Adaptation of Winter Wheat Cultivars to Different Environments: A Case Study in Poland

Round 1

Reviewer 1 Report

Comments to Authors

The study by Iwanska et al focused on the adaptation of winter wheat cultivars to different environments in Poland. Overall, I think it needs some major revisions before it could be acceptable for publication.  The major weakness of the study is that it was based only on a single year, with only two replications. Although the main objective is to develop a methodology per se, there should have been at least two years of field data, with more replications. Recommendations were also done based on a subset of only 29 winter wheat lines. Are these varieties adapted in the growing environments in the region? If so, I wonder if this sample size were already enough to make strong cultivar recommendations for efficient management for the whole country. Also, different parameters such as genotype specific reactions (GSR) were used to assess adaptation. I wonder how GSR is compared to other adaptability and stability measures such as Finlay-Wilkinson regression, AMMI stability indices, etc. Were there significant differences between the GSR values between the genotypes? These should be discussed in the manuscript. It might also be good to calculate FW and AMMI values for the datasets and make some comparisons.          

Other comments and suggestions:

1. Add more information in the Abstract, i.e. Conclusion and implication of the current study.
2. The Objectives were not clearly stated, I suggest revising them.
3. Lines 56-72 can be combined into a single paragraph.
4. Identify or mention rationale for each statistical analysis used.
5. Table 3: Define si, abij, m and bj in the footnotes and format Table 3 properly. Add more descriptions to the title.
6. Figure 1 is not clear- please add more description and improve figure captions. What does the regression line mean?
7. Figures 2 and 3: Captions and legends should be improved. Is the unit for average yield supposed to be in t/ha for Figure 3?
8. Table 5: Report as a Table, not a Figure and observe proper table formatting.
9. Line 355: Change section title to “The impact of environmental factors: soil and weather” as Soil was discussed first.
10. Section 4.2: Some of the sentences can be combined into a single paragraph, e.g. lines 366-369; 381-392. Please combine sentences into a single paragraph on other sections of the manuscript (i.e. avoid one sentence one paragraph structure).
11. What is voivodeships? It might be good to explain this term in the manuscript.
12. Table 6: Define GSR in the caption. Observe consistency in the Table format.
13. Remove period (.) in section titles, e.g. in Sections 2.2.1, 2.2.2, 2.2.3, etc.
14. Was GxE observed in the trials? If so, these should be quantified. An ANOVA table showing interaction between G and E would be ideal.
15. Observe proper formatting of references in the References section.

Author Response

Thank you very much for your thorough review of the manuscript and useful comments. We have corrected the required changes in the paper according to the comments. Below we respond to the comments and concerns addressed by the reviewers.

Some other minor language corrections were made in the manuscript and not highlighted.

Reviewer #1

• The study by Iwańska et al. focused on the adaptation of winter wheat cultivars to different environments in Poland. Overall, I think it needs some major revisions before it could be acceptable for publication. The major weakness of the study is that it was based only on a single year, with only two replications. Although the main objective is to develop a methodology per se, there should have been at least two years of field data, with more replications. Recommendations were also done based on a subset of only 29 winter wheat lines.

We thank the reviewer for these comments and suggestions. We agree that the results would have been stronger for a higher number of years and replications. Indeed the main objective of this paper was to propose new methodology for cultivar recommendation by considering the information of connected with environmental conditions and drought stress. The reasons for this approach to be based on one single year are: (i) often, the data available by researchers includes cultivars that are not repeated in consecutive years (this is the case for the COBORU research testing for variety testing); (ii) by including more than one year, many missing values would be included in the data and further strategies would need to be considered to generalize our proposal; and (ii) we were interested in proposing relevant methodology and conclusions/suggestions based on recent data that can be useful for practical use in polish plant breeding, instead of considering older data and a limited number of cultivars in a data set without missing values.

However, we do believe that this article introduces the basis for a long-term analysis taking into account weather conditions, and, therefore represents a valuable step in this direction.

Nevertheless, we intend to follow up on this suggestion and develop new methodology to analyze data collected along the time that can also account for missing values.

The limitations of the proposed methodology were highlighted in the conclusion.

• Are these varieties adapted in the growing environments in the region? If so, I wonder if this sample size were already enough to make strong cultivar recommendations for efficient management for the whole country. Also, different parameters such as genotype specific reactions (GSR) were used to assess adaptation. I wonder how GSR is compared to other adaptability and stability measures such as Finlay-Wilkinson regression, AMMI stability indices, etc. Were there significant differences between the GSR values between the genotypes? These should be discussed in the manuscript. It might also be good to calculate FW and AMMI values for the datasets and make some comparisons.

We thank the reviewer for this suggestion. The FW stability index and AMMI stability values were obtained and included and discussed in the context of the manuscript (Section 3.1, Table3; Section 4.3).

1. Add more information in the Abstract, i.e. Conclusion and implication of the current study.

The abstract was improved.

2. The Objectives were not clearly stated, I suggest revising them.

The objectives were revised to be made clearer.

3. Lines 56-72 can be combined into a single paragraph.

Done.

4. Identify or mention rationale for each statistical analysis used.

The missing rationale for statistical analyses was supplemented in Sections 2.2.1. and 2.2.2.

5. Table 3: Define si, abij, m and bj in the footnotes and format Table 3 properly. Add more descriptions to the title.

The symbols ai, bj, abij were added to the title of the table (in parentheses after their meaning), while the explanation of m was added to the footnote.

6. Figure 1 is not clear- please add more description and improve figure captions. What does the regression line.

Done.

7. Figures 2 and 3: Captions and legends should be improved. Is the unit for average yield supposed to be in t/ha for Figure 3?

The caption of Figure 2 was improved. Figure 3 was removed according to suggestion of other reviewer, as it did not include much added value to the manuscript.

8. Table 5: Report as a Table, not a Figure and observe proper table formatting.

Done.

9. Line 355 (: Change section title to “The impact of environmental factors: soil and weather” as Soil was discussed first.

Done.

10. Section 4.2: Some of the sentences can be combined into a single paragraph, e.g. lines 366-369; 381-392. Please combine sentences into a single paragraph on other sections of the manuscript (i.e. avoid one sentence one paragraph structure).

Done.

11. What is voivodeships? It might be good to explain this term in the manuscript.

That is right, the voivodeships is official translation for the first level's administrative units in Poland, but it might be confusing indeed. We replace voivodeships by province in the whole manuscript.

12. Table 6: Define GSR in the caption. Observe consistency in the Table format.

Done.

13. Remove period (.) in section titles, e.g. in Sections 2.2.1, 2.2.2, 2.2.3, etc.

Done.

14. Was GxE observed in the trials? If so, these should be quantified. An ANOVA table showing interaction between G and E would be ideal.

Yes, it was GxE experiment with explanatory data for environments. We only had the adjusted means for genotypes yields for each location and management level. Thus we didn’t have any replications and therefore the error term in the ANOVA analysis can’t be computed.

15. Observe proper formatting of references in the References section.

Done.

Reviewer 2 Report

I enjoyed reviewing this manuscript as this subject is of great interest to me. The methodology appears sound as well as the 1-2-3 strategy that summarizes how adaptation might be estimated and cultivar recommendations made.

My biggest criticism would be that, in my opinion, cultivar adaptation cannot be determined without sampling performance over multiple years as year to year variation is often of equal to or greater than location to location variation, at least in water limited environments. L29-30 states that productivity within environments is mainly conditioned by soil and that it is relatively stable over time. In my experience (in water-limited environments), this statement is not true.

The LS variable as I interpret it is a historical assessment of soil productivity based on specific soil parameters and historical assessment of crop productivity. In all models I would expect soil productivity to be positively related to crop productivity.

Strong review of applicable literature.

I think the authors did a great job in the one year study to develop methodology to assess cultivar adaptability and suggest that cultivar recommendations could be made using such methodology. However, it is my opinion that the authors have extrapolated results beyond this intended purpose by suggesting recommendations could or should be made based on the single year study. The one year study lessens the validity of any conclusions made in regards to adaptation.

The the observation that increased pH in the 4.9 to 7.0 range is concerning given Al toxicity often reduces wheat yield in many parts of the world. Given this observation in the current study this should be further addressed in the discussion. Potentially this could also be causal to part of the cultivar x location interaction, as some cultivars likely would perform better than others at the loe pH sites.

A few specific suggestions:

L55 define BBCH

Table 1. Define voivodshop and the quantitative variables presented in columns  4, 5, and 7. How do the variables (LS and DL) in Table 2 relate to Table 1?

Would you expect the response curve reported in Fig. 1 to be the same or similar if compared to a similar analysis conducted in another year? I would expect variation in precipitation and air temperature to vary significantly across years.

Fig. 2 Use different symbols to differentiate average yield from estimated yield rather than symbol color.

Fig. 3 Not very useful to try to present all cultivar response patterns on a single figure. Delete? or present representative cultivars denoting different types of response.

L303 Missing cultivar name

L326 'lower requirements regarding agrotechnology' many other possible explanations for specific cultivars.

Author Response

Thank you very much for your thorough review of the manuscript and useful comments. We have corrected the required changes in the paper according to the comments. Below we respond to the comments and concerns addressed by the reviewers.

Some other minor language corrections were made in the manuscript and not highlighted.

1. My biggest criticism would be that, in my opinion, cultivar adaptation cannot be determined without sampling performance over multiple years as year to year variation is often of equal to or greater than location to location variation, at least in water limited environments.

We thank the reviewer for these comment and suggestion. We agree that the results would have been stronger for a higher number of years and replications. Indeed the main objective of this paper was to propose new methodology for cultivar recommendation by considering the information of connected with environmental conditions and drought stress. The reasons for this approach to be based on one single year are: (i) often, the data available by researchers includes cultivars that are not repeated in consecutive years (this is the case for the COBORU research testing for variety testing); (ii) by including more than one year, many missing values would be included in the data and further strategies would need to be considered to generalize our proposal; and (ii) we were interested in proposing relevant methodology and conclusions/suggestions based on recent data that can be useful for practical use in polish plant breeding, instead of considering older data and a limited number of cultivars in a data set without missing values.

However, we do believe that this article introduces the basis for a long-term analysis taking into account weather conditions, and, therefore represents a valuable step in this direction.

Nevertheless, we intend to follow up on this suggestion and develop new methodology to analyze data collected along the time that can also account for missing values.

The limitations of the proposed methodology were highlighted in the conclusion.

2. L29-30 states that productivity within environments is mainly conditioned by soil and that it is relatively stable over time. In my experience (in water-limited environments), this statement is not true.

We meant that soil properties are relatively stable in time (excluding catastrophic events, such as flood or extreme erosion). We improved the text to clarify its meaning

3. The LS variable as I interpret it is a historical assessment of soil productivity based on specific soil parameters and historical assessment of crop productivity. In all models I would expect soil productivity to be positively related to crop productivity.

Actually, LS is a historical assessment of soil suitability for main crops, but it is still valid and strongly related to wheat (and other crops) productivity (see table 5 and improved respective part of results and discussion).

4. Strong review of applicable literature.

We did not understand whether this was a statement or a request. However, we included a couple of extra references in the manuscript.

5. I think the authors did a great job in the one year study to develop methodology to assess cultivar adaptability and suggest that cultivar recommendations could be made using such methodology. However, it is my opinion that the authors have extrapolated results beyond this intended purpose by suggesting recommendations could or should be made based on the single year study. The one year study lessens the validity of any conclusions made in regards to adaptation.

We refer to our answer to the first comment above for detailed explanation.

6. The observation that increased pH in the 4.9 to 7.0 range is concerning given Al toxicity often reduces wheat yield in many parts of the world. Given this observation in the current study this should be further addressed in the discussion. Potentially this could also be causal to part of the cultivar x location interaction, as some cultivars likely would perform better than others at the low pH sites.

We agree with the reviewer’s view. However, the methodology of COBORU trials is outside our influence. These trails are carried out mainly on soils suitable for wheat, because rye and triticale are preferred on weaker soils. Please remember, that the pH was measured in 1M KCl extract, so it is about 0.5 to 1 pH unit lower than pH measured in water. As consequence, in such soils the Al effect is neglible. It is clear indeed, that Al toxicity is one of the most important factors limiting wheat and other crops' productivity, however our study is not designed to assess the effect of Al on wheat or to assess the Al tolerance of wheat cultivars.

A few specific suggestions:

1. L55 define BBCH.

The BBCH scale is used to identify the phenological development stages of plants. BBCH-scales have been developed for a range of crop species where similar growth stages of each plant are given the same code. Phenological development stages of plants are used in a number of scientific disciplines (crop physiology, phytopathology, entomology and plant breeding) and in the agriculture industry (risk assessment of pesticides, timing of pesticide application, fertilization, agricultural insurance). The BBCH-scale uses a decimal code system, which is divided into principal and secondary growth stages, and is based on the cereal code system (Zadoks scale) developed by Zadoks. The abbreviation BBCH derives from the names of the originally participating stakeholders: "Biologische Bundesanstalt, Bundessortenamt und CHemische Industrie". Allegedly, the abbreviation is said to unofficially represent the four companies that initially sponsored its development; Bayer, BASF, Ciba-Geigy, and Hoechst.

2. Table 1. Define voivodshop and the quantitative variables presented in columns 4, 5, and 7. How do the variables (LS and DL) in Table 2 relate to Table 1?

We replaced voivodeship by province, to make it clearer. The voivodship is official translation of województwo, which is the Polish name of the first level administration unit in Poland

3. Would you expect the response curve reported in Fig. 1 to be the same or similar if compared to a similar analysis conducted in another year? I would expect variation in precipitation and air temperature to vary significantly across years.

Actually, we did similar graphs for Spearman;s rank coefficient between wheat yield and HTC, P and T for the years 2015, 2016, 2017 and 2018, both separately and mean for 2015-2016 period. This graphs were presented in scientific conference (Iwańska and Stępień 2019, [12] and it can be found here https://www.researchgate.net/publication/336209712_The_effect_of_soil_and_course_of_weather_conditions_during_the_growth_and_maturation_of_winter_wheat_on_yields_in_multi-environmental_trials), and are also discussed in present paper. We added some additional discussion of this aspect in the section 4.2:

4. 2 Use different symbols to differentiate average yield from estimated yield rather than symbol color.

Done.

5. 3 Not very useful to try to present all cultivar response patterns on a single figure. Delete? or present representative cultivars denoting different types of response.

Done.

6. L303 Missing cultivar name.

Corrected.

7. L326 'lower requirements regarding agrotechnology' many other possible explanations for specific cultivars.

We agree. We revised the text to give this as just one example of possible explanation.

Reviewer 3 Report

Dear Authors,

I appreciate the Content and results of your manuscript very much, nevertheless here are some suggestions for small corrections:

Line 28   22% -  should be written together

Line 36 to line 38: I would skip this sentence, because I doubt that this suggestion is practically realistic - and to my personal opinion it is not necessesary. 

Line 73: the knowledge of their response to …. 

Line: 75/76:..., being their effect... etc.….  ….this part of the sentence I cannot really understand. 

Maybe you want to say:

Environmental conditions include both soil and weather factors, the average yield of all cultivars of a given crop in a given location expresses their effect on the crop.

Line 76: The yield of a particular cultivar…. 

Line 89: …., and to elaborate a simple method….

Table 1: .. column 5: Average arable land suitability in points in the district to which the location belongs

Table 2, line 1: "second" - line 2 "2nd" - always use 2nd 

Table 2, line 5: April 10th and July 10th  (skip the)

Line 200... indicates a mean difference… 

Table 3: please explain all abbreviations from the list again in the header of the table. I think that each table should be readable by itself.

Maybe one could shorten the table - as MIM and HIM are the same numbers, just with different direction +/- - HIM alone would be enough. 7,7 m and -0,504 and +0,504 can be explained in the Header only - then you can Maybe make two or three columns with the varieties and shorten the table.

Line 224: The influence of HTC was positive or negative, independent of the period of the time, so......

Line 234: The response of winter wheat to the HTC index… ….  A negative...

Line 237/238: In contrast, a positive relashionship...

Figure 1. Decades influence….   ..?? on which trait? HTC? Figure 1 description is lacking information.

Line 250: this should be (Table 4). .. not (Table 3).

Figure 2: Estimatedaverage yield in Trial Locations based on .........… Explanation of the figure is not enough…  please repeat Explanation like in the text 

Figure 3 and Table 5 show identical information. If you add the Information on environmental average yield (t) to Table 5, you can skip Figure 3.

Table 5: Table description is lacking Information in abbreviations, what does 4,5,6 mean (I know it from Fig. 3 that this is probably Environmental average yield and from the text that this was obviously calculated by equation 1b) - please Mention everything in the table description. what means what? Specify that the table is sorted in descending order for yield at the highest management intensity level - or most productive environments, this is at 10 t per ha.

Include GSR into the Explanation of Figure 3. Explain not only the varieties but also the traits. I think it is better to skip Fig. 3 anyhow; Table 5 is more easy to read. Is there colour print possible? Maybe you can mark it with different amounts of grey - to avoid Colour print??

Line 315: … similar to the respective difference.. 

Line 318: A significant effect…. 

Line 329: , which were applied at HIM, and not at MIM Level, ...

Line 332 … cultivar by management interaction 

Line 333.... it may be useful in for recommendation ...

Line 347: ..in the current study.. better: in this study, the 10 Points assigned to the LS group.... 

Line 349: yield of the main cereals… 

Line 351: Currently, the Progress in the Technology used in Agriculture... led to an increase of yield...

Line 359: indicate a signifant and negative... 

Line 362: HTC in the last ten days of May and the first ten days of June....

Line 367: showed a negative relationship… 

Line 370 and 372: A negative coefficient … A negative effect....

Line 377: reducing the wheat yield by an amount ranging... 

Line 381-384 - I did not understand in the first place.

Suggestion: In conrast, a positive coefficient in the ANCOVA analysis for HTC indicates a decrease of yield, along with a low amount of HTC indicating water dificit and hence drought (Table 4). The lower the value of the HTC index, the greater will be the decrease of yield in the respective period.

Line 384: The  A positive Impact of HTC was noted…. ... of April, which corresponded... 

Line 389: During the third decade of May the lowest values of HTC significantly reduded wheat yield by an amount ranging from 0,0...

Line 397: Impact of drought on the winter wheat yield.. 

Line 399... determined in the 60-day-periods.... 

Line 400: CWB reported for Shorter periods, e.g. decades, would….

Line 407: Why were the five highest yielding cultivars chosen? Were they significantly higher yielding than the mean yield? Is there any "objective" reason for just five?

Table 5 does not give very much Information - it is mostly empty. I would appreciate ranking of the varieties in all the groups - and you may highlight the Top ranked genotypes in bold.

Line 432: … as follows…. 

Line 449: near to the heading… …., especially in early spring, i.e. during tillering, and during the ripening.

Line 451: calculated from precipitation… 

Line 453: in 60-day periods….

Line 455: ..., we propose a genotype specific…. 

Line 456: for the recommendation of a cultivar for environments of a determined wheat productivity level. 

I like the conclusions line 457-459! 

Line 460: .. farmers having long term experience, whose…. yield… expected on their farms….

Line 462: … then select the best-adapted cultivar for the respective wheat productivity level and also for their specific agrotechnology level.

Maybe, it is possible to shorten down some of the explanations and especially the refers to references. Maybe, just put them into parenthesis when discussing something similar based on your data.

It would be fine if you could include some more statistical Parameters in order to know the results of which genotypes are significantly different from  the others in the lists.

Good luck for improvement and good luck for publication!

Hopefully, some additional reviewers can help you more and better!

Best regards,

Franziska Löschenberger

Author Response

Thank you very much for your thorough review of the manuscript and useful comments. We have corrected the required changes in the paper according to the comments. Below we respond to the comments and concerns addressed by the reviewers.

Some other minor language corrections were made in the manuscript and not highlighted.

AUTHORS: We agree, we revised as requested:

1. Line 28   22% -  should be written together.

Done.

2. Line 36 to line 38: I would skip this sentence, because I doubt that this suggestion is practically realistic - and to my personal opinion it is not necessesary. 

Done.

3. Line 73: the knowledge of their response to …. 

Done.

4. Line: 75/76:..., being their effect... etc.….  ….this part of the sentence I cannot really understand. 

Done.

5. Maybe you want to say: Environmental conditions include both soil and weather factors, the average yield of all cultivars of a given crop in a given location expresses their effect on the crop.

Done.

6. Line 76: The yield of a particular cultivar…. 

Done.

7. Line 89: …., and to elaborate a simple method….

Done.

8. Table 1: .. column 5: Average arable land suitability in points in the district to which the location belongs

Done.

9. Table 2, line 1: "second" - line 2 "2nd" - always use 2nd 

Done.

10. Table 2, line 5: April 10th and July 10th  (skip the)

Done.

11. Line 200... indicates a mean difference… 

Done.

12. Table 3: please explain all abbreviations from the list again in the header of the table. I think that each table should be readable by itself.

Done.

13. Maybe one could shorten the table - as MIM and HIM are the same numbers, just with different direction +/- - HIM alone would be enough. 7,7 m and -0,504 and +0,504 can be explained in the Header only - then you can Maybe make two or three columns with the varieties and shorten the table.

We thank the review for this suggestion. In this case, we decided to keep the full table as we included two competing stability measures (the FW regression coefficient and the AMMI  stability measure) for comparison purposes.

14. Line 224: The influence of HTC was positive or negative, independent of the period of the time, so......

Done.

15. Line 234: The response of winter wheat to the HTC index… ….  A negative...

Done.

16. Line 237/238: In contrast, a positive relationship...

Done.

17. Figure 1. Decades influence…. ..?? on which trait? HTC? Figure 1 description is lacking information.

The caption of the figure was improved.

18. Line 250: this should be (Table 4). .. not (Table 3).

Done.

19. Figure 2: Estimated average yield in Trial Locations based on .........… Explanation of the figure is not enough… please repeat Explanation like in the text.

We improved the figure caption for an easier in interpretation.

20. Figure 3 and Table 5 show identical information. If you add the Information on environmental average yield (t) to Table 5, you can skip Figure 3.

Figure 3 was removed.

21. Table 5: Table description is lacking Information in abbreviations, what does 4,5,6 mean (I know it from Fig. 3 that this is probably Environmental average yield and from the text that this was obviously calculated by equation 1b) - please Mention everything in the table description. what means what? Specify that the table is sorted in descending order for yield at the highest management intensity level - or most productive environments, this is at 10 t per ha.

We improved the table caption and we added respective explanation to the footnote.

22. Include GSR into the Explanation of Figure 3. Explain not only the varieties but also the traits. I think it is better to skip Fig. 3 anyhow; Table 5 is more easy to read. Is there colour print possible? Maybe you can mark it with different amounts of grey - to avoid colour print??

We did remove Figure 3. Table 5 was kept in a similar shape to fulfil the journal guidelines.

23. Line 315: … similar to the respective difference..

Done.

24. Line 318: A significant effect….

Done.

25. Line 329: , which were applied at HIM, and not at MIM Level, ...

Done.

26. Line 332 … cultivar by management interaction

Done.

27. Line 333.... it may be useful in for recommendation ...

Done.

28. Line 347: ..in the current study.. better: in this study, the 10 Points assigned to the LS group....

Done.

29. Line 349: yield of the main cereals…

Done.

30. Line 351: Currently, the Progress in the Technology used in Agriculture... led to an increase of yield...

Done.

31. Line 359: indicate a signifcant and negative...

Done.

32. Line 362: HTC in the last ten days of May and the first ten days of June....

Done.

33. Line 367: showed a negative relationship…

Done.

34. Line 370 and 372: A negative coefficient … A negative effect....

Done.

35. Line 377: reducing the wheat yield by an amount ranging...

Done.

36. Line 381-384 - I did not understand in the first place.

Done.

37. Suggestion: In contrast, a positive coefficient in the ANCOVA analysis for HTC indicates a decrease of yield, along with a low amount of HTC indicating water dificit and hence drought (Table 4). The lower the value of the HTC index, the greater will be the decrease of yield in the respective period.

Done.

38. Line 384: The A positive Impact of HTC was noted…. ... of April, which corresponded...

Done.

39. Line 389: During the third decade of May the lowest values of HTC significantly reduded wheat yield by an amount ranging from 0,0...

Done.

40. Line 397: Impact of drought on the winter wheat yield..

Done.

41. Line 399... determined in the 60-day-periods....

Done.

42. Line 400: CWB reported for Shorter periods, e.g. decades, would….

Done.

43. Line 407: Why were the five highest yielding cultivars chosen? Were they significantly higher yielding than the mean yield? Is there any "objective" reason for just five?

We had to choose a given number of top cultivars and did indeed a subjective decision to choose the top-five cultivars.

44. Table 5 does not give very much Information - it is mostly empty. I would appreciate ranking of the varieties in all the groups - and you may highlight the Top ranked genotypes in bold.

Done.

45. Line 432: … as follows….

Done.

46. Line 449: near to the heading… …., especially in early spring, i.e. during tillering, and during the ripening.

Done.

47. Line 451: calculated from precipitation…

Done.

48. Line 453: in 60-day periods….

Done.

49. Line 455: ..., we propose a genotype specific….

Done.

50. Line 456: for the recommendation of a cultivar for environments of a determined wheat productivity level.

Done.

51. I like the conclusions line 457-459!

Thank you!

52. Line 460: .. farmers having long term experience, whose…. yield… expected on their farms….

Done.

53. Line 462: … then select the best-adapted cultivar for the respective wheat productivity level and also for their specific agrotechnology level.

Done.

54. Maybe, it is possible to shorten down some of the explanations and especially the refers to references. Maybe, just put them into parenthesis when discussing something similar based on your data.

Done.

55. It would be fine if you could include some more statistical Parameters in order to know the results of which genotypes are significantly different from the others in the lists.

We thank the reviewer for this suggestion. The FW stability index and AMMI stability values were obtained and included and discussed in the context of the manuscript (Section 3.1, Table3; Section 4.3).

We thank again the reviewer for such a detailed analysis and revision of our manuscript!

Round 2

Reviewer 1 Report

Significant improvements in the manuscripts have been done by the authors and I believe the manuscript will be acceptable for publication after considering some more suggestions.

It would be good to add the author’s response on why the study was based on just a single year in the Discussion section. Table 5 with the color codes also seems unclear to me; maybe we could include the color coding in the table description to make the table less confusing. Finally, I see the relevance of the current study for recommendations of cultivars based on some parameters, but its importance might be more realized when data is based on multiple years. Nonetheless, I think this would be a good starting point for us.       

Some minor comments:

1. Please revise lines 83-85 as these did not read clear to me.
2. Lines 102-104 might not be necessary to mention anymore and could instead be deleted.
3. Remove period (.) at the end of the section headings.
4. Line 241: replace “to” with “the”.
5. Line 292: replace “locantion” with “location”.
6. Line 299: “Triangles are the observed yield at the lower…” should be included in the caption for Figure 2.
7. The use of the term “decade” in the manuscript is confusing. I think it might be better to use other term to describe the “10-day periods” as mentioned in Table 4 and other parts of the manuscript.
8. Lines 435-445 could be combined into a single paragraph.
9. For Table 7, I suggest that ***, **, and * notations be used to indicate significance at P < 0.0001, 0.001, and 0.05, respectively, instead of reporting the actual p-value for the pairwise correlation coefficients. You may also place a dash (-) on the blank cells of the table.   

Author Response

Thank you very much for your thorough review of the manuscript and useful comments. We have addressed the required comments and made the corresponding changes in the enclosed manuscript. Below we respond to the comments and concerns addressed by the reviewer.

Some other minor language corrections were made in the manuscript and not highlighted.

Reviewer #1

• Significant improvements in the manuscripts have been done by the authors and I believe the manuscript will be acceptable for publication after considering some more suggestions. It would be good to add the author’s response on why the study was based on just a single year in the Discussion section.

We thank the reviewer for the suggestion. We added the following text to the end of the discussion:

The main limitation of our study is that it was based on single year. However, the main  objective of this paper was to propose new methodology for cultivar recommendation by considering the information of connected with environmental conditions and drought stress. The reasons for this approach to be based on one single year are: (i) often, the data available to researchers includes cultivars that are not repeated in consecutive years (this is the case for the COBORU research testing for variety testing); (ii) by including more than one year, many missing values would be included in the data and further strategies would need to be considered to generalize our proposal; and (iii) we were interested in proposing relevant methodology and conclusions/suggestions based on recent data that can be useful for practical use in polish plant breeding, instead of considering older data and a limited number of cultivars in a data set without missing values. However, we do believe that this article introduces the basis for a long-term analysis taking into account weather conditions, and, therefore represents a valuable step in this direction. Nevertheless, as future development, we intend to develop new methodology to analyze data collected along the time that can also account for missing values.

• Table 5 with the color codes also seems unclear to me; maybe we could include the color coding in the table description to make the table less confusing.

The caption of Figure 5 was updated. Now it reads:

Genotype specific reaction (GSR) in environments of determined productivity ranging from 4 to 10 t/ha. The row position in the table indicates relative productivity of a particular cultivar in comparison to the other cultivars. The intensity of shading informs the type and degree of winter wheat cultivar adaptation to environment productivity. The green color indicates high and positive reaction of cultivar while red means low and negative reaction in the environment of the specified productivity.

• Finally, I see the relevance of the current study for recommendations of cultivars based on some parameters, but its importance might be more realized when data is based on multiple years. Nonetheless, I think this would be a good starting point for us.  

We thank the reviewer for this support to our work

• Please revise lines 83-85 as these did not read clear to me.

This paragraph was revised.

• Lines 102-104 might not be necessary to mention anymore and could instead be deleted.

Done.

• Remove period (.) at the end of the section headings..

Done.

• Line 241: replace “to” with “the”.

Done.

• Line 292: replace “locantion” with “location”.

Done.

• Line 299: “Triangles are the observed yield at the lower…” should be included in the caption for Figure 2.

Done.

• The use of the term “decade” in the manuscript is confusing. I think it might be better to use other term to describe the “10-day periods” as mentioned in Table 4 and other parts of the manuscript.

We agree. We have replaced the term “decade” by “10-day periods” in the whole manuscript.

• Lines 435-445 could be combined into a single paragraph.

Done.

• Table 5: Report as a Table, not a Figure and observe proper table formatting.

Done.

• For Table 7, I suggest that ***, **, and * notations be used to indicate significance at P < 0.0001, 0.001, and 0.05, respectively, instead of reporting the actual p-value for the pairwise correlation coefficients. You may also place a dash (-) on the blank cells of the table.

Done.