Effects of Foliar and Soil Boron Fertilization on Yield, Leaf Physiological Traits and Fruit Attributes in Rainfed Almond Orchards
, Alfredo Aires 1,2, David Barreales 3, Manuel Â. Rodrigues 3, António C. Ribeiro 3, Berta Gonçalves 1,4 and Maria C. Morais 1,*
Round 1
Reviewer 1 Report
Dear Authors,
B is a specific element and, as indicated in the literature, the excess causes a reduction in yield in many plants (no wonder then that it belongs to the group of microelements). The article is quite nice, but I am asking the Authors to explain in detail why the extremely low yields of nuts were obtained in 2016, despite the fact that the other parameters (number of nuts, weight of nuts) were "typical" (Table 1).
Author Response
We thank you for the review and comments. In relation to the low yield observed in the second year of the study, several factors will have contributed to this result: alternate bearing pattern of the almond tree, climatic conditions observed during the flowering period of the year, and intense pruning executed in the year. Almond trees are prone to exhibit high (‘on’ year) and low (‘off’ year) yields in alternate years due to the tendency for individual spurs not to bear fruit in successive years (Tombesi et al. 2017). This phenomenon tends to be more pronounced in non-irrigated trees, such are these. Additionally, this pattern was aggravated by the occurrence of intense and continuous precipitation in spring (Figure 1), during blossom, which caused a marked flower drop in most trees, affecting pollination. This is particularly important for self-incompatible cultivars of almond (Vargas & Romero 1994), as used in this study (‘Glorieta’). The intense pruning performed in January of 2016 also contributed to the failure of production.
Vargas F.J., Romero M.A. 1994. Masbovera, Glorieta, and Francoli, three new almond varieties from IRTA. Acta Horticulturae, 373: 75-82. Doi: 0.17660/ActaHortic.1994.373.9
Tombesi S., Lampinen B., Metcalf S., Dejong T. 2017. Yield in almond is related more to the abundance of flowers than the relative number of flowers that set fruit. California Agriculture. 70: 68-74. Doi: 10.3733/ca.2016a0024.
Reviewer 2 Report
line50 .... replace "Moreover, this micronutrient is involved" with "this positive effect of boron could be due to its involvement in .....".
line57 ... you did not mention literatures about the effect of soil fertilization with boron
line 60 ... what is the crop the researchers used?
line77 ... there are notes under the title of the site description. you should add a table containing the chemical properties of the experimental site and its content of boron in particular, this will be useful in the discussion of your results. the concentration of any nutrient in the soil fluctuates from one year to another and you should not mention another literatures at this point "[2.16]". also, you are talking a lot about the site climate and the rainfall and temperature Which you did not use in discussing the results, please shorten it
line 108 ... why did you used this concentration (0.36 g L-1 B) particularly?
line 171 ... what did you mean about (Table S1), I found the titles of S1, S, and S3 without data
lines 180-181 ... this sentence should be written as a note below the table, please modify it in the other tables.
line 202 ... it is not necessary, you are already made the significance test. please remove it from the manuscript.
line 348 ... it is better to write "the results of this study...." than "our results ..."
line 372... delete "our"
Author Response
First of all, thank you for the constructive comments and suggestions. The responses are addressed bellow to each comment, with indication of lines where the changes can be seen in the “clean” version of the manuscript.
line50.... replace "Moreover, this micronutrient is involved" with "this positive effect of boron could be due to its involvement in .....".
RE: Thank you for your suggestion. The text was modified accordingly. Please see line 50.
line57... you did not mention literatures about the effect of soil fertilization with boron.
RE: We agree with your comment. As such, we have reformulated the sentence. Please see lines 57-59.
line 60... what is the crop the researchers used?
RE: We revised the sentence in order to mention the crop – almond. Please see line 61.
line77... there are notes under the title of the site description. you should add a table containing the chemical properties of the experimental site and its content of boron in particular, this will be useful in the discussion of your results. the concentration of any nutrient in the soil fluctuates from one year to another and you should not mention another literatures at this point "[2.16]". also, you are talking a lot about the site climate and the rainfall and temperature Which you did not use in discussing the results, please shorten it
RE: Following your suggestion, we added a new Table 1 with the results of soil properties. Please see lines 96-98.
In the Discussion, the site climate, mainly precipitation, were mentioned to justify the low yield in the second year. Please see lines 390-393.
line 108... why did you used this concentration (0.36 g L-1 B) particularly?
RE: Thank you for the question. The foliar B concentration was set based on the recommended B fertilization for rainfed almond orchards in Portugal (LQARS 2006).
LQARS (Laboratório Químico Agricola Rebelo da Silva). 2006. Manual de Fertilização das culturas. Instituto Nacional de Investigação Agrária, Lisboa
line 171... what did you mean about (Table S1), I found the titles of S1, S, and S3 without data
RE: Thank you for the question. Tables S1, S2 and S3 are added to the manuscript as supplementary material. Unfortunately, there was a mistake during the upload process.
lines 180-181... this sentence should be written as a note below the table, please modify it in the other tables.
RE: Thank you for the suggestion. The sentence “Different letters in each line indicate significant differences at p < 0.05 according to theTukey HSD test” was written below the tables, when necessary.
line 202... it is not necessary, you are already made the significance test. please remove it from the manuscript.
RE: Thank you for the suggestion. The sentence “Significant differences are marked in bold” was removed from the manuscript.
line 348... it is better to write "the results of this study...." than "our results ..."
RE: Thank you for the suggestion. The text was modified accordingly. Please see line 378.
line 372... delete "our"
RE: Thank you for the suggestion. The text was modified accordingly. Please see line 402.
Reviewer 3 Report
The authors of the manuscript have evaluated the impact of boron through the soil and foliar application on photosynthetic, yield and fruit quality of almond orchards during rainfed conditions. The works provide lots of information, and enough data. In this context, MS has its own importance. The authors have identified an important issue for sustainable agriculture. Hence, I suggest for publication of the MS after minor revisions as indicated below-
Line 25-27: Please incorporate the % gain of photosynthetic parameters for clarity
· Line 27-28: Almond yield and fruit characteristics were also enhanced (????), please mention increase, for ex. 15-25% as compared to control or absence of B application
· In Figure 1: Plz correct spell error (Aug in place of Ago) and Y-axis caption, regular style not caps as (Precipitation (mm)
· Why authors mention the 1971-2000 precipitation data, any specific reason behind this?
· In all tables, the different letters should be superscript, if possible
· Please correct the B concentration as B0, B1, B2 in place of B0, B1, B2
· Table 4 and Figure 3: Parameters unit should be correct
· Conclusion should also reflect limitations of the study
· English should be improved throughout the MS.
· Why photosynthetic (PN, gs, and E) and yield parameters have been studied avoiding other parameters?
Author Response
The authors of the manuscript have evaluated the impact of boron through the soil and foliar application on photosynthetic, yield and fruit quality of almond orchards during rainfed conditions. The works provide lots of information, and enough data. In this context, MS has its own importance. The authors have identified an important issue for sustainable agriculture. Hence, I suggest for publication of the MS after minor revisions as indicated below-
RE: Thank you for your positive feedback. The responses to your comments and suggestions are addressed bellow to each comment, with indication of lines where the changes can be seen in the “clean” version of the manuscript.
Line 25-27: Please incorporate the % gain of photosynthetic parameters for clarity
RE: Thank you for your suggestion. The sentence was reformulated to incorporate such percentage. Please see lines 27-28.
Line 27-28: Almond yield and fruit characteristics were also enhanced (????), please mention increase, for ex. 15-25% as compared to control or absence of B application
RE: Thank you for your suggestion. The sentence was reformulated to incorporate such percentage. Please see line 29.
In Figure 1: Plz correct spell error (Aug in place of Ago) and Y-axis caption, regular style not caps as (Precipitation (mm)
RE: Thank you for your criticism. The figure was corrected and the new one (Figure 2) was incorporated in the manuscript. Please see lines 112-115.
Why authors mention the 1971-2000 precipitation data, any specific reason behind this?
RE: We used this 30-year reference period to characterize the climatic conditions observed during the experiment. As far as we known, the 1971-2000 period is the last available one.
In all tables, the different letters should be superscript, if possible
RE: In all tables we used the typical presentation of significant differences (lowercase or capital letter) found in MDPI manuscript. For this reason, we decided to maintain the same format.
Please correct the B concentration as B0, B1, B2 in place of B0, B1, B2
RE: Following your suggestion, we replaced “B0, B1, B2, B3, F0 and F2” by “B0, B1, B2, B3, F0 and F2” in tables and figures.
Table 4 and Figure 3: Parameters unit should be correct
RE: Following your comment, the units of photosynthetic pigments and yield were corrected.
Conclusion should also reflect limitations of the study
RE: Thank you for the comment. A new sentence was added in the Conclusion section to reflect the limitations and needs of further studies. Please see lines 429-431.
English should be improved throughout the MS.
RE: The English was revised to provide clarity.
Why photosynthetic (PN, gs, and E) and yield parameters have been studied avoiding other parameters?
RE: In this study, we monitored several gas exchange (PN, gs, and E) and biochemical parameters (mainly leaf photosynthetic parameters), as well as RWC, and EL. We also evaluated the leaf chlorophyll fluorescence in 2015 but a malfunction in the equipment did not allow for reliable results. As such, we decided to include physiological data provided by gas exchange determination, RWC, EL, and complement this with yield data and fruit quality traits. Another manuscript with the chemical composition of almond kernels and their sensorial analysis is being prepared for submission.
