Use of Visible Spectral Index and Soybean Plant Variables to Study Hidden Nematicide Phytotoxicity

Round 1

Reviewer 1 Report

The manuscript entitled “Use of visible spectral index and soybean plant variables to 2 study hidden phytotoxicity” described hidden phytotoxicity effects of nematicides in soybeans using a smartphone in two soybean varieties. The manuscript is well written. The objective is clear. The experiments were well-designed. The results were well explained and discussed with the literature. However, some minor revision is needed before publication.

1.       It is better to introduce the two soybean varieties in the introduction section, especially at the end when “two soybean varieties” were mentioned.

 

2.       The conclusion is not clear. More information is needed. It is better to make it self-standing, so the audience can clearly know what was conducted and the corresponding outcomes. 

Author Response

agriengineering-2566681

Use of visible spectral index and soybean plant variables to study hidden nematicide phytotoxicity

 

Dear Reviewer 1

Thank you for taking the time to review this manuscript!

 

Please find the detailed responses below, and the revisions/corrections are highlighted in the re-submitted Word file “agriengineering-2566681.doc”.

 

Comment 1: It is better to introduce the two soybean varieties in the introduction section, especially at the end when “two soybean varieties” were mentioned.

Response 1: Dear reviewer, thank you for pointing this out. The quantity of soybean varieties was removed from the Introduction to be less specific. The soybean varieties and their characteristic are cited only in Material and Methods because we believe that the specific mention and characterization of the respective cultivars are essential in such a section to illustrate that soybeans with different characteristics were studied.

 

Comment 2: The conclusion is not clear. More information is needed. It is better to make it selfstanding, so the audience can clearly know what was conducted and the corresponding outcomes.

Response 2: Thank you for pointing this out. We agree with your comment. The Conclusions section was modified to be more clear to address the corresponding outcomes:

“The observations in the present study revealed no visible phytotoxicity in soybeans treated with the studied nematicides, indicating that hidden phytotoxicity might occur without evident symptoms.

Furthermore, cadusaphos led to a higher a/b chlorophyll ratio; however, the impact of nematicides on chlorophylls was transient and occurred earlier in the soybean cycle (within 47 days after sowing). Soybean biometrics indicated that abamectin and fluensulfone exerted a pronounced effect on plant growth during the later stages of the crop cycle.

Furthermore, we found moderate and significant correlations between the TGI spectral index and the total leaf area of the soybean plants. Integrating the TGI index into crop management practices holds promise for enhancing efficiency, potentially mitigating yield losses, and reducing environmental impacts.”

Reviewer 2 Report

Comments to the authors:

1. This study could provide important theoretical basis for the study of soybean phenomics.

2. There are also a lot of writing and languish error in the manuscript.

 

 

Minor editing of English language required

Author Response

agriengineering-2566681

Use of visible spectral index and soybean plant variables to study hidden nematicide phytotoxicity

 

Dear Reviewer 2

Thank you for taking the time to review this manuscript!

 

Please find the detailed responses below, and the revisions/corrections are highlighted in the re-submitted Word file “agriengineering-2566681.doc”.

 

Comment 1: This study could provide an important theoretical basis for the study of soybean phenomics.

Response 1: Thank you for pointing this out, and we agree with your comment. Despite not citing this topic specifically, we mentioned in the Discussion that plant phenomics could benefit from sensors able to measure and study plant growth and performance in response to treatments or the environment.

 

Comment 2: There are also a lot of writing and languish errors in the manuscript.

Response 2: A proficient English professional reviewed the manuscript’s text. Corrections and improvements are in the re-submitted Word file “agriengineering-2566681.doc”.

Reviewer 3 Report

The work was carried out on the current topic of research into the fight against plant infection. Understanding the possibility of combating threats to crops and maintaining productivity will help not only ensure food security, but also carry out the required technological operations in the required time frame. There are a number of comments regarding the work:

1. Perhaps the name was not chosen quite correctly.

2. The purpose of the study is not clearly formulated.

3. It is not clear what proportion of the crop suffers from plant nematodes and what the percentage losses are.

4. An analytical comparison of existing methods for identifying plant nematodes and their effectiveness is not provided.

5. An analytical comparison of existing information on the productivity of infected plants is not provided.

6. The theoretical prerequisites for conducting the experiment, selecting influencing factors and their levels have not been formulated.

7. Conclusions do not contain numerical data, results of achieving the research goal, directions for further research, etc.

Author Response

agriengineering-2566681

Use of visible spectral index and soybean plant variables to study hidden nematicide phytotoxicity

 

Dear Reviewer 3

Thank you for taking the time to review this manuscript!

Please find the detailed responses below, and the revisions/corrections are highlighted in the re-submitted Word file “agriengineering-2566681.doc”.

 

Comment 1: Perhaps the name was not chosen quite correctly.

Response 1: By “the name”, we understood “the manuscript title” and agreed with this comment. The title was changed to better express the study’s purpose.

 

Comment 2: The purpose of the study is not clearly formulated.

Response 2: Thank you for pointing this out; we agree with your comment. The purpose/objective of the study was improved to cover the real meaning of it.

 

Comment 3: It is not clear what proportion of the crop suffers from plant nematodes and what the percentage losses are.

Response 3: Thank you for the point, but since no plant-parasitic nematode was present in the substrate (substrate analysis indicated so), it was not expected any stress was caused exclusively by phytonematodes. Nematicides were the only change among treatments and caused the possible stresses/changes observed in the soybean plants.

 

Comment 4: An analytical comparison of existing methods for identifying plant nematodes and their effectiveness is not provided.

Response 4: Thank you for your point, but in Material and Methods (Planting substrate and fertilization section) is indicated that no plant-parasitic nematode was detected in the substrate used. The laboratory methodology to identify plant-parasitic nematode is already established and broadly used (Jenkins, 1964). Our goal was to study, in plant-parasitic nematode-free substrate, the usual chemical and biological control of plant-parasitic nematode interferences with the soybean plant and whether these interferences can be detected in advance using biometrical assessments and spectral evaluations. We choose to use a plant-parasitic nematode-free substrate because the significant changes observed result only from the variation of treatments (nematicides).

 

Comment 5: An analytical comparison of existing information on the productivity of infected plants is not provided.

Response 5: Thank you for your point, but as mentioned in the Introduction, the occurrence, prevalence, and extension of damage caused by a plant-parasitic nematode are related to its initial population, susceptibility of the plant host, crop management practices, soil characteristics, and climate conditions. However, a mention of the approximate crop loss due to plant-parasitic nematodes on a world basis is cited.

 

Comment 6: The theoretical prerequisites for conducting the experiment, selecting influencing factors and their levels have not been formulated.

Response 6: Thank you for pointing this out. We presented arguments in the Introduction to conduct the thoughts to a situation where the present study is justified. In short, there are stressful plant responses to nematicides reported in the literature that are not always perceptible to the bare eye; these plant stresses can be studied over plant biometrics, the leaf chlorophyll levels, and using accessible images to anticipate the identification of such stresses; still, potential nematicide stresses have not been yet studied in soybean with a spectral index. However, changes to the text were implemented to clarify the prerequisites.

 

Comment 7: Conclusions do not contain numerical data, results of achieving the research goal, directions for further research, etc.

Response 7: Thank you for pointing this out; we agree with your comment. The Conclusions were improved to include such information and readability.

Round 2

Reviewer 3 Report

The authors revised the source material taking into account these comments. The requested information has been added, including numerical ones, and the conclusions have been revised. The authors made appropriate explanations.

There are a few small comments left:

1. In the introduction it was worth adding numerical data on losses in the region under consideration (taking into account natural and climatic conditions).

2. In the conclusions, it was worth drawing a conclusion about the part of the crop losses that could be saved.

Author Response

Dear Reviewer 3

Thank you for taking the time for a second time to review this manuscript and improve it to become an even better publication!

Please find the detailed responses below, and the revisions/corrections are highlighted in the re-submitted Word file “agriengineering-2566681.doc”.

 

Comment 1: In the introduction, it was worth adding numerical data on losses in the region under consideration (taking into account natural and climatic conditions).

Response 1: General information about crop losses caused by nematodes in plants was included in the Introduction, but as also pointed out, the delineation of plant losses depends on a series of climate-soil-plant factors not quickly or precisely determined. We agree that providing regional numbers for biotic and abiotic losses would be exciting and highlight control measures’ importance; however, this is not the focus of the study presented.

Nematodes are an important threat to soybeans and other crops and are very difficult to control, as we point out in the manuscript. Control measures are being adopted, and nematicides are commonly used. This is one of the focus of the study! These products might have phytotoxic effects, leading to further losses in crop yield. Our study uses a new approach to analyze this problem. It shows for the studied nematicides that if there are phytotoxic effects, these could not be observed after 33 days from sowing. We also demonstrated that a mobile phone camera can collect information from images that can be processed with an RGB spectral index and observed plant responses.

 

Comment 2: In the conclusions, it was worth drawing a conclusion about the part of the crop losses that could be saved.

Response 2: We demonstrated that no phytotoxic effects were observed after 33 days from sowing when the nematicides were applied. Therefore, we do not have an estimate of savings from using the demonstrated technique to estimate plant disease stresses. In fact, the study shows a new procedure to monitor eventual phytotoxic effects. We expect that others will be enticed to test this methodology to explore the effects of other pesticides on soybeans and other crops worldwide.