Plum Trees’ Leaf Area Response to Fertilization and Irrigation in the Nursery

Round 1

Reviewer 1 Report (New Reviewer)

Comments and Suggestions for Authors

A very interesting experiment describing the results of the leaf area of ​​maiden plum trees of two varieties under the influence of 4 levels of irrigation and fertilization. The methodology does not provide much important information, i.e. what rootstock was used for plum varieties, how leaf samples were taken to measure their area, how many of them were there at what specific time. Fertilization in August can seriously reduce the frost resistance of trees. Was the soil's macronutrient content tested? The description of temperature and precipitation in individual months is excessive. The description of the obtained results can also be reduced. On the other hand, the discussion should be extended to include the results of the same treatments on the growth of fruit trees in the orchard, not focusing only on the leaf area.

Comments for author File: Comments.pdf

Author Response

The study was conducted utilizing a 4 x 2 x 4 split-split-plot design with five replications, featuring plots of four two-year-old trees planted at a spacing of 0.7 x 0.25 m. The primary factor was irrigation, which included four levels (non-irrigated control; 10 mm; 20 mm; 30 mm), while the second factor was cultivar (Stanley and Cacanska Lepotica), and the third factor was fertilization with four levels (unfertilized control; N8P8K8; N16P16K16; N24P24K24). To achieve the three levels of fertilization (N8P8K8; N16P16K16; N24P24K24), a complex fertilizer with a ratio of 16:16:16 was applied in three increments (50, 100, and 150 kg/ha). The irrigation schedule was based on variations in soil moisture, with applications occurring on August 17, August 22, and August 27. Fertilizers were incorporated into the soil at a sampling depth of 15 cm on August 19, August 25, and August 29. The rootstocks were planted in the spring of 2023 and grafted during the summer of the same year. Leaf area measurements were conducted in August 2024, following leaf drop after the first frost, which typically occurs in October. Considering that the trees are removed from the second field of the nursery and prepared for sale, they are not affected by frost, since when frost occurs, the trees are already planted in the orchard. The leaf area was measured on one tree in each plot. One typical tree was chosen in each plot, normally developed, healthy, without defects. Different leaves of average size were chosen, located on the average annual growth area. Measurements were made on 10 leaves from each tree, and the arithmetic mean of the results obtained was calculated.  A leaf area meter was employed for these measurements, featuring a scanning speed of up to 20 mm/sec, a maximum width of 103 mm, a maximum length of 2 m, linear precision/repeatability of 1%, area accuracy of +/- 2%, perimeter accuracy of +/- 5%, and a resolution of 0.065 mm².

 

In this section of Materials and methods, I mentioned how the leaf samples were taken to measure their area and about the fact that fertilization in August did not affect trees’ resistance to frost, because they are in the nursery and in October they are removed and prepared for sale.

I mentioned in the Discussion the following In the same study, the effects of irrigation, fertilization, and variety on different morphological traits of plum, including shoot growth, shoot weight, crown diameter, branching growth, and tree yield, were also determined. Concerning the physiological traits in plum, the leaf area and photosynthesis rate were examined under the influence of irrigation and fertilization.

But I did not emphasize on the growth of fruit trees, because maybe the other 2 reviewers may find this irrelevant. This research is about leaf area…

Reviewer 2 Report (New Reviewer)

Comments and Suggestions for Authors

The manuscript addresses an important aspect of nursery management by evaluating the impact of fertilization and irrigation on the leaf area of plum trees, which has practical implications for improving fruit tree production. The experimental work is relevant and timely, particularly under changing climatic conditions and increasing demands for optimized resource use in horticulture. However, several areas need improvement before the manuscript can be considered for publication. The experimental design and methodology require more straightforward presentation, especially regarding the layout, treatment descriptions, and measurement intervals. Some parts of the text use informal or non-scientific language, and the results should be more clearly supported with appropriate statistical analysis. Tables and figures must be more self-explanatory, and terminology should be used consistently throughout the manuscript. Additionally, the introduction and conclusion sections could be strengthened by better connecting the findings to broader scientific literature and practical applications.

I encourage the authors to revise the manuscript carefully to improve its clarity, scientific rigor, and overall impact.

1. The current title — "Impact of Fertilization on the Leaf Area of Plum Tree in an Irrigated Nursery Setting" — captures part of the study, but based on the abstract, it's not fully accurate or comprehensive. It excludes irrigation as a variable, even though the study analyzes fertilization and irrigation effects. "Plum Tree" is singular, which sounds odd since you're evaluating two cultivars and multiple replications. Irrigated nursery setting” is vague and could be misread, meaning all treatments were irrigated, which isn’t the case (there was a non-irrigated control).
2. The abstract is informative but misses a few critical elements that would make it technically stronger and more complete. The abstract should begin with a concise statement of why the study was done. Right now, it jumps straight into the methods. Since two cultivars were studied, the abstract should indicate whether they responded differently to treatments—or confirm that they behaved similarly. While percentage increases are mentioned, it’s unclear whether they are statistically significant. The abstract does not mention the time during which the measurements were taken (e.g., one season, a specific growth stage, or full growing period). The conclusion is too general. It should highlight a practical implication or recommendation, such as optimal irrigation/fertilization levels for nursery management.
3. Remove any keywords that are already mentioned in the title, as repeating them adds redundancy and reduces the effectiveness of keyword indexing.
4. The purpose of the study is currently introduced abruptly without sufficient background or contextual foundation, which disrupts the logical flow of the introduction. To enhance clarity and coherence, the authors should first present the relevant background and problem statements—specifically those between lines 22 and 38—immediately following the statement and problem description. This reordering will provide a stronger scientific rationale and context, allowing the study’s objective to be justified and better integrated within the introduction.
5. Line 96 Research conducted in Romania has, which please specify.
6. The transitions between paragraphs (e.g., lines 36–39 and 48–50) could be smoother. Consider adding linking sentences that better connect irrigation practices with plant physiological needs.
7. There are several sections where similar ideas are repeated (e.g., lines 107–116 and 125–134). These can be combined or shortened for conciseness.
8. Some statements (e.g., 140–154) become highly generalized. Try to tie these general practices back to plum seedling nurseries specifically.
9. Reference Quality and Integration:
10. Ensure all references are recent and relevant.
11. Terms like "transpiration coefficient" (line 58) and “active moisture range” (line 104) should be briefly defined or referenced for clarity with a short explanation or example.
12. Several long sentences can be split to improve readability—for instance, lines 107–116 and 140–148.
13. The objective at the end (line 155) should be presented more clearly.
14. Terms like “fruit tree seedlings,” “plum seedlings,” and “rootstocks” are used interchangeably. Make sure these are clearly defined and consistently applied where appropriate.
15. The title "Natural Framework of the Experimental Field" sounds vague and unclear. It doesn’t specify what the section or its content covers.
16. Before using Roman numerals to represent months in the table, it is advisable to include a note or legend clarifying that these numerals correspond to specific months of the year. This will help readers interpret the data accurately without confusion.
17. The table title indicates that the climate data represent overall conditions of the broader research field or region. However, since the experiment was conducted specifically in the nursery, providing climate data directly from the nursery site would be more appropriate. If such localized data are not available, the authors should clarify this in the text and discuss how the broader regional climate data relate to the nursery conditions, highlighting any potential limitations this may impose on interpreting the experimental results.
18. The statement in lines 177–178 regarding the timing and location of the experiment is unclear and potentially confusing. The authors mention the experiment was conducted in "field II of the nursery," but this is the first time "field II" is introduced. No prior description or context about this specific location is provided. To improve clarity, the authors should introduce and describe “field II” earlier in the manuscript, ideally in the materials and methods section. Furthermore, separate and consistent terms should be used to distinguish between the planting period (2023) and the research period (summer 2024) to prevent ambiguity, as ROMAN letters have previously been used for months.
19. Change the table's location; it should be where it is/was 1^st time cited.
20. Add the unit of parameters in Table 1.
21. Line 180: The manuscript states that the average annual temperature is 11.81 °C (Table 1), but this average value is not presented or calculated in Table 1. Please either include the estimated yearly average temperature explicitly in the table or remove the statement if the given data cannot support it. Consistency between the text and table content is essential for clarity and accuracy. Revise for other parameters as necessary.
22. In Table 1, the authors use Roman numerals to denote months, whereas full month names are used in lines 177 to 191. This inconsistency may confuse readers. It is recommended to use a consistent format for months throughout the manuscript—either Roman numerals or full month names—and clearly explain the notation in the table caption if Roman numerals are retained.
23. Break section 2,1 into two sections for clarity.
24. In Table 2, the authors present a depth-wise analysis; however, this is not clearly described or referenced in the text between lines 203 and 231. It is essential that the authors first clarify the sampling locations or experimental setup in the preceding section before presenting depth-related data. Additionally, several parameters in Table 2 are given using abbreviations or terms such as "horizon" and "deep," which are not defined or introduced in the text. Clarification is needed on what these terms refer to— for example, whether "deep" relates to sampling depths or another context.
25. Tmin- Minimum threshold of what?
26. t/m3 and t/m³ are used, please check this.
27. I think section 2.2 should be section 2.1.
28. Line 252: What criteria or threshold values of soil moisture were used to determine when to irrigate?, How was soil moisture monitored? Which method or instrument was used (e.g., gravimetric, tensiometer, TDR)?
29. The experimental layout is somewhat unclear. It appears that only three different intervals were used for irrigation and fertilizer application, but the rationale behind selecting these specific intervals is not explained. Additionally, the total duration of the experiment is not clearly stated. For better clarity and reproducibility, the authors should specify the full experimental period, justify the choice of irrigation and fertilization intervals, and explain whether these intervals were fixed or based on specific criteria (e.g., crop growth stage, soil moisture levels, etc.).
30. Line 169, Formula 17 is mentioned but does not appear in the manuscript. Please clarify whether this refers to a referenced source or an actual equation within the text. Additionally, ensure that all equations used in the study are cited and explained at appropriate locations in the main text. Several equations are presented without proper citation or contextual explanation, which may confuse readers.
31. Some equations are italic, some are not; consider any one.
32. Line 284, ET, unit? And m3/ha or m³/ha
33. In the Results and Discussion sections, the authors refer to months using their full names (such as section 3.1 and Table 3), while in Table, Roman numerals represent the months. This inconsistency can confuse readers. Adopting a uniform format—either consistently using month names or Roman numerals throughout the manuscript—is recommended to enhance clarity and readability.
34. Rf1 or Rf₁? Check for all others.
35. The manuscript introduces several variables (e.g., Ri, Pe, ET, Rf1, M, Rf2) in the description below Table 3. Still, many of these are either not clearly defined or not directly discussed in the main text (lines 264–299), where the soil water balance and irrigation calculations are explained. For example, Rf1 and Rf2 are mentioned in the table note but do not appear in the equations or explanatory text, and terms like “Initial reserve” and “Final reserve” are not supported with definitions, methods, or actual data references in the methodology section. To improve clarity and consistency, ensure that all variables listed in table captions or figure legends are clearly defined and explained in the main text, especially in the Methods section.
36. Improve the figures quality.
37. Figure 1. Daily average consumption for plum seedlings in the nursery, consumption of what?
38. Add most recent studies to justify the results.
39. The conclusion provides a reasonable summary of the results. Still, some improvement is needed to make it technically strong and complete, such as clarifying the statistical significance of factors, “various NPK fertilisation methods”, and “watering norms”, and including a sentence on how the findings can inform field practices or nursery management (e.g., what growers should apply under certain conditions).
40. Line 659: The statement “Irrigation led to notable increases in leaf area, ranging from 4.42% to 14.27% when compared to the control group” comes across as marketing language. It would be more appropriate to support such claims with statistical analysis, such as indicating whether the differences are statistically significant. I suggest avoiding subjective terms like “notable” unless backed by proper statistical justification. Revise such types of statements throughout the manuscript.

Author Response

1. I changed the title, according to your suggestion
2. I improved the abstract with some additional information.
3. I changed the keywords.
4. I mentioned more information about the purpose of the study.
5. I deleted this sentence.
6. I rephrased this part.
7. I shortened these parts which contain similar information.
8. I rephrased these statements
9.  This point did not contain an observation.
10. I added 3 more relevant references.
11. I defined "active moisture range" and "transpiration coefficient" in the Introduction section.
12. Long sentences were rephrased or split.
13. At the end of the Introduction section I emphasized the research objective.
14. The different terms were applied where appropriate. In some cases I used fruit trees instead of fruit trees seedling (after grafting).
15.  This title was deleted and replaced with 2 other subtitles.
16. I deleted the Roman numerals for months and used full month names.
17. I mentioned in the Materials and methods that 

    Information regarding climate conditions was sourced from the Meteorological Station, which monitors the temperature and precipitation patterns for each area. The rainfall patterns were assessed using a rain gauge placed in the experimental field. - There are no potential limitations regarding climate conditions.

18. I described in the Materials and methods section what does the field II of the nursery mean, to make it clear for the readers. 
19. I changed the table's location.
20. I added the unit of parameters in Table 1.
21. I deleted the sentence that contained this value.
22. I used full months names, to be clear for the readers.
23. I broke section 2.1, according to the recommendation.

24. In subsection 2.3 is described the term "depth".

25. Tmin- Minimum threshold of soil humidity
26. I corrected the writing mistake.
27. I reorganized the Material and methods section, because another reviewer recommended me to move some parts from Results.
28.      

    To assess the direct water usage, the soil water balance was evaluated by measuring the soil water reserves at the beginning and the end of each month from April to September. Soil moisture content was determined using a gravimetric method, where soil samples were collected from the field at the beginning and midpoint of each month, weighed before and after being dried in an oven. The calculation of soil moisture was based on the difference between the two weight measurements using the formula [17]: [17]: 

                                 W=100 x (B – A) / A;                            (1)

    where W- represents soil moisture (%); A- mass of wet soil sample (g); B - mass of dry soil sample.

    When the soil moisture fell below 10%, it was deemed low, potentially signaling a water deficit, which could necessitate the application of irrigation. 
29. To achieve the three levels of fertilization (N₈P₈K₈; N₁₆P₁₆K₁₆; N₂₄P₂₄K₂₄), a complex fertilizer with a ratio of 16:16:16 was applied in three increments (50, 100, and 150 kg/ha). The irrigation schedule was based on variations in soil moisture, with applications occurring on August 17, August 22, and August 27. Fertilizers were incorporated into the soil at a sampling depth of 15 cm on August 19, August 25, and August 29. 
30. 17 refers to reference no. 17
31. I corrected the italic equations.
32. I mentioned the unit and corrected the writing mistake.
33. I also used full months names in Tables.
34. Corrected the writing mistake.
35.  I described the variables in the subsection Calculations
36. Unfortunately, this is how the statistic program generated the figures. 
37. Water consumption.
38. I added 3 more relevant references.
39. I mentioned that 

      It is essential for nursery owners and horticulture enthusiasts to consider various factors, such as soil conditions, species, variety, rootstock, density, and anticipated production when implementing irrigation and fertilization practices. Additionally, understanding the rainfall patterns, the low water permeability of the soil, and groundwater levels can be helpful for establishing appropriate irrigation standards. The optimal level of NPK in the field must be set after analysing a series of soil properties, knowing the requirements imposed by the crop and those related to ensuring a certain quantitative and qualitative level of production. It is also recommended to carry out chemical laboratory analyses on the qualitative and quantitative presence of various nutrients in the soil.

    I can not generalize what growers should apply and when, because every region (research field) has its specific climate conditions. Maybe the useful watering norms and NPK level suitable for my experimental field, is not appropriate for other research fields.
40. I deleted the term "notable".  I consider that results from the obtained results, that the differences are statistically significant. 

Reviewer 3 Report (New Reviewer)

Comments and Suggestions for Authors

Dear authors,

       Greetings!

     The objective of this research had been to establish the influence of irrigation, fertilization and plant variety on a physiological character in the plum species in the nursery. Based on the expected results of this research, it would be concluded that the efficient and optimal utilization of fertilizers within a rational fertilization system would be possible only by adhering to all the necessary requirements dictated by the cultivation technology. However here so-called the necessary requirements dictated by the cultivation technology couldn't be determined because the wrong data statistical analysis.

         According to the results which were statistically processed using ANOVA associated to 4 x 2 x 4 split-split-plot design in the manuscript, all the interactive effects were significant, so the optimal combinations between any two factors and among three factors had to be determined through the multiple comparisons with the protection of two-way ANOVA, in fact, the optimal combination among the irrigation, the cultivars and the fertilizers  were ignored completely in the manuscript.

      The section 3.1 might be transferred into the section materials and methods because it displayed how to carry on the treatment of the different irrigation treatments, meanwhile, how to carry on the fertilizer treatments needed addition in detail too. Additionally, the section abstract needed rewritting because some important results are loss.

Author Response

To establish the optimal combination, the value (leaf area) associated with each combination must be correlated with the costs associated with applying that combination (watering-fertilization for each cultivar). As is known, the costs associated with the studied combinations are not presented in this paper.
Table 8 compares the effects of fertilization on the leaf area of ​​each cultivar under the effect of different watering norms, as well as the comparisons between the two cultivars in terms of their capacity to capitalize on the different combinations between watering norms and fertilization treatments. These results are presented in section 3.5.
Regarding the leaf area of ​​the Stanley cultivar under 30 mm irrigation and fertilization with N24P24K24, a significantly higher value was recorded compared to the rest of the irrigation x fertilization combinations, except for the combinations: N8P8K8 and N16P16K16 under 30 mm irrigation conditions, respectively N16P16K16 and N24P24K24 for 20 mm irrigation, along with the treatment with N24P24K24 for 10 mm irrigation.
For the Cacanska Lepotica cultivar, the highest leaf area values ​​were recorded under the effect of the N24P24K24 combinations for 20-30 mm irrigation, associated with significant increases compared to the rest of the combinations except for the one related to N16P16K16 fertilization and 30 mm irrigation.

 

I transferred section 3.1. into the section Materials and methods, according to your recommendation. I also added some information in the abstract section.

Round 2

Reviewer 1 Report (New Reviewer)

Comments and Suggestions for Authors

The author has made additions to the publication. Either cultivar or variety should be standardized throughout the publication. The columns in table 1 should be corrected, too close together and the numbers overlap, one row in table 3 is also shifted. The statistics for the development of results should be more broadly defined, i.e. what was the variable factor, whether there were two or three (irrigation, fertilization, variety). The publication is too extensive in the description of the methodology regarding the measurements given in the graphs and then described (shortened)

Instead of the term plum seedling, the term (maiden plum tree) should be used

Author Response

I replaced "variety" with cultivar. I corrected Table 1, I used Roman numerals for the full month names and mentioned at the end of the table the meaning of each Roman numeral. I also mentioned that  "The study was conducted utilizing a 4 x 2 x 4 split-split-plot design with five replications, featuring plots of four two-year-old trees planted at a spacing of 0.7 x 0.25 m. The primary factor was irrigation, which included four levels (non-irrigated control; 10 mm; 20 mm; 30 mm), while the second factor was cultivar (Stanley and Cacanska Lepotica), and the third factor was fertilization with four levels (unfertilized control; N₈P₈K₈; N₁₆P₁₆K₁₆; N₂₄P₂₄K₂₄). "- regarding the statistics for the development of results.

I shortened a little bit the description of the graphs (methodology). I also used maiden plum tree(s), instead of plum seedling(s), according to your suggestion. 

Thank you very much for your support.

Reviewer 2 Report (New Reviewer)

Comments and Suggestions for Authors

The author has revised the manuscript as per the suggestions provided.

Author Response

Thank you very much for your suggestions and support. They helped me to improve the manuscript's quality. 

Reviewer 3 Report (New Reviewer)

Comments and Suggestions for Authors

Dear authors,

         Greetings!

     Although you have given some explanations to me about the questions on the data statistical analysis results, the method you insisted isn't  optimal really. I think perhaps you don't know the data statistical analysis method well, so I suggest you study how the interactive effect between two experiment factors influence the treat factors combination effect. 

Author Response

Thank you very much for your suggestion. I will take it into consideration for the future researches.  Also thank you for your support.

This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

See remarks (file)

Comments for author File: Comments.pdf

Comments on the Quality of English Language

No comments

Author Response

1. In the new Abstract section I included the obtained results (The application of NPK fertilization variants led to the recording of significant increases in leaf surface growth by 6.53-16.14% compared to the control. The addition of fertilization from 8 to 16 kg and from 16 to 24 kg, respectively, was effectively utilized by the plum trees that achieved significant increases of 180-226 cm2. The irrigation generated significant increases of leaf area by 4.42-14.27% compared to control).
2. I shortened the Introduction section, it was really too long. I mentioned the significance of using irrigation and fertilization in the nursery and some findings of other researches regarding this topic.
3. In the Discussion section I underlined the significance of using rational irrigation and fertilization in the nursery, I also mentioned some recommandations for nursery managers/ owners regarding, as a results of my research (including economic drawbacks- cost of irrigation and fertilization).

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The article presents an interesting and relevant study, as plant management in nurseries is key in forestry and agricultural development. Below are my suggestions to improve the quality of the paper.

 

Abstract

In my opinion, the abstract provides little information on the significance and context of the research. To enhance its impact, I recommend expanding on the study’s relevance, objectives, and key findings. A greater connection between the research question and its practical implications would improve its effectiveness.

 

Introduction

The introduction well-researched but dense, making it difficult to follow. Some sentences are overly long and complex. There are multiple instances where the same concepts (e.g., the importance of irrigation, nutrient management, and fertilization) are reiterated in slightly different ways.

Additionally, the section primarily relies on general statements, often lacking specific data or references to recent research findings. The citations mostly appear toward the end of paragraphs rather than integrating with the arguments of each paragraph. Furthermore, given the length of the introduction, several statements would benefit from citations supporting their claims. I suggest restructuring the introduction to improve clarity and reduce redundancy while ensuring that all variables (irrigation, nutrients, cultivars) are acknowledged and supported by rreferences.

 

Materials and methods

The section thoroughly explains the framework, providing enough details for replicability. However, it is recommended to avoid redundancy throughout the section.

Additionally, certain details are presented without clear justification. For example, the inclusion of spontaneous vegetation species is valuable, but their impact on the study is not explicitly discussed. Do these species compete with the cultivated plants or impact on irrigation needs? I think that this question should be addressed in the study.

Similarly, soil analysis results are presented, but their implications are not clearly stated. Does soil alkalinity affect plant growth or fertilizer efficiency in your case? I think this point is relevant, particularly in field nurseries planting rather than pots or container-grown plants.

 

Results

The results section could be better structured to clearly differentiate the effects of irrigation, fertilization, and cultivar. For instance, Section 3.1 (“Effect of Irrigation and Fertilization on Leaf Area”), actually starts discussing cultivar influence, which disrupts the logical flow. The organization of the results could be improved to highlight more effectively the main points of the research.

The Stanley and Cacanska Lepotica cultivars are discussed separately. However, should a direct statistical comparison between them relevant to highlight the results?

Many sentences list raw values ​​(e.g., "leaf surface area was between 4343 and 5008 cm²") without emphasizing their relative change. Consistently structuring results with a clear focus on percentage changes, statistical significance, and practical implications would improve comprehension.

 

Discussion

The discussion is quite short, and lacks references to previous studies that could help validate or contrast the main findings. Moreover, the discussion starts with a broad introduction about Romania’s agricultural sector, which feels disconnected from the results previously showed.

The study also does not address limitations such as climatic variability and soil heterogeneity, despite mentioning these factors and conditions as influential in nursery plant development. I think they should be considered for the discussion.

Also, do you think that the increased fertilization has environmental or economic drawbacks (nutrient leaching, costs of irrigation). I believe that the article would benefit from providing actionable recommendations for nursery managers based on the results.

 

Conclusions

The conclusion effectively summarizes the effects of fertilization but does not translate the findings into clear recommendations for farmers or nursery managers. Thus, I would recommend to strength the conclusion section.

The conclusion states the effects of fertilization but does not explicitly translate them into recommendations for farmers or nursery growers. In addition, a few sentences or responses seems vague: “fertilization had a significantly higher influence on this character”.

While the study analyzes both irrigation and fertilization, the conclusion only mentions fertilization. Finally, the suggested future research direction could be more specific.

Comments on the Quality of English Language

The english could be improved to more clearly express the main ideas by enhancing repetitiveness and readibility. 

Author Response

1. In the Abstract section I mentioned the goal and the key findings of the research. ( The goal of this research was to investigate the variation of leaf area in trees of Cacanska Lepotica and Stanley plum cultivars under different irrigation (non-irrigated control; 10 mm; 20 mm; 30 mm) and fertilization (unfertilized control; N8P8K8; N16P16K16; N24P24K24) treatments. The study was conducted at a private nursery located in Romania's northwest using a 4 x 2 x 4 split-split-plot design with five replications. The application of NPK fertilization variants led to the recording of significant increases in leaf surface growth by 6.53-16.14% compared to the control. The addition of fertilization from 8 to 16 kg and from 16 to 24 kg, respectively, was effectively utilized by the plum trees that achieved significant increases of 180-226 cm2. The irrigation generated significant increases of leaf area by 4.42-14.27% compared to control).
2. I shortened the Introduction section, it was really too long. I mentioned the significance of using irrigation and fertilization in the nursery and some findings of other researches regarding this topic.
3. In the Materials and methods section, I eliminated the spontaneous vegetation, it is not relevant for the research. It does not influence the research and the obtained results. Regarding the alkalinity of the soil, I mentioned that fruit trees prefer soil with a neutral pH, slightly acidic or slightly alkaline soil.
4. I restructured the Results with the following sections 31. Analysis of watre balance and consumption under different irrigation conditions (I described the elements of soil water, the daily average consumption for plum seedling, the dynamic of soil humidity under different irrigation conditions); 3.2.Analysis of the variance components; 3.3. Effect of Irrigation and Cultivar on Leaf Area; 3.4. Effect of Irrigation and Fertilization on Leaf Area; 3.5. Effect of Cultivar and Fertilization on Leaf Area; 3.6. Combined Effect of Irrigation, Fertilization and Cultivar on Leaf Area.

I also discussed the two cultivars together. I restructured the sentences, highlighted the percentage changes and statistical significance.

5. In the Discussion section I underlined the significance of using rational irrigation and fertilization in the nursery, I also mentioned some recommandations for nursery managers/ owners regarding, as a results of my research (including economic drawbacks- cost of irrigation and fertilization). I also mentioned that in the present research, it is worth noting that both climate and soil are favorable to tree cultivation and do not represent limiting factors.
6. In the Conclusions section, I highlighted the obtained results using percentage. Also mentioned irrigation, not only fertilization, as previous.

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

Despite the fact, that the article is unpublishable in its current form, I state that it can be published after 80% revision.

Specific recommendations, questions and comments are also listed in bubbles within the text.

Line

8- The main, most important findings should be included in the abstract. See the instruction for authors.

19 - The introduction is disproportionately extensive (it has 5 pages) and yet it lacks global information about what is known in the given field and what is currently being researched worldwide. The chosen style has the character of presenting knowledge from a textbook for university students. This fact is also confirmed by the list (references), in which the first 14 works consist of textbooks - books, or. of the total number of 35 cited works, most of the works are of a book nature, which confirms that the introduction does not present the latest knowledge in the given field (verified truths are written in books). The introduction must be created anew.

28 - Avoid such expressions (our country).

349 - That's the dimension. Add the units.

350 - Write clearly what the distance between the rows is and what the distance in the row is (0.06 m)

352 - Please provide the planting date and the age of the trees at the time of planting. The pictures below show that these are older trees. The methodology must be written clearly – in detail.

353 - add the word "NPK"

355 - Write the date or growth stage when you applied the fertilizer. Indicate the depth of the soil to which you applied the fertilizer. You write that you used only one fertilizer, NPK 16:16:16. You did not use other fertilizers. You used that one fertilizer in three doses (50, 100 and 150 kg). In this context, do not use the designation 50 kg N8P8K8 or 150 kg N24P24K24, this is incorrect, because you did not apply such fertilizers.

This is how you can designate variants.

355 - Table 3 shows that a control, unfertilized variant was also established. You must state this here, in the text. In Table 3, you have incorrectly labeled the variants of the experiment.

365 - I recommend deleting the word model.

365 - When was the AM 350 used for measurement? Please indicate the growth phases or at least the dates.

372 - Is this an AM 350 device?

374 - All parameters you need for calculations (which are given in the equations) must have described methodological procedures for their determination. You must write the procedures by which you obtained them (how and when you collected the samples, the name of the author of the methodology). Add the names of the authors of the methodologies to the list of used literature.

415 - NPK dose - It's not the NPK doses, nor the designation of the experiment variants, but the designation of what you compared with what. Rework it. It can't stay like this.

434 - For what level of significance do the letters a, b, c, or y, z apply?

Fill in this information below the table.

608 - This is not a discussion. You are missing an explanation of the reasons for the measured parameters. You should discuss why you recorded the specific numbers of the mentioned parameters. You did not compare your measured parameters with the results of other authors dealing with this issue. Try to combine the results and discussion into one chapter and immediately evaluate the measured parameters, confront them with scientific knowledge.

 

Comments for author File: Comments.pdf

Author Response

1. In the Abstract section I mentioned the goal and the key findings of the research. ( The goal of this research was to investigate the variation of leaf area in trees of Cacanska Lepotica and Stanley plum cultivars under different irrigation (non-irrigated control; 10 mm; 20 mm; 30 mm) and fertilization (unfertilized control; N8P8K8; N16P16K16; N24P24K24) treatments. The study was conducted at a private nursery located in Romania's northwest using a 4 x 2 x 4 split-split-plot design with five replications. The application of NPK fertilization variants led to the recording of significant increases in leaf surface growth by 6.53-16.14% compared to the control. The addition of fertilization from 8 to 16 kg and from 16 to 24 kg, respectively, was effectively utilized by the plum trees that achieved significant increases of 180-226 cm2. The irrigation generated significant increases of leaf area by 4.42-14.27% compared to control).
2. I shortened the Introduction section, it was really too long. I mentioned the significance of using irrigation and fertilization in the nursery and some findings of other researches regarding this topic.
3. Deleted the expression (our country); I wrote the distance of 0.7 x 0.25, it is known that in Horticulture, first is expressed the distance between the rows and second the distance in the row.
4. I mentioned the age of the trees and the planting date (The research was organized using a 4 x 2 x 4 split-split-plot design with five replications, and plots of four trees (two years old) planted at 0.7 x 0.25 m. Irrigation with four levels (non-irrigated control; 10 mm; 20 mm; 30 mm) was used as the main factor, cultivar (Stanley and Cacanska Lepotica) as the second factor and fertilization with four levels (unfertilized-control; N8P8K8; N16P16K16; N24P24K24) as the third factor. To generate the three levels of fertilization (N8P8K8; N16P16K16; N24P24K24) complex fertilizer 16:16:16 was applied in three doses (50, 100 and 150 kg/ha). The timing of irrigation was determined based on soil moisture variation and the minimum ceiling being reached. Thus, irrigation was applied on August 17, August 22, August 27. The fertilizers were applied on August 19, August 25, and August 29 by incorporating them into the soil at a depth of 15 cm. The rootstocks were planted in the spring of 2023 and grafted in the summer of the same year. Given that the leaves fall after the first frost, which usually occurs in October, the leaf area measurements took place in August 2024. The leaf area meter device was used to calculate the leaf area, has scanning speed up to 20 mm/sec, maximum measured width 103 mm, maximum measured length 2 m, linear precision/repeatability 1%, area +/- 2%, perimeter + /- 5% and a resolution of 0.065 mm²).

First, they were planted rootstocks in the nursery and after grafting, they became trees. I deleted the photos, because they were not relevant, but the photos resembled the fruit trees after grafting, in the second field of the nursery.

I also mentioned the time when irrigation and fertilizer were applied, also the depth of the soil. Also mentioned that to generate the three levels of fertilization (N8P8K8; N16P16K16; N24P24K24) complex fertilizer 16:16:16 was applied in three doses (50, 100 and 150 kg/ha).

5. I deleted Table 3.
6. I deleted the word model.
7. I mentioned that given the fact that the leaves fall after the first frost, which usually occurs in October, the leaf area measurements took place in August 2024.
8. I mentioned the author of the methodolgy and the procedure (The data regarding the leaf area were statistically processed using ANOVA associated to 4 x 2 x 4 split-split-plot design, and LSD test at p<0.05. The results were expressed as mean ± standard error).
9. Different letters (a, b, c) in the column indicate significant differences (p < 0.05) between watering norms; Different superscript letters (x, y, z) in the row indicate significant differences (p < 0.05) between NPK levels. Capital letters were used for irrigation mean (A, B, C, D) comparisons- mentioned below the table
10. In the Discussion section I underlined the significance of using rational irrigation and fertilization in the nursery, I also mentioned some recommandations for nursery managers/ owners regarding, as a results of my research (including economic drawbacks- cost of irrigation and fertilization). The investigations carried out so far on the use of irrigation and fertilization in the nursery refers to fruit shrubs or woody species, not to the fruit nursery, so it is impossible to compare the different results obtained.

 

Author Response File: Author Response.pdf

Reviewer 4 Report

Comments and Suggestions for Authors

First of all, I would like to thank Horticulturae for trusting me to contribute to the evaluation of this manuscript.

Below are some considerations, as well as highlights I made in the manuscript (attached).

My specific comments are:

1) The Introduction is very long and contains very well-consolidated information that does not need to be presented. The introduction is well written, but it seems more like a chapter in a book about plant nutrition. It should be more effective in explaining the study's hypotheses.

2) It is known that they will study irrigation, cultivars and fertilization, but the objective is not clearly written and it is not clearly identified where the authors want to get to.

3) The factors are my biggest question. I do not agree with the factor levels. Applying 0, 10, 20 and 30 mm is not a scientific way to find the best water demand of the seedlings (different stages and climate). Why not work with percentages of evapotranspiration measured daily to establish the watering allocation for the next week? Why work with fertilizer containing the same proportion of N-P-K?  I do not see this methodology as the most correct one to carry out the search for better soil fertilization and plant nutrition. For the nutrient levels in the soil, there are different doses of each nutrient to be replaced. A study of response curves could be done, with doses for each nutrient or with a factorial of them (studying the interaction).
I don't see any point in working with doses of the same fertilizer where increasing the dose increases the amounts of N-P-K in the same proportion.

4) Create a subitem (2.4) explaining how the statistical analyses were performed.

5) As I do not agree with the treatments I did not read the Results, Discussion and Conclusion items.

6) There are no callouts for figures 1 and 2 in the text before their introductions. 

I hope you understand my observations and that they are useful to you.

Comments for author File: Comments.pdf

Author Response

1. I shortened the Introduction section, it was really too long. I mentioned the significance of using irrigation and fertilization in the nursery and some findings of other researches regarding this topic. Also mentioned the objective (The objective of this research has been to establish the influence of irrigation, fertilization and plant variety on a physiological character in the plum species in the nursery. Based on this research, it can be concluded that the efficient and optimal utilization of fertilizers within a rational fertilization system is possible only by adhering to all the necessary requirements dictated by the cultivation technology. Effective agricultural techniques, even in conditions where lower doses of fertilizers are used, can lead to increased crop yields due to the growth in the fertilizer utilization coefficient. The efficiency of the fertilization system is higher when the physical-chemical properties of the fertilizer are considered and a differentiated application is made, corresponding to the soil properties and the biological particularities of the species).
2. I can not change anymore the factors level, unfortunately. But I can take the advice into consideration, for the next researches. We usually use these amounts of NPK in the nursery.
3. I mentioned the how statistical analysis were performed (The data regarding the leaf area were statistically processed using ANOVA associated to 4 x 2 x 4 split-split-plot design, and LSD test at p<0.05. The results were expressed as mean ± standard error).
4. Figure 1 and 2 were replaced with another one.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

No comments regarding this revised version

Reviewer 2 Report

Comments and Suggestions for Authors

The authors have conducted major changes. However, there are parts of the article that were not clarified. Below are my comments about the modifications and the current form of the paper.

 

Abstract

In my opinion, the abstract has been considerably improved. It provides information about the significance of the study and the main results obtained. However, I think it would benefit from a final phrase highlighting the main conclusion of the research, since it ends quite abruptly.

 

Introduction

The introduction has been significantly modified, and several references have been added to support the main statements. However, there are still minor errors that should be corrected (grammatical or writing errors) and others that could be improved (English structure). For example, in page 2, line 76 the phrase “it can enhance product quality, extends the growing season” can be found. Also, in page 2, line 92 the phrase “show that that the situation” can be found. I would suggest a thorough revision of the text to correct such errors.

Overall, the main structure of the introduction remains now clear and concise, with relevant information added to support the primary statements.

 

Materials and methods

This section would still benefit from improvements. The Table 1 and Table 2 have been unified, eliminating information about the years 2022 and 2023. I would suggest specifying the temporal resolution of the study, in order to justify the inclusion of data from 2024 only.

New Figures 2-5 in Results section show the humidity dynamics of the soil. However, the Materials and methods section does not explain how the humidity was monitored throughout the study.

 

Results

The section has been thoroughly modified and improved. A better comprehension of the practical implications has been achieved during the results section. However, there are minor errors that should be corrected. For instance, captions of Figures 2-5 show the grammatical error “soiul” (Dynamics of soiul humidity). Please, refine the body of the text.

 

Discussion

Please, avoid phrases such as “according to Carl Rosen and Bert T. Swanson, in their research entitled Fertilization for Nursery and Landscape Management”. After a statement supported by the literature, specify the reference by using numbers (e.g., “according to Rosen and Swanson [number of the reference].

Conclusions

The conclusions highlight the main results obtained and the relevant of the findings. However, there are grammatically confusing and slightly unclear comments, such as “addition of fertilization” instead of “fertilizer additions”, or “increases of leaf area” instead of “increases in leaf area”.  

Comments on the Quality of English Language

The english could be grammatically improved.

Reviewer 3 Report

Comments and Suggestions for Authors

Please complete, correct, indicate:

Line

14 - It is not clear from this statement how many kg of nutrients (how much N, P, K) you applied. Please provide this information.

15 - Please provide information on what irrigation doses caused these increases.

199 -202 - Please provide at least the names of the methodologies used to determine these parameters. Ideally, you would also describe them in a few words.

Reviewer 4 Report

Comments and Suggestions for Authors

Dear Authors and Editor, I appreciate your trust in listening to me.

I hate to disapprove a study. However, despite recognizing the improvements made to the manuscript, I maintain my previous understanding and opinion, which is why I do not see a scientifically correct study. It is correct from the point of view of execution, but not of conception. Applying 0, 10, 20 and 30 mm of water is not an irrigation method for me, it is giving water to the plant without understanding the parameters that will influence this water demand. Increasing the NPK dose seems very incoherent to me and, again, unscientific. The fact that the plant responds positively does not mean that it needs these three elements in the way proposed. Most likely, the proportion changes as the dose is increased. In other words, when going from 50 to 150 g NPK in the proportion of 1 to 3, which nutrient is the increase due to? Could it be that we are not consuming luxury amounts of some of these three nutrients? I am sorry, but I maintain my decision not to accept this manuscript. 
Thank you for your attention.