Freshwater Algae Biostimulant in Mitigating Impacts of Saline Irrigation on Onions

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The study addresses a very relevant issue, salinity stress in agriculture and tests a natural solution (algae-based biostimulants), which is a topic of current global interest. The authors are reuqested to view the following comments to improve the manuscript information more concisely

Major comment

1. Inclusion of strees mechanism in introduction. The introudction can be more informative by including the generation of reactive oxygen species (ROS), hydrogen peroxide generation, superoxide dismutase and catalase activity. A few is mentioned in the discussion but it should be clearily stated in the introduction.

1. There is little mention of negative controls (untreated + salinity only). Please give more convenient information how much of the effect is due to the biostimulant alone.
2. While plant growth was measured, no physiological or molecular validation was performed for pathways involving cytokinins or stress markers. If the athours can address the issues, it may be a great addition.
3. The is in need Chlorophyll and antioxidant parameters interpretation more concisely and elaborately
4. No mention of long-term soil effects: The study shows the product does not reduce soil salinity, only helps plants cope. Please add this long-term soil effects limitaion.

Minor comments

L35-36, Rewrite with a quantified statement such as Salinity affects over ??% of irrigated land worldwide..

L42-43, Impressive results, but the authors should clarify if these values are statistically significant (for instance p < 0.05)

L46, This is a key limitation. Please place it at the end of the abstract as a clear caution for long-term sustainability.

L67-70, Good mechanistic writing. However, no details are given about the specific cytokinin or hormone types, and whether the extract was characterized.

L80-81, Addition a clear research gap is recomended, for instance “the comparative performance of foliar vs. soil-applied algal biostimulants in onion remains unexplored.”

L195-198, The lack of significance in bulb firmness, Brix, pH should be mentioned in the abstract and discussion to avoid overstating product quality claims are requested.

L316-319: Use “improved” only where P-values show statistical significance. Otherwise, change to “showed a trend of improvement.”

L337-339, Please rephrase

Line 392–393, Productivity gains are promising, but authors do not adjust for seasonal yield variability or provide error margins. Caution is advised in this case

Line 410–414, Rewrite for smooth expression

L447-451, Climate data are well reported. Please include soil EC classification reference to justify “C3 saline class” in later analysis.

L459-463, Design is well stated, but there is no mention of replication or randomization procedures (such as, plot size, spacing, layout). This is critical for agronomic trials.

L613, Why were only Na⁺ and K⁺ tested? also Cl⁻, as it plays a direct role in salt toxicity and osmoregulation.

Author Response

See the Annex.

Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

After reviewing the article "Freshwater algae biostimulant in mitigating impacts of saline irrigation on onions", I would like to propose the following comments:

1.In the abstract, briefly mention the specific components of the biostimulant used.

2.In the abstract, clarify how salt stress was implemented. Was it through irrigation with saline water (and if so, what was the electrical conductivity of the saline water) or due to the inherent salinity of the soil?

3.Since the author mentioned irrigation with saline water, it is suggested to add background information on the scarcity of freshwater and the importance of saline water irrigation. It is recommended to cite (https://doi.org/10.1016/j.fcr.2025.109747).

4.The images are too blurry. It is suggested to redraw them to ensure clarity.

5.Discuss the correlation between soil electrical conductivity and plant growth and yield indicators to further reveal the mechanisms by which soil salinity affects onion growth.

6.It is recommended to provide a more detailed description of the salinity composition of the irrigation water, such as whether it is primarily composed of sodium ions or if it contains other ions as well.

7.In the discussion, regarding the changes in potassium and sodium ion content, it is suggested to add a discussion on the mechanisms of ion balance within the plant, particularly how the biostimulant affects the plant's absorption of potassium ions and exclusion of sodium ions.

8.The discussion should provide an in-depth analysis of the mechanisms by which biostimulants affect onion growth and yield, especially their effects on plant hormone pathways and ion balance.

9.Add a discussion on the potential risks and sustainability issues associated with the long-term use of biostimulants, such as their long-term impact on soil ecosystems and plant dependence on biostimulants.

10.Emphasise the potential of biostimulants in mitigating salinity stress in the conclusion, while also pointing out their limitations and areas for further research to make the conclusion more objective and comprehensive.

Author Response

See the Annex.

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The authors completed each response carefully. 

Reviewer 2 Report

Comments and Suggestions for Authors

good job now