Composting Spent Mushroom Substrate from Agaricus bisporus and Pleurotus ostreatus Production as a Growing Media Component for Baby Leaf Lettuce Cultivation under Pythium irregulare Biotic Stress

Round 1

Reviewer 1 Report

The use of spent mushroom substrates (SMS) after composting, for growing plants, has been studied previously by several authors. The originality of the present work is to combine SMS from a wood degrading white rot fungi (Pleurotus ostreatus) cultivated on lignocellulosic materials with low N contents and from a litter degrader (Agaricus bisporus) cultivated in composted lignocellulosic materials enriched with N of animal origin.

Only one composting process per SMS and the mixture (only one) are presented and the composts were used at only one rate of partial replacement of peat (1:4). Consequently, the conclusions of the study can not be enlarged on other SMS with different qualities and the hypotheses on the origin of the effects observed are weakly supported by the experiment. You should honestly add few words on these limits in the manuscript.

Italics are missing for Latin names of the species and the rule of abbreviation of genus after the first citation in the text (without abstract) is not respected.

The abstract needs sound rewriting. I am not sure to understand the first sentence. Maybe you mean: an alternative for partial replacement of peat in horticulture.” You should replace “used as partial component of growing…” with “used for replacement of 1/5 of peat as growing media”. You also should add quantitative information on the level of improvements using composted SMS.

The last sentence is not supported by the manuscript, you only tested one combination. You should find another one.

 

Specific comments:

Line 66 : AgPI has been defined in abstract, but the manuscript should be read without the abstract. Then you should develop here or delete AgPI

Line 67: It is the first time that Trichoderma harzianum is cited, then add the full name.

Lines 70-71. You should delete SMS in (Ag SMS) and in (Pl SMS) because in the other parts of the manuscript Ag and Pl are used also for composted SMS or for treatments.

Line 78: was this sentence for both Ag and Pl? You could use directly SMS as it is defined line 70. Was the casing layer removed in Ab SMS? If not, what was its composition? You should add information in the text.

Line 103: What was the origin of the strain of P. irregulare you used.

Lines 65-65: Please add in Materials and Methods how this was checked.

Line 236: “SMS and winery”, maybe “SMS and by-products of winery”

Line 286: “one method”. Replace with “one of the methods” or “a method”.

Line 289: replace I with It

Line 293-294: SMS were composted for a long time and at high temperatures, then I do not agree with this explanation of the non-efficiency of Trichoderma treatment. Interactions with several bacteria in mushroom cultivation substrates or composts (Paenibacillus sp. and other Bacillus sp.) should be at the origin of the non-growth of T. harzianum or other Trichoderma species. Such bacteria are used as biocontrol agents by mushroom growers. You should change the sentence and add information.

 

Line 303: You can not conclude on the importance of selecting the right combination as only one combination was tested here. Would this conclusion be the same with SMS from other origins (there are many ways used to produce mushroom cultivation substrates)? Comments are needed in the manuscript.

Line 306: This is not a conclusion supported by your work. You did not demonstrate this, but only observed that T. harzianum did not developed in presence of AgPl.

Author Response

Autor notes to Reviewer is in the attached doc

Author Response File: Author Response.pdf

Reviewer 2 Report

The bibliographic references need to be revised, because from 40 bibliographic references presented there are 9 self-citations for Margarita Ros and 12 for Jose Antonio Pascual. As a recommendation, the authors should present furthermore other bibliographic sources in addition to those that are self-citations of some co-authors to this article, because a simple search in specialized scientific journals, similar topics of scientific articles can be found.

At point 2.2 ”The composting process” of Material and method chapter, some technical data on the ambient temperature where the composting of the components took place should be presented, to see whether or not it influenced the temperature of the experimental mixtures and whether it could affect composting period, if the experience were repeated in other environmental conditions (eg. at another climate zone, altitude, latitude, etc.).

It would also be interesting to mention the height of the compost piles, because from a volumetric point of view, 2500 kg of components differ quite a lot depending on the mixed components, as well as the presentation of the distance from the edge of the pile, were the temperatures of the composted mixtures was measured for each experimental variant.

 

 

Author Response

Answer to your suggestion in the attached doc

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Thank you for your replies and changed in the manuscript.

Following are few comments for additional minor revisions:

Lines 60-61 : The sentence is still confusing. I may suggest: ‘… the use, as a component of plant growing media, of compost made from spent mushroom substrate (SMS) after culture of A. bisporus (Ag), or P. ostreatus (Pl), or a combination combination of 70% A. bisporus and 30% P. ostreatus (AgPl) mixed with peat (1:4; compost:peat), increases germination…’

 

Line 64 :… compared to …

Line 77: You should add a sentence on the mushroom substrates making plant, i.e. The mushroom cultivation substrates were produced by ???

Line 82: Both substrates for A. bisporus ….

Line 83: you should add here information given in the cover letter: (around 30-40 farms in a radio circle of 20 km from the substrate plant production).

Table 3, footnote: A. is missing before bisprous

Figure 2: No error bars on the figures whereas indicated in the legend. You should add them.

Figure 3: no error bars in 3A and 3C ?

Line 299: italics for Bacillus

 

Author Response

The answer to the reviewers has been uploaded in the attached doc