Anaerobic Soil Disinfestation as a Tool for Nematode and Weed Management in Organic Sweetpotato

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The manuscript is a well written description of research into the potential of anaerobic soil disinfestation to control southern root-knot nematode (Meloidogyne incognita) and weeds, particularly yellow nut sedge for organically growing sweetpotato. 
Line 141.  Describe how the nematodes were extracted from the soil
Lines 149-150 Please provide information on where the microcosm experiment was located (in a greenhouse?) and how were the environmental conditions maintained
Supplementary Figures and Tables. The results of the chemical analyses are presented in different units in the various Supplementaries, namely (a) in % and ppm for Tables S1 (b) in lbs/A in Table S2; (c) in lb/ha in Figure S2 and (d) in ppm in Figure S2 (presumably this should be Fig S3).
Please convert all these values to concentrations as either % or mg/kg (ppm) as appropriate. Please check the value of 420% for NO3-N in Table S1.
Please also provide in the Materials and Methods the references to methods used for extraction of ‘available’ phosphorus and potassium. Please correct the incorrect spelling of ‘phosphorous’ at several places in the manuscript.
In the Supplementary Materials, the lettering indicating significant differences in Figure S2 shows no difference for P before and after ASD treatment, and no difference for K before and after ASD, even though differences are apparent.  Please check that the letters have been applied correctly.  Also please present the concentrations of P and K for control as well as organic amendment treatments after ASD. 
Line 180. Change ‘Untransformed means’ to ‘Back-transformed means’ 
Line 213 Change ‘carpet weed’ to ‘carpetweed’
There are several places in the paper including captions where scientific names need to be italicised.
Line 249 Caption to Fig 5.  Change ‘Reproduction of Meloidogyne incognita…’ to ‘Number of juveniles (J2) of Meloidogyne incognita…’
Line 256 Caption to Fig 6.  Change ‘Reproduction of Meloidogyne incognita…’ to ‘Number of eggs of Meloidogyne incognita…’
In the captions to all Figures please state what the line bars with the means represent, namely, standard error of the means (SEM) or standard deviations?
Lines 347-348 is, ‘The increased activities of microorganisms initiate anaerobic decomposition of the added organic amendment, which results in the depletion of oxygen [19,43,44].’  It is not the ‘anaerobic decomposition’ that results in the ‘depletion of oxygen’. It is the initial aerobic respiration of the microbes that results in the depletion of the oxygen in the sealed microcosms which then results in the solely anaerobic decomposition of the organic matter.  Rephrase this sentence to something like, ‘The increased microbial respiration in response to the organic amendments leads to depletion of oxygen and subsequent solely anaerobic decomposition’.
Line 426-427 in the Discussion states, ‘Significantly higher phosphorous (sic) and potassium values after ASD (Supplementary Figure S1).’  The sentence requires a verb and presumably is referring to Figure S2 not Figure S1.  Also the statement is not supported by the lettering for statistical significance in Figure S2.  The lettering is probably incorrectly applied as stated above. 

Author Response

Please see attached.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

Review Report

 

Manuscript ID: agronomy-3478557

Title: Anaerobic soil disinfestation as a tool for nematode and weed management in organic sweet potato

Authors: Simardeep Singh, Matthew Cutulle, William Rutter, Phillip A. Wadl, Brian Ward, Churamani Khanal

 

Dear Authors,

I saw only a few technical details that need to be corrected. I described these details in the reviewer's comments in the pdf file.

The authors in the reviewed manuscript described anaerobic soil disinfestation (ASD) as a promising method of pest and weed control, which may be particularly useful in organic farming - without synthetic chemicals. They focused on assessing the usefulness of this method in controlling the nematode Meloidogyne incognita and Cyperus esculentus in Ipomoea batatas. As an organic carbon source and a factor conditioning anaerobic conditions in the soil, they used a mixture of chicken manure and molasses versus control (without additional) carbon. The influence of the study factors on 20 sweet potato genotypes was analyzed. The results suggest that the addition of organic carbon is a factor conditioning the possibility of generating anaerobic conditions for disinfestation. Under such conditions, the authors obtained a significant inhibition of the soil population growth and reproduction of SRKN eggs compared to no additional carbon and a reduction in weed infestation, which resulted in increased dry above- and below-ground biomass and improved plant vigor during plant growth.

Yours sincerely

Reviewer

Comments for author File: Comments.pdf

Author Response

Please see attached.

Author Response File: Author Response.pdf