Influence of Spirulina Extract on Physiological, Qualitative, and Productive Traits of Four Sugarcane Genotypes

Thank you very much for taking the time to review this manuscript.

3. Point-by-point response to Comments and Suggestions for Authors

Comments 1: Page 1. Line 34. Because they. They, does it refer to the growth parameters?

Response 1: Thank you for pointing this out. (They refer to microalgae and cyanobacteria in line 35)

Comments 2: (Page 1. Line 39-40. g 100 g-1. Write g 100 g-1)

Response 2: Agree. We changed it.

Comments 3: (Page 1. Line 38. Protein. Write this word as protein)

Response 3: Agree. We changed it.

Comments 4: Page 1. Line 40. Eliminate protein

Response 4: Agree. We eliminate protein

Comments 5 : Page 1. Line 40-42. Changer the position of this paragraph to line 37 before as stated

Response 5: Agree. We changed the position

Comments 6: Page 2. Line 46. Are the Seaweed extracts (SEs) the same that Spiritual algae extracts (SEs)?

Response 6: No

Comments 7: Page 2. Line 64. Sugar cane or sugarcane?

Response 7: sugarcane

Material and Methods

Comments 8: Page 2 Line 80, 85. How was spirulina extract obtained? Does the powder diluted in water to prepare the different concentrations? How the spirulina extract was applied in the sugarcane field? How many liters per plot?

Response 8: How was spirulina extract obtained? Spirulina extract obtained from National Research Center located in Dokki, El-Giza, Egypt as powder. Does the powder diluted in water to prepare the different concentrations? Yes. How the spirulina extract was applied in the sugarcane field? By spring on sugarcane leaves at three time (at 60,90 and 120 days after sowing). How many liters per plot? 3.5 liters per plot at every time. 

Comments 9: Page 2. Line 86. Plant cane and first ratoon were both harvested at 12 months after planting? Generally, the plant cycle is longer than that of ratoons. What was the planting distance?

Response 9: Plant cane and first ratoon were both harvested at 12 months after planting?yes. What was the planting distance? 1 meter between rows. 

Comments 10: Page 2. Line 88-90. Was the experiment fertilized? If fertilization was carried out, then how did this factor into the effect of the algae extracts applied.

Response 10:Was the experiment fertilized?yes.If fertilization was carried out, then how did this factor into the effect of the algae extracts applied.The cane leaves were sprayed with algae extracts and fertilization was carried out at the soil. We utilized spirulina extract to enhance crop yield and juice quality in the same area.

Comments 11: Page 2. Line 94. Minolta SPAD-502 don’t measure chlorophyll content. It measures a relative value of chlorophyll. It was calibrated with the spectrophotometric method?

Response 11: We agree with this comment. We understand the mistake and corrected it. It was calibrated with the spectrophotometric method? No  

Comments 12: Page 2. Line 95. How many leaves remained on average per plant at harvest in each genotype studied?

Response 12: We didn't record these data at the harvest. It may be from 10 to 15 leaves per plant.

Comments 13: Line 107-121. Brix% or Brix %, Sucrose% or Sucrose %, sugar recovery% or sugar recovery %

Response 13: Brix %, Sucrose %, sugar recovery %. We corrected it.

Comments 14:Page 3. 123-125. What was the experimental design applied for data analysis? Which Software was used?

Response 14: Split-split plot design. Statistical analysis of data was done using a Co-Stat Software (2004) computer program.

Results

Comments 15: Page 3. Line 133. (SE) or (SEs)

Response 15: SE

Comments 16:Page 5. Line 218. Positive correlations with chlorophyll must be taken with caution, since they may be subject to the effect of other factors such as NPK supply by the soil, or abiotic

Response 16: Agree.We have control without being treated with spirulina extracts. 

Comments 17:Page 7. Figure 2. Why does first ratoon have a better response to spirulina extract than plant cane? Generally, the production (growth and millable tillers) and quality traits are lower in ratooning cycles.

Response 17:Sugar cane planting in Egypt grows for 3-5 years in the field and the growth starts to decrease from the third year, also first ratoon has more tillers than the plant cane.

Comments 18: Page 7, 8, 9. Tables 2, 3 and 4. Please indicate the respective statistics in the average column

Response 18: Mean in the column expresses the average behavior of each trait during plant cane and first ratoon.

Discussion

Comments 19:Page 10. Line 283. Gibberlins or gibberellins

Response 19: gibberellins

Comments 20: Page 10. Line 287-289. How do you explain the effect of low concentrations of spirulina on the accumulation of sucrose in sugarcane?

Response 20: May be the presence of micronutrients, vitamins, amino acids, as well as growth-promoting substances such as IAA, IBA, and gibberellins (A & B), in spirulina extract has a noteworthy effect on sucrose at lower concentrations. However, excessive hormones or a high mineral concentration at higher concentrations can hinder the accumulation of sucrose. (I did not find references to explain this point)

Comments 21: Page 11. Line 306. Number of tillers is number of millable tillers?

Response 21: yes

Thank you very much for taking the time to review this manuscript

 Point-by-point response to Comments and Suggestions for Authors

Comments 1: Edit tables so that headings and data are on the same page - maybe use a smaller font

Response 1:We agree with this comment. We done

Comments 2:  Suggest how spirulina may act in sugar can supported by some of the experimental data with some scientific references eg

• Nutrient boost

• Bioactive stimulation

• Defence against abiotic and/or biotic stresses

• Improves photosynthesis

Response 2: Agree. However, I did not find a reference to this point because there are a few references that used spirulina extract on sugar crops. This is a problem we found in writing.  

 Comments 3: Explain the term ton/fed with reference to sugar cane production

Response 1:fed=feddan. Feddan is the common unit used for measuring farmer land area in Egypt, and it amounts to 4200 square meters .

Thank you very much for taking the time to review this manuscript

 Point-by-point response to Comments and Suggestions for Authors

Comments: To this end, a more detailed description of the cultivation method and Spirulina methods of administration is necessary in the Materials and Methods section.

Response 1: We agree with this comment. We done

Comments 2: Lines 93-94: How was leaf width determined? 

Response 2: At the middle part of the leaf blade were obtained

Comments 3: - Line 100: Was the soil area per plant not a constant value?

Response 3: No

Comments 4: Line 117: Remove the quotation marks

Response 4: Agree. We removed it

Comments 5: Line 142: There is a punctuation error.

Response 5: Agree. We corrected it

Comments 6: Tables 2, 3, 4: The most suitable statistical method for processing this kind of experimental data is ANOVA with interaction analysis. The authors must show the levels of significance for differences between mean values, using different letters and Tukey’s test. I suggest presenting the data graphically.

Response 6: We agree with this comment. We utilized distinct letters to represent the mean value.

Comments 7: Table 5: The authors can evaluate the effects of Spirulina on the association between variables  by applying a multivariate analysis to the data. I suggest using a discriminant analysis of parameters that differentiated the four data groups: controls, 0.1%, 0.2%, and 0.3% Spirulina extract.

Response 7: Thank you for your suggestion. But we can't do that in our software