Activity of Ailanthus altissima (Mill.) Swingle Extract as a Potential Bioherbicide for Sustainable Weed Management in Horticulture
, Sonia Demasi 1,†, Fabrizio Caldera 2, Nilesh Kumar Dhakar 2, Francesco Trotta 2 and Valentina Scariot 1Round 1
Reviewer 1 Report
I suggest to eliminate the world “pre-emergence” from the title because herbicidal activity of studied extracts was evaluated also on the leaves of common sage and carnation. I propose following title: “Studies on herbicidal activity of Ailanthus altissima (Mill.) Swingle extracts”
Line 22: it should be “seven common weeds”; Digitaria sanguinalis (L.) Scop. should be added. It would be better “Leaf extract was therefore used in greenhouse on the indicator species and seven common weeds…”
Line 23: it should be Stellaria media (L.) Vill.
Lines 23-24: it would be better”…and in nursery in cultivation of Salvia officinalis L.,
Lines 25-16: it would be better “percentage of weed presence pots…”
Line 80: it should be “…seven common weeds..”; Digitaria sanguinalis (L.) Scop. Should be added.
Line 81-82: it should be Stellaria media (L.) Vill. and S. rosmarinus (L.) Schleid.
Table 2: it should be Digitaria sanguinalis (L.) Scop., Poaceae; Stellaria media (L.) Vill., Salvia rosmarinus (L.) Schleid.
Line 160-163: detailed information about how the extracts were sprayed is necessary.
Line 169: Plant growth index should be explained, especially that it`s unit is cm-3. It is difficult for a reader to look for it in Caser`s papers. Also leaf damage should be described more precisely – chlorosis ?, necrosis ?
Line 189-190: It would be better: Effect of extract type, dosage, and days after treatment (DAT) on the germination index (IGe%) of Raphanus sativus and Lepidium sativum seeds in growth chamber assay.
Line 196: it should be 2.56-44.70%
Line 199-201: title of Table 4, it would be better: Effect of extract type, dosage, and days after treatment on its persistence along time and on germination index of Raphanus sativus seeds in growth chamber bioassay.
Line 206-208: the same suggestion as for Table 4.
Line 216: instead of “However, the most effective and persistent…” it should be: “More effective and persistent…”.
Line 219: instead of “…in reducing the studied parameters…” it should be : “…in reducing the studied parameter..”. Studied parameter was one – IGe%.
Lines 224-238: results obtained in a previous experiment and already published should not be presented as a part of results obtained in this study. They can be used and discussed in the chapter “Discussion”. Moreover, the comments are not consistent with the bars presented in Fig. 1. In the case of R. sativus there were significant differences at 18 DAT. And in the case of L. sativum there were also significant differences between “b” and “c” and “d”.
Line 246 and Figure 2: it should be Achillea millefoilum, not millefolia.
Line 253 Experiment 1. It is a fault of this experiment that substrate contained only few weed seeds. 1.3-3.1 weeds per pot germinated in control treatment. It is difficult to evaluate herbicidal activity in situation when one weed can make the difference significant. In the praxis, usually more weeds grow in one container. It is a pity that because of this it was not possible to evaluate susceptibility of different weed species to studied extracts like it was in greenhouse assay. Because of this, the authors created a new parameter “weed presence vase” which is not used in weed science. Main parameter in weed science is “weed density” with detailed description of weed flora. This should be mentioned in the “Discussion”.
Line 253: it should be “Effect of leaf extracts on weeds, Salvia offcinalis, S. rosmarinus and Dianthus caryophyllus under pot cultivation in nursery”
Line 255: it should be Erigeron annuus (L.) Pers.
Line 258: instead “treated vases” it should be “treated pots”. The authors inform correctly in “Materials and methods” that the plants were “cultivated in plastic pots”. In nursery production, the terms “pot” or “container” are used. This remark should be taken into account in several other places were the term “vase” was used.
Line 296, Table 7: I suggest to eliminate “Leaf damages” column containing only zeros because the extracts were applied directly to soil surface, not on plants like in first experiment and therefore one should not expect any leaf damages. It would be possible to expect some plant damage after extract absorption by the sage roots but such damages were not observed. It is enough to mention this in one sentence as a comment to obtained results. Explanation what is “Growth Index” is necessary.
Line 359: “O. sativa” - is it Oryza sativa L. ?
Line 386: it should be: Barbarea verna (Mill.) Asch.
Line 389: it should be: Setaria viridis (L.) P. Beauv.
Line 436-437: it should be: “Ailanthus altissima extracts showed very high phytotoxic activity towards different weeds, already at very low dosage in growth chamber and greenhouse assays”. High herbicidal activity was not proved in nursery conditions and laboratory results differ often from those obtained in open field.
Line 437-438: the sentence “Extracts were generally more effective….than the pure ailanthone, previously tested.” Should be placed in “Discussion”. “Conclusion” should refer only to the results obtained in experiments presented in this paper.
Line 495: it should be”…germination and seedling growth…” and not “…Growth…”.
Line 541: is should be “…Gniazdowska…” and not “…Gniazdowsk…”.
Author Response
May, 18th 2020
To:
Editorial Office
Agronomy
Dear Editorial Office,
we submit a revised version of the article “Insights in the pre-emergence herbicidal activity of Ailanthus altissima (Mill.) Swingle extracts. New candidates for sustainable weed management in horticulture.” by Matteo Caser, Sonia Demasi, Fabrizio Caldera, Nilesh Kumar Dhakar, Francesco Trotta and Valentina Scariot for publication in the Special Issue “Sustainability and Quality in Ornamental Horticulture: Challenges and Perspectives” of the journal “Agronomy”.
We thank for the comments and suggestions that were very helpful to further improve clarity of the manuscript.
For the preparation of the revised manuscript, we followed all the comments and suggestions of the editor and reviewers as stated below. We highlighted the main changes to the text by red.
Reviewer 1
REV: I suggest to eliminate the world “pre-emergence” from the title because herbicidal activity of studied extracts was evaluated also on the leaves of common sage and carnation. I propose following title: “Studies on herbicidal activity of Ailanthus altissima (Mill.) Swingle extracts”.
Line 22: it should be “seven common weeds”; Digitaria sanguinalis (L.) Scop. should be added. It would be better “Leaf extract was therefore used in greenhouse on the indicator species and seven common weeds…”
Line 23: it should be Stellaria media (L.) Vill.
Lines 23-24: it would be better”…and in nursery in cultivation of Salvia officinalis L.,
Lines 25-16: it would be better “percentage of weed presence pots…”
Line 80: it should be “…seven common weeds..”; Digitaria sanguinalis (L.) Scop. Should be added.
Line 81-82: it should be Stellaria media (L.) Vill. and S. rosmarinus (L.) Schleid.
Table 2: it should be Digitaria sanguinalis (L.) Scop., Poaceae; Stellaria media (L.) Vill., Salvia rosmarinus (L.) Schleid.
AUT: We modified the text, accordingly.
REV: Line 160-163: detailed information about how the extracts were sprayed is necessary.
Line 169: Plant growth index should be explained, especially that it`s unit is cm-3. It is difficult for a reader to look for it in Caser`s papers. Also leaf damage should be described more precisely – chlorosis ?, necrosis?
AUT: In the “2.5. Nursery assay” paragraph we detailed the information about the extracts application by professional sprayer. We also better define plant Growth Index and leaf damage.
REV: Line 189-190: It would be better: Effect of extract type, dosage, and days after treatment (DAT) on the germination index (IGe%) of Raphanus sativus and Lepidium sativum seeds in growth chamber assay.
Line 196: it should be 2.56-44.70%
Line 199-201: title of Table 4, it would be better: Effect of extract type, dosage, and days after treatment on its persistence along time and on germination index of Raphanus sativus seeds in growth chamber bioassay.
Line 206-208: the same suggestion as for Table 4.
Line 216: instead of “However, the most effective and persistent…” it should be: “More effective and persistent…”.
Line 219: instead of “…in reducing the studied parameters…” it should be : “…in reducing the studied parameter..”. Studied parameter was one – IGe%.
AUT: We modified the text, accordingly.
REV: Lines 224-238: results obtained in a previous experiment and already published should not be presented as a part of results obtained in this study. They can be used and discussed in the chapter “Discussion”. Moreover, the comments are not consistent with the bars presented in Fig. 1. In the case of R. sativus there were significant differences at 18 DAT. And in the case of L. sativum there were also significant differences between “b” and “c” and “d”.
AUT: We moved this part to “Discussion” section and we modified the text, accordingly.
REV: Line 246 and Figure 2: it should be Achillea millefoilum, not millefolia.
AUT: We modified the text, accordingly.
REV: Line 253 Experiment 1. It is a fault of this experiment that substrate contained only few weed seeds. 1.3-3.1 weeds per pot germinated in control treatment. It is difficult to evaluate herbicidal activity in situation when one weed can make the difference significant. In the praxis, usually more weeds grow in one container. It is a pity that because of this it was not possible to evaluate susceptibility of different weed species to studied extracts like it was in greenhouse assay. Because of this, the authors created a new parameter “weed presence vase” which is not used in weed science. Main parameter in weed science is “weed density” with detailed description of weed flora. This should be mentioned in the “Discussion”.
AUT: We add this sentence in the “Discussion” section: “…In this experiment, the substrate contained only few weed seeds (1.3-3.1 weeds per pot germinated in control), therefore it was not possible to evaluate the susceptibility of different weed species to the studied extracts as did in the greenhouse assay. For the same reason, the parameter “weed presence pot (%)” was used instead of the commonly used "weed density”…”
REV: Line 253: it should be “Effect of leaf extracts on weeds, Salvia offcinalis, S. rosmarinus and Dianthus caryophyllus under pot cultivation in nursery”
Line 255: it should be Erigeron annuus (L.) Pers.
Line 258: instead “treated vases” it should be “treated pots”. The authors inform correctly in “Materials and methods” that the plants were “cultivated in plastic pots”. In nursery production, the terms “pot” or “container” are used. This remark should be taken into account in several other places were the term “vase” was used.
Line 296, Table 7: I suggest to eliminate “Leaf damages” column containing only zeros because the extracts were applied directly to soil surface, not on plants like in first experiment and therefore one should not expect any leaf damages. It would be possible to expect some plant damage after extract absorption by the sage roots but such damages were not observed. It is enough to mention this in one sentence as a comment to obtained results. Explanation what is “Growth Index” is necessary.
Line 359: “O. sativa” - is it Oryza sativa L. ?
Line 386: it should be: Barbarea verna (Mill.) Asch.
Line 389: it should be: Setaria viridis (L.) P. Beauv.
Line 436-437: it should be: “Ailanthus altissima extracts showed very high phytotoxic activity towards different weeds, already at very low dosage in growth chamber and greenhouse assays”. High herbicidal activity was not proved in nursery conditions and laboratory results differ often from those obtained in open field.
AUT: We modified the text, accordingly.
REV: Line 437-438: the sentence “Extracts were generally more effective….than the pure ailanthone, previously tested.” Should be placed in “Discussion”. “Conclusion” should refer only to the results obtained in experiments presented in this paper.
AUT: We preferred to maintain the original text in the “Conclusion” section because we believe that this is one of the most interesting results of this work. For this reason it should be part of the main conclusions of this study.
REV: Line 495: it should be”…germination and seedling growth…” and not “…Growth…”.
Line 541: is should be “…Gniazdowska…” and not “…Gniazdowsk…”.
AUT: We modified the text, accordingly.
Reviewer 2 Report
Dear colleague,
I have reviewed your manuscript entitled “Insights in the pre-emergence herbicidal activity of Ailanthus altissima (Mill.) Swingle extracts. New candidates for sustainable weed management in horticulture”. This manuscript presents an extensive study on the potential use of A. altissima extracts as herbicide in horticulture. I believe this is definitely an interesting topic, improving our knowledge on the potential use of natural products as environmental-friendly herbicides could facilitate the development of sustainable weed control tools. This study includes a set of consecutive experiments, ranging from extraction and quantification of active compounds to the evaluation of herbicidal effect with different bioassays under growth chamber, greenhouse and nursery conditions. The experimental design is robust and accurate.
The manuscript is well-written and flowing, the adopted methodologies are well-described. Result presentation and discussion are exhaustive and interesting. I would like to point out some minor comments and suggestions, hoping that you will find them useful.
Lines 61-63 I would specify that A. altissima is a perennial invasive species known to cause major negative impacts on human activities, especially in urban areas.
Line 138 I would suggest specifying the meaning of the parameters included in the Equation 1, even if they have been already presented in a previous publication, to facilitate comprehension by readers. I suppose that a sentence like the one at Lines 150-151 would be enough.
Lines 169-171 In this part it is stated that leaf damage was rated using 5 classes, but this response variable is reported as % of damage in Table 6 and Table 7. Were the damage class data back-transformed to damage %? Maybe this passage should be clarified.
Line 324 There is probably a typo here, I think that the word “end” is missing (at the end of the trial).
Lines 356-358 I would not assume that A. altissima extracts have no effect on the environment, given that they exhibit diverse biological activities, as stated in Lines 61-63. I would rather say in the text that accurate studies are required to evaluate environmental impacts of A. altissima extracts, as for any other pesticides or biologically active compounds used in agriculture.
Line 435 I would mention in the Conclusion section that mechanical operations are commonly performed to control A. altissima, consequently plant material for the extraction of active compounds can be available at low cost. This can make the use of A. altissima extracts as herbicides more convenient that other bio-herbicides.
Author Response
May, 18th 2020
To:
Editorial Office
Agronomy
Dear Editorial Office,
we submit a revised version of the article “Insights in the pre-emergence herbicidal activity of Ailanthus altissima (Mill.) Swingle extracts. New candidates for sustainable weed management in horticulture.” by Matteo Caser, Sonia Demasi, Fabrizio Caldera, Nilesh Kumar Dhakar, Francesco Trotta and Valentina Scariot for publication in the Special Issue “Sustainability and Quality in Ornamental Horticulture: Challenges and Perspectives” of the journal “Agronomy”.
We thank for the comments and suggestions that were very helpful to further improve clarity of the manuscript.
For the preparation of the revised manuscript, we followed all the comments and suggestions of the editor and reviewers as stated below. We highlighted the main changes to the text by red.
Reviewer 2
REV: Dear colleague,
I have reviewed your manuscript entitled “Insights in the pre-emergence herbicidal activity of Ailanthus altissima (Mill.) Swingle extracts. New candidates for sustainable weed management in horticulture”. This manuscript presents an extensive study on the potential use of A. altissima extracts as herbicide in horticulture. I believe this is definitely an interesting topic, improving our knowledge on the potential use of natural products as environmental-friendly herbicides could facilitate the development of sustainable weed control tools. This study includes a set of consecutive experiments, ranging from extraction and quantification of active compounds to the evaluation of herbicidal effect with different bioassays under growth chamber, greenhouse and nursery conditions. The experimental design is robust and accurate.
The manuscript is well-written and flowing, the adopted methodologies are well-described. Result presentation and discussion are exhaustive and interesting. I would like to point out some minor comments and suggestions, hoping that you will find them useful.
AUT: We We thank the reviewer for their positive comments on the work.
REV: Lines 61-63 I would specify that A. altissima is a perennial invasive species known to cause major negative impacts on human activities, especially in urban areas.
AUT: We added this sentence to the “Introduction” section: “…Ailanthus altissima (Mill.) Swingle is a perennial invasive species known to cause major negative impacts on human activities, especially in urban areas. However, the extracts obtained from different parts of this species were reported…”.
REV: Line 138 I would suggest specifying the meaning of the parameters included in the Equation 1, even if they have been already presented in a previous publication, to facilitate comprehension by readers. I suppose that a sentence like the one at Lines 150-151 would be enough.
AUT: We specified each parameters of the Equation 1 by adding this sentence in the “2.3. Growth chamber assay” paragraph: “…Where n is the number of germinated seeds and r the mean root length in treated sample (s) and control (c).”
REV: Lines 169-171 In this part it is stated that leaf damage was rated using 5 classes, but this response variable is reported as % of damage in Table 6 and Table 7. Were the damage class data back-transformed to damage %? Maybe this passage should be clarified.
AUT: We clarified this passage in the “2.5. Nursery assay” paragraph by adding this sentence: “…and transformed to percentage (%) of leaf damage as reported by Caser et al…”.
REV: Line 324 There is probably a typo here, I think that the word “end” is missing (at the end of the trial).
AUT: We modified the text, accordingly.
REV: Lines 356-358 I would not assume that A. altissima extracts have no effect on the environment, given that they exhibit diverse biological activities, as stated in Lines 61-63. I would rather say in the text that accurate studies are required to evaluate environmental impacts of A. altissima extracts, as for any other pesticides or biologically active compounds used in agriculture.
AUT: We specified this aspect in the “Discussion” section by adding this sentence: “…Accurate scientific studies must however be conducted to evaluate environmental impacts of A. altissima water extracts, as for any other pesticides or biologically active compounds used in agriculture…”.
REV: Line 435 I would mention in the Conclusion section that mechanical operations are commonly performed to control A. altissima, consequently plant material for the extraction of active compounds can be available at low cost. This can make the use of A. altissima extracts as herbicides more convenient that other bio-herbicides.
AUT: We specified this aspect in the “Conclusion” section by adding this sentence: “…As mechanical operations are commonly performed to control A. altissima, plant material for the extraction of active compounds can be available at low cost. This can make the use of A. altissima extracts as herbicides more convenient that other bio-herbicides…”.
