The Effect of Foliar Spray Treatments with Various Biostimulants and Fertilisers on the Growth of M.9 Rootstock Stoolings

Round 1

Reviewer 1 Report

Dear authors,

The manuscript entitled "The Effect of Foliar Spray Treatments with Various Biostimulants and Fertilizers on the Growth of M.9 Rootstock Stoolings Cultivated with a Reduced Dose of Mineral Fertilizer" deals with an interesting topic. It is scientifically proven that the application of biostimulants can achieve higher yields and crop quality. In addition, their positive effect on the physiological parameters of plants is also proven.

The aim of the author was to prove the possibility of supplementing mineral fertilizers in the cultivation of M.9 Rootstock Stoolings using biostimulants and foliar fertilization. Similar approaches are necessary to achieve sustainability in agriculture, so I evaluate the experiment positively.

Nevertheless, I have a few comments:

I recommend English and stylistic editing of the manuscript.

The MM chapter requires special attention (see appendix).

Due to the fact that the author solved a multi-year experiment, I recommend evaluating the results presented in 3.1 as an average for the whole period.

Detailed comments are in the appendix.

Comments for author File: Comments.pdf

Author Response

All comments of the reviewer were addressed and appropriate changes were introduced.

Only sub-section 2.1 has not been split into two additional sections, as the name of the section also includes plant growth conditions. And separating a very short section (one sentence) would complicate the workflow.

The methodology did not specify exactly what amount of the biostimulator solution or fertilizer was applied, as it changed depending on the phase of plant growth, and more specifically on the leaf surface that was treated during the spraying treatments.

Complicated figures with different units were replaced with simple results presented in tables. The plant growth results were statistically compiled for each year separately due to the fact that plants were grown on the same site (soil) for three years, so the year was rejected as a variable. Therefore, the mean results for the three years total and for each treatment are without statistical variation designation.

Reviewer 2 Report

Dear authors, I sincerely appreciated your work with apple-tree and biostimulants because of the complexity of working with fruit rootstocks time needed to complete the data collection. However, I think this paper needs some work to improve and therefore change my recommendation.

Introduction:

The introduction is brief and goes straight to the point addressing the main aspects of this study. Nonetheless, the authors must undertake some changes:

1. General use of English. "Which" is a problem in some areas (in three consecutive lines 35, 36, 42, Which is used three times).
2. Line 42 "biostimulators" must be a mistake.
3. Several sentences have "according to some researchers" or "some researchers," I think it must be used some studies instead to avoid starting some sentences with "they".
4. Line 49 the word cultivation.

Material and methods

1. Points 2.1 and 2.2 should be reduced to one, and a table with the treatments and the application times should clarify the point. 
2. Point 2.3 is repeated twice. The first one could have the title "Stoolings growth and leaf gas exchange measurements."
3. The sentence in lines 126 and 127 must be deleted; It belongs to results.
4. The second point, 2.3 must be rewritten. Analytical methods should have at least a reference. The "universal method" need explanation.
5. 2.4 Title: Statistical Analysis and line 144 could start with "data analysis proceeded…."
6. Finally, The variable called "Efficiency of mother plants" is not described in material and methods, and this variable measures the Efficiency of who concerning to. 

Results

1. Data represented in figures 1, 2 and 3 should be expressed in another format. I suggest variables with no significant changes over the years such as Efficiency, diameter, and the number of roots could be grouped in a table and the rest in a figure.
2. Figure 2 shows and * in controls, and Efficiency and number of roots shows error bars. 
3. Generally, results in writing could be improved by adding countable differences between treatments and exploring the variation over the years of experiments. 

Discussion

1. Again as mentioned in the introduction, please avoid using "the author of the experiment" or "the authors." 
2. I think the discussion should address three major points:

• The first one should address the fact that all the biostimulants did not show significant differences with control plants in all the variables, except for leaf area and fresh weight.
• The second one is related to these two variables. All the biostimulants induced higher leaf weight and area, but not all of them induced higher photosynthesis rates, and this could be related to the significant reduction of the stomatal conductance by almost 40% in some treatments.
• The third one is related to the foliar application of biostimulants. These treatments showed similar leaf accumulations of macro and micronutrients. Plants provably did not show deficiency symptoms, and this should be highlighted. In addition, because the paper aims to reduce mineral fertilization by using biostimulants; Biostimulant treatments compensate for the lack of Efficiency of the mother plants compared with control? Is it worth it from the economic point of view? An economic comparison should be made.

Author Response

Almost all of the reviewer's suggestions were done. However, all growth results of plants are presented in the form of tables, and not only those growth traits that had no significant differences, as suggested by the reviewer. Three figures were not left for only two features (fresh weight of leaves and total leaf area) as this increases the volume of work with the introduction of additional tables showing other growth features.

Complicated graphs with different units were replaced with simple results presented in tables. The plant growth results were statistically compiled for each year separately due to the fact that plants were grown on the same site (soil) for three years, so the year was rejected as a variable. Therefore, the mean results for the three years total and for each treatment are without statistical variation designation.

Round 2

Reviewer 2 Report

The authors almost fulfilled all the recommendations made by the reviewer. My recommendation is to accept this paper, but the final decision is up to the editor.

Author Response

Two sentences were added in the conclusions regarding the economic aspect
of the treatments.

Author Response File: Author Response.pdf