The Efficiency of Foliar Kaolin Spray Assessed through UAV-Based Thermal Infrared Imagery
, Sara Bernardo 1, Lia-Tânia Dinis 1, Carlos Correia 1, José Moutinho-Pereira 1 and Joaquim J. Sousa 2,3
Round 1
Reviewer 1 Report
Reviewer’s comments
Introduction
The Introduction section lacks key research background of the current advance and progress in the effect of kaolin on crops growth in the authors’ countries, and other nations.
Line 61, use showed instead of shown.
Line 72, It becomes possible estimate... there exists grammatical mistakes.
2. Materials and methods
There exists serious drawback and weakness in the experiment design: the number of flight campaigns were too small, which may not fully explain the results of your study. There is no replicated years in the study, in which the weather conditions in different precipitation years were not included.
Irrigation level was not arranged in this experiment. How did you compute the CWSI values using T data in two flights?
CWSI and IG both use the Tdry, Twet, and Tc, so what is the difference between the two indices? And why did you choose to use IG since CWSI was already selected?
4. Results & Discussion
The discussion section did not fully explain what is the significance of kaolin application, and why the mineral can lower canopy temperature. The mechanism of its effect on decreasing Tc, increasing yield is not well explained.
Generally, I can not agree that the paper can well advance the science in related research field.
Comments for author File: 
Comments.pdf
Author Response
We would like to thank the reviewer for the relevance and importance of the comments/suggestions made, as they helped to significantly improve the manuscript.
Please find the changes highlighted in the manuscript.
Author Response File: Author Response.pdf
Reviewer 2 Report
Dear authors,
your article “The efficiency of foliar Kaolin spray assessed through UAV-based thermal infrared imagery” is interesting and easy to read.
Using the UAVs’ platforms for proximal remote sensing became a common practice for rapid assessment and monitoring of crops or other permanent culture. Combination of various type of sensors (i.e. optical, multispectral, hyperspectral, thermal, LIDAR etc) are making possible the retrieval of important data about the state of the plants/soils and gives the farmers possibility to intervene where necessary. The aim of your study was to see if the kaolin sprayed on grapevines culture is effective for protecting the leaves against sunburn.
However, some methodological aspects should be clarified:
- why there are differences in flight parameters for the two surveying periods (see table 1) and how this is influencing the results of your study
- what was the reason to divide the study area into eight polygons and what were the criteria of their delineation?
For some other specific comments see the attached document.
Comments for author File: Comments.pdf
Author Response
The authors would like to thank the reviewer for its comments and suggestions.
The documment was revised accoding to the points raized by the reviewer which helped to improve the manuscript.
Please find the changes highlighted in the manuscript.
Author Response File: Author Response.pdf
Reviewer 3 Report
I would like to raise the following questions for the authors to clarify in the article.
1. Where is the location of the figure 4 in the whole study area showed in figure 1 or 3?
2. Were the inverse behaviors observed in figure 6 and 7 related to the uneven spray of Kaolin in these plots?
Author Response
The authors would like to thank the reviewer for its comments and suggestions.
The documment was revised considering the points raized by the reviewer, which helped to improve the manuscript.
Please find the changes highlighted in the manuscript.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
The authors address all my concerns, and the quality of the MS has improved after revision.
