Late Ripening Apple Production Benefits from High Shading and Water Limitation under Exclusion Netting

Round 1

Reviewer 1 Report

Please see my comments on the paper. The abstract, Introduction and methodolgy sections need lot of rewriting. It looked like the sections starting from Statistical analysis were comparatively well written and had fewer errors. The scientific reasoning was not fully convincing. Format the tables uniformly across the paper. Abstract is unclear.

Comments for author File: Comments.pdf

Author Response

Here below you may find the Reviewer’s comments, along with the changes that were made in red

Please see my comments on the paper. The abstract, Introduction and methodolgy sections need lot of rewriting. It looked like the sections starting from Statistical analysis were comparatively well written and had fewer errors. The scientific reasoning was not fully convincing. We did our best to improve the aims of the study, at the end of the Introduction chapter. Format the tables uniformly across the paper. Some tables could not be adapted due to their dimensions, or for clarity reasons. Abstract is unclear. We did our best to improve the abstract without exceeding the max. word limit.

Regarding comments related to English language, the authors (being bilingual, C1+ level and being highly experienced in writing scientific articles) will amend those that are considered relevant.

Response to specific comments:

who introduced? done Is it the first time your research introduced this system? We gave a reference Give a little more introduction about it We gave 8 references about the topic

was this your control? Yes

This whole section needs to be clearly written We added the field map.

Reviewer 2 Report

 

Manuscript “Late ripening apple production benefits from high shading and water limitation, under exclusion netting”

Although the main idea of the manuscript (reduction of irrigation due to use of exclusion net), is unexplored field, since majority of paper and experiments deals with pest control, there is some problems with execution of experiment (according to material and method chapter).

The main problem of manuscript is irrigation. Despite different irrigation regimes, there is no significant difference in water potential, meaning that reduction in irrigation regime did not cause water deficiency in plats. Without proof of water deficiency one can assume that control regime is simply 30-50% more than tress optimally required. In line with mentioned there is no difference in yield, quality and firmness while crop load is higher in only one case (E net in 2021), however different methodology was used in two years (6 trees in 2020 and 9 trees in 2021). If excess irrigation is applied, than conclusion of manuscript can cause water deficiency to anyone who will applied conclusions from this study (reduction of irrigation regime). In order to be certain about amount of water which is added by irrigation, initial water content in soil must be determined, and then addition of water by methodology presented in manuscript is appropriate.  

Throughout the manuscript there is a problem of inconsistency in methods (crop load 6 or 9 trees for different years), different statistical methods for two different years…. Considering results, difference in yield between years (3 fold) is too big and mentioning of late frost could be factor that can influence fruit yield and quality more than irrigation regimes and nets.

Until irrigation and netting are correctly described, and late frost are eliminated as relevant factor, which all significantly reduce validity of obtained results and conclusions I will have to reject manuscript.

Other comments to manuscript:  

Please define abbreviations on the first use (Et0,  Etc, SNK)

Introduction

Lines 53-55, Sentence “The following study reports the results of medium-strong shading application to a late ripening variety, to demonstrate its effectiveness, even if prolonged during the season, until the autumn period” does not describes aim of the work (as requires by instructions for authors of Horticulturae Journal) and should be rewritten (Usually sentence should start with “Aim of this study is to….”)

Material and Methods

Line 61. How many trees were in one row?

Line 70. Is the division of orchard on A and E kept in 2021?

Line 71. Instead of “A net” should be “under net described under 2.1 (A)” in order to better define netting.

There is confusion considering number of rows. Lines 70-73 states that 5 rows are under each net (which implies 10 rows for whole experiment). Latter in text there is mention of two water regimes (line 80) which are letter explained (lines 86-91) which are applied in 5 rows at each sector (line 95), implying  that there is 20 rows (4 regimes X 5 rows). Please rewrite mentioned parts so that is clear how many rows are per treatment, what is total number of rows. I will also suggest to add schematic presentation of whole experiment design.

Lines 74-75: How was measurement of reduction of shading (50%) performed (instrument, model). Also manufacturer of E nets must be stated (Producer, model).

Line 75-76: Since article [9] is not available yet, please describe in detail all information about netting systems

Lines 77-79. “…with three weather stations”. Please be more precise 3 stations per sector or 3 stations for all experiment. Where was weather stations located (under A, E and outside)? Please state manufacturer and model of weather stations. Please present result of relative humidity [%] for both net sectors.

How PAR values are obtained?

How Average marketable fruit weight was calculated? If it calculated value, how statistics was calculated?

Line 81. How were values for Et0 obtained?

Line 82. Please present Hargreaves-Samani equation.

Lines 82-86. How was in season rain calculated in irrigation regime?

Line 85. Please define control irrigation regime for both nets? How control irrigation regime was calculated?

Line 86. Why is 30% chosen for reduction? Is there literature? 30% reduction in irrigation correspond only to 2021, in 2020 reduction around 20%.

Lines 97-99. Was the same trees used for experiment on both years?

Lines 97-99. There is a good description in term of numbers of treated trees but how was control trees selected?

Lines 99-101. Both, installed and ad hoc system must be described in detail since whole experiment relays on irrigation regime difference (especially since [9] is not published yet].

Line 131. For each treatment, all 6 trees were harvested, “plus an extra 3 in 2021” – Why extra 3? How those 3 trees was chosen? Please add explanation in material and methods, because ONLY difference between treatments and years is in crop load.  

Lines 150-152. Please, be consistent, use crop load as covariate in all calculations (consistency). Although effect of factor used as covariance is not always significant, it use will reduce residual error.

Results.

On figure 1 only Et outside the nets were presented. Since Et was calculated for both nets, please make another figure where Et outside and inside nets were presented, for both years.

Table 1. There is difference in Material and methods description of irrigation regime (lines 80-94) (30% reduction) and real irrigation. In order to better explain irrigation, please move table 1 in material and methods chapter.

Lines 203-204 is it possible that differences between years are caused by different methodology (different number of fruit)

Lines 211 – 212 Is it possible that late frost is main reason for differences in crop load in 2021?

Line 214 “In 2021, crop load did not significantly affect the seasonal growth of fruit (P = 0.58).” where is  P=0.58 located?

Table 2. Please add statistical evaluation (statistical significance of treatments)

Line 220 “higher shading in 2021 generated differences between E70 and A trees (Table 3)” – there is no mentioned difference in table 3.

Line 222 “in fact, E70 appeared to have significantly larger fruit (Table 3)” fruit size is not in table 3!

Figure 6. Please add statistical evaluation in figure 6, according to lines 163-164.

Discussion

Lines 265-267. There is no difference in marketable fruit weight. Please rewrite

Lines 267-269. Significantly higher crop load is recorded only in 2021.

Lines 270-271. As stated before (Lines 238-239) there is no difference in table 4

Line 271. “Peel and visual color values showed more red fruit for E treatments” please rewrite, there is no differences in 2020.

Lines 273-275. Partially true. Difference in SSC and firmness are present only in 2020.

Lines 284-285. Improvements highly depend on year in tables 3 and 4

Author Response

Here below you may find the Reviewer’s comments, along with the changes that were made in red

Manuscript “Late ripening apple production benefits from high shading and water limitation, under exclusion netting”

Although the main idea of the manuscript (reduction of irrigation due to use of exclusion net), is unexplored field, since majority of paper and experiments deals with pest control, there is some problems with execution of experiment (according to material and method chapter).

The main problem of manuscript is irrigation. Despite different irrigation regimes, there is no significant difference in water potential, meaning that reduction in irrigation regime did not cause water deficiency in plats. Without proof of water deficiency one can assume that control regime is simply 30-50% more than tress optimally required. In line with mentioned there is no difference in yield, quality and firmness while crop load is higher in only one case (E net in 2021), however different methodology was used in two years (6 trees in 2020 and 9 trees in 2021). If excess irrigation is applied, than conclusion of manuscript can cause water deficiency to anyone who will applied conclusions from this study (reduction of irrigation regime). In order to be certain about amount of water which is added by irrigation, initial water content in soil must be determined, and then addition of water by methodology presented in manuscript is appropriate. The point is relevant, but we used an irrigation scheduling DSS (the one provided by the CER irrigation project https://www.irriframe.it/Irriframe) that is constantly improved and is considered to be the state of the art in Italy and beyond. Furthermore, the actual aim of this study was to demonstrate that exclusion netting is a powerful technique that can reduce apple crop water requirements. Our control IRRIGATION treatment received water based on the Harg.Samani eq., which gives a certain Et0; in Italy at the moment, the great majority of orchards is irrigated following this equation (if not using the Pen.Monteith equation). Since this equation needs solar radiation as a factor, we reasoned that exclusion netting would generate more shade, i.e. less radiation and, as a consequence, a lower Et0. It suggests that exclusion netting can be used to reduce apple crop water needs, thus adding an additional reason to investing in them. As we lowered our Et0, we used tree stem water potential as a reliable reference to the water status of our trial plants. We believe 50% reduction in irrigation without consequences goes a long way towards demonstrating the potential of modulating the light environment of the orchard for water savings. It was not our goal to establish the absolute minimum to which water can be reduced. That may be subject to many ‘local’ factors and is a discussion for another day. We are confident, comparing ours to published values of stem water potential (Naor et al., 1995, Naor, 2012, Lopez et al.,2018), that we managed to reduce the water requirement of the trees without losses in their production potential. We think the size of water savings is quite relevant and worth reporting.

Throughout the manuscript there is a problem of inconsistency in methods (crop load 6 or 9 trees for different years), different statistical methods for two different years…. Considering results, difference in yield between years (3 fold) is too big and mentioning of late frost could be factor that can influence fruit yield and quality more than irrigation regimes and nets. The statistical analyses focused on the results of the single year; we did not compare the 2 years. Therefore, working on 6 or 9 trees was not a limiting factor in our analysis (in fruit tree studies the minimum of trees would be around 3-4). In lines 170-187, the different statistical methods and analyses are given in high detail and are justified, based on the different crop load that occurred during the 2 years. We harvested 9 trees in 2021 because we wanted to overcome single-tree variability.

Until irrigation and netting are correctly described, and late frost are eliminated as relevant factor, which all significantly reduce validity of obtained results and conclusions I will have to reject manuscript. We will give details about netting; however we consider irrigation treatments application thoroughly and exhaustively described.

Other comments to manuscript: 

Please define abbreviations on the first use (Et0,  Etc, SNK) done

Introduction

Lines 53-55, Sentence “The following study reports the results of medium-strong shading application to a late ripening variety, to demonstrate its effectiveness, even if prolonged during the season, until the autumn period” does not describes aim of the work (as requires by instructions for authors of Horticulturae Journal) and should be rewritten (Usually sentence should start with “Aim of this study is to….”) done

Material and Methods

Line 61. How many trees were in one row? Information updated

Line 70. Is the division of orchard on A and E kept in 2021? Yes

Line 71. Instead of “A net” should be “under net described under 2.1 (A)” in order to better define netting. We believe it makes the sentence too long to read.

There is confusion considering number of rows. Lines 70-73 states that 5 rows are under each net (which implies 10 rows for whole experiment). Latter in text there is mention of two water regimes (line 80) which are letter explained (lines 86-91) which are applied in 5 rows at each sector (line 95), implying  that there is 20 rows (4 regimes X 5 rows). Please rewrite mentioned parts so that is clear how many rows are per treatment, what is total number of rows. I will also suggest to add schematic presentation of whole experiment design. For better comprehension, we updated the manuscript with the field map.

Lines 74-75: How was measurement of reduction of shading (50%) performed (instrument, model). Also manufacturer of E nets must be stated (Producer, model) done.

Line 75-76: Since article [9] is not available yet, please describe in detail all information about netting systems done

Lines 77-79. “…with three weather stations”. Please be more precise 3 stations per sector or 3 stations for all experiment. Where was weather stations located (under A, E and outside)? Please state manufacturer and model of weather stations done. Please present result of relative humidity [%] for both net sectors. Et0 results are shown for both years. This parameter is considered a reliable indicator of the local weather and microclimatic conditions.

How PAR values are obtained? According to the equation widely used in literature. This information has been updated (lines 86-87).

How Average marketable fruit weight was calculated? Already described in lines 155-158 If it calculated value, how statistics was calculated? Please check the Statistical analysis section

Line 81. How were values for Et0 obtained? Already described in lines 88-92.

Line 82. Please present Hargreaves-Samani equation. Such equation has been cited with its original paper.

Lines 82-86. How was in season rain calculated in irrigation regime? Information updated (lines 122-123)

Line 85. Please define control irrigation regime for both nets? How control irrigation regime was calculated? Already detailed in lines 88-92.

Line 86. Why is 30% chosen for reduction? Is there literature? 30% reduction in irrigation correspond only to 2021, in 2020 reduction around 20%. We decided to apply a 30% reduction because we did not want trees to enter severe stress, based on our experience and past trials on apple (Naor et al., 1995, Naor, 2012, Lopez et al., 2018).

Lines 97-99. Was the same trees used for experiment on both years? Yes

Lines 97-99. There is a good description in term of numbers of treated trees but how was control trees selected? Randomly.

Lines 99-101. Both, installed and ad hoc system must be described in detail since whole experiment relays on irrigation regime difference (especially since [9] is not published yet]. Information updated

Line 131. For each treatment, all 6 trees were harvested, “plus an extra 3 in 2021” – Why extra 3? How those 3 trees was chosen? Please add explanation in material and methods, because ONLY difference between treatments and years is in crop load. Information updated (153-154)

Lines 150-152. Please, be consistent, use crop load as covariate in all calculations (consistency). Although effect of factor used as covariance is not always significant, it use will reduce residual error. Crop load was used to discriminate treatments. However, when this parameter does not vary among trees and treatments, the physiology of the plant is not influenced by the number of fruit it carries. Since we did not compare years, we chose a simple anova for 2020 (Please see the comments above, first page).

Results.

On figure 1 only Et outside the nets were presented. Since Et was calculated for both nets, please make another figure where Et outside and inside nets were presented, for both years. We present PAR values for both nets, in both years (Fig.3). We considered this information more valuable, as it demonstrates a significant difference in the microenvironment of the two nets.

Table 1. There is difference in Material and methods description of irrigation regime (lines 80-94) (30% reduction) and real irrigation. In order to better explain irrigation, please move table 1 in material and methods chapter. Done

Lines 203-204 is it possible that differences between years are caused by different methodology (different number of fruit) Possibly, however we did not intend to compare different years.

Lines 211 – 212 Is it possible that late frost is main reason for differences in crop load in 2021? It is highly probable. In spring 2020, we experienced temperatures below zero during pink-balloon stage. This very probably affected the number of available fruit. However, the damage we incurred did not result in advantages for the control fruit, and indication that, if their growth was not limited, it wasn’t so even at 50% of that irrigation volume.

Line 214 “In 2021, crop load did not significantly affect the seasonal growth of fruit (P = 0.58).” where is  P=0.58 located? We present the P value in the text for brevity, but preserving the necessary statistics rigour.

Table 2. Please add statistical evaluation (statistical significance of treatments) Done

Line 220 “higher shading in 2021 generated differences between E70 and A trees (Table 3)” – there is no mentioned difference in table 3. We thought the sentence: “Total yield in year 2020 was not affected by net, nor by irrigation treatments, whereas higher shading in 2021 generated differences between E70 and A trees (Table 3)” was sufficiently clear.

Line 222 “in fact, E70 appeared to have significantly larger fruit (Table 3)” fruit size is not in table 3! Fruit size and weight can be considered related to one another.

Figure 6. Please add statistical evaluation in figure 6, according to lines 163-164. Since classes are all similar, we added this comment to the Figure caption.

Discussion

Lines 265-267. There is no difference in marketable fruit weight. Please rewrite There are indeed differences in AVERAGE MARKETABLE FRUIT WEIGHT. Please check Table 3 results and p-values.

Lines 267-269. Significantly higher crop load is recorded only in 2021. Done

Lines 270-271. As stated before (Lines 238-239) there is no difference in table 4 We don’t understand the request. The lines are not matching in the text of the original manuscript.

Line 271. “Peel and visual color values showed more red fruit for E treatments” please rewrite, there is no differences in 2020. There are indeed differences. Please, check the p values.

Lines 273-275. Partially true. Difference in SSC and firmness are present only in 2020. Done

Lines 284-285. Improvements highly depend on year in tables 3 and 4 We don’t understand the request.

Reviewer 3 Report

The paper reports the effect of shading on an apple production and apple physiology. It is a follow up on earlier work by the same group. The data obtained are well worth communicating. The authors report a lack of an effect of reduced irrigation under exclusion netting on yield and fruit quality parameters demonstrating that considerable amounts of irrigation water can be saved. These results deserve publication and are well within the scope of the journal.

The experimentation is straight forward, the materials and methods the results are presented in a logical way. The discussion is focused and the conclusions are well justified.

I only have minor points that the authors should consider when presenting a revised version:

1.       Line 15: Et0 not defined.

2.       There seems to an unusual use of brackets and parenthesis. Usually brackets are used when between the brackets parentheses have to be used. The authors use it consistently the other way around. Please check authors instructions. As is the use of brackets is unusual (e.g. L 78, L 104, 105, L 142-146

3.       L. 184 to 186. Is easier to read if you had separate sentences.

4.       L. 212 replace ‘presented’ by ‘had’

5.       L. 233, 234: Wording is complex. Had a higher presence of the lower sizes…. Means really fruit were smaller. – The latter reads much easier.

6.       L. 239: …although only some resulted significantly different…. May be easier to write:…..results differed significantly .

7.       L. 280, 281: reword: …..E did not significantly differ from A ……

8.       Reference section: Check authors instructions: Titles of Journal articles are usually not capitalized.

 

Other than these items, I recommend the paper to be published.

Comments for author File: Comments.pdf

Author Response

The paper reports the effect of shading on an apple production and apple physiology. It is a follow up on earlier work by the same group. The data obtained are well worth communicating. The authors report a lack of an effect of reduced irrigation under exclusion netting on yield and fruit quality parameters demonstrating that considerable amounts of irrigation water can be saved. These results deserve publication and are well within the scope of the journal.

The experimentation is straight forward, the materials and methods the results are presented in a logical way. The discussion is focused and the conclusions are well justified.

I only have minor points that the authors should consider when presenting a revised version:

1. Line 15: Et0 not defined. Done
2. There seems to an unusual use of brackets and parenthesis. Usually brackets are used when between the brackets parentheses have to be used. The authors use it consistently the other way around. Please check authors instructions. As is the use of brackets is unusual (e.g. L 78, L 104, 105, L 142-146 Ok
3. L. 184 to 186. Is easier to read if you had separate sentences. Done
4. L. 212 replace ‘presented’ by ‘had’ Done
5. L. 233, 234: Wording is complex. Had a higher presence of the lower sizes…. Means really fruit were smaller. – The latter reads much easier. We tried simplifying the sentence.
6. L. 239: …although only some resulted significantly different…. May be easier to write:…..results differed significantly . Done
7. L. 280, 281: reword: …..E did not significantly differ from A …… Done
8. Reference section: Check authors instructions: Titles of Journal articles are usually not capitalized. We checked and it appears the name of journals is capitalized

 

Round 2

Reviewer 2 Report

 

Manuscript “Late ripening apple production benefits from high shading and water limitation, under exclusion netting”.

Authors did provide significant improvement of manuscript however I do not think that improvement is significant enough for results to be published. The idea of water saving is always worth of considering, but presented results rises questions weather irrigation and nets are responsible for presented results, or external factors.

Considering explanation provided by authors in response to questions about irrigation, I am satisfied with answer (in author response). However, explanation about irrigation scheduling DSS and CER irrigation project MUST be added to material and method chapter (if I am unaware of irrigation scheduling DSS and CER irrigation project I suppose that many other readers are unaware also). Having in mind that whole irrigation calculation relays on CER irrigation project, application of results can be considered local (to Italy), which reduces practical application of results (there is still possibility that initial irrigation is 30-50% more than it is actually needed). Based on mentioned, conclusion provided by authors “An overall decrease of 50% water for irrigation purposes did not compromise yields, nor fruit quality, on the contrary it improved it” cannot be applied a priori all over the world, which is the weakness of manuscript. Please pay attention how irrigation scheduling DSS and CER irrigation project will be presented in manuscript, because CER irrigation project is excellent idea and would like to see similar project in my country!

Also regarding irrigation, thank you for providing figure 1. It is now much clearer how was experiment conducted. However, it remains unclear which irrigation regime was applied on the other parts of field (white, unmarked parts). I assume that white parts are not irrigated. Please incorporate answer in manuscript.

Considering difference in yield between two years and explanation, provided by authors, that late frost was limiting factor in available fruit in 2020 and consequently crop load, results regarding crop load from 2020 should be discarded, because late frost (due reduction of flowers injured by low temperatures) could mask effect of nets and irrigation.  It is very well known that thinning have effects on fruit quality, and since late frost did reduced yield by almost 1/3 (compared to 2021 and having in mind that orchard was in 6^th and 7^th year of age, difference in yield between year should be considerable lower), which could be seen as thinning, fruit growth, yield and quality in 2020 cannot be used to evaluate effect of nets and irrigation, and it should be discarded.

 

Other comments:

Line 70. Is the division of orchard on A and E kept in 2021? Yes – please include answer in manuscript

Lines 77-79. “…with three weather stations”. Please be more precise 3 stations per sector or 3 stations for all experiment. Where was weather stations located (under A, E and outside)? Please state manufacturer and model of weather stations done. Please present result of relative humidity [%] for both net sectors. Et0 results are shown for both years. This parameter is considered a reliable indicator of the local weather and microclimatic conditions. Please explain in manuscript, and please incorporate involvement of CER irrigation project with explanation.

Line 86. Why is 30% chosen for reduction? Is there literature? 30% reduction in irrigation correspond only to 2021, in 2020 reduction around 20%. We decided to apply a 30% reduction because we did not want trees to enter severe stress, based on our experience and past trials on apple (Naor et al., 1995, Naor, 2012, Lopez et al., 2018). – There is no answer to second part of question “30% reduction in irrigation correspond only to 2021, in 2020 reduction around 20%”.

Table 2. Please add statistical evaluation (statistical significance of treatments) Done There is no treatment significance level, nor L. contrasts added in table 2.

Line 271. “Peel and visual color values showed more red fruit for E treatments” please rewrite, there is no differences in 2020. There are indeed differences. Please, check the p values. I am sorry for not being precise. Sentence “Peel and visual color values showed more red fruit for E treatments; red coloration was promoted probably because of the scattering of light in the canopy caused by the white covering materials, influencing anthocyanin synthesis [28]” should be rewritten since in 2020 all numbers are denoted with “a”.

Author Response

Answers to reviewer #2 comments are written in red

Authors did provide significant improvement of manuscript however I do not think that improvement is significant enough for results to be published. The idea of water saving is always worth of considering, but presented results rises questions weather irrigation and nets are responsible for presented results, or external factors. The manuscript already describes the orchard management practices, prior and during the years of the study, declaring these did not change, especially during the conducted experiments. The only modifications the orchard was subjected to were the light environment and irrigation restitution volumes, during the two years. The results depend on these two factors, since fruit trees (plants, generally speaking) primarily respond to these two parameters. The authors need more details as to which external factors might be involved, in order to properly address the reviewers concern. Lacking these, we strongly support the soundness of our experimental set-up.

 

Considering explanation provided by authors in response to questions about irrigation, I am satisfied with answer (in author response). However, explanation about irrigation scheduling DSS and CER irrigation project MUST be added to material and method chapter (if I am unaware of irrigation scheduling DSS and CER irrigation project I suppose that many other readers are unaware also). Having in mind that whole irrigation calculation relays on CER irrigation project, application of results can be considered local (to Italy), which reduces practical application of results (there is still possibility that initial irrigation is 30-50% more than it is actually needed). Based on mentioned, conclusion provided by authors “An overall decrease of 50% water for irrigation purposes did not compromise yields, nor fruit quality, on the contrary it improved it” cannot be applied a priori all over the world, which is the weakness of manuscript. Please pay attention how irrigation scheduling DSS and CER irrigation project will be presented in manuscript, because CER irrigation project is excellent idea and would like to see similar project in my country!

The CER DSS has been employed by farms all over Italy for over 2 decades. In fact, the most recent figure released by CER is upwards of 15000. This quite state of the art DSS is constantly tweaked, based upon ongoing results of research projects such as the one reported here. It is well known worldwide and has been utilized in many EU-funded projects. There is no English version of the website (unfortunately we have no control over this), so we understand the reviewers concerns but we can report that under the hail net section, the Kc never exceed the value of 0.9, and then only for the interval mid-june late-july. We do not think that such a value is indicative of over-watering.

 

Also regarding irrigation, thank you for providing figure 1. It is now much clearer how was experiment conducted. However, it remains unclear which irrigation regime was applied on the other parts of field (white, unmarked parts). I assume that white parts are not irrigated. Please incorporate answer in manuscript. Information was added in the Figure’s caption.

Considering difference in yield between two years and explanation, provided by authors, that late frost was limiting factor in available fruit in 2020 and consequently crop load, results regarding crop load from 2020 should be discarded, because late frost (due reduction of flowers injured by low temperatures) could mask effect of nets and irrigation. It is very well known that thinning have effects on fruit quality, and since late frost did reduced yield by almost 1/3 (compared to 2021 and having in mind that orchard was in 6th and 7th year of age, difference in yield between year should be considerable lower), which could be seen as thinning, fruit growth, yield and quality in 2020 cannot be used to evaluate effect of nets and irrigation, and it should be discarded. 

Data provided in tab2 are meant to illustrate the actual crop loads so that the readers can better assess the performance in fruit quality resulting from the irrigation regimes adopted. They merely provide a baseline information upon which readers can inform their on decisions on the validity of our results. As we did not attempt to mitigate the effects of frosts (both years were frost damaged, although to different degrees), we simply had to live with their effect. That in 2020 no differences in crop load were found, strengthens our results, relative to fruit quality, in our opinion.

 

Other comments:

Line 70. Is the division of orchard on A and E kept in 2021? Yes – please include answer in manuscript Done

Lines 77-79. “…with three weather stations”. Please be more precise 3 stations per sector or 3 stations for all experiment. Where was weather stations located (under A, E and outside)? Please state manufacturer and model of weather stations done. Please present result of relative humidity [%] for both net sectors. Et0 results are shown for both years. This parameter is considered a reliable indicator of the local weather and microclimatic conditions. Please explain in manuscript, and please incorporate involvement of CER irrigation project with explanation.  The CER DSS computed Et0 for unobstructed, full-field conditions using data from the weather station situated in an open field, adjacent the experimental orchard. The values of Kc for the 2 sections of the orchard (A and E) were determined by the CER DSS using data from each of the 2 weather stations that were located in each section (A and E) of the experimental orchard. Multiplying Et0xKc, provides the actual volumes to be supplied for 100% restitution. This basic knowledge should not need to be included in the text. The volumes applied in the 70% and 50% treatment used the Et0xKc value from the A section. In our IOT configuration the CER DSS directly controlled the orchard irrigation controller. The last information is already provided in the manuscript.

Line 86. Why is 30% chosen for reduction? Is there literature? 30% reduction in irrigation correspond only to 2021, in 2020 reduction around 20%. We decided to apply a 30% reduction because we did not want trees to enter severe stress, based on our experience and past trials on apple (Naor et al., 1995, Naor, 2012, Lopez et al., 2018). – There is no answer to second part of question “30% reduction in irrigation correspond only to 2021, in 2020 reduction around 20%”.  In 2020, we followed the actual evapotranspiration difference between the two nets, given by the weather stations. Under the E net, the difference was around 20%, during most of the season. Since it was the first year of the trial, we preferred a cautious approach, while in 2021 we felt more confident to increase the difference to 30%. However, our real aim was to test the possibility to reduce irrigation to 50% which we achieved in both years.

Table 2. Please add statistical evaluation (statistical significance of treatments) Done There is no treatment significance level, nor L. contrasts added in table 2.  As outlined above (and already outlined in the text, see CHAPT-2.6), in our study information relative to crop load is to be considered almost as supplementary, to allow readers a better handle on our results, for a more thorough evaluation. Therefore, we only present an ANOVA to detail the lack of significant differences.

Line 271. “Peel and visual color values showed more red fruit for E treatments” please rewrite, there is no differences in 2020. There are indeed differences. Please, check the p values. I am sorry for not being precise. Sentence “Peel and visual color values showed more red fruit for E treatments; red coloration was promoted probably because of the scattering of light in the canopy caused by the white covering materials, influencing anthocyanin synthesis [28]” should be rewritten since in 2020 all numbers are denoted with “a”. Since we had a significant treatment effect (see Tab.4, p=0.016), then the results of the linear contrasts are legit, therefore we think that it is not necessary to rewrite the sentence.