Identification of the Spectral Patterns of Cultivated Plants and Weeds: Hyperspectral Vegetation Indices
Round 1
Reviewer 1 Report
This Brief Report, "Identification of the Spectral Patterns of the Cultivated Plants and Weeds: Hyperspectral Vegetation Indices" (agronomy-2220578), presents approach for the development of methods for spot application of herbicides in crops. The study was conducted on different species of cultivated and weed plants in experimental fields. The values of 15 spectral index dependences were calculated and analysed to determine the relationship structure and information content of vegetation parameters.
Reformulate the introduction, materials and methods, results, and discussion sections to improve spelling and grammar in English. However, the manuscript does not present scientific innovations. If it presents, make it clear in your work.
Change scientific names to italic.
Put keywords in alphabetical order.
Standardize equipment/reagents/software nomenclature with the manufacturer, city, state, and country (three-letter).
Check the manuscript for proper standardization.
Add references in L45-48.
Change "common" to "point" in Table 3 and 4. The matrix of correlation needs reformulation as it is unattractive and shows lines between rows incorrectly. The value of "0.7" might not be appropriate, and higher values such as 0.99 or 0.95 might be considered.
Correct the English in L217-219.
Clarify the meaning of No. 9, 10, 11, etc. in L.222; 223, etc.
Improve the quality of figures 1 and 2 by changing "common" to "dot" and ensuring the x-axis is correct.
Best
Author Response
This Brief Report, "Identification of the Spectral Patterns of the Cultivated Plants and Weeds: Hyperspectral Vegetation Indices" (agronomy-2220578), presents approach for the development of methods for spot application of herbicides in crops. The study was conducted on different species of cultivated and weed plants in experimental fields. The values of 15 spectral index dependences were calculated and analysed to determine the relationship structure and information content of vegetation parameters.
Point 1: Reformulate the introduction, materials and methods, results, and discussion sections to improve spelling and grammar in English. However, the manuscript does not present scientific innovations. If it presents, make it clear in your work.
Response 1: According to the remark to improve the English language, please explain in what places, if possible. We turned to a professional translator to translate our article into English.
The main provision on the scientific innovation of this work is formulated in the purpose of the research, it consists in studying the spectral features of cultivated and weed plants that form the basis of agrocenoses in a particular region (Krasnodar Territory) to assess the potential possibility of their classification using Earth remote sensing tools.
Point 2: Change scientific names to italic.
Response 2: As noted, the text of the manuscript has been amended.
Point 3: Put keywords in alphabetical order.
Response 3: As noted, the text of the manuscript has been amended.
Point 4: Standardize equipment/reagents/software nomenclature with the manufacturer, city, state, and country (three-letter).
Response 4: As noted, the text of the manuscript has been amended.
Point 5: Check the manuscript for proper standardization.
Response 5: This remark was taken into account, the manuscript was checked.
Point 6: Add references in L45-48.
Response 6: This note has been taken into account, the relevant links have been added.
Point 7: Change "common" to "point" in Table 3 and 4. The matrix of correlation needs reformulation as it is unattractive and shows lines between rows incorrectly. The value of "0.7" might not be appropriate, and higher values such as 0.99 or 0.95 might be considered.
Response 7: According to the Kaiser-Maiser-Olkin adequacy criterion, which characterizes the degree of applicability of factor analysis to a particular sample, the value of the correlation coefficient in the range from 0.7 to 0.8 is acceptable.
Point 8: Correct the English in L217-219.
Response 8: As noted, the text of the manuscript has been amended.
Point 9: Clarify the meaning of No. 9, 10, 11, etc. in L.222; 223, etc.
Response 9: This remark was taken into account, changes were made to the text of the manuscript.
Point 10: Improve the quality of figures 1 and 2 by changing "common" to "dot" and ensuring the x-axis is correct.
Response 10: According to the comments to the reviewers on the quality of figures 1-3, the authors decided to replace them with a single generalized table 5, which presents the results of a posteriori comparison of the values of variable indices (according to the Duncan criterion).x
Author Response File: 
Author Response.docx
Reviewer 2 Report
The manuscript entitled „Identification of the Spectral Patterns of the Cultivated Plants and Weeds: Hyperspectral Vegetation Indices” presents interesting study on recognition of weeds based on remote sensing data.
Detailed comments:
1) Please use italic font for Latin names of the species
2) Please use simply “remote sensing” instead of “Earth remote sensing tools”
3) Please explain abbreviations used in Table 2. PXXX indicate wavelength in nm? What does it mean “Predegre”?
4) Please use dot not comma as a decimal separator of numbers
5) In the beginning of the results basic statistics should be presented, i.e. mean values of the vegetation indices for the studied species.
6) The results presented in Figures 1-3 are not clear. What are the numbers 1-10?
7) I suggest to present spectral profiles for reflectance for each species. It would allow to compare spectral differences between the weed species.
8) The aim of the study was development of methods of classification of the species. Please present more results which are directly connected with classification of the weed species. I suggest to apply cluster analysis based on individual bands or/and vegetation indices. Application of Linear discriminant analysis (LDA) or normal discriminant analysis (NDA) would allow to classify the species based on multiple variables.
9) The Conclusions are very general and should be more specific. It requires additional analyses of the results.
10) References are not formatted according guidelines for authors.
Author Response
The manuscript entitled „Identification of the Spectral Patterns of the Cultivated Plants and Weeds: Hyperspectral Vegetation Indices” presents interesting study on recognition of weeds based on remote sensing data.
Detailed comments:
1) Please use italic font for Latin names of the species
Response 1: As noted, the text of the manuscript has been amended.
2) Please use simply “remote sensing” instead of “Earth remote sensing tools”
Response 2: As noted, the text of the manuscript has been amended.
3) Please explain abbreviations used in Table 2. PXXX indicate wavelength in nm? What does it mean “Predegre”?
Response 3: As noted, Table 2 has been amended.
4) Please use dot not comma as a decimal separator of numbers
Response 4: As noted, the text of the manuscript has been amended.
5) In the beginning of the results basic statistics should be presented, i.e. mean values of the vegetation indices for the studied species.
Response 5: According to the comments to the reviewers on the quality of figures 1-3, the authors decided to replace them with a single generalized table 5, which presents the average values of vegetation indices and their comparison according to the Duncan criterion.
6) The results presented in Figures 1-3 are not clear. What are the numbers 1-10?
Response 6: According to the comments to the reviewers on the quality of figures 1-3, the authors decided to replace them with a single generalized table 5, which presents the results of a posteriori comparison of the values of variable indices (according to the Duncan criterion).
7) I suggest to present spectral profiles for reflectance for each species. It would allow to compare spectral differences between the weed species.
Response 7: In accordance with the proposal, a new figure No. 1 "Average graphs of the dependence of spectral brightness on the wavelength of cultivated and weed plants" was added to the manuscript.
8) The aim of the study was development of methods of classification of the species. Please present more results which are directly connected with classification of the weed species. I suggest to apply cluster analysis based on individual bands or/and vegetation indices. Application of Linear discriminant analysis (LDA) or normal discriminant analysis (NDA) would allow to classify the species based on multiple variables.
Response 8: In the present studies, the spectral characteristics of cultivated and weed plants were converted into 15 generally accepted vegetation indices that characterize various vegetation parameters of these plant objects (the content of chlorophyll, carotenoids, and anthocyanins, photochemical activity, stress, and so on). In our case, the use of factor analysis is justified by the very statement of the goal of research aimed at studying the structure of the correlation relationship of variable values of vegetation indices with the aim of combining them into separate factors characterizing the totality of spectral features of different plant species in order to assess the possibility of their classification, both by common factor characteristics and according to the values of individual vegetation indices.
9) The Conclusions are very general and should be more specific. It requires additional analyses of the results.
Response 9: We have tried to refine the conclusions in accordance with the remark.
10) References are not formatted according guidelines for authors.
Response 10: This remark was taken into account, the manuscript was checked.
Author Response File: Author Response.docx
Reviewer 3 Report
Title: in my experience Hyperspectral Vegetation Indices normally refers to hyperspectral imaging, while in this case the sensor is a spectrometer integrated over an area of 0.25m2. Thus I would change the title accordingly.
MAIN COMMENT:
What is the rationale behind the choice of the composition of the test plots' To the eyes of the reader the test plots are looking like "random" selections. Why did you chose such compositions? which proportions (in case of multiple species)? why those combniations' why those growing stages? why those densities?
Authors must clearly explain the relevance of that selection, to make the reader clearly understand the relevance of the results.
And as a consequence explain the reesults to the light of the specific crops in the plos.
WHat is the relevance of the work? How can one generalize the proposed results? what is the differeence between crops and weeds? WHat is the influence of weeather conditions?
what about other spectral length?
there are really many questions that might be addressed, but before that the authors must beteter explain what was the research question and how they addressed it.
MINOR COMMENTS
Please use brackets in the formula in table 2
The footnote in table 3 is almost unreadable
please check the acronynm for mNPVI and mNDVI throughout the paper: are you indicating the same index?
MNPVI should be mNDVI in table
Author Response
Title: in my experience Hyperspectral Vegetation Indices normally refers to hyperspectral imaging, while in this case the sensor is a spectrometer integrated over an area of 0.25m2. Thus I would change the title accordingly.
MAIN COMMENT:
What is the rationale behind the choice of the composition of the test plots' To the eyes of the reader the test plots are looking like "random" selections. Why did you chose such compositions? which proportions (in case of multiple species)? why those combniations' why those growing stages? why those densities?
Authors must clearly explain the relevance of that selection, to make the reader clearly understand the relevance of the results.
And as a consequence explain the reesults to the light of the specific crops in the plos.
WHat is the relevance of the work? How can one generalize the proposed results? what is the differeence between crops and weeds? WHat is the influence of weeather conditions?
what about other spectral length?
there are really many questions that might be addressed, but before that the authors must beteter explain what was the research question and how they addressed it.
Response 1: The main provision of the scientific innovation of this work is the study of spectral features and their relationship between cultivated and weed plants that form the basis of agrocenoses in a particular region (Krasnodar Territory) to assess the potential for their classification using Earth remote sensing tools.
These types of cultivated and weed plants form the basis of the agrocenoses of the Krasnodar Territory of the Russian Federation, and are also relevant components of artificial plant communities in other geographical regions of the world. Therefore, in our opinion, the results presented in the article, as a brief message, can be further used by specialists to develop specialized technologies for monitoring agroecosystems.
MINOR COMMENTS
Please use brackets in the formula in table 2
Corrections have been made to table 2.
The footnote in table 3 is almost unreadable
The footnote in Table 3 has been corrected.
please check the acronynm for mNPVI and mNDVI throughout the paper: are you indicating the same index?
Abbreviation checked and corrected
MNPVI should be mNDVI in table
Abbreviation checkedx
Author Response File: Author Response.docx
Round 2
Reviewer 1 Report
I consider the authors made important changes in the manuscript and it was highly improved. I recommend the publication of the manuscript in its current form. Best regards,
Author Response
We thank you for your attention and analysis of our manuscript, comments and suggestions, which helped us to significantly improve its quality. Best regards.
Reviewer 2 Report
The manuscript was substantially improved, according almost all my comments. However, one comment was not included in the improved version of the manuscript (application of multivariate dicriminate analysis, eg. LDA). Despite of that, current version of the manuscript is suffcient for publication. Some minor changes are still requried becase references are not formatted according all guidelines for authors and some latin names of the species are not written in italic.
Author Response
We thank you for your attention and analysis of our manuscript, comments and suggestions, which helped us to significantly improve its quality. We edited the links according to the design rules and highlighted the Latin names in italics. Best regards.
Reviewer 3 Report
The paper hsa undergone some amendments, nevertheless, the mani issues have not been addressed. I am writing them here again:
What is the rationale behind the choice of the composition of the test plots? To the eyes of the reader the test plots are looking like "randomly selected areas" rather than experimental plots defnied on the basis of a design of experiments. Why did you chose such compositions? which proportions (in case of multiple species)? why those combniations? why those growing stages? why those densities?
Authors must clearly explain the relevance of that selection, to make the reader clearly understand the relevance of the results.
And as a consequence explain the reesults to the light of the specific crops in the plos.
How can one generalize the proposed results? what is the difference (in terms of spectral signals) between crops and weeds? What is the influence of weather conditions on specttral signal?
Author Response
The choice of experimental sites was not random, it was formulated in the purpose of the study (the study of the spectral characteristics of cultivated and weed plants that form the basis of the agrocenoses of the Krasnodar Territory to assess the potential for their classification using Earth remote sensing tools.). As objects, species of cultivated and weed plants were chosen, which form the basis of the agrocenoses of the Krasnodar Territory of the Russian Federation, which are also actual components of artificial plant communities in other geographical regions of the world. Specialists herbologists have studied and described quite well the species and quantitative composition of weeds on agricultural crops in the Krasnodar Territory (1). In our experiments, each experimental site had a certain quantitative and qualitative description of weeds. The phases of crops and weeds at the time of the survey were described. What is important for the development of protective measures.
The study of the spectral characteristics of the selected objects was carried out at a specific point in time, so the influence of weather conditions in the context of the research methodology was to take into account the nature of the illumination. As a rule, spectrometric measurements were carried out on a clear sunny day from 10:00 to 13:00. In this case, the device recorded the radiation reflected from the objects. In the process of measurements, the state of the atmosphere was taken into account for the variability of illumination. To calibrate the measurement results, a white panel was used, which is a reference reflector.
- Tretyakova, A.S.; Baranova, O.G.; Luneva, N.N.; Terekhina, T.A.; Yamalov, S.M.;. Lebedeva, M.V.; Khasanova, G.R.; Grudanov, N.Y. Segetal flora of some regions of Russia: characteristics of the taxonomic structure. Proceedings on Applied Botany. Genetics and Breeding. 2020, 181(2), 123 133. https://doi.org/10.30901/2227-8834-2020-2-123-133
Author Response File: Author Response.docx
