Impact of CO₂ Enrichment on Growth, Yield and Fruit Quality of F1 Hybrid Strawberry Grown under Controlled Greenhouse Condition

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Genarl Comments

1. Title: the first idea was if it is necessary "grow" due, yield and quality is the consequence of crop develop along the cycle. But, in the methods, you are measured some agronomic variables, such as suze, dimeter, dry and fresh conditions, pheraps its adequate, Grow, yield and quality

2. Abstrac and introduction: To be clear in the objective

3. In general it is a good research and presentation, just one comment regarding methods, For this reviewer opinion, it is not clear the statistical design

Some specific comments are in the manuscript

Comments for author File: Comments.pdf

Author Response

Dear Reviewer 

Thank you very much for taking the time to review this manuscript. Please find the detailed responses below and the corresponding revisions/corrections highlighted, YELLOW, in the re-submitted files.

Comment 1: Title: the first idea was if it is necessary "grow" due, yield and quality is the consequence of crop develop along the cycle. But, in the methods, you are measured some agronomic variables, such as suze, dimeter, dry and fresh conditions, pheraps its adequate, Grow, yield and quality

Response: Thank you for this comment. Usually, we use the “noun”- growth” not the “verb - grow” in the title, so I would prefer to keep “growth”. Many references used “Growth” in the title, even they measured some agronomic variables:

• Namizaki et al. Effects of Elevated CO₂Levels on the Growth and Yield of Summer-Grown Cucumbers Cultivated under Different Day and Night Temperatures. Agronomy 2022, 12, 1872. https://doi.org/10.3390/agronomy12081872
• Balasooriya et al.. Interaction of elevated carbon dioxide and temperature on strawberry (Fragaria × ananassa) growth and fruit yield. International Journal of Biological, Life and Agricultural Sciences. 2018; 11:1–9.
• Etc…

However, according to your suggestion, in the title, I changed the word “productivity” to “yield”.

Comment 2: Abstract and introduction: To be clear in the objective

Response: Thank you for this comment. Therefore, we modified abstract [Lines16-18] and introduction [Lines 91-93] to show clear objective.

Comment 3: For this reviewer opinion, it is not clear the statistical design

Response: Thank you for this comment. Modified in the text under “statistical analysis”

Manuscript comments 

Comment 1: “Arid zones” line 14

Response: Thank you for this comment. Agree, changed to “worldwide”. Line 14

Comment 2: Treatments, line 99

Response: Thank you for this comment. Agree, changed in the text to “One-week post transplanting, plants were treated with two carbon dioxide concentrations”. Line 115

Comment 3: line 155 “Tow”

Response: Thank you for this comment. Agree, corrected to “Two”. Line 184

Comment 4: normally is in the introduction all references, at least about research results [37-46]

Response: Thank you for this comment. Agree, more references for research results are listed in the introduction text. Lines 61-70.

Comment 5: perhaps, will be interesting to do some reflection regarding the difference or not between crops, strawberry, tomato, cucumber, lettuce. Of course related to co2 or photosynthesis process

Response: Thank you for this comment. More research references are listed in the text. Lines 280-286.

Best

Reviewer 2 Report

Comments and Suggestions for Authors

General comments:

In this paper there are some details missing but the statistical evaluation using ANOVA may not be the most appropriate for the design which is CO₂ concentrations times three strawberry hybrids which requires a more subtle statistical evaluation to draw out the statistical interaction between CO₂ and the hybrids. An appropriate test would be a general linear modelling procedure (GLM is readily available  in the SAS software used by the authors)  which can easily evaluate the interactions which are the core of this paper. An omission was not to provide standard errors which are an integral component of all SAS analyses and should be provided on all meaned data.

Adopting the Results and Discussion has lead to the authors^' not discussing their results except that they compare their results with the literature. For instance, not mentioned is the cultivar E which shows a consistent pattern over both CO₂ concentrations as the lowest in terms of fruit attributes compared to the other cultivars. By contrast, the cultivar which has the highest response in fruit attributes varied according to what attribute was being assessed.

The results were characterised as lacking in details. For instance, the CO₂ control system has no details as to how the CO₂ was measured, where in the greenhouse, flow rate and the diagram in Fig. 1 does not address these questions. Certainly, the legend to Fig. 2 does not convey any details as to how the CO₂ was measured. Some comment about the general rise in CO₂ and the community concerns should be commented on in the introduction.

Consistent with these omissions, the details of the LI6400 Irga are also missing, such as leaf temperature, photon flux density, and vapour pressure deficit. As a user of the LI6400 system, I am fully aware that all these variables and many others are automatically logged. The range of leaf temperatures used each day should be provided and natural light ranges should also be provided. 

The presentation of the results does not convey the interactive nature of the experimental design and simple graphs I drew on the manuscript  shows that figures convey the interaction between CO₂ and hybrid very well. 

It was noteworthy that the growth attributes showed very few statistical results and across the hybrids there were no consistent patterns. Why was this, warrant some discussion.

The conclusions do not address the core of the paper that is to compare the three hybrids in response to varying CO₂. As alluded, the hybrids are not equal and this must be addressed and an evaluation as to why this is so.

Minor details:

Fruit is plural so no need to add an 's' at the end.

L211 interaction - how tested?

L213 highest values..... not height

L215 Who explained, giving the reference is poor expression.

L220 - 224 is some attempt at discussion.

L229 who pointed out.....?

Table 2 place the units of each attribute immediately underneath, do not put them at the bottom of the table.

L276 who reported ......?

L284 response to CO₂ .......

Standard errors on Fig. 3?

L313 such as what various factors? Reference needed to Alao and Taub

 

 

Comments on the Quality of English Language

There are some grammatical mistakes and the use of the definite article (the) and the indefinite article (an) are missing in many places and will improve the flow of the text.

Author Response

Dear Reviewer:

Thank you very much for taking the time to review this manuscript. Please find the detailed responses below and the corresponding revisions/corrections highlighted, YELLOW, in the re-submitted files.

Comment 1: In this paper there are some details missing but the statistical evaluation using ANOVA may not be the most appropriate for the design which is CO2 concentrations times three strawberry hybrids which requires a more subtle statistical evaluation to draw out the statistical interaction between CO2 and the hybrids. An appropriate test would be a general linear modelling procedure (GLM is readily available in the SAS software used by the authors) which can easily evaluate the interactions which are the core of this paper.

Response: Thank you for this comment.

This paper is a part of PhD thesis. The core of this manuscript is to introduce CO2 enrichments as a tool for local Saudi farmers, declare that CO2 enrichment might provide a sustainable solution to increase yield under our condition and provide the local farmers. Also, this work aims to introduce good strawberry hybrids replacing the old used cultivars. The core experimental design is rigorous, and the data collection is comprehensive, covering many aspects such as plant growth, photosynthesis, fruit yield and quality, and the results are highly reliable. Stander error is provided in tables and figures.

Comment 2: For instance, not mentioned is the cultivar E which shows a consistent pattern over both CO2 concentrations as the lowest in terms of fruit attributes compared to the other cultivars. By contrast, the cultivar which has the highest response in fruit attributes varied according to what attribute was being assessed.

Response: Thank you for this comment.

An explanation for the constant pattern of E cultivar is added in the discussion.  Lines 320-328.

Comment 3: For instance, the CO2 control system has no details as to how the CO2 was measured, where in the greenhouse, flow rate and the diagram in Fig. 1 does not address these questions. Certainly, the legend to Fig. 2 does not convey any details as to how the CO2 was measured.

Response: Thank you for this comment.

The details about how CO2 was measured are provided in Fig. 1.

 

Comment 4: Some comment about the general rise in CO2 and the community concerns should be commented on in the introduction.

Response: Thank you for this comment. Some comments regarding the community concerns are provided in the introduction. Lines 53-57.

Comment 5: Consistent with these omissions, the details of the LI6400 Irga are also missing, such as leaf temperature, photon flux density, and vapour pressure deficit. As a user of the LI6400 system, I am fully aware that all these variables and many others are automatically logged. The range of leaf temperatures used each day should be provided and natural light ranges should also be provided. 

Response: Thank you for this comment.

The following sentence is added in the material and methods: “Measurements were performed from 8:00-10:00, the chamber relative humidity was 70%, leaf temperature at 24°C, leaf-to-air vapour pressure deficit of 1.0 ± 0.1 kPa and light intensity at 400-600 μmol m^-2 s^-1 PAR”

Comment 6: It was noteworthy that the growth attributes showed very few statistical results and across the hybrids there were no consistent patterns. Why was this, warrant some discussion.

Response: Thank you for this comment.

This manuscript is a part of PhD thesis, one of our objectives is to proof that CO2 enrichment improve strawberry production and introduce hybrids to the local farmers community. Our plan in the future to discuss the growth analysis for each cultivar through whole the growing cycle based on monthly observation. However, an explanation is provided in the text. Lines 242-248.

Comment 7: The conclusions do not address the core of the paper that is to compare the three hybrids in response to varying CO2. As alluded, the hybrids are not equal, and this must be addressed and an evaluation as to why this is so.

Response: Thank you for this comment. The conclusion is modified

Comment 8: Fruit is plural so no need to add an 's' at the end.

Response: Thank you for this comment. Corrected in the text

 

Comment 9: L211 interaction - how tested?

Response: Thank you for this comment. Changed in the text to: “A similar pattern was observed when plants were grown under both CO2 concentartions for the three grown strawberry varieties.”. Lines 264-265.

Comment 10: L213 highest values..... not height

Response: Thank you for this comment. Agree, corrected in the text

Comment 11: L215 Who explained, giving the reference is poor expression.

Response: Thank you for this comment. Modified in the text

Comment 12: L220 - 224 is some attempt at discussion.

Response: Thank you for this comment. However, the comment was not clear, but we improved the text,

Comment 13: L229 who pointed out.....?

Response: Thank you for this comment. Reference [51]

Comment 14: Table 2 place the units of each attribute immediately underneath, do not put them at the bottom of the table.

Response: Thank you for this comment. Agree, corrected in the text

Comment 15: L276 who reported ......?

Response: Thank you for this comment. Reference [64]

Comment 16: L284 response to CO2 ......

Response: Thank you for this comment. Agree, corrected in the text

Comment 17: Standard errors on Fig. 3?

Response: Thank you for this comment. Stander error is provided in tables and figures.

Comment 18: L313 such as what various factors? Reference needed to Alao and Taub

Response: Thank you for this comment. Agree, modified and supplied with more references in the text. Lines 378-382.

Comment 19: Comments on the Quality of English Language

Response: Thank you for this comment. Language and grammar have reviewed, and the text is improved.

Best

Reviewer 3 Report

Comments and Suggestions for Authors

1. The experimental design is rigorous and the data collection is comprehensive, covering many aspects such as plant growth, photosynthesis, fruit yield and quality. The data analysis method is scientific and reasonable, and the results are highly reliable.

2. The results show that CO2 enrichment significantly improves the yield and quality of strawberries, which has important application value for greenhouse agriculture in arid areas and can provide feasible technical solutions for local agricultural production.

3. The study fills the academic gap on the effect of CO2 enrichment on F1 hybrid strawberries, provides a new scientific basis and reference, and plays an important role in promoting the research in related fields.

Suggestion

1. The experiment was conducted under highly controlled greenhouse conditions, which may not fully reflect the complex environmental factors in actual agricultural production, and the extrapolation of the results may be limited.

2. Although the study found that CO2 enrichment led to a decrease in the contents of nitrogen, phosphorus, potassium and magnesium in strawberry leaves, the explanation of the mechanism of this phenomenon was not thorough enough, which may affect the persuasive results.

3. Although the experimental design is reasonable, the sample size is relatively small, which may affect the robustness and universality of statistical results. It is suggested to increase the sample size to improve the reliability of results.

Author Response

Dear Reviewer

Thank you very much for taking the time to review this manuscript. Please find the detailed responses below and the corresponding revisions/corrections highlighted, YELLOW, in the revised manuscript.

Comment 1: The experiment was conducted under highly controlled greenhouse conditions, which may not fully reflect the complex environmental factors in actual agricultural production, and the extrapolation of the results may be limited.

Response: Thank you for this comment.

Indeed, the technology used for this experiment is highly controlled. This was needed to confirm the results and provide growers with a successful model for hybrid strawberry cultivation and CO2 enrichment technology. However, the government of KSA is currently supporting local growers to use Hi-Tech greenhouses in different regions to improve vegetable production. Also, many investors and commercial agricultural companies adopting Hi-Tech technology, including CO2 enrichment, to increase profit. So, we expect that our results will be valuable for stockholders either with strawberry or other vegetables crops.  

https://www.hortidaily.com/article/9459594/high-tech-greenhouses-in-saudi-arabia/

In addition, lower greenhouse technologies consume high amount of water which is limiting factor in arid zone like Saudi Arabia, so that Hi-Tech greenhouses is needed to reduce water requirements.

Comment 2: Although the study found that CO2 enrichment led to a decrease in the contents of nitrogen, phosphorus, potassium and magnesium in strawberry leaves, the explanation of the mechanism of this phenomenon was not thorough enough, which may affect the persuasive results.

Response: Thank you for this comment.

More references are added to the discussion, with a conclusion that the response of grown plants under elevated CO2 on mineral uptake and utilization are contradictory and different with crop species and experimental capabilities. Lines 390-396.

Comment 3: Although the experimental design is reasonable, the sample size is relatively small, which

may affect the robustness and universality of statistical results. It is suggested to increase the sample size to improve the reliability of results.

Response: Thank you for this comment.

We have fully automated Horti-Max system, glass venlo-type glasshouse, that allows the compartments to be in a stable and flat growth condition whole the growing cycle, that is why the sample size was small since plants are uniform, however, we would increase sample size in next experiments.

Best

Reviewer 4 Report

Comments and Suggestions for Authors

This paper is meaningful, analyzed the effects of high CO2 concentration on the agrinomic character of strawberry. The results could provide direction on the quality improvement of strawberry. This paper have flaws that need improvement, the details are shown as follow.

1. line 91, the word sepirated, i believe is wrong, should be separated.

2. the response of plant to CO2 is highly effected by its variety, so in this study, why do you chose these three vatieties?

3. line 100, the unit PPm is abandoned and no longer used in scientific documents, so it should not used in this paper. usually we use ul/l. Please change it through whole paper.

4. the concentration 600 ppm, according what information the author use this concentration?

5. this data in tables, do not express the standard  deviation, it can mislead that the measurement do not have replication, please add the SDs of data in tables.

Author Response

Dear Reviewer:

Thank you very much for taking the time to review this manuscript. Please find the detailed responses below and the corresponding revisions/corrections highlighted, YELLOW, in the revised manuscript.

Comment 1: line 91, the word “sepirated”

Response: Thank you for this comment. Agree, corrected to “separated”

Comment 2: the response of plant to CO2 is highly affected by its variety, so in this study, why do you chose these three varieties?

Response: Thank you for this comment.

Several reports expressed the importance of using F1 hybrid strawberry seeds in improving production of strawberry. Also, the preliminary experiment at our research center for this varieties indicated its good yield and fruit quality for Saudi market. Listed some references related to hybrid strawberry cultivation.

- [10.17660/ActaHortic.2017.1156.89]

- [10.1186/s43170-022-00110-w]

- [10.17660/ActaHortic.2017.1156.89]

- [10.1051/bioconf/202412201024]

https://www.fruitnet.com/fresh-produce-journal/soraya-strawberry-unlocks-year-round-potential/246627.article

https://estidamah.gov.sa/sites/default/files/202306/23.%20Strawberry%20Poster%20True%20seeds%20-%20ss.pdf

 

Comment 3: line 100, the unit PPm is abandoned and no longer used in scientific documents, so it should not used in this paper. usually we use ul/l. Please change it through whole paper.

Response: Thank you for the comment.

I would prefer to keep ppm as it is, because CO2 (gas) is measured in parts-per-million (ppm) or micromol mol-1 (10^-6 mol CO2 per mol of dry air), which is common in agronomy experiments (10.3390/agronomy12081872) (10.1016/j.compag.2020.105811). If ppm is expressed as the volume of particles to a unit volume of water (which is not our case), then ppm by volume is equal to µl/l.

Comment 4: the concentration 600 ppm, according what information the author use this concentration?

Response: Thank you for the comment.

Early work in the 1980’s suggested that CO2 enrichment increased the average yield of all plants tested in the range of 700 to 900 ppm with concentration more than 1000 ppm having a negative impact on plant growth and yield. The enrichment level of CO2 in vegetable inside the greenhouse has ranged between 500-1000 ppm, many reports proved that 600 ppm is meaningful for strawberry than higher concentrations: below list of some references since beginning of 1990s:

• Namizaki et al. Effects of Elevated CO₂Levels on the Growth and Yield of Summer-Grown Cucumbers Cultivated under Different Day and Night Temperatures. Agronomy 2022, 12, 1872. https://doi.org/10.3390/agronomy12081872
• Tagawa, et al Y. Effects of CO₂Enrichment on Yield, Photosynthetic Rate, Translocation and Distribution of Photoassimilates in Strawberry ‘Sagahonoka’. Agronomy 2022, 12, 473. https://doi.org/10.3390/agronomy12020473
• Doddrell et al.. Feeding the world: impacts of elevated [CO₂] on nutrient content of greenhouse grown fruit crops and options for future yield gains. Hortic Res. 2023 Feb 21;10(4): doi: 10.1093/hr/uhad026.
• Balasooriya et al.. Impact of elevated carbon dioxide and temperature on strawberry polyphenols. J Sci Food Agric. 2019; 99:4659–69
• Balasooriya et al.. Interaction of elevated carbon dioxide and temperature on strawberry (Fragaria × ananassa) growth and fruit yield. International Journal of Biological, Life and Agricultural Sciences. 2018; 11:1–9.
• Lieten, F. (1997). effect of co₂enrichment on greenhouse grown strawberry. Acta Hortic. 439, 587-596.https://doi.org/10.17660/ActaHortic.1997.439.98.
• Wang S, Bunce J. Elevated carbon dioxide affects fruit flavor in field-grown strawberries (Fragaria × ananassaDuch). J Sci Food Agric. 2004; 84:1464–8
• Sánchez-Guerrero MC, Lorenzo P, Medrano et al. Effect of variable CO₂enrichment on greenhouse production in mild winter climates. Agric For Meteorol. 2005; 132:244-52
• Sung FJM, Chen JJ. Gas exchange rate and yield response of strawberry to carbon dioxide enrichment. Sci Hortic. 1991; 48:241–51
• Etc……

Comment 5: this data in tables, do not express the standard deviation, it can mislead that the measurement do not have replication, please add the SDs of data in tables.

Response: Thank you for the comment. Stander error is provided in tables and figures.

Best