Efficiency of the CL, DRIS and CND Methods in Assessing the Nutritional Status of Eucalyptus spp. Rooted Cuttings

Round 1

Reviewer 1 Report

General

This is a well-organized and designed study to compare methods for assessing nutritional deficiency for commercial Eucalyptus clones. Given the global extent of commercial Eucalpytus plantations and forestry, this study has broad relevance for the forestry community. The study uses standard measures of seedling quality as the performance criteria, which is relevant and valuable for tree nurseries. What the manuscript fails to adequately address is the independent role of plant nutrient status in seedling quality and ultimately performance in the field. Only the effect of nutritional status on growth or biomass allocation are considered. While this is not the purpose of this study, it should be addressed in the Discussion as an additional factor to consider beyond considering fertilization primarily as a means to achieve growth and biomass allocation targets.

The manuscript contains a number of small writing errors that need to be corrected. I did not mark up the manuscript with these errors, as most can be found with adequate proofreading.

Introduction

The descriptions of the seedling quality and nutrient diagnosis methods are too brief to give readers an adequate understanding of their purpose and function, especially DRIS and CND. This is important to interpret the formulae and methods in the Material and Methods section.

Materials and Methods

The description of the Eucalptus clone is insufficient. Species or parentage for a hybrid is needed. The method of cloning should be included. The general starting size of the rooted plant should be included, since the height and RCD are measured as treatment responses. Using the term “seedling” (Line 86), while convenient, is inappropriate, since it is a clone.

If the authors have data on the nutritional status of the clones at the beginning of the experiment, that would be valuable to include.

I don’t quite understand the calculations for Table 2. “Counting cases” seems like the authors added up the sum of cases, but they do not indicate how many cases they counted, so the acceptable values  (> 50) has no reference to give it meaning.

Results

Table 3. This table is insufficiently detailed to understand the data. By categorizing the nutrient concentrations according to categories of dry matter, the authors ignore their own fertilization treatments and the effects they may have on growth (DM) and nutrient uptake. There also is no clear justification for the DM or DQI categories.

Line 241-2 and 250: I think the authors are referring to Table 3, not Table 4. In neither table are mean DM or DQI values presented. There are other misaligned references to tables in the text, suggesting the authors changed the table numbering and need to carefully screen references in the text.

Figures 2 and 3. While the correlations of DM and DQI to nutrient concentration are significantly positive, the relative range of concentrations are much greater than DM or DQI, i.e. the slope of a potential regression relationship would be relatively low. This is perhaps important to note.

Figure 4. These figures demonstrate that the fertilization treatments are maximizing growth but not nutrient concentration. In other words, the high fertilization treatments are inducing luxury consumption, and there is some indication of incipient toxicity effects with lower DM. This is an important threshold for the fertilization treatments, so it is worth mentioning in the manuscript. Inducing luxury consumption is also a more widely recommended nursery practice to improve plant performance in the field.

Figure 6. These figures should not include a linear equation, since the stated analysis is correlation, not regression.

Table 6. Using the formulae in Table 2, the calculations of AccDef seem incorrect in some cases, e.g. using DM to calculate deficiency for P. There are also superscripts (1) and (2) in the table column labels but no explanatory notes associated with them.

Discussion

Line 389: “DQI content” is misleading. DQI is a calculated index, not a quantity of material. The term “DQI level” is used previously and is appropriate here.

Given the diversity of nutrient data in the study, the long history of use of different nutrient diagnoses, and the variable results, I think the discussion could include more analysis of DRIS and CND and under what conditions they may be preferred for nutrient diagnosis than CL. Clearly, there is a desire for simplicity and uniformity, but insights from the authors about whether certain instances of better performance for DRIS and CND are perhaps merely random results or have some physiological basis and potential importance for pant performance are worth including.

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 2 Report

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The paper presents an evaluate the quality of diagnoses obtained using the critical level, diagnosis and recommendation integrated system and compositional nutrient diagnosis methods to assess the nutritional status of Eucalyptus spp. seedlings. The statistical methods are correctly applied. The paper is well written, although the "Conclusions" chapter is too general. 

I would like to comments (to give recommendations) on the work as follows:

1. Authors should be more to emphasize manuscript novelty.

2.Figure 4  x-axis – ’’concentration’’ should be replace with ’’content’’ analogous to the y-axis and to the others figures

3. Figure 5 x-axis – ’’concentration’’ should be replace with ’’content’’ analogous to the y-axis

4. Figure 5 part B x-axis  – text should be translated to the English language

5. Chapter Conclusions – too general, should be re-written

Author Response

Please see the attachment.

Author Response File: Author Response.docx