Late to the Party—Transferred Mulch from Green Manures Delays Colorado Potato Beetle Infestation in Regenerative Potato Cropping Systems

#

Reviewer correction

Author's revision

position

Correction: “The Faculty of Organic Agricultural Sciences” was corrected into “Department of Agricultural and Biosystems Engineering”

Affiliation

Legend was made more precise, e.g. instead of +2.0°C it now reads >+2.0°C

Table 3.

Funding was extended: ”, by The European Union’s Horizon 2020 Research and Innovation programme, under Grant Agreement no. 773554 (EcoStack) and”

Funding

1

Improve the description of the experimental design. From the applied perspective there are some short-comings. The LTE is not clear to me.

The paragraph

“The experiments in 2014/15 and 2018/19 were integrated into two parallel long term ex-periments (LTE) started in 2010 and 2011, respectively, comparing plough tillage with reduced tillage (RT) with and without the application of compost. These are described in detail elsewhere [31]”

Was changed into

“The experiments in 2014, 2015 and 2018, 2019 were integrated into two parallel long term experiments (LTE), shifted in time by 1 year, and that had been started in 2010 (Experiment 2014 and 2018) and 2011 (Experiment 2015 and 2019). The LTE´s compared plough tillage with reduced tillage (RT) with and without the application of compost. In 2014 and 2015, only the reduced tillage treatments received mulch. The Experiments are described in detail elsewhere [31].”

120-126

2

Expand on this "assessments for Initial immigrating adult CPBs were conducted at potato budding (BBCH 51) +/- 10 days depending on the progress of infestation in all experiment"

The Sentence

“Assessments for Initial immigrating adult CPBs were conducted at potato budding (BBCH 51) +/- 10 days depending on the progress of infestation in all experiments.”

was expand to

“Since plant development and CPB colonization vary depending on climate conditions, plots were regularly scouted and assessments started when the first beetles were seen. For the initial immigrating adult CPBs this occurred +/- 10 days of potato budding (BBCH 51)…”

155-158

3

Graphs are too busy and hard to read. Especially Figure 1 and 2.

Figures have been optimized as follows:

- the absolute numbers were for the most part removed,

- optimized the y-axis labeling

- * were colored darker

- the graphics were slightly enlarged

205, 223

4

Which other issues did your crop faces yearly? can you expand on late bligh effect in your results.

The paragraph

“Furthermore, beetle development was terminated or interfered with by late blight and as-sociated leaf area losses in 2014, 2015 and 2016[42][10] and a Bt treatment after extreme initial infestation in 2019.”

Was expand to

“Additional complications arose as beetle development was terminated or interfered with by the destruction of the foliage through late blight in 2014, 2015 and 2016. Both early blight (Alternaria solani) [42] and late blight [10] can be delayed by transfer mulch. This leads to longer green leaf area duration in mulched compared to unmulched plots and in consequence to migration of adult CPBs to the mulched plots. In 2019, the extremely high CBP infestation had to be terminated by spraying Bacillus thuringensis to save the experiment”

316-322

5

Conclusions should lead to recommendation. I missed it on this paper.

The paragraph

“However, spreading the mulch is an operational challenge and therefore especially interesting for small direct-marketing farms.”

was taken out from discussion and added in the conclusion. The same applies to the sentence:

“the available data cannot explain the reason for the delay in infestation nor is it possible to unequivocally show if the developmental time from egg to larva to adult is changed.”

Conclusion was extended to indicate missing information (first paragraph) and recommendations (second paragraph):

“The initial infestation of CPB and its subsequent stages can be reduced by using transferred green manure mulch. However, the available data cannot explain the reason for the delay in infestation nor is it possible to unequivocally show if the developmental time from egg to larva to adult is changed. This will require detailed controlled feeding experiments. A monocausal explanation for the delay or even suppression of the different CPB stages is unlikely. Research approaches to separate physiological effects on CPB development from agroecological interactions need to be explored to provide insights into the mechanics of the interacting effects. In addition to the yield impact of the delaying effect, further research needs to examine whether mulch causes i) visual and ii) olfactory irritation, in addition to iii) a physical barrier effect for CPB. Is (iv) delayed plant development due to mulch the cause of delayed CPB infestation? Also consider whether (v) plant nutrition through mulch contributes to CPB suppression. Finally, (vi) potato beetle predators for Central Europe should be identified and their mutual population dynamics investigated.

Just as regenerative agriculture has the soil as its base, agroecological crop protection should be thought of from the soil. We recommend embedding transferred mulch into complementary regenerative, soil fertility management and other agro-ecological practices, to increase effectiveness. However, spreading the mulch is an operational challenge and therefore especially interesting for small direct-marketing farms. Nevertheless, the described systemic approach can on the one hand elegantly reduce CBB abundance and overcome the need for direct intervention with insecticides while at the same time providing nutrients and additional plant protection with respect to late blight and weeds.”

375, 361, 360

#

Reviewer correction

Author's revision

position

Correction: “The Faculty of Organic Agricultural Sciences” was corrected into “Department of Agricultural and Biosystems Engineering”

Affiliation

Legend was made more precise, e.g. instead of +2.0°C it now reads >+2.0°C

Table 3.

Funding was extended: ”, by The European Union’s Horizon 2020 Research and Innovation programme, under Grant Agreement no. 773554 (EcoStack) and”

Funding

1

In the introduction section, the author should provide a novelty statement at the end. What new things have authors done or correlated in this research compared to old ones?

The following text passage has been added to the introduction

"This study presents data investigating the effectiveness of nutrient rich mulches on Colorado potato beetle stages over several years under different climatic conditions. In addition, their combination with regenerative cropping measures such as reduced tillage and compost application is investigated."

at the end.

108-111

2

The systematic abstract is missing. Introduce the need for study in 1-2 lines. Then please give a clear-cut point problem source as a problem statement that is tackled in the current study. Also, give a logical reason for selecting the current strategy or treatments. Then provide a definitive conclusion withdrawn through research in a single line.

14

3

Give a logical reason for selecting the current strategy, i.e., Foliar Application of Different Iron Forms.

We are sorry, no foliar applications of what is suggested by the reviewer have been made. Thus, no comment on this.

4

The authors should follow the title in the introduction section, i.e., Late to the Party – Transferred Mulch from Green Manures Delays Colorado Potato Beetle Infestation in Regenerative Potato 3 Cropping Systems. Do you consider the topic original or relevant in the field? Does it address a specific gap in the field?

See changes under #1 introduction and in the extension in the discussion:

“All mulch materials, regardless of C/N ratio (from 19 to 52) and application rate (23 to 37 t DM ha-1 ) reduced the initial infestation with adult beetles and confirmed that besides straw that had been shown to reduce CPB infestation in the older literature, fertilizing mulch with a narrow C/N ratio can also reliably regulate CPB.”

281

5

Keywords should be in alphabetical order and should not duplicate words appearing in the title

Was changed as suggested from "organic mulch, colorado potato beetle, potato production, regenerative agriculture, organic farming, reduced tillage, compost, regenerative plant protection, agroecology"

to

" agroecology, compost, organic farming, organic mulch, reduced tillage, regenerative agriculture, regenerative plant protection”.

28

6

The authors should remove table 1 and write a paragraph on the effect of organic mulch on Colorado Potato Beetle. And sort the number of tables according to order.

We are really sorry but we can't agree with that. Table 1 represents the core of the introduction and briefly and succinctly summarises the complete research to date on the effect of mulch on the Colorado potato beetle. Changing this to text would cost at least one more page and make things much less systematic. By using the tabular presentation much more details can be made visible. The tables are numbered according to the first time they are mentioned as requested by the journal.

7

The authors should improve the format of figures and table with respecting the font and color (black color and Palatino Linotype font)

- Table:

- /ha was changed into ha^-1

- writing size, and - positition were optimized

^- Legend was made more precise, e.g. instead of +2.0°C it now reads >+2.0°C

Figures have been optimized as follows:

- the absolute numbers were for the most part removed,

- optimized the y-axis labeling

- * were colored darker

- Palino Linotypes makes the figures difficult to read, which is why the font of the illustrations has not been changed. There are no specifications that Palatino Linotype have to be used as the font in figures. However, it is pointed out that the fonts of the figures must be embedded (https://www.mdpi.com/authors/layout#_bookmark38), which is not the case here as these are jpg files.

- the graphics were slightly enlarged

Thanks for the suggestions, the figures look clearer now.

92, 138, 153, 205, 233

8

The author should write in the legend of the figure the type of bars above the columns indicating to what “standard error or standard division”.

The legends include the following: “Lines above the bars indicate the positive standard deviation.”

206, 223, 256

9

Page 9 line 236: the authors should subscript the “-1” in the following unit “ha-1” and throughout the manuscript.

Corrected as suggested.

10

I request that the authors they can provide Pearson correlation and parallel plots for a better understanding of the data.

The use of Pearson R² is not appropriate for this type of data because of their structure. To calculate a Pearson R² one needs at least interval scaled data as dependent and explanatory variable. In addition, the requirements of linearity and normal distribution are not met here.

Furthermore, it was pointed out by Spiess and Neumeyer (2010) that R² is an inadequate measure for nonlinear models.

See doi.org/10.1186/1471-2210-10-6

11

The authors mentioned that there are supplementary data (S1) but they not indicating or cited to context.

Mistake is corrected.

12

The conclusion is so much descriptive. Please provide a conclusive conclusion, Add the targeted beneficiary audience who will get benefit from this research. Also, give clear-cut recommendations Give future prospective regarding this research.

The paragraph

“However, spreading the mulch is an operational challenge and therefore especially interesting for small direct-marketing farms.”

was taken out from discussion and added in the conclusion. The same applies to the sentence:

“the available data cannot explain the reason for the delay in infestation nor is it possible to unequivocally show if the developmental time from egg to larva to adult is changed.”

Conclusion was extended to indicate missing information (first paragraph) and recommendations (second paragraph):

“The initial infestation of CPB and its subsequent stages can be reduced by using transferred green manure mulch. However, the available data cannot explain the reason for the delay in infestation nor is it possible to unequivocally show if the developmental time from egg to larva to adult is changed. This will require detailed controlled feeding experiments. A monocausal explanation for the delay or even suppression of the different CPB stages is unlikely. Research approaches to separate physiological effects on CPB development from agroecological interactions need to be explored to provide insights into the mechanics of the interacting effects. In addition to the yield impact of the delaying effect, further research needs to examine whether mulch causes i) visual and ii) olfactory irritation, in addition to iii) a physical barrier effect for CPB. Is (iv) delayed plant development due to mulch the cause of delayed CPB infestation? Also consider whether (v) plant nutrition through mulch contributes to CPB suppression. Finally, (vi) potato beetle predators for Central Europe should be identified and their mutual population dynamics investigated.

Just as regenerative agriculture has the soil as its base, agroecological crop protection should be thought of from the soil. We recommend embedding transferred mulch into complementary regenerative, soil fertility management and other agro-ecological practices, to increase effectiveness. However, spreading the mulch is an operational challenge and therefore especially interesting for small direct-marketing farms. Nevertheless, the described systemic approach can on the one hand elegantly reduce CBB abundance and overcome the need for direct intervention with insecticides while at the same time providing nutrients and additional plant protection with respect to late blight and weeds.”

361

13

Update the old references (citations) especially numbers from 13 and 16

There are no more recent studies that could explicitly highlight the effect mentioned in the questioned literature. It is clearly important to point out that certain findings were made already long ago.

14

Minor English language mistakes should be corrected

done

#

Reviewer correction

Author's revision

position

Correction: “The Faculty of Organic Agricultural Sciences” was corrected into “Department of Agricultural and Biosystems Engineering”

Affiliation

Legend was made more precise, e.g. instead of +2.0°C it now reads >+2.0°C

Table 3.

Funding was extended: ”, by The European Union’s Horizon 2020 Research and Innovation programme, under Grant Agreement no. 773554 (EcoStack) and”

Funding

1

Sorry, I don’t understand the difference between egg and egg masses, can you add an explanation in the text?

the paragraph

"In all years, CPB infestation dynamics by overwintering adults were recorded early in the season in regular intervals as well as the ensuing egg masses and larval densities."

became

"In all years, CPB infestation dynamics by overwintering adults were recorded early in the season in regular intervals as well as the ensuing egg depositions into clutches, hereafter referred to as egg masses, and larval densities. In 2016, 2018, and 2019, the total number of eggs was also recorded."

98

2

Also line 153-154 are not understandable to me, “Due to...three assessments were conducted.”

163

3

I found typing mistakes, I underlined in the attached file, such as species names that must always be written in   italics. Genus in capital letter, species in low letter.

Thank you for your suggestions, the text has been changed according to the notes

4

Line 125:  you mention Novodor as “Bacillus thuringensis”, I think it’s more appropriate to add “toxin” as in Novodor are present toxin, not the bacteria.

”Bacillus thuringiensis (Novodor® FC) was sprayed in 2019 to regulate CPB when it went out of hand. ”

”The Bacillus thuringensis toxin (Novodor® FC) was sprayed in 2019 to regulate CPB when it went out of hand. ”

135

5

In the references I made some corrections.

Thank you for the corrections, they have all been taken over.

6

It is not clear, could you explain?

See answer to comment # 2