Critical Time for Weed Removal in Corn as Influenced by Planting Pattern and PRE Herbicides

Round 1

Reviewer 1 Report

Paper needs extensive editing.  There are many misspellings and words missing.  With no line numbers, I cant indicate where changes are needed.  In some tables, it appears that growing degree days (GGD) are confused with days after emergence (DAE).  These are different measures.  In figure 2, percent yield is presented in figures from 2000 to 14000.  I dont understand these numbers.  Percent normally is presented from 0 to 100%, or slightly more.  Yields would be clearer if presented as hard figures.  Percent of control is a derived figure, and should not be used as the basis for statistical comparison. 

There was extreme difference in weather between years, making comparisons very difficult.  That fact that untreated treatments had more weeds than treated plots is not new information.  There were few differences between treatments in weed control or yield. 

Author Response

Point 1: Paper needs extensive editing. There are many misspellings and words missing.  With no line numbers, I cant indicate where changes are needed. 

Response 1: Dear Reviewer, we much appreciate a well-targeted criticism for improving our paper. But I don't know which version you read, the version (agriculture-1237632) which is online on the MDPI site, has line numbers, so other reviewers submitted comments using line numbers where they told me what changes I need to make to improve the manuscript. If the English style needs to improve more, we are ready to send the paper to the MDPI English editing service.

In some tables, it appears that growing degree days (GGD) are confused with days after emergence (DAE). These are different measures.  In figure 2, the percent yield is presented in figures from 2000 to 14000.  I don't understand these numbers.  Percent normally is presented from 0 to 100%, or slightly more.  Yields would be clearer if presented as hard figures.  Percent of control is a derived figure, and should not be used as the basis for statistical comparison. 

Thank you very much for your suggestions. We corrected all of them in the new version of our manuscript.

 

Point 2: There was  extreme difference in weather between years, making comparisons very difficult.  That fact that untreated treatments had more weeds than treated plots is not new information.  There were few differences between treatments in weed control or yield. 

Response 2: Yes, there was a difference in weather conditions in all years, which is good to see when will start CTWC under that conditions and compare influence planting patterns and variants with and without PRE herbicide. Also, under different weather conditions was a different number of weeds and yield or yield loss, which is important for CTWC for that location and weather condition. In agriculture we can't influence on weather conditions and farmers when start their production they can just can adapt to them. With this information, we will help them to form an adequate strategy for controlling weeds.

Reviewer 2 Report

1. Tables should be placed in numbering order as described in the text (Table 3 at the end of the manuscript after Tables 4, etc.). 
2. No reference to Table 4 in the text.
3. Figure 2. The description of the y-axis is correct? In brackets should be % of weed-free or kg ha-1 (values on the axis from 0 to 1400). 

Comments for author File: Comments.pdf

Author Response

Dear Reviewer,

Thank you very much for your constructive comments for improving our manuscript. Below we present our answers to your comments.

 

Point 1: Line 386: Tables should be placed in numbering order as described in the text (Table 3 at the end of the manuscript after Tables 4, etc.).

 Response 1: Corrected as suggested (Now table 3 is in line 220).

 

Point 2: Line 204: No reference to Table 4 in the text.

Response 2: Corrected as suggested (Corrected version is now in line 200 and 219)

 

Point 3: Line 260: Figure 2. The description of the y-axis is correct? In brackets should be % of weed-free or kg ha-1 (values on the axis from 0 to 1400).

Response 3: Corrected as suggested. (Corrected version is now in line 290)

Reviewer 3 Report

The manuscript is a good scientific out put well written with a lot of effort, which when published will contribute to knowledge in the field of agronomy. However, there are a few minor errors that need to be addressed to improve the quality of the manuscript. The observed minor issues which urgently need to be addressed include:

ABSTRACT

• Line 11: the sentence should read an integrated weed management weed management "plan" and not "plans"

INTRODUCTION

• Line 29: the phrase "over than" should be changed to "more than"
• Line 38: the sentence should start as "Other studies" or "Others" and not "Other"
• Line 43: Insert "be a" between could and very
• Line 46: Put full stop (.) after control
• Line 58: Replace "tree" with "three"
• Line 59: Put "which" after loss
• Line 81: Put "the" after therefore
• Line 89: Insert ranged between chemical properties and from
• Line 93: Put "to" in place of "and"
• Line 128: You say that relative yield was calculated from the equation described above, but there is no equation above. So reference your writing
• Line 153: Delete "d" before "by"
• Line 164: Delete "were" and put "where"
• Line 167: Replace "calculate" with "calculated"

RESULTS

• Line 173: Insert was between "which" and "was"
• Line 174: Insert "the" between "were" and "dominant species"
• Line 174 & 175 and throughout the work: Choose between "broad leaf" and "broad leaved". There should consistency in your choice of words and terms
• Line 178: Insert "the" between "were" and "dominant"
• Line 179: Replace "are" with "were"
• Line 181: Delete "at" before "2015"
• Line 182: Correct "patters" to "patterns"
• Line 183: Replace "then" with "than"
• Line 188: Replace "trend" with "trends" and insert "observed" after "were"
• Line 195: The sentence should read "the five dominant species" and not "the dominant five species"
• Line 210: Put full stop (.) after (7.8%)
• Line 211: Start the sentence like this "In the same treatment............ weed population was" and delete "is"
• Line 212: Replace "were" with "was"
• Line 216: Check the sentence very well. I can't understand what you mean by "which result is the lover thanks to the functioning......."
• Line 220: Delete "where is" and put "143.3 weeds m^-2" into brackets and delete "it"
• Line 225: Replace "high" with "highest"
• Line 226: Delete "in" after "however" and delete "it was" before "lowest" and insert "recorded the" before " to make it read like "However, the wet season............. recorded the lowest total weed density.............."
• Line 229: Insert "is" after "it" before "compared"
• Line 265: Delete "in" after "weedy"
• Line 278: Replace "loses" with "losses"
• Line 297: Delete "a" and insert "when" before "compared" and put "the" after "with"
• Line 332: The word "imperative" does not fit there. so replace it with "goal" or "objective"
• Line 343: Replace "pattern" with "patterns"
• Line 343 & 345: Which do you prefer in describing the year 2015, driest or dry? You have to be consistent.
• Line 349: Insert "that" after "yield"
• Line 436: Replace "yields" with "yield"
• Line 355: Insert "due" after "likely"
• Line 356: Replace "other research has shown" with "other studies have shown"
• Line 358: Replace "weed" with "weeds"
• Line 372: Replace "field with "fields"

Author Response

Response to Reviewer 3 Comments

Dear Reviewer,

Thank you very much for your constructive comments for improving our manuscript. Below we present our answers to your comments.

 

ABSTRACT

Point 1: Line 11: the sentence should read an integrated weed management weed management "plan" and not "plans"

Response 1: Corrected as suggested.

 

INTRODUCTION

Point 2: Line 29: the phrase "over than" should be changed to "more than"

Response 2: Corrected as suggested.

 

Point 3: Line 38: the sentence should start as "Other studies" or "Others" and not "Other"

Response 3: Corrected as suggested.

 

Point 4: Line 43: Insert "be a" between could and very

Response 4: Corrected as suggested.

 

Point 5: Line 46: Put full stop (.) after control

Response 5: Corrected as suggested.

 

Point 6: Line 58: Replace "tree" with "three"

Response 6: Corrected as suggested (Corrected version is now in line 62).

 

Point 7: Line 59: Put "which" after loss

Response 7: Corrected as suggested (Corrected version is now in line 63).

 

Point 8: Line 81: Put "the" after therefore

Response 8: Corrected as suggested (Corrected version is now in line 85).

 

Point 9: Line 89: Insert ranged between chemical properties and from

Response 9: Corrected as suggested (Corrected version is now in line 93).

 

Point 10: Line 93: Put "to" in place of "and"

Response 10: Corrected as suggested (Corrected version is now in line 96).

 

Point 11: Line 128: You say that relative yield was calculated from the equation described above, but there is no equation above. So reference your writing..  

Response 11: Corrected as suggested (Corrected version is now in line 133).

 

Point 12: Line 153: Delete "d" before "by"

Response 12: Corrected as suggested (Corrected version is now in line 160).

 

Point 13: Line 164: Delete "were" and put "where"

Response 13: Corrected as suggested (Corrected version is now in line 171).

 

Point 14: Line 167: Replace "calculate" with "calculated"

Response 14: Corrected as suggested (Corrected version is now in line 175).

 

RESULTS

Point 15: Line 173: Insert was between "which" and "was"

Response 15: Corrected as suggested (Corrected version is now in line 181).

 

Point 16: Line 174: Insert "the" between "were" and "dominant species"

Response 16: Corrected as suggested (Corrected version is now in line 182).

 

Point 17: Line 174 & 175 and throughout the work: Choose between "broad leaf" and "broad leaved". There should consistency in your choice of words and terms

Response 17: Corrected as suggested (Corrected version is now in line 183).

 

Point 18: Line 178: Insert "the" between "were" and "dominant"

Response 18: Corrected as suggested (Corrected version is now in line 185).

 

Point 19: Line 179: Replace "are" with "were"

Response 19: Corrected as suggested (Corrected version is now in line 187).

 

Point 20: Line 181: Delete "at" before "2015"

Response 20: Corrected as suggested (Corrected version is now in line 192).

 

Point 21: Line 182: Correct "patters" to "patterns"

Response 21: Corrected as suggested (Corrected version is now in line 193).

 

Point 22: Line 183: Replace "then" with "than"

Response 22: Corrected as suggested (Corrected version is now in line 194).

 

Point 23: Line 188: Replace "trend" with "trends" and insert "observed" after "were"

Response 23: Corrected as suggested (Corrected version is now in line 199).

 

Point 24: Line 195: The sentence should read "the five dominant species" and not "the dominant five species"

Response 24: Corrected as suggested (Corrected version is now in line 206).

 

Point 25: Line 210: Put full stop (.) after (7.8%)

Response 25: Corrected as suggested (Corrected version is now in line 241).

 

Point 26: Line 211: Start the sentence like this "In the same treatment............ weed population was" and delete "is"

Response 26: Corrected as suggested (Corrected version is now in line 241).

 

Point 27: Line 212: Replace "were" with "was"

Response 27: Corrected as suggested (Corrected version is now in line 241).

 

Point 28: Line 216: Check the sentence very well. I can't understand what you mean by "which result is the lover thanks to the functioning......."   

Response 28: Corrected as suggested (Corrected version is now in line 245-248).    

 

Point 29: Line 220: Delete "where is" and put "143.3 weeds m-2" into brackets and delete "it"

Response 29: Corrected as suggested (Corrected version is now in line 249).

 

Point 30: Line 225: Replace "high" with "highest"

Response 30: Corrected as suggested (Corrected version is now in line 253).

 

Point 31: Line 226: Delete "in" after "however" and delete "it was" before "lowest" and insert "recorded the" before " to make it read like "However, the wet season............. recorded the lowest total weed density.............."

Response 31: Corrected as suggested (Corrected version is now in line 254 and 255).

 

Point 32: Line 229: Insert "is" after "it" before "compared"

Response 32: Corrected as suggested (Corrected version is now in line 258).

 

Point 33: Line 265: Delete "in" after "weedy"

Response 33: Corrected as suggested (Corrected version is now in line 295).

 

Point 34: Line 278: Replace "loses" with "losses"

Response 34: Corrected as suggested (Corrected version is now in line 310).

 

Point 35: Line 297: Delete "a" and insert "when" before "compared" and put "the" after "with"

Response 35: Corrected as suggested  (Corrected version is now in line 333 and 336).

 

Point 36: Line 332: The word "imperative" does not fit there. so replace it with "goal" or "objective"

Response 36: Corrected as suggested  (Corrected version is now in line 369).

 

Point 37: Line 343: Replace "pattern" with "patterns"

Response 37: Corrected as suggested (Corrected version is now in line 381).

 

Point 38: Line 343 & 345: Which do you prefer in describing the year 2015, driest or dry? You have to be consistent.

Response 38: Corrected as suggested (Corrected version is now in line 380).

 

Point 39: Line 349: Insert "that" after "yield"

Response 39: Corrected as suggested (Corrected version is now in line 386).

 

Point 40: Line 436 (probably the reviewer meant on the line number 346): Replace "yields" with "yield"

Response 40: Corrected as suggested (Corrected version is now in line 382).

 

Point 41: Line 355: Insert "due" after "likely"

Response 41: Corrected as suggested (Corrected version is now in line 392).

 

Point 42: Line 356: Replace "other research has shown" with "other studies have shown"

Response 42: Corrected as suggested (Corrected version is now in lines 397 and 398).

 

Point 43: Line 358: Replace "weed" with "weeds"

Response 43: Corrected as suggested (Corrected version is now in line 398).

 

Point 44: Line 372: Replace "field with "fields"

Response 44: Corrected as suggested (Corrected version is now in line 413).

Round 2

Reviewer 1 Report

The major finding of this paper is that preemergence herbicides improve corn yield.  See lines 377-378 and 408-414.  This is not new information.  The use of regression analysis in this type of experiment is inappropriate.  The added numbers obfuscate the results. 

Author Response

Dear Reviewer,

Below we present our answers to your comments.

 

Point 1: The major finding of this paper is that preemergence herbicides improve corn yield.  See lines 377-378 and 408-414.  This is not new information. 

Response 1:

Based on your criticism, we modified one sentenced to clarify the message.

The twin row planting pattern is a newer approach model of production in the USA, and other parts of the world where farmers are encountering such production for the first time. The general advantage of sowing in twin rows is increased yields due to increased plant population and adverse effects on weeds  as influenced by  presence or absence of PRE herbicides. In addition, we showed the effects agroecological conditions across years and herbicides on the CTWR. This is all new information for corn production.

 

Point 2:

The use of regression analysis in this type of experiment is inappropriate.  The added numbers obfuscate the results. 

Response 2:

The use of regression analysis is based on the “recipe” developed at University of Nebraska in 2002 by our co-author Dr. Knezevic (see Knezevic et al 2002) and then further amended in 2015 by Knezevic and Data (2015). Both “recipes” were published in Weed Science journal.  This methodology was utilized effectively in many projects worldwide over a 20 year period.      

Below are examples of few references:

Knezevic SZ, Evans SP, Blankenship EE, Van Acker RC, Lindquist JL (2002). Critical period of weed control: the concept and data analysis. Weed Sci 50:773–786.

Knezevic S. and Datta A. 2015. The Critical Period for Weed Control: Revisiting Data Analysis. Weed Science. Special Issue. 188-202.

Knezevic SZ, Streibig JC, Ritz C (2007). Utilizing R software package for dose response studies: the concept and data analysis. Weed Technol 21:840–848.

Evans SP, Knezevic SZ, Lindquist JL, Shapiro CA, Blankenship EE (2003). Nitrogen application influences the critical period for weed control in corn. Weed Sci 51:408–417.

Knezevic, Z. S., S. Evans and M.Mainz. 2003. Row spacing influences critical time of weed removal in soybean. Weed Tech. 17:666-673.

Gustafson T, S. Knezevic, T. Hunt and J. Lindquist. 2006.  Early-season insect defoliation influences the Critical time for weed removal in soybean. Weed Sci, 54: 509-515.

Knezevic S, Elezovic I, Datta A, Vrbnicanin S. 2013. Delay in the critical time for weed removal in

imidazolinone-resistant sunflower (Helianthus annuus) caused by application of pre-emergence herbicide. Intern. J. Pest Management, Vol. 59, No. 3, 229–235

Tursun N., Tuncel E. Datta A. Knezevic S. 2015. Nitrogen application influenced the critical period for weed control in cotton. 2015. Crop Protection. (74) 85-91.

Tursun N., Tuncel E. Datta A. Knezevic S. 2015.  Effect of row spacing on the critical period for weed control in cotton. 2015. Crop Protection. Accepted.

Elezovic I, Datta A, Vrbnicanin S, Glamoclija D, Simic M, Malidza G, Knezevic SZ (2012). Yield and yield components of imidazolinone-resistant sunflower (Helianthus annuus L.) are influenced by pre-emergence herbicide and time of post-emergence weed removal. Field Crops Res 128:137–146.