Anthocyanin Composition in Cabernet Sauvignon Grape Skins: Effect of Regulated Deficit Irrigation in a Warm Climate

Round 1

Reviewer 1 Report

The issue of wine quality in relation to external factors is current. Given the fact that water deficit is a global problem, this manuscript has a wide impact not only on the professional public. In the manuscript, attention is focused on the chemical composition of wine must, including skins. The manuscript is written relatively carefully, but I still have a few comments or notes about it. Rather older literature is cited throughout the manuscript. Given the fact that this issue is still current, it would be appropriate to include current literature in the text. It is a pity that the design of the experiment completely lacks a control that was not irrigated, as this comparison would be more appropriate than a simple comparison within individual irrigation regimes. I also recommend supplementing the methodology with soil characteristics – nutrient content and organic components, pH and possibly also moisture conditions. The graphs are relatively small, and graph 3 does not show the percentage of the individual components. The term "only slight differences" appears in the text. Are these inconclusive differences? Please add the units to the values ​​(line 186-188). The discussion is rather descriptive.

Author Response

The issue of wine quality in relation to external factors is current. Given the fact that water deficit is a global problem, this manuscript has a wide impact not only on the professional public. In the manuscript, attention is focused on the chemical composition of wine must, including skins. The manuscript is written relatively carefully, but I still have a few comments or notes about it. Rather older literature is cited throughout the manuscript. Given the fact that this issue is still current, it would be appropriate to include current literature in the text.

R: Thanks to the reviewer comments. We update the literature cited with actually literature in the topic of hydric stress in the entire document. Please see reference section marked in yellow color.

 

It is a pity that the design of the experiment completely lacks a control that was not irrigated, as this comparison would be more appropriate than a simple comparison within individual irrigation regimes.

R: Regarding to the lack of control treatment, fully irrigation treatment is not convenient for the production of grapevines for enological purposes since it is well known that controlled water deficit increase the accumulation of phenolic compounds increasing the organoleptic quality of grape berries. For this reason, we established three irrigation regimes from weak to moderate water deficit in field. 

 

I also recommend supplementing the methodology with soil characteristics – nutrient content and organic components, pH and possibly also moisture conditions. 

R: Thank to the suggestions. In lines 96-98 we expand the soil information.

 

The graphs are relatively small, and graph 3 does not show the percentage of the individual components.

R: We apprecciate the suggestion made by the reviewer. We expand the figures but the final size depends of the journal. In Figure 4, the percentage of the individual components appers in the Y axis.

 

The term "only slight differences" appears in the text. Are these inconclusive differences? Please add the units to the values ​​(line 186-188). The discussion is rather descriptive.

R: We appreciate the suggestion made by the reviewer. We delete the words that make some mistake in our results in the entire doument, to demostrate the real impact of water deficit on anthocyanin composition. We put the units in the values, please check lines 188-189.

Reviewer 2 Report

The manuscript with the title: "Anthocyanin composition in Cabernet Sauvignon grape skins: Effect of regulated-deficit irrigation in a warm climate" brings important practical information for the viticulture world, especially in this context of real and worrying climate changes.

I would recommend some additions:

- name the abbreviations: T1 ? ETp = ? T2 = ? T3 = ?

- complete with some details the working techniques for tannins, anthocyanins, total phenols.

Author Response

The manuscript with the title: "Anthocyanin composition in Cabernet Sauvignon grape skins: Effect of regulated-deficit irrigation in a warm climate" brings important practical information for the viticulture world, especially in this context of real and worrying climate changes.

I would recommend some additions:

- name the abbreviations: T1 ? ETp = ? T2 = ? T3 = ?

R: We appreciatte the suggestion made by the reviewer. Change was done. Please check lines 113-114.

- complete with some details the working techniques for tannins, anthocyanins, total phenols.

R: Thanks for the suggestion. We expand the techniques used for spectrophotometry analysis. Please check lines 147-164.

 

Reviewer 3 Report

In the manuscript, the authors studied the effect of regulated deficit irrigation on the anthocyanins' composition in the skins of the Cabernet Sauvignon variety during ripening and grown in a warm geographical area for two consecutive seasons. It is the older vintages of 2014 and 2015 that represent a smaller deficiency of the manuscript in connection with current climate changes.

The manuscript is adequately written and experimentally well executed. The 50 references used are slightly older, in the review of publications and also in the extensive discussion of the obtained results. The latter are numerous, shown in 1 table (with statistical processing) and 4 figures. In addition, the manuscript has a supplement, with 1 figure and 3 tables.

Irrespective of the older successive harvest years, the authors obtained the expected differences in the concentration of total anthocyanins with three different irrigation regimes from veraison to harvest. An important finding is that mild water stress causes slight changes with different behavior between seasons and that the water condition did not cause differences in the different proportions of anthocyanins at harvest, which could mean that different irrigations did not affect the greater accumulation of one or the other type of anthocyanins.

I have no corrections in the manuscript, so I am not attaching it either. I'm just suggesting an update with newer references.

Author Response

In the manuscript, the authors studied the effect of regulated deficit irrigation on the anthocyanins' composition in the skins of the Cabernet Sauvignon variety during ripening and grown in a warm geographical area for two consecutive seasons. It is the older vintages of 2014 and 2015 that represent a smaller deficiency of the manuscript in connection with current climate changes.

The manuscript is adequately written and experimentally well executed. The 50 references used are slightly older, in the review of publications and also in the extensive discussion of the obtained results. The latter are numerous, shown in 1 table (with statistical processing) and 4 figures. In addition, the manuscript has a supplement, with 1 figure and 3 tables.

Irrespective of the older successive harvest years, the authors obtained the expected differences in the concentration of total anthocyanins with three different irrigation regimes from veraison to harvest. An important finding is that mild water stress causes slight changes with different behavior between seasons and that the water condition did not cause differences in the different proportions of anthocyanins at harvest, which could mean that different irrigations did not affect the greater accumulation of one or the other type of anthocyanins.

I have no corrections in the manuscript, so I am not attaching it either. I'm just suggesting an update with newer references.

R: We appreciate the suggestion made by the reviewer. We updated the literature cited in the entire document. Please check the years of the new references in the References section.