Direct and Joint Effects of Genotype, Defoliation and Crop Density on the Yield of Three Inbred Maize Lines

Round 1

Reviewer 1 Report

The topics discussed in the article have a practical aspect that is important for maize seed producers. The article „The Direct and Joint Effects of the Genotype, Environment, and the Crop Density on the Yield Loss of Maize Inbred Lines in Different Defoliation Treatments „ concern the analysis of factors influencing the yield of maize hybrids depending on: genotypes (inbred lines), environment, and cultivation practices used.
The methodological description and interpretation of the results are
detailed and comprehensive. Several aspects of the article need
clarification and correction:
1. The meteorological data presented needs to be revised and corrected:
- In Figure 1 a. on the axis (OX) the description of months should be rearranged, and the data should be verified (checked) .
-The axis of graphs should be described, and ranges of presented values should be unified for both graphs (e.g. for temperature 0- 30 ^oC, and for precipitation e.g. 0-160 mm).
-I propose to change the way the data is presented: precipitation should be presented as a bar chart, while temperature as a line graph.
2. The authors should more extensively describe and explain why the G3 genotype responded with such a large reduction in grain yield in the adverse year of 2017  compared to  the genotypes G1 and G2? What could have caused the reduction in grain yield? 
3. Table 1 (line 145-146) needs clarification and possible improvement, „Analysis of variance for grain yield, kernel rows number, kernel number per rows, ear length, 1000-kernel weight, germination (ANOVA)” lacks the analysis (results) for germination although this parameter is mentioned in the table description and statistical calculations are given under the table
(f. R Squared = .339 (Adjusted R Squared = .011).
4. In Table 3, I propose in statistical analyses - instead of standard deviation, the authors should present the coefficient of variation, which will better describe the variability of the analyzed variants. Also, in Table 3, N should be changed  to No in the description.
5. In conclusion, I propose to present in more detail the effect of
different environmental conditions (rainfall) on seed yield
production with an indication of which genotype is the most
stable in yield.

Author Response

Response to Reviewer 1 Comments

 

Point 1. The meteorological data presented needs to be revised and corrected:

- In Figure 1 a. on the axis (OX) the description of months should be rearranged, and the data should be verified (checked) .

-The axis of graphs should be described, and ranges of presented values should be unified for both graphs (e.g. for temperature 0- 30 ^oC, and for precipitation e.g. 0-160 mm).

-I propose to change the way the data is presented: precipitation should be presented as a bar chart, while temperature as a line graph.

 

Response 1:

We are thankful to the reviewer for noticing this mistake charts have been corrected for all proposed points:

- in Figure 1, the months were rearranged and the data were checked,

- the axis is described and the range of the axis is equal for both figures,

- the display mode has been changed: precipitation is shown as a bar and temperatures as lines.

 

Point 2. The authors should more extensively describe and explain why the G3 genotype responded with such a large reduction in grain yield in the adverse year of 2017 compared to  the genotypes G1 and G2? What could have caused the reduction in grain yield?

 

Response 2:

 

Authors: In the chapter “3.2. Seed yield in trial variants”, after the sentence that ends with “...significant reduction in yield.”, the following is added: According to data, G3 responded with a large reduction in grain yield in the unfavourable year of 2017 compared to the genotypes G1 and G2. The reason for this may be that G3 has a longer growing season that the remaining two inbred lines, thus grain filling in this inbred under conditions of drought in 2017 ceased earlier than in G1 and G2.

 

Point 3. Table 1 (line 145-146) needs clarification and possible improvement, „Analysis of variance for grain yield, kernel rows number, kernel number per rows, ear length, 1000-kernel weight, germination (ANOVA)” lacks the analysis (results) for germination although this parameter is mentioned in the table description and statistical calculations are given under the table (f. R Squared = .339 (Adjusted R Squared = .011).

 

Response 3:

-the title has been rearranged to be clearer,

- the word germination was deleted as well as the given results, because they were not included in this manuscript.

 

Point 4. In Table 3, I propose in statistical analyses - instead of standard deviation, the authors should present the coefficient of variation, which will better describe the variability of the analyzed variants. Also, in Table 3, N should be changed  to No in the description.

 

Response 4:

According to the reviewer's suggestion:

-the standard deviation has been changed to variance,

-in Table 3 ( after review table 5.) N has not been changed to N₀, because N denotes the sample size. The statistical symbol used for sample size is N.

Point 5. In conclusion, I propose to present in more detail the effect of different environmental conditions (rainfall) on seed yield production with an indication of which genotype is the most stable in yield.

 

Response 5:

Authors have accepted this suggestion: Conclusion has been expanded with  more details about the effect of different environmental conditions (rainfall) on seed yield production. Also, the genotype with the most stable in yield is emphasised.  The following sentences were added: Environmental conditions, especially those related to rainfall, were more unfavourable for the maize production in 2017 than in 2016, which resulted in significantly lower yields obtained in E3 and E4 than in E1 and E2.  The rank of genotypes by yields (G2 - 5549.4 kg/ha, G1 - 5186.3 kg/ha and G3 - 4791.3 kg) deviated, to some extent, from the rank of genotypes by yield stability, based on values of their coefficients of variation (G1 - 33.07%, G2 - 47.80% and G3 - 71,48%).  

Reviewer 2 Report

The research topic is very interesting and may have great importance in maize production.  This manuscript contains many valuable results.  However, the manuscript is sometimes hard to read. I am not a native English speaker, so I advise to have the paper checked with a native English speaker. 

Title: Title is too long and not correct. Please, correct and try to summarize it. A suggestion: Direct and joint effects of genotype, defoliation and crop density on the yield of three inbred maize lines

Abstract: The first sentence is not clear. Does it come from your results or is a literature statement? Please, restructure the abstract. The first sentence should be introduction/ the significance of the study or the aim of the study. Do not start with information about your findings.

Line 16: Not clear what the authors mean under “four ecological conditions of the environment”. Please be specific. What is the difference among the four environments?

Key words: Do not repeat expressions/words which are used in the title.

Introduction

Line 50, 59, 61, 64 etc. Not necessary to write out the year of publication when the serial number of publication is in a bracket. Please delete the years of publications throughout the manuscript.

Line 60. Please correct: … Mo17, and Os420…

Line 67-68: The sentence is not clear. Please rewrite.

Line 71-73. Please rewrite. The sentence is not clear.

Materials and Methods

Line 92-93: I do not agree that the authors had four different environments. The experiment was carried out for two years, in two locations with different soil types. So, they can evaluate the year and location/environment effect. Authors can use “environment” instead of locations, but they did not study four different environments. I understand that the weather conditions were different for the years, but this is a year effect not impacts of “ecological environment”. Furthermore, authors did not examine ecological effects because ecology is the study of the relationships between living organisms, including humans, and their physical environment. So, avoid to use the environment expression in this study.

This is an agriculture based study so do not use expressions which are connecting to ecology.

Line 96: Please delete ‘respectively’

Line 107: Did the authors determine or measure the parameters? My guess is, they measured them, so please be specific. Which kind of balance was used to measure the weight? How was the moisture content measured? How was the ear length measured and with what? (e.g.ruler?)

Line 108: Why do you use AM as an abbreviation of kernel weight? I suggest to use KW.

Please present the data of soil analysis for both years and both locations.

Add the treatments in a table format for a better understanding.

Line 110: Please use Precipitation and temperature data – because authors did not presents all meteorological conditions e.g.  number of sunny days, heat sum, etc.

Line 111-112. This sentence does not connect to the MM section. Please move this to Results.

Line 15-16: Move the second part of the sentence in Results. (…,whereby…)

Line 119-120: Move this to Results section.

Line 123-135: Please indicate literary reference(s) for the used statistical methods.

Results

Line 136: The title of this section is confusing. Authors used some literary references in here so they should use Results and Discussion.

Line 142-143: Please add reference here.

Line 175: Please put at the end of the sentence: …in this study.

I would encourage the authors to use more literary references in this part of their paper.

Line 191: Please correct: Average yield (kg/ha) of … if it is correct that the numbers are averages.

Table 1. Please indicate the meaning of *, **, and *** under the table. Please also indicate ns=not significant under the table.

Line 282: What do the authors mean here?  I can’t see any standard deviations in Table 7.

Overall, I can suggest a major revision and English check.

 

Author Response

Pleas see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

I would like to thank the authors for their responses to my comments.

The manuscript has been improved significantly. I am glad that authors deleted the "four different ecological environments" and they are using now year-location interactions. It sounds much better! 

Some spelling/typing errors are still exist in the MS. e.g. Line 142: ...with a ruler ...

Over all, I can suggest to correct typographical errors. 

 

Author Response

Please see the attachment.

Author Response File: Author Response.pdf