November for two consecutive years (2010 & 2011). This manuscript performed an inter-annual comparison, but not inter-seasonal comparison.

L-235: Revise the title of Table

L-364: in conclusion add some numerical data and percent change.

Suggested Citations

L 50:  Ata-Ul-Karim, S.T., Cao, Q., Zhu, Y., Tang, L., Rehmani, M.I.A., and Cao, W. (2016). Non-destructive Assessment of Plant Nitrogen Parameters Using Leaf Chlorophyll Measurements in Rice. Frontiers in Plant Science 7.

L 56: Ata-Ul-Karim, S.T., Zhu, Y., Cao, Q., Rehmani, M.I.A., Cao, W., and Tang, L. (2017). In-season assessment of grain protein and amylose content in rice using critical nitrogen dilution curve. European Journal of Agronomy 90, 139-151.

Author Response

Please see the attachment. Comments and revisions are in blue.

Author Response File: Author Response.docx

Reviewer 4 Report

Title

I would suggest the Author to change the title because it is quite long and not completely clear. The manuscript test durum wheat genotypes subjected to different nitrogen fertilization programs; this is not clear in the current title.

Abstract

Line 20 à Nitrogen is an important resource, while Nitrogen fertilizers are an agronomical tool necessary to support crop yield. This first sentence is not completely correct from an agro-ecological point of view I suggest to rewrite it.

Line 21 à represents

Line 25 à yield in low case letter, similarly protein content. You can decide or all word in high case letter and in all in low case letter. Be consistent.

The experimental design should be well reported in order to give a clear idea for the potential readers of the manuscript.

In my opinion, the conclusion does not reflect the goal of the manuscript and should be rewritten.

Introduction

Line 46 à here the letter are reported in low case, the authors should be consistent through the manuscript.

Line 58 à durum wheat could be better reported as Triticum durum Desf.

Please add the hypothesis of the manuscript

Materials and Methods

Line 100 à there is a double parenthesis please correct the mistake.

Line 104 à Durum wheat was cultivated from June to November, this sound not correct as in the Mediterranean environment as that of the manuscript durum wheat is a winter cereal and it is normally cultivated from autumn to spring season, especially under rainfed conditions. In the result section, the data reported a cultivation period from November to June, therefore, I suppose it is a mistake. Please check and in case explain why it was tested in summer period.

Line 113 please specify also the size of each plot

Results

Line 159 – 160 à please delete the sentence, this is already reported in M&M

Table 3 in the ANOVA results, it is missing the interaction effect of N x G and it is reported twice the interaction S x N. is it a mistake?

Discussion

Line 294 please report the reference as suggested in the guide of author. In this case name of the first author et al. [33]

Line 295 address the reference (see above)

Conclusion

Based on the results of this study could be possible to report that landrace genotypes could be also used in low input systems?

Author Response

Please see the attachment. Comments and revisions are in blue

Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

The article has been revised and improved, but there are still the following problems.

1. Line 168-169 Please add soil nitrogen and mineralized nitrogen data. The calculation of N use efficiency is expressed by a formula. 

2. There are some multiple comparison results of figures and tables in this article, and the use of letter marking method is wrong, please check it carefully.（figure 2 and table 4）

3.The conclusion should be simple and clear. The current content is too tedious. Please simplify it.

Author Response

Please see the attchment

Author Response File: Author Response.docx

Reviewer 3 Report

Authors have significantly improved the manuscript.

Current version of manuscript is acceptable, however, some minor corrections are required.

L-122: change "Seed were" to "Seeds were"

Figure 1, 2 & Table 4: also mention years i.e., 2010 & 2011 

In Figure 1, Temperature S1 & S2 are displayed using some function, better show trends of monthly temperature means without any log or function.

Best of luck

Author Response

Please see the attachment

Author Response File: Author Response.docx