Impact of Row Distance and Seed Density on Grain Yield, Quality Traits, and Free Asparagine of Organically Grown Wheat

Round 1

Reviewer 1 Report

Two – year field trial was established to investigate the impact of row distance and seed density on yield, quality aspects and free aspargine of two winter wheat cultivars, and the relation between grain number per spike, crude protein, free aspargine and acrylamide formation.

The subject is interesting, written in good English. The publication will also be useful in the Baltic States, where wheat is also cultivated in both conventional and organic farming systems.

Figure 3 needs to be modified, because my computer shows not curves.

 Recommendation: Use more recent literature (2012-2019) in your publication.

Author Response

Dear reviewer 1,

Please see the attachment.

Kind regards

Author Response File: Author Response.docx

Reviewer 2 Report

Overall comments:

This is a very interesting study and appears to be a well performed experiment, but presentation of results and their implication needs to be improved. Paragraphing needs to improve significantly to make the manuscript more readable. In the current format some content that “belong” to the same paragraph are split up in many short paragraphs, some paragraphs only consists of one sentence. Use of several subheadings in the “results and discussion” would make this section much easier to follow, alternatively split up to separate “results” and “discussion” sections.
The manuscript is a bit too lengthy, authors should try to write in a more short and concise manner to better highlight the outcomes of the study.

Abstract:

Too long, the word limit for this journal is 200 words.

Introduction:

Baking properties should be introduced here, which quality traits are relevant to study and why?

Line 45: ”exploitation” is not an appropriate word in this context.

Line 82-83: Fuhrer et al. 1990 (Fuhrer, J., Lehnherr, B., Moeri, P.B., Tschannen,W., Shariatmadari, H., 1990. Effects of ozone on the grain composition of spring wheat grown in open-tip field chambers. Environ. Pollut. 65.) showed increasen in crude protein but not Asn in wheat grown under ozone exposure.

Methods:

Numbering of subheadings are not correct, also the paragraph for each subheading is very short and several of these could preferably be combined, e.g. “baking properties” or “grain quality”

Line 189: conversion factors for N to protein was updated in: Mossé, J. Nitrogen to protein conversion factor for ten cereals and six legumes or oilseeds. A reappraisal of its definition and determination. Variation according to species and to seed protein content. J. Agric. Food Chem. 38, 18–24 (1990).

Results and Discussion:

Please present the results for grain yield (kg ha-1) in table 3 together with the yield components. This will make it easier to get an overview of the “treatment” effect on grain yield.

Line 255-256: Clarify if the results for grain yield are area based or some other unit (e.g. g per plant)

Line 276: Clarify that “seed density” is a treatment and not a result. The table would also be more readable if standard deviation is removed from the header and values put in brackets after the mean value.

Line 287: replace “fewer” with lower

Line 324: this study does not test the FN effect on baking quality but the effect of row distance and seed density on FN, which is a baking quality trait.

Line 350: Figure 2. Results are much easier to compare if figures are made in a uniform way, use the same structure and include results from all treatments in all figures. Fig 2a does not show the individual results for each cultivar or seed density, if the shown values are averages this should be clarified in the figure caption. Preferably all figures should include the results for all treatments and the two cultivar and ears, if averages are used it should be done in a uniform way for all figures to make results comparable. Legend for figure is missing; the meaning of solid and hatched bars should be shown in a legend or explained in figure caption.

Line 420-421: If figure 2 is done in more complete manner (see previous comment) this table is not needed. The current table does not tell what “seed density” treatment and year the results are taken from.

Line 450-451: the authors should develop the section of the relationship between free Asn and crude protein content, what does the literature say? This is very central to the study since it is of high importance to maintain a high protein content in wheat grains, both for baking quality but also nutritional aspects, but at the same time limit the amount of free Asn.

Line 453: figure 3. Data is missing in the figures, only R2 values are visible. Probably some fuzz with converting format of figures.

Line 460: reference to Table 3 is not correct. R2 is not a measure of correlation, it is the coefficient of determination, which you get from regression, thus assuming that there is one dependent and one independent variable. Performing regression analysis would be suitable for the testing the relationship between free Asn and AA. If correlation between variables are tested, the outcome would be the correlation coefficient “Pearson’s r”, preferably with a p-value indicating significance.
The R2 value cannot be a negative number (figure 3D).

Line 485-488: the relationship between free Asn and pre-harvest sprouting could be tested in this study, since Hagberg falling number is a measure of this.

Author Response

Dear reviewer 2,

Please see the attachment.

Kind regards

Author Response File: Author Response.docx

Reviewer 3 Report

Materials and Methods

In soil conditions description, it is worth providing soil acidity (pH) and humus content.

Results and discussion

Line 403: By contrast, cv Bussard did not chance the number of grains spikes-1 if seed density was lowered. – chance or change?

Line 483: Navrotskythe et al. – needs improvement

in the discussion of results it is worth mentioning what average Asn content in grain from conventional wheat cultivation is obtained. What is the range of variation in Asn content in wheat grain

Author Response

Dear reviewer 3,

Please see the attachment.

Kind regards

Author Response File: Author Response.docx