Morphophysiology, Productivity and Quality of Soybean (Glycine max (L.) Merr.) cv. Merlin in Response to Row Spacing and Seeding Systems
, Jan Buczek, Dorota Bobrecka-Jamro, Ewa Szpunar-Krok, Renata Tobiasz-Salach and Wacław Jarecki
Round 1
Reviewer 1 Report
The Manuscript (agronomy-1118662) entitled as "Morphophysiology, productivity and quality of soybean (Glycine max (L.) Merr.) cv. Merlin in response to row spacing and seedling systems” by Jańczak-Pieniążek et al, reported the various row spacing and sowing density do not affect the productivity of soybeans directly by a three-year field experiment.
Although the authors do an admirable job of morphophysiology, productivity and quality of soybean in response to row spacing and seedling systems, I don't find that this paper has sufficient novelty to warrant publication. Because many precedent studies that are similar to this article are reported.
The Results and discussion are too long and redundant, and are hard to understand. And, I felt that discussions are insufficient from in your data. Although present study that the row spacing and sowing density do not affect the productivity of soybean directly, are somewhat interesting, I do not feel it is sufficient to merit publication.
Author Response
Response to Reviewer 1 Comments
Thank you for the constructive and informative comments of the Reviewer. Below are our point-by-point responses to the concerns raised during review process.
Point 1: Although the authors do an admirable job of morphophysiology, productivity and quality of soybean in response to row spacing and seedling systems, I don't find that this paper has sufficient novelty to warrant publication. Because many precedent studies that are similar to this article are reported.
The Results and discussion are too long and redundant, and are hard to understand. And, I felt that discussions are insufficient from in your data. Although present study that the row spacing and sowing density do not affect the productivity of soybean directly, are somewhat interesting, I do not feel it is sufficient to merit publication.
Response 1:
We disagree with Reviewer's comments, that our manuscript has not sufficient novelty to warrant publication, because many studies are similar to our article. During the preparation of the manuscript, authors did not find similar publications.
In the last years there has been an interest in the cultivation of soybeans on a large scale, especially in Europe. However, due to the high variability of the climate in recent years and the resulting variability of soybean yields in different parts of Europe (and often within the country), the results of research on the effect of sowing density and row spacing are inconclusive. There are no studies carried out under very different thermal and humidity conditions and at the same time on the effect of these factors on the development of morphological and physiological-increasing yield of soybeans (especially chlorophyll fluorescence parameters (e.g. Fv/Fm, Fv/F0 and PI parameters) in field conditions. The presented research is therefore a suplement of research on soybean cultivation and brings a practical conclusions that the differentiation of the row spacing and sowing density does not directly affect the productivity of soybeans. In the soybean cultivation technology, a lower sowing density can be used, regardless of the row spacing, and obtain a stable seed yield and higher yield structure parameters, which results a lower costs associated with the purchase of seed material of this species. The study of physiological parameters of the efficienty of the soybean photosynthesis process also confirm the high phenotypic plasticity of soybean plants depending of thermal and precipitation factors, therefore it is recommended to adjust the sowing density and row spacing to the current environmental conditions in the region.
The result and discussion were improved according to Reviewer’s suggestion.
Reviewer 2 Report
The authors designed and conducted a split-plot field experiment in three years to evaluate the impact of row spacing and sowing density on soybean productivity, seed quality as well as morphological and physiological features. It was found that the two factors had no direct effects on soybean yield, but significantly related to the variations in some phenotypic traits. Two optional combinations of row spacing and sowing density were recommended by the authors. This topic seems interesting to farmers in planting the certain soybean type in the meteorological area and those who study plant morphological mechanisms to field operations. Specific comments and questions are as follows.
General: The manuscript is a little bit wordy and needs improvements in the language styles
Introduction
Is sowing density a dependent variable of row spacing? Is there any difference between them in terms of negatively affecting soybean production?
The significance of this topic is not explained well. The authors need to explain how the two factors are decided currently in practice and summarize all previous studies on this topic.
Materials and Methods
Line 82: '000++' What does the code mean?
Line 89: Please give full names to these elements.
Table 1: Please represent the dates in ISO standard.
Line 126: What does BBCN stand for?
Section 2.6 ANOVA: It is necessary to present the ANOVA model for readers to understand the split-plot data collected multiple times in multiple years.
Results and discussion
The presented results in 3.1-3.4 are not clear. Need the descriptive results to show if there are differences in chlorophyll content and others caused by row spacing and sowing density or if it was interactively affected.
Figure 2a: It was from one year's data or three years? Same question to the following similar figures.
Line 186: 'lower': You mean higher?
In the discussion part of some paragraphs, the author presented some contradictory results from previous studies, for example, Line 187-194, which is very confusing. The authors should present them in a more concise way and investigate the reasons that cause contradictory results, instead of simply listing them.
Line 220: The full name of PAR should move forward to Line 208.
Line 288-293: But your results did not confirm this. What happened?
Line 297-298: This seems to be at the opposite side of the statements in Line 61-63.
Line 302-306: If results in 2018 are really outliers, the authors should then check on data in 2017 and 2019 if they were more like a normal situation. Because the goal was to evaluate row spacing and sowing density effects. You should figure out a way to eliminate or reduce environmental factors.
Author Response
Response to Reviewer 2 Comments
Thank you for the constructive and informative comments of the Reviewer. Below are our point-by-point responses to the concerns raised during review process.
Point 1: Introduction: Is sowing density a dependent variable of row spacing? Is there any difference between them in terms of negatively affecting soybean production? The significance of this topic is not explained well. The authors need to explain how the two factors are decided currently in practice and summarize all previous studies on this topic.
Response 1: According to Reviewer’s suggestion, the introduction was supplemented with studies on the effect of sowing density and row spacing on soybean productivity. L: 53-59 and 65-72
Point 2: Line 82: '000++' What does the code mean?
Response 2: ‘000++’ is the international designation for the maturity group of soybean cultivars, which indicates the suitability of the cultivar for growing in a specific area. In this case, the Merlin cv. has the code 000 ++, which means that it belongs to the mid-early group.
Point 3: Line 89: Please give full names to these elements.
Response 3: According to Reviewer’s suggestion we gave full names of elements (P, K, N). We inserted sentences: “The soil mineral fertilisation was applied before sowing. The doses of phosphorus, potassium and nitrogen were 35 kg ha-1, 95 kg ha-1 and 30 kg ha-1, respectively.” instead: “The soil was fertilized with 35 kg P/ha, 95 kg K/ha and 30 kg N/ha before sowing the soybean.” L: 108-109
Point 4: Table 1: Please represent the dates in ISO standard.
Response 4: Changed in accordance with Reviewer’s comment.
Point 5: Line 126: What does BBCH stand for?
Response 5: The BBCH scale (Biologische Bundesanstalt, Bundessortenamtund CHemische Industrie) is used to identify the phenological development stages of plants. Information about BBCH was added in L: 100-101
Point 6: Section 2.6 ANOVA: It is necessary to present the ANOVA model for readers to understand the split-plot data collected multiple times in multiple years.
Response 6: Information about ANOVA with repeated measurements was added in L: 183-184
Point 7: The presented results in 3.1-3.4 are not clear. Need the descriptive results to show if there are differences in chlorophyll content and others caused by row spacing and sowing density or if it was interactively affected.
Response 7: The description of presented results were improved according to Reviewer’s comments.
Point 8: Figure 2a: It was from one year's data or three years? Same question to the following similar figures.
Response 8: Changed in accordance with Reviewer’s suggestion. In description of Figures 2a, 3a, 4a, 5a and 6a information about years of experiment was added.
Point 9: Line 186: 'lower': You mean higher?
Response 9: Changed in accordance with Reviewer’s suggestion. L: 213
Point 10: In the discussion part of some paragraphs, the author presented some contradictory results from previous studies, for example, Line 187-194, which is very confusing. The authors should present them in a more concise way and investigate the reasons that cause contradictory results, instead of simply listing them.
Response 10: The discussion was improved according to Reviewer’s comment.
Point 11: Line 220: The full name of PAR should move forward to Line 208.
Response 11: Changed in accordance with Reviewer’s suggestion.
Point 12: Line 288-293: But your results did not confirm this. What happened?
Response 12: In line 329 mistakenly wrote that decreased of sowing density affected to produce by plants more branches, which increase the number of pods and thus seeds per plant, resulting in a higher yield. Instead it should be written that decreased of sowing density resulted in greater production per individual. This agrees with the results obtained in the present study.
Point 13: Line 297-298: This seems to be at the opposite side of the statements in Line 61-63.
Response 13: In introduction (L: 61-63) was wrote, that if the row spacing is reduced and the sowing density increases, the photosynthesis efficiency is reduced as a result of the soybean plants overlap, which is related to the yield level of soybean plants. On the other hand own research shows that there was only tendency (statistically insignificant) to increase the yield with a narrower row spacing. The lack of statistical differences is largely due to the phenotypic plasticity of this species. The results of the research conducted by Devlin et al. (1995), who obtained a higher yield of soybeans using narrower row spacing, are inadequate due to the use of a much larger row spacing than in the own research, and was removed from this publication.
Point 14: Line 302-306: If results in 2018 are really outliers, the authors should then check on data in 2017 and 2019 if they were more like a normal situation. Because the goal was to evaluate row spacing and sowing density effects. You should figure out a way to eliminate or reduce environmental factors.
Response 14: Numerous studies conducted in the natural conditions of Poland confirm that both the vegetative and generative development of soybean plants, as well as the yielding depend primarily on weather conditions, and less on the cultivar or sowing density (Kozak et al. 2008a; Kozak et al. 2008b; Prusiński and Nowicki 2020). In 2018, there were favorable conditions for the growth and development of soybean plants, which resulted in obtaining a higher seed yield. However, in 2017 and 2019, they were characterised by the course of weather conditions typical of this region of Poland. In these years, the yield was obtained at a similar level (no statistically significant differences). This demonstrates the phenotypic plasticity of soybean plants in response to varied row spacing and sowing density. In order to eliminate the influence of environmental factors, a canonical analysis was performed.
Reviewer 3 Report
Paper "Morphophysiology, productivity and quality of soybean (Glycine max (L.) Merr.) cv. Merlin in response to row spacing and seeding systems" is interested but needs major revision.
Nomenclature:
not "pcs./m2" but "pcs. m-2"
not "t/ha" but "t ha-1"
Results and Discussion: Lack information about interactions.
Figure 2 needs LSD or HSD values.
Figure 3 needs LSD or HSD values.
Figure 4 needs LSD or HSD values.
Figure 5 needs LSD or HSD values.
Figure 6 needs LSD or HSD values.
Tables 4, 5 and 6: Letters indicated homogenous groups should be after mean values not after standard deviations.
Lines 163-165: "the Pearson’s linear correlation coefficients were calculated between the analysed parameters at the significance level of p = 0.05". In papre lack of Pearson correlation analysis between observed traits.
Figure 7: Wrong nomenclature: "74.92%" not "74,92%".
Figure 7. Scree plot is not for "matrix of correlation".
Quality of Figure 8 is very poor.
Statistical analyses used in this paper are incorrect for presented data. The principal component analysis is incorrect method for data with replications. Authors should be using the canonical variate analysis. Other tool for presenting of information from Figure 8a and Figure 8b in one figure is bi-plot. Authors should contact with statistician.
Paper needs major revision.
Author Response
Response to Reviewer 3 Comments
Thank you for the constructive and informative comments of the Reviewer. Below are our point-by-point responses to the concerns raised during review process.
Point 1: Nomenclature: not "pcs./m2" but "pcs. m-2", not "t/ha" but "t ha-1"
Response 1: The nomenclature throughout the work has been changed according to Reviewer’s suggestion.
Point 2: Results and Discussion: Lack information about interactions.
Response 2: The information about interactions were added in text of manuscript (L: 390-391, 448-450). There were no statistically significant interactions between row spacing and sowing density in shaping the values of the tested parameters, except for thousand seed weight (TSW) (this interaction is described in L: 375-379)
Point 3: Figure 2 needs LSD or HSD values.
Figure 3 needs LSD or HSD values.
Figure 4 needs LSD or HSD values.
Figure 5 needs LSD or HSD values.
Figure 6 needs LSD or HSD values
Response 3: The HSD values were added in description of Figures 3, 4, 5, 6 (Tukey’s HSD test, p = 0.05)
Point 4: Tables 4, 5 and 6: Letters indicated homogenous groups should be after mean values not after standard deviations.
Response 4: Changed in accordance with Reviewer’s suggestion (Table 4, 5, 6).
Point 5: Lines 163-165: "the Pearson’s linear correlation coefficients were calculated between the analysed parameters at the significance level of p = 0.05". In papre lack of Pearson correlation analysis between observed traits.
Response 5: According to suggestion by another Reviewer, we removed Pearson’s linear correlation.
Point 6: Figure 7: Wrong nomenclature: "74.92%" not "74,92%".
Response 6: The description on principal component analysis was changed to canonical variate analysis.
Point 7: Figure 7. Scree plot is not for "matrix of correlation".
Response 7: The description on principal component analysis was changed to canonical variate analysis.
Point 8: Quality of Figure 8 is very poor.
Response 8: The description and figures showing on principal component analysis was changed to canonical variate analysis.
Point 9: Statistical analyses used in this paper are incorrect for presented data. The principal component analysis is incorrect method for data with replications. Authors should be using the canonical variate analysis. Other tool for presenting of information from Figure 8a and Figure 8b in one figure is bi-plot. Authors should contact with statistician.
Response 9: We used the canonical correlation analysis (CCA) for presented our data. The obtained results were presented using a tri-plot graph (Figure 7) and correlation matrix of set 1 and 2 (Table S1 and S2).
Round 2
Reviewer 1 Report
Authors revised Results and discussion concisely
Author Response
Response to Reviewer 1 Comments
Thank you for the constructive and informative comments of the Reviewer. Below are our point-by-point responses to the concerns raised during review process.
Point 1: Authors revised Results and discussion concisely
Response 1: We thank the Reviewer’s for his constructive and informative comments that have improved our manuscript.
Reviewer 3 Report
Authors observed few quantitative traits and relationships between them are very interesting. Paper needs correlation coefficients.
In second version of manuscript Authors used canonical correlation analysis. This is incorrect method for data obtained in experiment. Authors should be using the canonical variate analysis and estimated Mahalanobis distances. Authors should contact with statistician.
Paper needs major revision.
Author Response
Response to Reviewer 3 Comments
Point 1: Authors observed few quantitative traits and relationships between them are very interesting. Paper needs correlation coefficients. In second version of manuscript Authors used canonical correlation analysis. This is incorrect method for data obtained in experiment. Authors should be using the canonical variate analysis and estimated Mahalanobis distances. Authors should contact with statistician. Paper needs major revision.
Response 1:
According to Reviewer’s suggestions we used the canonical variate analysis (CVA) instead canonical correlation analysis (CCA). The obtained results were presented using bi-plot graph (Figure 7). We also used correlation coefficient (Table S1), and estimated Mahalanobis distances (Table S2).
We thank for his constructive and informative comments that have improved our manuscript.
