Evaluating Farm Management Performance by the Choice of Pest-Control Sprayers in Rice Farming in Japan
Round 1
Reviewer 1 Report
This is a much needed information, addressing the economics of using UVAs for pest management, especially spraying pesticides. The authors took a bold approach to provide as much as an economic analysis as they could. I truly believe this information will contribute to advance our knowledge on the use of UVA for many processes, including pest control. However, I am recommending to reject this manuscript as its current form. I am hopeful that authors will consider to make all the necessary changes and resubmit this study.
It was really difficult to follow along and read the entire manuscript. It is clear that there were sections were direct translations to English were used. There were several sentences that has no meaning or were incomplete thoughts. In addition, the sections provided by the authors in the Results & Discussion part have no connectivity among them. So, here are my first major suggestion: 1) re-write the manuscript separating the Discussion from the Results. This will help the readers to understand the thought process of the authors, after reading all the results first.
There was repetition of information, as portions written on the body of the text and in Tables and Figures. A clear example is Table 1. And then, there is a need to better visualize some of the results from this study. My second suggestion is to consolidate information (either as presented as tables or in the text), and use graphs to facilitate the interpretation of results. An example of needing a graph is converting Table 5 into a bar graph.
And here is my major concern, and one of the reasons why I am proposing to reject this manuscript as its current form. Authors seems to oversight the fact that cost and most of the parameters associated with spraying 15-ha 30-ha units are similar between UAVs and tractors with boom sprayers (see Table 4, as one example). This finding has to be clearly stated on the manuscript. I do understand the desire of authors to showcase the economics of using UAVs. However, benefits of using UVAs could be brought up to our attention within the discussion.
I tried my best to include as many edits as possible. I have included all those edits and several comments that need to be addressed in the attached PDF file.
Comments for author File: 
Comments.pdf
Author Response
We greatly appreciate for your comment on the manuscript. We have been able to incorporate changes to reflect most of the suggestions provided. Our responses to your two major comments are described in below. All comments and suggestions of yours in pdf were checked and revised one by one. Especially, based on your comments about Table 4 in the initial submission, we re-discussed carefully about the numerical values and we found that results of UAVs and boom sprayers were comparable, i.e. be hard to conclude that UVAs should be superior than boom sprayer. Therefore, we revised the results, the discussion, and the conclusion, consistently. We believe this greatly improved the manuscript. We have highlighted in blue for the changes in the manuscript. The manuscript has been edited carefully by MDPI English editing service.
Comment: Re-write the manuscript separating the Discussion from the Results.
Response: Thank you for the suggestion. We rewrote the manuscript separating the Discussion from the Results (line 135, page 4~line 256, page 7).
Comment: Consolidate information (either as presented as tables or in the text), and use graphs to facilitate the interpretation of results. An example of needing a graph is converting Table 5 into a bar graph.
Response: We agree. We deleted Table 1 and converted Table 5 to a bar graph and revised the results and the discussion (line 174, page 5).
Reviewer 2 Report
The article adds novel information to the state-of-the-art in respect to smart agriculture by mean of using technology, unmanned aerial vehicles (UAVs), comparatively to tractor mounted boom sprayer or remote-control spraying helicopter, for the pest-control in rise farming.
The article is weel-written and offers good perspective about the better work capacity and cost efficiency of UAVs assessed by data envelopment analysis.
However, this reviewer has reservations about how worthy is the authors approach considering that they are not identifying targeted crop pests. Although they target rice fields and paddy fields as the object or the research, they do not point out the pest they propose to control. Are they proposing the treatment to control fungal agents, through fungicide application, insects or mites with insecticides?? It look necessary to me identify the harmful pests they want to fight, since this can be conditioned by seasonality, outbreaks, preventive or curative treatments available (those have been neither identified), disease dispersion... To my understanding, those issues can condition the cost of application and the detection of crop damage.
Therefore, I recomend the authors to review the article in this respect before accepting the article for publication.
Author Response
We appreciate for your comment on the manuscript. It made the research scope clearly and greatly helpful to consolidate the results. We have been able to incorporate changes to reflect most of the suggestions provided. We have highlighted in the yellow the changes within the manuscript. The other major revision in the manuscript is to separate the results and the discussion and converted Table 5 to the graph (Figure 1). Please check in the manuscript. The manuscript has been edited carefully by MDPI English editing service.
Comment: However, this reviewer has reservations about how worthy is the authors approach considering that they are not identifying targeted crop pests. Although they target rice fields and paddy fields as the object or the research, they do not point out the pest they propose to control. Are they proposing the treatment to control fungal agents, through fungicide application, insects or mites with insecticides?? It look necessary to me identify the harmful pests they want to fight, since this can be conditioned by seasonality, outbreaks, preventive or curative treatments available (those have been neither identified), disease dispersion... To my understanding, those issues can condition the cost of application and the detection of crop damage.
Response: Thank you for pointing this out. We agree it was not specified in the manuscript and could lead misunderstanding the scope of the manuscript. However, in the case of our study, it seems slightly out of scope because pest control in this study was assumed preventive. Pesticides are generally applied to prevent the breakout of pests in advance in East Asia monsoon climate region, for example, twice a year in July and August in Japan regularly, to maintain the effect for a long period and obtain a stable control effect with a small number of control times. Thus, in this study, we assumed the typical pesticides types in rice production reported by Ministry of Agriculture, Forestry, and Fishery of Japan (MAFF) set same among three targeted sprayers and collected the amount and the costs of pesticides from the statistics of MAFF. Hence, we focused on the performance of the machineries. We believe your comment is strongly needed to clarify the research scope and to help understanding the manuscript. We have, accordingly, added it into the manuscript (line 58~59, page 2, line 141~142, page).
Reviewer 3 Report
Great paper! I found it timely and nessicary as a reference for convincing growers to adopt this newer technique. I have only two comments. While I am not familiar with the agricultural labor standards in Japan, in other industrial countries such as the USA and PRC there is very cheap labor so even when just comparing rice management systems I can see those costs greatly fluctuate globally and problematic if one were to try and extrapolate your estimates to other countries. Second for arial spraying where I am in the USA we have different applications rates and concentrations that are used when the spray is done by air so I was also not sure if the pesticide amount used and cost be the same for all 3 groups, but I am not familiar with Japanese regulations
Author Response
We appreciate for your insightful comments on the manuscript. We have been able to incorporate changes to reflect most of the suggestions provided. We have highlighted in yellow the changes within the manuscript. Your comments and responses are below. The other changes have been made by separating the results and the discussion and converting Table 5 in the initial submission to the graph (Figure 1). Please check in the manuscript. The manuscript has been edited carefully by MDPI English editing service.
Comment. While I am not familiar with the agricultural labor standards in Japan, in other industrial countries such as the USA and PRC there is very cheap labor so even when just comparing rice management systems I can see those costs greatly fluctuate globally and problematic if one were to try and extrapolate your estimates to other countries.
Response: We agree with your comment that it clearly would hard to compare directly the numbers estimated in this paper to other countries, especially where agricultural standards differ from Japan. However, we would like to clarify that our scope is to show the strategic planning scheme to introduce the new technology to rice production, which deals with the cost estimation and machinery performance evaluation. We believe that it would be applicable to other regions in the world. We added the above comments to the manuscript (line 264~265, page 7)
Comment. Second for arial spraying where I am in the USA we have different applications rates and concentrations that are used when the spray is done by air so I was also not sure if the pesticide amount used and cost be the same for all 3 groups, but I am not familiar with Japanese regulations.
Response: Thank you for raising an important point here. However, UAVs in agriculture are still challenging in Japan and just finished the project to test preliminary implementation in 2020 by Ministry of Agriculture, Forestry, and Fishery. Therefore, we interviewed farmers (line 83~84, page 2; line 157~159, page 5; line 198~199, line 220~221, page 6) and collected data from above project [2,17] (we referred to the government reports of the project scheme and the interim report). They revealed that the yield kept mostly same level with a same amount of pesticides. It was deemed that Japanese regulation of the pesticides amount would be enough or excessed, which is larger than other countries according to FAO [16] and could had been able to ignore possible uneven spraying of UAVs (or possibly due to relatively small farm size compared to other countries, 3 ha in average, subsequently hard to differentiate among farms). We revised the manuscript to clarify above (line 195~205, page 6).
Round 2
Reviewer 1 Report
I would like to congratulate the authors for revising this manuscript. What a great job!
I truly enjoyed reading this revised version. It is now well-written, and has a very good flow. Breaking the information into the Result and Discussion sections helps the reader to analyze the statements presented. Reducing the number of tables and using a figure helped to make this manuscript cleaner. This time, I was able to provide a much better revision since I followed along the information presented.
I am glad that the authors decided to re-summit this manuscript. Based on its current merit, I am proposing its acceptance after addressing very minor edits, especially at referencing Figure 1 (now, it is unproperly called on the body of the text as Table 1). All my proposed edits and comments are included in the attached PDF file. I used an orange highlighter to denote the location of those edits, as well as the comment function. I am hoping that authors can address my two comments in the introduction section. I do not need to review a final version of this manuscript, as long as the authors address the proposed edits.
Looking forward to seeing this paper published and start using it as a citation.
Comments for author File: Comments.pdf
Author Response
Thank you for your encouraging comments. We highlighted major revised parts according to the comments (orange color in the PDF file) in yellow color, and the others in blue color. We appreciate again for the insightful and helpful comments. They have improved greatly the manuscript. The responses to the specific comments are as follows:
Comment: Assuming that Figure 1 is part of this section: Could authors add a couple of sentences summarizing the main results from Figure 1? This could be place at the end of this paragraph.
Response: Thank you for the suggestion. We added the summarizing the main results from Figure 1 in the end of the paragraph (line 161~164, page 5) as below:
It showed that the overall efficiencies increased along with the farm size. The efficiency of UAVs at 3-ha to 30-ha field were 1. The efficiencies of UAVs were slightly higher than boom sprayers, representing the same tendency through the farms. Boom sprayer marked 1 at 30-ha field. The efficiency of RC helicopters ranging from 0.5-ha to 30-ha field were the lowest among the three sprayers.
We also revised “Table 1” to “Figure1”, and titled to “Efficiency for pest-control calculated using the data development analysis (DEA), for rice farms ranging in size from 0.5 to 30 ha, and using either a boom sprayer (light gray bars), a RC helicopter (black bars) or a UAV (dark gray)”. (line 161~166, page 5)
Comment: All my proposed edits and comments are included in the attached PDF file. I used an orange highlighter to denote the location of those edits, as well as the comment function.
Response: Thank you for the suggestion and comments in detail including English editing. We revised one by one according to your notes and highlighted in blue color.
Comment: I am hoping that authors can address my two comments in the introduction section.
Response: Thank you for the suggestion. We revised the introduction referring to two comments (orange). First, the reference to support “Subsequently, the average cultivation area per worker is expanding” was added in line 26, page 1. Secondly, we revised to “pest-control cost” to clarify in line 49, page 2.
Comment: Is this a software? If so, please include the information of the manufacturer and its location.
Response: Thank you for pointing this out. DEAP Version 2.1 is the computer program described in the academic paper [23]. It doesn’t have the manufacturer and its location.
