Comparison of the Yield and Chemical Composition of Eleven Timothy (Phleum pratense L.) Genotypes under Three Locations in Poland

Round 1

Reviewer 1 Report

Confidential comments to the editor

The paper entitled “Comparison of the yield and chemical composition of 2 some timothy (Phleum pratense L.) genotypes under 3 diverse environmental conditions” by Radkowski et al. is well written and articulated and reports scientific information on the yield and chemical composition of 2 some timothy (Phleum pratense L.) genotypes under 3 diverse environmental conditions. The bibliographical reference base is well appropriate in all part of the manuscript. The authors have determined the main differences between timothy strains and cultivars in dry matter yield, jointly with the content of crude protein, crude fibre and macronutrients under diverse habitat conditions and analysed the genotype-by-environment interaction for observed quantitative traits. They observed that cultivars and strains varied substantially in the dry matter yield, crude protein content and crude fibre content, that the meteorological and habitat conditions contributed significantly to the differences between the cultivars and strains and that the content of the organic ingredients and minerals in the dry matter of the timothy strains and cultivars under analysis reflects their high value as a feed. They found a significant genotype-by-environment interaction.

The manuscript has been prepared in good way. The research methods were properly selected and the statistical procedures were adequate.

I am very satisfied by the work that the authors have carried out and I believe that their paper could be published in Agronomy after minor revision. In my opinion, there are just some points which I would like to see improved and a series of small punctuation points to revise before publication.

 

General and specific comments

In the Results, the authors describe the climate conditions of the experimental site. However, with regard to temperature, they refer to average temperature values, only. Why? In my opinion, it is very important to show maximum and minimum air temperature values in Table 2 in order to understand some physiological mechanisms and processes of timothy, such as the production of the crude fibre. The average temperature is a too much restrictive from a agronomic point of view and it does not give a complete information. I suggest the authors to modify Table 2 and to add minimum and maximum air temperature values. Furthermore the authors should correlate the results of climate with their findings and explain how temperatures and rainfall affected them. This is missin in the results and discussion.

 

Author Response

The paper entitled “Comparison of the yield and chemical composition of 2 some timothy (Phleum pratense L.) genotypes under 3 diverse environmental conditions” by Radkowski et al. is well written and articulated and reports scientific information on the yield and chemical composition of 2 some timothy (Phleum pratense L.) genotypes under 3 diverse environmental conditions. The bibliographical reference base is well appropriate in all part of the manuscript. The authors have determined the main differences between timothy strains and cultivars in dry matter yield, jointly with the content of crude protein, crude fibre and macronutrients under diverse habitat conditions and analysed the genotype-by-environment interaction for observed quantitative traits. They observed that cultivars and strains varied substantially in the dry matter yield, crude protein content and crude fibre content, that the meteorological and habitat conditions contributed significantly to the differences between the cultivars and strains and that the content of the organic ingredients and minerals in the dry matter of the timothy strains and cultivars under analysis reflects their high value as a feed. They found a significant genotype-by-environment interaction.

Response: Thank you very much.

 

The manuscript has been prepared in good way. The research methods were properly selected and the statistical procedures were adequate.

Response: Thank you very much.

 

I am very satisfied by the work that the authors have carried out and I believe that their paper could be published in Agronomy after minor revision. In my opinion, there are just some points which I would like to see improved and a series of small punctuation points to revise before publication.

Response: Thank you very much.

 

General and specific comments

In the Results, the authors describe the climate conditions of the experimental site. However, with regard to temperature, they refer to average temperature values, only. Why? In my opinion, it is very important to show maximum and minimum air temperature values in Table 2 in order to understand some physiological mechanisms and processes of timothy, such as the production of the crude fibre. The average temperature is a too much restrictive from a agronomic point of view and it does not give a complete information. I suggest the authors to modify Table 2 and to add minimum and maximum air temperature values. Furthermore the authors should correlate the results of climate with their findings and explain how temperatures and rainfall affected them. This is missin in the results and discussion.

Response: Table 2 has been modified and minimum and maximum temperatures have been added. Now, This Table is an Supplemetary Materials as a Table S1.

 

Author Response File: Author Response.doc

Reviewer 2 Report

The study includes a large dataset from two years field trials on three locations and with a sound methodology. It is also good that breeders publish and share such data. However, the presentation of the whole story need to be improved and shortened, and to rather focus on the patterns, relationships between traits and the main results, with a few figures and tables, and put the details as supplementary material. 

The tables are too many and very long compared to the content and what it gives the readers of Agronomy. Some of them can be presented as Supplementary material, like Table 2 on climate details and the large result tables. Table 3 with MS is not so interesting for the readers, rather focus on mean values of the parameters and provide significance level as stars as you do. I have problems with interactions when it comes to three and four levels of interactions, and how this shall be interpretated. 

The heatmaps are good, they tell much on the patterns on how the traits are inter-related. I think it could be a good idea to rather focus on the bigger picture and patters and attached the details as supplementary tables. 

The final comments and conclusions is a little too general or unclear to me. Conclusion 1 is not at all new, 2 and 3 are unclear and 4 does not give meaning, or tells nothing. 

The title is ok but instead om some tell how many and instead of diverse say three locations in Poland. By the way, it is not so diverse environmental conditions. 

There are more details:

• Soil type Table 1: I cannot believe podzol is the type on cultivated land, it is the natural original wild type, I would rather present the soil type regarding clay, silt, sand or so.
• On fertilizer, provide kg P and K per ha. 
• Provide references to all methods used, and statistical tools
• Make a separate section on yield assessment and quality analysis
• specify that year 1 of the timothy was 2018 and year 2 was 2019, so that this also comes into the discussion of the results - e.g. line 150-152.
• Some places you repeat yourself, eg in the introduction, line 44-45 and 49-50
• Some sentences are not needed as they do not tell much, as line 142-144.
• Some figures need more explaining in the caption, like fig 7

Author Response

The study includes a large dataset from two years field trials on three locations and with a sound methodology. It is also good that breeders publish and share such data. However, the presentation of the whole story need to be improved and shortened, and to rather focus on the patterns, relationships between traits and the main results, with a few figures and tables, and put the details as supplementary material.

Response: Thank you very much.

 

The tables are too many and very long compared to the content and what it gives the readers of Agronomy. Some of them can be presented as Supplementary material, like Table 2 on climate details and the large result tables. Table 3 with MS is not so interesting for the readers, rather focus on mean values of the parameters and provide significance level as stars as you do. I have problems with interactions when it comes to three and four levels of interactions, and how this shall be interpretated. The heatmaps are good, they tell much on the patterns on how the traits are inter-related. I think it could be a good idea to rather focus on the bigger picture and patters and attached the details as supplementary tables.

Response: Tables 2-6 are presented in Supplemetnary Materials as Tables S1-S5.

 

The final comments and conclusions is a little too general or unclear to me. Conclusion 1 is not at all new, 2 and 3 are unclear and 4 does not give meaning, or tells nothing.

Response: We corrected Conclusions section. New Conclusions: “On the basis of the results it can be concluded that the meteorological and habitat conditions contributed significantly to the differences between the cultivars and strains. Thus, the total protein content of plants was affected by air humidity. Lower humidity increased total protein content in grass, and phosphorus content was favourably affected by lower temperatures. Magnesium content was the only parameter not affected by water conditions. Based on the long-term observations reflected in a statistically significant genotype by the environment interaction, it was concluded that detailed observations must be continued to identify valuable strains. Agronomic characteristics are of particular importance in timothy breeding programmes. The content of organic ingredients and minerals in the dry matter of the timothy strains and cultivars studied in the experiment reflects their high value as a feed.”.

 

The title is ok but instead om some tell how many and instead of diverse say three locations in Poland. By the way, it is not so diverse environmental conditions.

Response: We corrected the title of manuscript. New title: “Comparison of the yield and chemical composition of eleven timothy (Phleum pratense L.) genotypes under three locations in Poland”.

 

There are more details:

 

Soil type Table 1: I cannot believe podzol is the type on cultivated land, it is the natural original wild type, I would rather present the soil type regarding clay, silt, sand or so.

Response: I accept the comment, and after a detailed analysis, I introduce an amendment.

 

On fertilizer, provide kg P and K per ha.

Response: Thank you for your attention, it has been corrected.

 

Provide references to all methods used, and statistical tools

Response: Thank you for your attention, the references has been inserted.

 

Make a separate section on yield assessment and quality analysis

Response: We divided Results section on sub-sections.

 

specify that year 1 of the timothy was 2018 and year 2 was 2019, so that this also comes into the discussion of the results - e.g. line 150-152.

Response: The year 1 of timothy was 2017, year 2 was 2018 and year 3 was 2019. We added more information in the manuscript.

 

Some places you repeat yourself, eg in the introduction, line 44-45 and 49-50

Response: We corrected manuscript and delated text: “The nutritive value of timothy is determined by controllable factors such as farming method, including harvest dates, selection of cultivars and fertilization, depending on the degree of maturity, as well as uncontrollable factors such as climate conditions.”.

 

Some sentences are not needed as they do not tell much, as line 142-144.

Response: We corrected text of manuscript and delated “In Tables 4-6, the statistics obtained are presented mean values and standard deviations for dry matter yield (Table 4), crude protein, crude fiber (Table 5), phosphorus, potassium, calcium, magnesium and sodium (Table 6), respectively.”

 

Some figures need more explaining in the caption, like fig 7

Response: We corrected description of Figures 1, 2, 3 and 7. New captions:

Figure 1. Heatmap for linear Pearson’ correlation coefficients between dry matter yield, crude protein, crude fiber, phosphorus, potassium, calcium, magnesium and sodium in first cut (r_cr = 0.19).

Figure 2. Heatmap for linear Pearson’ correlation coefficients between dry matter yield, crude protein, crude fiber, phosphorus, potassium, calcium, magnesium and sodium in second cut (r_cr = 0.19).

Figure 3. Heatmap for linear Pearson’ correlation coefficients between dry matter yield, crude protein, crude fiber, phosphorus, potassium, calcium, magnesium and sodium in third cut (r_cr = 0.19).

Figure 7. Density plots of the values of Mahalanobis distances, classified by the cuts. Mahalanobis distances were calculated on the basis of all observed traits: dry matter yield, crude protein, crude fiber, phosphorus, potassium, calcium, magnesium and sodium. The range of violins mean minimal and maximal values of Mahalanobis discances between studied genotypes for particular cuts. The points (crosses inside violins) are plotted along a line, with a kernel density smooth on either side to indicate the density of points along the line.

Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

Detailed and good edits.