Effects of Inorganic Fertilizers on Virulence of the Entomopathogenic Nematode Steinernema glaseri and Peanut Germination under Field Conditions
Round 1
Reviewer 1 Report
This paper reports the effect of some inorganic fertilizers, widely used in Egypt, on the virulence of the indigenous entomopathogenic nematode Steinernema glaseri. In particular, the objective of this study was to estimate the effect of three concentrations for each of ten different inorganic fertilizers on the virulence of S. glaseri and peanut germination.
This paper could have a significant value in the Integrated Pest Management, and it could be worth publishing with revisions. The experimental design is well projected, and the data set is complete and effective. However, I have some concerns regarding statistical analysis.
Major points
My main concern pertains to consider two different trials (1, S. glaseri was added by irrigation water seven days before fertilization; 2, S. glaseri was added by irrigation water seven days after seeding to all treatments) and then to apply one-way ANOVA analysis for each of the trials (materials and methods section and result sections). In my opinion, there is a unique well-designed trial, and the authors should apply a more complex data elaboration such as two-way or three-way ANOVA analysis.
Minor points
Materials and methods – It is not correct to report tables 2 and 3 in the section of the field experiment, because they include the results. Instead, considering the very complex experimental design, a synthetic graphic to visualize the whole trial should be necessary in this section.
Author Response
Authors’ response to reviews
Title: Effects of inorganic fertilizers on virulence of the entomopathogenic nematode Steinernema glaseri and peanut germination under field conditions.
Dear reviewer,
Thank you very much indeed for your efforts while reviewing this manuscript and your helpful comments were addressed accordingly. Here, they are as follows:
Reply to Reviewer # 1:
Reviewer: My main concern pertains to consider two different trials (1, S. glaseri was added by irrigation water seven days before fertilization; 2, S. glaseri was added by irrigation water seven days after seeding to all treatments) and then to apply one-way ANOVA analysis for each of the trials (materials and methods section and result sections). In my opinion, there is a unique well-designed trial, and the authors should apply a more complex data elaboration such as two-way or three-way ANOVA analysis.
Response: As mentioned in the text, we used a completely randomized design for data analysis to comply with the designed irrigation system. The design on which the irrigation system was built did not enable us to apply two-way or three-way ANOVA analysis. Yet, the method of applying nematodes via such a common irrigation system is one of the modern techniques that should be used after making sure of their usefulness. Future improvements in irrigation systems would enable such analyses.
Reviewer: Materials and methods – It is not correct to report tables 2 and 3 in the section of the field experiment, because they include the results. Instead, considering the very complex experimental design, a synthetic graphic to visualize the whole trial should be necessary in this section.
Response: OK, we moved the mentioned tables to the results section. However, we think the simplified clarification via phrasing the complex experimental design takes away additional work such as synthetic graphic to visualize the whole trial.
Reviewer 2 Report
Use of alternative measurements for the pest control is expected to be gaining importance also in conventional production system. Studies such as this are important to reveal how different measures (eg. Fertilization) affect the "efficacy" of EPN. Manuscript is faily well written, however, few recommendations for improvement are sugested.
- It is unclear how the statistical model was specified and what program was used for the calculations. Authors are encuraged to add explanation.
- Adding EPN as a suspension with fertilisers is not common way off application. Authors are encuraged to review the data if some combinations are interesting for the practice
- Mortality of EPN in different suspensions with fertilisers would be informative. Comparing mortality of Galleria between two ways of application is only indirect comparisson, not revealing the true cause of reduced mortality.
- Authors are encuraged to add more in depth discussion on possible reasons of lower mortality with phosphorus fertlisers.
Author Response
Reviewer #2
Dear reviewer,
Thank you very much indeed for your efforts while reviewing this manuscript and your helpful comments were addressed accordingly. Here, they are as follows:
Reviewer: Use of alternative measurements for the pest control is expected to be gaining importance also in conventional production system. Studies such as this are important to reveal how different measures (eg. Fertilization) affect the "efficacy" of EPN. Manuscript is faily well written, however, few recommendations for improvement are sugested.
- It is unclear how the statistical model was specified and what program was used for the calculations. Authors are encuraged to add explanation.
Response: We added in ‘Materials and methods’: ‘Data were subjected to analysis of variance via Microsoft Excel using its spreadsheet software for statistical analyses.’ Also, as mentioned in the text, we used a completely randomized design for data analysis to comply with the designed irrigation system. By this we meant that irrigation system dictated the statistical analyses.
Reviewer:
- Adding EPN as a suspension with fertilisers is not common way off application. Authors are encuraged to review the data if some combinations are interesting for the practice.
Response: We added in the ‘Discussion’: ‘Therefore, combinations of the first application system are more interesting for the practice than the second application system.’
Reviewer:
- Mortality of EPN in different suspensions with fertilisers would be informative. Comparing mortality of Galleria between two ways of application is only indirect comparisson, not revealing the true cause of reduced mortality.
Rebuttal: Nothing substitutes experimentations under actual field conditions. Also, the true cause of reduced mortality may be inferred when compared with the non-treated (not fertilized check (control).
Reviewer:
- Authors are encuraged to add more in depth discussion on possible reasons of lower mortality with phosphorus fertlisers.
Response: We added in the ‘Discussion’ concerning possible reasons of lower mortality with phosphorus fertlisers: ‘The basis for these different reactions require physiological investigation [9]’.
