The Electrical Conductivity and Drying Method Changed the Secondary Metabolite Content and Photoprotective Effects of Hydroponically Cultivated Agastache rugosa Kuntze
Round 1
Reviewer 1 Report
Review Agronomy 2561065
Line
27 use keywords additional to Title
30-36 remove
95 plant density? Please mention
96 use 4 weeks after sowing instead of “then”
98 use mmol/l per element instead of ppm per fertilizer . with mmol/l figures are comparable; in ppm reader does not now what you are doing.
98 did you add any micro elements? Please add in tekst, see also line 106
No specialist on methods 121-178
195 Unclear why you choose week 6, 8 and 9. Is that specific growing period in soil? Are there other reasons. Wouldn’t it be better to grow a longer period, 10 or 12 weeks or just as long as in traditional cultivation method? Please explain.
244/245 sentence is clear from Table. However any reason why these differences? Now you sampled directly after cultivation/drying. Is there any influence of the drying method after 4 week or 8 or 12 wks after cultivation?? Explain or in Discussion. Additional: you don’t show data about week 8. Perhaps you have already similar results in absolute quantity of substances. In that case growth period might be shorter. If data are available, say something about it.
254 1) and 2) unclear in Table
341/343 excessive EC in tomato cultivation is often caused by Na+ accumulation, but not necessarily. You can also supply an EC of 4 by useful fertilizer. So your argument used is not valid. Besides ëxcessive EC” is beyond EC of 6-8, not at 4. So rewrite.
440 after 9 weeks of growth (Days after planting)
Author Response
We appreciate your sincere comments and we apologize our mistakes in the original manuscript. We tried to correct and change as your comments appropriately in the revised manuscript. We trust we have addressed all of your concerns.
27 use keywords additional to Title
- Keywords were added using the title as you mentioned.
30-36 remove
- the first paragraph you mentioned were removed.
95 plant density? Please mention
- information of planting density was added as you mentioned (Line 91).
96 use 4 weeks after sowing instead of “then”
- We corrected it (Line 91).
98 use mmol/l per element instead of ppm per fertilizer . with mmol/l figures are comparable; in ppm reader does not know what you are doing.
In hydroponic cultivation, fertilizers are used in the form of compounds such as potassium nitrate, calcium nitrate, and potassium phosphate rather than individual minerals like nitrogen, phosphorus, and potassium.
Therefore, in this manuscript, parts per million (ppm) was used as a measurement unit to easily calculate the quantity of fertilizers. And We have added the names of fertilizer manufacturing companies to provide the necessary information for individual mineral content calculation.
98 did you add any micro elements? Please add in tekst, see also line 106
As you commented, we have added the information of micronutrient (Line 95-96).
The ratio of each nutrients in solutions was same with that of modified Otsuka House’s nutrient solution, but the concentration of the total nutrients was adjusted to 1.5, 2.0, and 4.0 dSžm-1, respectively.
No specialist on methods 121-178
195 Unclear why you choose week 6, 8 and 9. Is that specific growing period in soil? Are there other reasons. Wouldn’t it be better to grow a longer period, 10 or 12 weeks or just as long as in traditional cultivation method? Please explain.
Thank you for your pointing.
Vertical farms aim to achieve economic efficiency through use of multi-tiered cultivation units (each tier is approximately 60 cm in height) and aim rapid turnover rates. In addition, it is important to harvest plants before lignification to improve extraction yield of their secondary metabolites.
In the preliminary study, the A. rugosa plants began lignifying and exceeded height of 60 cm at 9 week. Therefore, the cultivation period was determined to be 9 weeks in this study.
Plant’s response to changes of EC in the hydroponic cultivation is usually noticeable from around two weeks after treatment. Therefore, we sampled the A. rugosa plants before treatment (week 6) and, two and three weeks (week 8 and 9) after treatment.
244/245 sentence is clear from Table. However any reason why these differences? Now you sampled directly after cultivation/drying. Is there any influence of the drying method after 4 week or 8 or 12 wks after cultivation?? Explain or in Discussion. Additional: you don’t show data about week 8. Perhaps you have already similar results in absolute quantity of substances. In that case growth period might be shorter. If data are available, say something about it.
The reasons why different drying methods change the secondary metabolites contents is elucidated in discussion section. In brief, we surmise that some enzymes could have worked in cold-air drying process and they changed the chemicals in sample.
We did not testify the drying methods for earlier week samples because we focused on industrial use of A. rugosa in present study. We decided that 9 week is the optimum cultivation period for A. rugosa in our installation; therefore, we only verified the drying methods for 9 week plant. The assessment of different drying process is required in industries because companies use different drying process considering their conditions like costs and accessibilities. Thus, we wanted to explain the effects of drying condition in the study.
As mentioned in the previous your comment, we have decided cultivation period of 9 weeks as the optimal duration for cultivating A. rugosa plants in the vertical farm.
In Figures 3C and 3E, biomass of A. rugosa is over 30% larger in week 9 than 8. Therefore, to ensure both an ample biomass and secondary metabolites (extraction efficiency), week 9 is the most efficient harvesting point.
In addition, we investigated growth indicators (week 6, 8 and 9) to determine if EC changes caused stress to the A. rugosa plants. We also analyzed secondary metabolites and photo-protective effectives of A. rugosa on week 9 (the most efficient harvesting timing).
254 1) and 2) unclear in Table
We corrected in in the table 1.
341/343 excessive EC in tomato cultivation is often caused by Na+ accumulation, but not necessarily. You can also supply an EC of 4 by useful fertilizer. So your argument used is not valid. Besides ëxcessive EC” is beyond EC of 6-8, not at 4. So rewrite.
We gladly embrace your valuable comment and we recognized that our description could confuse readers. We slightly revised the relevant sentence. And we rewrote some sentence could emphasize that our condition did not cause any evident osmotic stress like you pointed.
(Line 348-349) Therefore, we concluded that EC 2.0 to 4.0 do not cause osmotic stress and they would be the optimal conditions to obtain lavish A. rugosa.
440 after 9 weeks of growth (Days after planting)
We corrected it (Line 441).
Reviewer 2 Report
Agastache rugosa, commonly known as Korean mint, blue licorice, or purple giant hyssop, is a species of plant native to East Asia. The leaves of Agastache rugosa are frequently used in traditional medicine due to their antimicrobial, anti-inflammatory, and antioxidant properties. This paper discusses the effects of cultivation and drying methods on A. rugosa production and proposes alternative industrial production techniques. The results presented in this paper are clear and intriguing, making them worthy of publication. However, before its publication, the authors should consider addressing the following points.
My primary concern involves the term "electrical conductivity" (EC), which is hypothesized as a key parameter for the hydroponic cultivation of A. rugosa. I understand that the EC value of the nutrient solution in hydroponics is crucial as it signals whether the necessary minerals and nutrients are present in the correct balance. If the EC value is too high, the salt concentration could become excessive and potentially detrimental to the plant. It is undoubtedly true that monitoring and adjusting the EC value is crucial for optimizing plant health and growth. Many commercial hydroponic systems are equipped with features that automatically monitor and adjust EC values as needed. However, as nonprofessionals may not be familiar with the scientific background of EC in hydroponic cultivation, they might simply follow the instructions of suppliers. It is essential to remind that theoretically, any type of salts can achieve the same EC value, which may not align with the authors' intention.
Although the authors seem to apply culture media with differing electrical conductivity levels (1.2, 1.5, 2.0, 4.0 dS/m), I did not find an explanation of how they adjusted the solutions to the specific EC values. Given that the authors may have relied on commercially available monitoring systems, I presume that EC may have been adjusted by increasing the nutrient solution to elevate EC and using distilled water to decrease it. Please remember that hydrogen ions also contribute to EC, so a pH stat system is vital for this type of system. The authors should describe in detail how they established the different EC conditions in this study and also explain the composition, including micronutrients such as heavy metals, of the modified Otsuka House's nutrient solution used in this research.
The current title requires reevaluation. The two terms, "electrical conductivity" and "drying method," are mutually independent, making them unsuitable for combination under the single umbrella term "effects." Furthermore, EC is a physical term that may lead to misunderstandings, suggesting that the EC value might be a determinant for plant growth. Given that one can obtain the same EC value with any kind of ions, it seems that the authors can only use this term for hydroponic culture users. Therefore, careful use of terminology is necessary to avoid misconceptions.
Author Response
We appreciate your sincere comments and we apologize our mistakes in the original manuscript. We tried to correct and change as your comments appropriately in the revised manuscript. We trust we have addressed all of your concerns.
My primary concern involves the term "electrical conductivity" (EC), which is hypothesized as a key parameter for the hydroponic cultivation of A. rugosa. I understand that the EC value of the nutrient solution in hydroponics is crucial as it signals whether the necessary minerals and nutrients are present in the correct balance. If the EC value is too high, the salt concentration could become excessive and potentially detrimental to the plant. It is undoubtedly true that monitoring and adjusting the EC value is crucial for optimizing plant health and growth. Many commercial hydroponic systems are equipped with features that automatically monitor and adjust EC values as needed. However, as nonprofessionals may not be familiar with the scientific background of EC in hydroponic cultivation, they might simply follow the instructions of suppliers. It is essential to remind that theoretically, any type of salts can achieve the same EC value, which may not align with the authors' intention.
As you pointed, we think that the non-professional readers could not follow our intention due to the insufficient knowledge. Therefore, we supplemented the basic conception of EC in introduction section like as follows:
(Line 62-64) Electrical conductivity (EC) is a material’s ability to develop electrical current and EC is a fundamental hydroponic environmental factor for vertical farming because EC value connotes the concentrations of nutrients in the nutrient solution.
Although the authors seem to apply culture media with differing electrical conductivity levels (1.2, 1.5, 2.0, 4.0 dS/m), I did not find an explanation of how they adjusted the solutions to the specific EC values. Given that the authors may have relied on commercially available monitoring systems, I presume that EC may have been adjusted by increasing the nutrient solution to elevate EC and using distilled water to decrease it. Please remember that hydrogen ions also contribute to EC, so a pH stat system is vital for this type of system. The authors should describe in detail how they established the different EC conditions in this study and also explain the composition, including micronutrients such as heavy metals, of the modified Otsuka House's nutrient solution used in this research.
Thank you for your valuable comment. As you pointed, we recognized that readers could confuse the EC value in the present study. Therefore, we added sentence that elucidate relevant information in detail (Line 92-98 and 104-106).
The ratio of each nutrients in solutions was same with that of modified Otsuka House’s nutrient solution described above, but the concentration of the total nutrients was adjusted to 1.5, 2.0, and 4.0 dSžm-1, respectively.
We also added how pH was managed for nutrient solution during cultivation period in M&M section.
The current title requires reevaluation. The two terms, "electrical conductivity" and "drying method," are mutually independent, making them unsuitable for combination under the single umbrella term "effects." Furthermore, EC is a physical term that may lead to misunderstandings, suggesting that the EC value might be a determinant for plant growth. Given that one can obtain the same EC value with any kind of ions, it seems that the authors can only use this term for hydroponic culture users. Therefore, careful use of terminology is necessary to avoid misconceptions.
We understand your concerns, but electrical conductivity is the term that many researchers already popularly used in the research papers. Moreover, we supplemented more detailed information what EC means following your suggestion. Therefore, we think that readers can understand the meaning of EC in our study.
In title, the “changed” is the verb that modify “electrical conductivity” and “drying method”. And the EC and drying method mainly changed two main factors in the present study, that are “secondary metabolite content” and “photo-protective effects”. We recognized that our title could confuse some readers, but we think that the current title properly presents the objective and main outcomes of our study.
Reviewer 3 Report
The manuscript is well written and discussed, minor revision is needed as follows
The first paragraph entitled How to use this tempelate should be deleted as it is not related to the paper subject.
Add the DOI to all the references in the reference list
The manuscript typing mistakes should be revised carefully
Author Response
We appreciate your sincere comments and we apologize our mistakes in the original manuscript. We tried to correct and change as your comments appropriately in the revised manuscript. We trust we have addressed all of your concerns.
The first paragraph entitled How to use this tempelate should be deleted as it is not related to the paper subject.
As your comment, we removed it.
Add the DOI to all the references in the reference list
We have added the DOI for references.
The manuscript typing mistakes should be revised carefully
Thank you for your comment. We tried to check and correct our mistakes in this manuscript.
