Managing Water Stress in Olive (Olea europaea L.) Orchards Using Reference Equations for Midday Stem Water Potential

Round 1

Reviewer 1 Report

The manuscript, entitled "Managing water stress in olive (Olea europaea L.) orchards using reference equations for midday stem water potential " aims to study water stress management based on reference equations for midday stem water potential. It irrigates olive orchard by designing three different treatments to measure many midday stem water potential and leaf conductance data. Although studies like this are valuable, the studies are not novel. I suggest that that the manuscript should also provide the performance figures of three different treatments to support the reliability of the study, rather than just images for data statistical analysis. In addition, Shortcomings or inadequacies of the SWP reference equations should also be discussed for valuable and improving implications. 

Author Response

Answer to reviewer

Reviewer 1

Thank you very much for your comments. We have improved the document to try to answer your main suggestions.

We have increase the number of references in the introduction and include a more extensive background.

 

The aim of this work was to compare the relationship between SWP and evaporative demand indicators (VPD and maximum temperature) but using SWP data grouped according to leaf conductance reductions. We have obtained these data of different irrigation treatments. From our point of view, methodology is clearly presented, but some additional comments have been included.

 

Regarding to you comment about “provide the performance figures of three different treatments to support the reliability of the study, rather than just images for data statistical analysis.” The aim of this work was to obtain this statistical analysis not to compare these treatments as irrigation strategies. The reliability of the study is supported with the SWP and leaf conductance of the treatments where you can compare the seasonal pattern of each treatment. In addition, data about applied water each season and treatment is included in Material and methods section.  Moreover, average yield of each season were also included to describe the alternate bearing pattern of the trees. From our point of view, these data (applied water and average yield) are enough to frame the conditions were the experimental data were obtained. However, we have included in the new version data about the pattern of water uptake and the soil cover which could also improve the respond to irrigation treatments.

 

Reviewer 2 Report

 

Optimising the use of water quantities in fruit production is a hot topic in times of climate change and water scarcity. The article focuses on establishing reference equations for calculating the optimal amoubt of irrigation throut the growing season of olive trees. that is an interesting subject since it is fundamental for predictive models that can help the farmers in decision making.

The article is well written, but for some parts where some sentences need to be arranged to improve comprehension. Data are well presented. Tables and graphics, all well done. The design is appropriate, analyses are sound, and the results drawn are clearly justified. The methods are sufficiently detailed to permit replication of the study. The analyses are appropriate and well interpreted and the conclusions are justified. This is a contribution to the body of knowledge that has several novel and innovative components.

English Level is good.

Minor revision is necessary:

Line 31 “on yield” (instead of IN) and “physiological phase” (instead of MOMENT)

Line 33 …was based on this assumption, but, while the physiological phases in which apply irrigation have been described…but, there is less information…

Line 46 “firstly” instead of first time

Line 50-54 the concept must be better explained, it is not clear. maybe it was to short explained and leaves a lot of non-explained concept that can be hard to get.

Line 65-66 this point too is not clear. Maybe “thus, specific reference equations could be selected in each phase, according to the effect on leaf conductance.” (since you didn’t measure gas exchange)

Line 271 maybe better “isohydric/nonisohydric response”

Line 272-273 can be deleted (the percentage of roots in dry soil has been already indicated in the previous line, it looks like a repetition.

Line 276 From the reference you are citing (28), I think the sentence will be more correct as: “leaf conductance was affected by the presence of stress signals from roots, even with the same SWP”

Line 295 maybe “especially” instead of EVEN. Otherwhise I don’t understand the sense of the sentence.

 

Line 342 “Establishing”

 

English language is generally good, but for some parts that I indicated in the previous comments. 

Author Response

Reviewer 2

Thank you very much for your comments. Specific revisions are answered below.

Line 31 “on yield” (instead of IN) and “physiological phase” (instead of MOMENT)

Changed. But, instead of “physiological phase”, we have considered that it is better phenological phase

Line 33 …was based on this assumption, but, while the physiological phases in which apply irrigation have been described…but, there is less information…

Changed

Line 46 “firstly” instead of first time

Changed

Line 50-54 the concept must be better explained, it is not clear. maybe it was to short explained and leaves a lot of non-explained concept that can be hard to get.

We have included several sentences in order to explain

Line 65-66 this point too is not clear. Maybe “thus, specific reference equations could be selected in each phase, according to the effect on leaf conductance.” (since you didn’t measure gas exchange)

Our hypothesis is that the distance of the reference equations to the baseline would be related with the reduction in leaf conductance. For example, if they were parallel (first point), you can characterise that a small reduction in leaf conductance (90-100%) would be just a few distance from the baseline (I.e. -0.1 MPa). But greater reductions (i.e. 75%) would be in a parallel reference equation but with a great distance (i.e. -1 MPa). We have included new sentences that explain this point.

Line 271 maybe better “isohydric/nonisohydric response”

Changed in all the document

Line 272-273 can be deleted (the percentage of roots in dry soil has been already indicated in the previous line, it looks like a repetition.

Deleted

Line 276 From the reference you are citing (28), I think the sentence will be more correct as: “leaf conductance was affected by the presence of stress signals from roots, even with the same SWP”

Changed

Line 295 maybe “especially” instead of EVEN. Otherwhise I don’t understand the sense of the sentence.

Changed

Line 342 “Establishing”

Changed

Round 2

Reviewer 1 Report

The revised manuscript data better reflects the research conclusions.