Responses and sensitivities of maize phenology to climate change from 1971 to 2020 in Henan Province, China.

Climate change affects many aspects of the physiological and biochemical processes of growing maize and ultimately its yield. A comprehensive climate suitability model is proposed that quantifies the effects of temperature, precipitation, solar radiation, and wind in different phenological stages of maize. It is calibrated using weather and yield data from China's Henan Province. The comprehensive suitability model showed the capability of correctly hindcasting observed temporal and spatial changes in maize phenology in response to climatic factors. The predicted yield based on the suitability model can well match the recorded field yield very well from 1971-2020. The results of correlation showed that the yields are more closely related to multi-weather factors, temperature and precipitation than to solar radiation and wind. The sensitivity analysis illustrates that temperature and precipitation are the dominant weather factors affecting yield changes based on a direct differentiation method. The comprehensive suitability model can provide a scientific support and analysis tool for predicting grain production considering climate changes.

Introduction

Agriculture is an industry especially sensitive to climate change [1, 2]. Since the 1960s, climate change has had a greater impact on agricultural production. The changes in global climate make it important to study the meteorological suitability of each growth period of a crop to guide agricultural production [3, 4]. Nowadays, evaluating the suitability of meteorological conditions has gradually shifted from qualitative to quantitative [5-8]. Some scholars have studied the suitability evaluation models of meteorological conditions based on local climate conditions and established various crop climate suitability, evaluation models [9-12]. According to the simulation and prediction of crop growth period, suitability evaluation models can provide some commands to manage farmland timely, choosing appropriate genotypes, and forecasting yields at each growth stage of crops based on agrometeorological conditions.

Many scholars have researched the assessment of the climate suitability of crops. The climatic suitability of crops is mainly based on the membership function method in fuzzy mathematics [13-15]. Through the establishment of a series of quantitative indices or mathematical models, the quantitative changes of the main agricultural climatic factors (solar radiation, precipitation, and temperature) are transformed into the effects of crop growth and development, yield, and quality [16, 17]. Gu et al. [18, 19] have proposed the concept of agroclimatic suitability describing a region’s suitability for growing particular crops such as maize and wheat. Gonzalez et al. [20] have established a model to simulate the growth of crops and the effects of climatic factors. It nicely represents the impact of precipitation and temperature on the growth period of rice in Spain [20]. Olesen et al. [21] study the effect of extreme climate events on agricultural production and the interaction with the surrounding natural ecosystems. Lamptey [22] uses a water suitability model to explore the effect of precipitation on crop yields and provides several ways to improve the utilization of agricultural water resources and rational use of renewable energy to promote stable agricultural production. Wang et al. [23] used meteorological data spanning 1961 to 2000 to fit a suitability model suitable for the main meteorological factors at Datong in China’s Shanxi Province. They proposed three hierarchical models of agroecological climate. Matthews and Wassmann [24] analyzed the temporal evolution of the climate’s suitability for rice in the Philippines over the past 100 years and induced a model relating climate change to rice yield. He predicts that the adaptability of Philippine rice to climate change will continue to decline.

Crop yields are generally affected by a variety of climatic factors, especially by temperature, precipitation, solar radiation, and wind speed. A few researchers have proposed a development simulation model based on growing degree-days (GDD) and physiological development time (PDT). The model is mechanistic and takes into account thermal effects, insolation, and different varieties [25-27]. Zhao et al. [28] have used fuzzy mathematics to build a comprehensive climate suitability model for winter wheat in China’s Henan Province, establishing temperature, solar radiation, and precipitation suitability functions. Yao et al. [29] analyzed the solar radiation, temperature, and water climate suitability and its temporal and spatial distribution laws in each growth period of Gansu Province’s corn and Hebei Province’s cotton in the past 40 years according to the requirement for solar radiation, temperature, and precipitation in different growth stages of crops. There has not, however, been systematic research on the climate’s suitability for growing maize in Henan.

This paper establishes a comprehensive climate suitability model to quantify the effect of temperature, water, solar radiation, and wind in a maize growth cycle based on the maize physiological growth model. The model is used to predict the effect of climatic factors on the yield of corn in Henan in the past 50 years. This model is combined with the direct differentiation method to analyze the climatic factor sensitivities on the yield of corn. The practical purpose of this research is to be able to provide a tool for accurately predicting corn yield in the face of climate change.

Materials and methods

A comprehensive climate suitability (CCS) model for maize

According to the growth characteristics of maize in China’s Henan Province, its whole growth period can be divided: seedling stage (conventionally June 1 to June 15), heading stage (June 16 to July 15), pollination stage (July 16 to August 15) and maturity stage (August 16 to September 15). A comprehensive suitability model is proposed in the growth period to study the effect of temperature, precipitation, solar radiation, and wind speed on the yield of maize. In actual crop growth, those four factors are not completely independent. There are certain correlations between temperature and precipitation, temperature and insolation, temperature and wind speed, and of course precipitation and solar radiation. Therefore, the independent suitability models need to be first established for the four factors.

Temperature suitability model

To quantitatively analyze the satisfaction degree of heat resources to the growth of maize, a useful temperature suitability model can be defined as [30], where and F(t) is the temperature suitability index on the ith day in the maize growth period, t is the daily average temperature recorded by the climate station. The variables t, t, t0 are the daily minimum, maximum and optimum temperature for the current growth stage of maize, i.e., the three basic point temperatures, which are determined by the temperature requirement of maize at different growth stages. This paper provides a three basic point temperature of four stages based on the comprehensive reference of several pieces of literature [30], as shown in Table 1.

Table 1

The three basic temperatures at each growth stage of maize.

Growth stage	Period	tL (°C)	tH (°C)	t0 (°C)
Seedling stage	June 1—June 15	17	35	25
Heading stage	June 16—July 15	21	35	26
Pollination stage	July 16—Aug 15	22	35	26
Mature stage	August 16—September 15	18	32	22

The annual average temperature suitability index for maize can then be calculated as where n is the number of days in the entire growth cycle of maize—107 days. The index T ranges between 0 and 1, with T = 1 indicating that temperature has no negative effect on the growth of maize.

Precipitation suitability model

Water plays an important role in many physiological processes of maize. Excessive rain leads to slender maize stems and poor tenacity, while drought will inhibit maize growth, reducing the photosynthetic rate and dry matter accumulation [31-33]. Summer in Henan has high temperatures and high evaporation. The water consumption of the whole growth period is 350–450mm, but it differs over the four growth stages. Less than 70% of that is considered mild drought, and more than 130% is mild waterlogging. Wei et al. [34] suggest that the precipitation suitability of maize can be quantified as where F(r) is the precipitation suitability index in the ith maize growth period, r is the accumulated precipitation in the ith growth period, and r0 is the period’s water requirement for maize. The water requirements in different growth stages of maize are shown in Table 2.

Table 2

Water requirement of maize at different development stages.

Growth stage	Period si (day)	Water requirement (mm)
Seedling stage	15	30
Heading stage	30	100
Pollination stage	31	150
Mature stage	31	150

The annual average precipitation suitability index for maize can be calculated as where s is the number of days in growing stage i. Similarly, the index R then also ranges between 0 and 1, with R = 1 indicating that precipitation has no negative effect on maize growth.

Solar radiation suitability model

Solar radiation is the energy source for crop growth, as well as for the processes of accumulation, distribution, and transfer of photosynthetic products that determine maize yield [35, 36]. Solar radiation enhanced leaf photosynthesis of maize during the daytime, which lead to more photosynthetic products being carried to roots to promote the growth process of maize [37, 38]. As a C4 plant, the carboxylation pathway of maize photosynthesis has a strong correlation with solar radiation [39]. Generally, the development period of maize is advanced under 8 to 9 hours of daily solar radiation. When the solar radiation is inadequate, the nutritional growth slows down and yield decreases. Therefore, sufficient solar radiation can promote the high yield of maize. The solar radiation hours over the whole growth period average in Henan province are 600–900h. In a certain range, the more solar radiation in the whole growth period, the higher the yield. According to the previous research results, 70% of the theoretical solar radiation is the most suitable [40]. Li et al. [40] suggest the following solar radiation suitability model. where F(s) is the solar radiation suitability index of the ith day in a maize growth period and si is the hours of solar radiation length on that day. The variable S0 is the critical solar radiation representing 70% of the theoretical maximum. b is an empirically-derived coefficient, and its reference values are shown in Table 3 [40]. The index F(s) is also a membership function ranging from 0 to 1. When the actual hours of sunshine exceed S0, F(s) is 1 and the response of maize to solar radiation is the most suitable.

Table 3

The critical length of solar radiation (S0) and the fitting coefficient b in the different growth stages of maize in Henan.

Growth stage	Length of critical solar radiation (h)	Empirical coefficient
Seedling stage	8.85	4.77
Heading stage	9.42	5.08
Pollination stage	9.53	5.14
Mature stage	9.71	5.24

The annual average solar radiation suitability index of maize can then be calculated as, then also ranges between 0 and 1, with S = 1 indicating the ideal insolation.

Wind suitability model

Wind will affect the yield of maize crops in two ways. 1) During flowering and pollination (usually about August 1-August 15), strong wind (wind speed greater than 10.0 m·s-1) is easy to cause maize stigma dryness. 2) During the mature period of maize, strong wind (such as in a typhoon) can easily cause maize lodging [41]. Generally, Henan Province is not affected by typhoons, and the problem of maize lodging can be solved by planting a suitable cultivar [42]. In the current study, the focus was made on flowering and pollination from August 1 to August 15. During that period the most suitable wind speed is less than 6.0 m·s-1 [43]. When the wind speed is greater than 10.0 m·s-1, the stigma will dry up, affecting the yield. The wind suitability model for maize can be expressed as [43] where F(w) is the wind suitability index on the ith day in a maize growth period, w and w are the lowest and the highest critical wind speeds. The annual average wind suitability index for maize can then be calculated as where nw is the number of days in the flowering period—15 days [43].

A comprehensive reduced yield model

The ideal temperature, water, solar radiation and wind differ in maize’s different growth stages, and the contribution coefficient of each meteorological parameter is also different [9, 43]. In addition, these four climatic factors are not completely independent in the actual crop growth period. Temperature and precipitation, temperature and solar radiation and of course precipitation and solar radiation have a certain correlation. The reduced yield index caused by a single weather factor can be calculated using the appropriate independent climatic suitability model, The temperature reduced yield index D = 1-T, the precipitation reduced yield index D = 1-R, the solar radiation reduced yield index D = 1-S, and wind reduced yield index D = 1-W.

A comprehensive reduced yield index can be calculated as a weighted average of the four single climatic reduced yield indices, where b, b, b, b, b, b and b are the weights of individual or coupled climatic reduced yield indices. They need to be determined empirically by the reverse analysis based on recorded and predicted yields.

Sensitivities of comprehensive reduced yield model

The climatic factors that affect the maize yield are often diverse [3, 4]. Due to the growth characteristics of maize in four growth stages being quite different and the whole growth cycle is longer, the maize yield is more sensitive to climate change. The sensitivity of any phenological change refers to the days over which the maize’s phenology changes as the weather factors by one unit. In the current study, a direct differentiation method can be used to quantify the sensitivity of maize weather yields and the comprehensive reduced yield index obtained from the comprehensive reduced yield model. The sensitivity of the comprehensive reduced yield index concerning a single weather variable can be calculated as

Taking temperature as an example, i.e., θ = t, where, and

Similarly, the sensitivities of the comprehensive reduced yield index to other weather variables can be calculated similarly.

Results and discussion

The comprehensive suitability model can be employed to hindcast maize yields in Henan Province from 1971 to 2020. As shown in Fig 1, the black line represents the maize raw yield recorded in Henan Province during 1971–2020. It is assumed that the annual yield increase is also affected by seed regeneration, chemical fertilizer, and other human factors, and it is showing a linear growth trend, i.e., linear yield (see red line) [29, 44]. The effect of climate on maize yields can be expressed as a weather yield ratio η which can be calculated as where YR represents the raw yield and YL represents the linear prediction. The larger the η, the more the maize was affected by unfavorable weather. The weather yield ratio is set to zero when η<0, and it is an index between 0 and 1.

Fig 1

Maize yield in Henan Province over 50 years a.) raw yield vs. linear yield, b.) weather yield ratio.

The four individual reduced yield indices are calculated using the four climatic suitability models. Based on the meteorological data of Henan Province from 1971 to 2020, the annual temperature reduced yield index D of maize can be calculated using Eqs 1–3 and historical meteorological data for Henan Province from 1971 to 2020. The relationship between the temperature reduced yield index D and the weather yield ratio is shown in Fig 2. There is clearly a strong correlation between D and the weather yield ratio. The correlation coefficient is 0.46. That shows that the temperature suitability model can correctly simulate the trends in the weather yield ratio, though the simulated index is higher. The possible reason is that the suitable temperature range of maize adopted in the current study is rather small, and maize has a better ability to resist temperature changes.

Fig 2

Temperature reduced yield index and the weather yield ratio.

The relationship between the precipitation reduced yield index D and the weather yield ratio is shown in Fig 3. The correlation coefficient there is 0.39. The index is again a little higher than the weather yield ratio, which may be due to the drought tolerance of maize.

Fig 3

Precipitation yield reduction index and weather yield ratio.

Fig 4 shows comparable plots for solar radiation reduced yield index D and weather yield ratio. The correlation coefficient between solar radiation reduced yield index and weather yield ratio is 0.38. The precipitation reduced yield index best simulates the peak values of the weather yield ratio, but their trends show a certain correlation.

Fig 4

Solar radiation reduced yield index and the weather yield ratio.

The relationship between the wind reduced yield index D and weather yield ratio is shown in Fig 5. The correlation coefficient is 0.24. Their correlation is poor because the wind is only critical during the flowering and pollination period. The effect of wind on the whole growth cycle is limited.

Fig 5

Wind reduced yield ratio and the weather yield ratio.

The order of importance of the four factors is temperature, precipitation, solar radiation, and wind speed. Temperature and precipitation dominate over the whole growth cycle of maize.

Two different reduced yield models can be used to simulate the effect of climate change on maize yield. Using the comprehensive reduced yield (CRY) model proposed in the current study, the reduced yield model can be calculated using Eq 9. The CRY model is employed to simulate the field yield from 1971–2020 affected by climate change after reverse analysis training uses yield from 1971–2010. The traditional reduced yield (TRY) model in D can be calculated as proposed in previous literature [28–30, 34, 40]. The yields predicted by the two reduced yield models are shown in Fig 6.

Fig 6

Raw yield vs. simulated yield.

The correlation coefficient between raw yield and simulated yield obtained by the CRY model is 0.75 which is larger than that obtained by the TRY model (0.37). It illustrates that the comprehensive reduced yield model can well simulate the field yield affected by climate change. The correlation coefficient between raw yield and the CRY predictions is higher than that between any single weather factor index and the raw yield. The CRY model simulates the raw yields from 2010 to 2020 well because it considers the correlations among various weather factors based on their weighted average and reverses analysis.

To study the sensitivities of maize yield to climate change in Henan Province, a direct differentiation method was used to study the sensitivity of the comprehensive climate suitability (CCS) model based on the direct differentiation method. The sensitivities of the weather yield ratio obtained by Eq 13 are shown in Fig 7. The sensitivities to temperature and precipitation are great, and the change is obvious. It indicates that maize yield is sensitive to changes in temperature and precipitation. However, the effect of a one-unit change in solar radiation or wind on maize yield is relatively limited.

Fig 7

The sensitivities of the weather yield ratio to weather factors in different years.

The maximum values of the sensitivities over the past 50 years are shown in Fig 8. It shows that temperature and precipitation have the greatest impact on the weather yield ratio. The fluctuation of temperature and precipitation may lead to the decrease of maize yield in different years (through frostbite, withering, drought, waterlogging, and other disasters). Solar radiation and wind are not often important, though in general an increase in light hours will increase yields and higher wind speeds will decrease them [28]. The conclusion of the sensitivity analysis is consistent with actual crop growth characteristics.

Fig 8

Maximum weather yield ratio sensitivity to the four factors.

The maize comprehensive suitability model proposed in this article can simulate historical data and predict maize yields affected by climate change. The sensitivity analysis results obtained by the sensitivity algorithm of the CCS model illustrate that temperature and precipitation are the dominant weather variables affecting yields. However, too high temperature and precipitation will also have a negative impact on the yield, e.g., through withering, drought, waterlogging and other disasters. Appropriate reduction of wind speed and increase of light intensity is conducive to the increase of yield. The above conclusions have some regional particularities, and they can only be used as a reference for maize yield analysis in Henan Province.

Conclusions

A comprehensive climate suitability model has been developed for maize in Henan Province based on its temperature, precipitation, solar radiation, and wind requirements in different growth periods. Long-term observation of agrometeorological data and recorded field yields well verify that the maize comprehensive suitability model can better simulate observed historical maize yields affected by climate change. The maize predicted forecast obtained by the CCS model can match the recorded field yield very well from 1971–2020. Applying the sensitivity algorithm based on the direct differentiation method to the CCS model, the sensitivity analysis shows that temperature and precipitation are the dominant climate factors affecting yield changes, while less sunlight and stronger winds will adversely affect crop yields to some extent. The maize comprehensive suitability model and its sensitivity algorithm can provide an efficient analysis tool for predicting yield reductions due to climate change.

(CSV)

Click here for additional data file.

(CSV)

Click here for additional data file.

6 Dec 2021

A rebuttal letter that responds to each point raised by the academic editor and reviewer(s). You should upload this letter as a separate file labeled 'Response to Reviewers'.

A marked-up copy of your manuscript that highlights changes made to the original version. You should upload this as a separate file labeled 'Revised Manuscript with Track Changes'.

An unmarked version of your revised paper without tracked changes. You should upload this as a separate file labeled 'Manuscript'.

If you would like to make changes to your financial disclosure, please include your updated statement in your cover letter. Guidelines for resubmitting your figure files are available below the reviewer comments at the end of this letter.

If applicable, we recommend that you deposit your laboratory protocols in protocols.io to enhance the reproducibility of your results. Protocols.io assigns your protocol its own identifier (DOI) so that it can be cited independently in the future. For instructions see: https://journals.plos.org/plosone/s/submission-guidelines#loc-laboratory-protocols. Additionally, PLOS ONE offers an option for publishing peer-reviewed Lab Protocol articles, which describe protocols hosted on protocols.io. Read more information on sharing protocols at https://plos.org/protocols?utm_medium=editorial-email&utm_source=authorletters&utm_campaign=protocols.

We look forward to receiving your revised manuscript.

Kind regards,

Vassilis G. Aschonitis

Academic Editor

PLOS ONE

Journal Requirements:

1. When submitting your revision, we need you to address these additional requirements.

Please ensure that your manuscript meets PLOS ONE's style requirements, including those for file naming. The PLOS ONE style templates can be found at

https://journals.plos.org/plosone/s/file?id=wjVg/PLOSOne_formatting_sample_main_body.pdf and

https://journals.plos.org/plosone/s/file?id=ba62/PLOSOne_formatting_sample_title_authors_affiliations.pdf

2. We note that the grant information you provided in the ‘Funding Information’ and ‘Financial Disclosure’ sections do not match.

When you resubmit, please ensure that you provide the correct grant numbers for the awards you received for your study in the ‘Funding Information’ section.

3. Thank you for stating the following in the Acknowledgments Section of your manuscript:

("The authors gratefully acknowledge financial support from China’s National Key Research and Development Program under grant 2016YFC0701106 and from China’s National Science Foundation through grants 51978591 and 51578473.")

We note that you have provided funding information that is not currently declared in your Funding Statement. However, funding information should not appear in the Acknowledgments section or other areas of your manuscript. We will only publish funding information present in the Funding Statement section of the online submission form.

Please remove any funding-related text from the manuscript and let us know how you would like to update your Funding Statement. Currently, your Funding Statement reads as follows:

("The authors gratefully acknowledge financial support from China’s National Key Research and Development Program under grant 2016YFC0701106 and from China’s National Science Foundation through grants 51978591 and 51578473.")

Please include your amended statements within your cover letter; we will change the online submission form on your behalf.

4. We note that you have stated that you will provide repository information for your data at acceptance. Should your manuscript be accepted for publication, we will hold it until you provide the relevant accession numbers or DOIs necessary to access your data. If you wish to make changes to your Data Availability statement, please describe these changes in your cover letter and we will update your Data Availability statement to reflect the information you provide.

[Note: HTML markup is below. Please do not edit.]

Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: Partly

Reviewer #2: Yes

Reviewer #3: Yes

**********

2. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: Yes

Reviewer #2: Yes

Reviewer #3: Yes

**********

3. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: No

Reviewer #2: Yes

Reviewer #3: Yes

**********

4. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: No

Reviewer #2: Yes

Reviewer #3: Yes

**********

5. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: Recommendation: Reject

The survey reports an interesting topic that points out the effect of climate change on maize phenology and its sensitivity. The manuscript presents a certain gap in standard English. A large amount of reliable references lacks to statements making the manuscript with low basis on previous study (that are largely found). The manuscript didn’t show any effect of climate change on detailed phenological stages. It only showed the effect of climate change on yield and on all phenological stages. It is a huge gap that lead me to take my decision concerning the manuscript. Additionally, authors mentioned several times the term “weather” which is not the case of studying meteorological parameters over a 50 years-period (being climate rather than weather). Moreover, results weren’t approximately discussed nor compared to previous studies, which was also one of the major gaps of the manuscript. Authors mentioned that all the data were present in the manuscript and its supporting files; while it is not the case as the data on which they relied to present the predictions and all presented models isn’t available. I think that the manuscript doesn’t fully merit to be published in PLOS One; however, I ask authors to take into consideration the following comments which will help them to improve their manuscript.

1. Page 1, line 12: Kindly adjust as follow: “ultimately its yield”.

2. Page 1, lines 13–14: Kindly replace “in different growth periods of maize” by “in different phenological stages of maize”.

3. Page 1, line 14: Kindly replace “historical weather” by “climate” as the climate is a state of weather at a very long time starting 30 years and more.

4. Page 1, line 15: Kindly adjust the sentence as follow: “The comprehensive suitability model showed capability of correctly…”

5. Page 1, lines 15–18: “The comprehensive… data”: The sentence is quite long; accordingly, kindly reformulate it to be more concise.

6. Page 1, lines 18–19: “The correlation… are analyzed”: Kindly mention the type of correlation and its strength in the abstract part. You cannot mention it as an analyzed factor while the objective is to mention what did you find in the abstract’s results mention.

7. Page 1, lines 19–20: “The sensitivities… method”: Same recommendation as mentioned in the previous comment.

8. Page 3, lines 37–42: “Many… quality”: This whole section lacks reliable sources (references); accordingly, kindly provide them.

9. Page 3, line 42: Kindly adjust as follow: “Gu et al. [13,14]”.

10. Page 3, line 43: “for growing particular crops”: Kindly mention these crops.

11. Page 3, line 43: Kindly adjust the sentence as follow: “Gonzalez et al. [15] established a model…”

12. Page 3, line 46: Kindly remove reference 16 as it has no relation with the mentioned statement.

13. Page 3, line 46: Kindly adjust the sentence as follow: “Lamptey [17] used…”

14. Page 4, lines 48–49: Kindly adjust as follow: “Wang et al. [18]”.

15. Page 4, line 51: Kindly remove “[18]”, adjust as follow: “Robin [19] and provide the corresponding reliable source “19” in the references list as the one present is different than mentioned in the text.

16. Page 4, line 55: Kindly remove “but”.

17. Page 4, lines 58–59: Kindly adjust the sentence as follow: “The model is mechanistic and takes into account thermal effects, insolation, and different varieties [20-22].”

18. Page 4, line 59: Kindly adjust the sentence as follow: “Zhao et al. [23] used fuzzy…”

19. Page 4, line 61: Kindly remove “[23]”.

20. Page 4, line 62: Kindly adjust as follow: “Yao et al. [24]”.

21. Page 4, line 65: Kindly remove “[24]”.

22. Page 4, lines 65–66: Kindly adjust as follow: “systematic research on…”

23. Page 4, line 66: Kindly remove “That was the object of this study.”

24. Pages 4–5, lines 69–71: “The model… corn”: These statements are related to the Materials and methods section as they describe the approaches take on. Accordingly, kindly remove them.

25. Page 5: Kindly add the title: “2. Materials and methods”.

26. Page 5, line 74: Kindly adjust the title numbering as: “2.1. A comprehensive climate suitability (CCS) model for maize”.

27. Page 5, lines 75–76: “Kindly adjust the sentence as follow: “its whole growth period can be divided…”

28. Page 5, line 79: Kindly adjust “considers” and remove “should”.

29. Page 5, lines 82–83: Kindly adjust the sentence as follow: “Therefore, the independent suitability models need to be first established for the four factors.”

30. Page 5, line 84: Kindly adjust the title numbering as: “2.2. Temperature suitability model”.

31. Page 6, line 103: Kindly adjust the title numbering as: “2.3. Precipitation suitability model”.

32. Page 6, lines 104–106: “Winter… accumulation”: These statements lack reliable sources (references); accordingly, kindly provide them.

33. Page 7, line 108: Kindly adjust as follow: “Wei et al. [26] suggested…”

34. Page 7, line 108: The sentence is incomplete; accordingly, kindly reformulate it.

35. Page 7, lines 108–109: Kindly remove “In this paper” and adjust the sentence as follow: “the precipitation suitability was calculated using the following equation”.

36. Page 7, lines 114–115: “That generates… Table 2”: The sentence is badly written in standard English; accordingly, kindly reformulate it.

37. Page 7, line 121: Kindly adjust the title numbering as: “2.4. Sunshine suitability model”.

38. Pages 7–8, lines 122–126: “Maize… maize”: These statements lack reliable sources; accordingly, kindly provide them.

39. Page 8, line 124: Kindly remove “every day”.

40. Page 8, line 125: Kindly adjust as follow: “inadequate” and “slows down”.

41. Page 8, lines 127–129: “In a certain… suitable”: These statement lack reliable sources; accordingly, kindly provide them.

42. Page 8, lines 129–130: Kindly adjust as follow: “Li et al. [27] suggested…”

43. Page 8, line 138: Kindly provide the source of Table 3 parameters details.

44. Page 9, line 143: Kindly adjust the title numbering as: “2.5. Wind suitability model”.

45. Page 9, lines 144–148: “Wind… variety”: These statements lack reliable sources (references); accordingly, kindly provide them.

46. Page 9, lines 148–149: Kindly adjust this sentence as follow: “In the current study, focus was made on flowering…”

47. Page 9, lines 149–151: “During that… yield”: These statements lack reliable sources (references); accordingly, kindly provide them.

48. Page 9, lines 154–155: “which are taken as 6.0m/s and 10m/s in this discussion”: Kindly remove “in this discussion” and mention the source you relied on to state these numbers as suitable to adopt.

49. Page 9, line 157: “where nw is the number of days in the flowering period—15 days in this discussion”: Kindly remove “in this discussion” and mention the source you relied on to state this number as suitable to adopt.

50. Page 9, line 158: Kindly adjust the title numbering as: “2.6. A comprehensive reduced yield model”.

51. Page 10, lines 159–163: “The ideal… correlation”: These statements lack reliable sources (references); accordingly, kindly provide them.

52. Page 10, line 173: Kindly adjust the title numbering as: “2.7. Sensitivities of comprehensive reduced yield model”.

53. Page 10, lines 174–178: “The climatic… one unit”: These statements lack reliable sources (references); accordingly, kindly provide them.

54. Page 10, line 178: Kindly replace “In this paper” by “In the current study”.

55. Page 11, line 191: Kindly replace this title by “3. Results and discussion”.

56. Page 11, lines 194–195: “It is assumed… factors”: This statement lacks a reliable source (reference); accordingly, kindly provide it.

57. Page 11, line 199: Kindly adjust as follow: “YL”.

58. Page 11, line 200: You’re discussing a climate change over 50 years, you cannot say “weather” !!

59. Page 12, line 206: Kindly remove “firstly”.

60. Page 12, line 207: “Based on the meteorological data of Henan Province from 1971 to 2020”: We are not able to observe the detailed data in these years; accordingly, kindly provide them in a supplementary file”.

61. Page 12, line 209: Kindly adjust as follow: “The relationship between…”

62. Page 12, line 214: Kindly replace “set in this paper” by “adopted in the current study”.

63. Page 14, line 229: Kindly adjust as follow: “The relationship between…”

64. Page 14, lines 230–232: “That is not… 15 days”: The sentence is badly written in standard English; accordingly, kindly reformulate it.

65. Page 14, line 236: Kindly remove “So”.

66. Page 14, line 239: Kindly replace “in this paper” by “in the current study”.

67. Page 15, line 240: Kindly adjust as follow: “to simulate”.

68. Page 15, line 243: Kindly adjust as follow: “in previous literature”.

69. Page 16, line 264: Kindly adjust as follow: “The fluctuation of temperature and precipitation”.

70. Page 16, lines 264–267: “The decrease… decrease them”: These statements lack reliable sources (references); accordingly, kindly provide them.

71. Page 17, line 271: Kindly remove “In summary”.

72. Page 17, lines 271–279: This whole section is a summary of the current’s study findings. Kindly remove it.

Reviewer #2: "Responses and sensitivities of maize phenology to climate change from 1971 to 2020 in Henan Province, China" is well written. It is about the climate change effects on maize under particular conditions of China.

Reviewer #3: Dear author

In a general review of your paper, I found that the computational and mathematical aspects of this paper are predominant, and such writing certainly demonstrates the authors' mastery of the concepts of simulation and the use of performance prediction models using real farm multi-year data.

Therefore, considering the importance of predicting the change of yield of important crops such as corn in the face of climate change, I consider this article to be very important and practical. However, it is necessary to use specialized words that are generally accepted by experts in this field in expressing biological topics. I have suggested some tips in this regard.

In addition, I found the method of referring to the research of others unconventional in the text of your article. However, to address this shortcoming, I have written some suggestions for you that I hope you will find useful.

**********

6. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files.

If you choose “no”, your identity will remain anonymous but your review may still be made public.

Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy.

Reviewer #1: No

Reviewer #2: No

Reviewer #3: Yes: Majid AghaAlikhani(Ph.D.)

Professor

Weed-Crop Ecophysiology

Medicinal and Aromatic Plants Agrotechnology

Department of Agrotechnology

Faculty of Agriculture

Tarbiat Modares University

PO Box 14115-336

Tehran, Iran

Phone:+98 21 48292099

[NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files.]

While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (PACE) digital diagnostic tool, https://pacev2.apexcovantage.com/. PACE helps ensure that figures meet PLOS requirements. To use PACE, you must first register as a user. Registration is free. Then, login and navigate to the UPLOAD tab, where you will find detailed instructions on how to use the tool. If you encounter any issues or have any questions when using PACE, please email PLOS at figures@plos.org. Please note that Supporting Information files do not need this step.

Submitted filename: Reviewer Recommendation and Comments.docx

Click here for additional data file.

14 Dec 2021

Journal: PLOS ONE

Title: Responses and sensitivities of maize phenology to climate change from 1971 to 2020 in Henan Province, China

Manuscript ID: PONE-D-21-35009

Dear Prof. Vassilis G. Aschonitis,

Thank you very much for your letter that enclosed the reviewers’ comments for our manuscript. We have studied the comments carefully and tried our best to improve the manuscript. We would like to submit the revised manuscript with all revisions marked in blue color. The following are our responses to the reviewers’ comments. Some essential contents have been added in the revised manuscript, however, these changes will not influence the conclusions.

We wish to take this opportunity to thank you and all the reviewers for your consideration and instructive comments. Look forward to hearing from you!

Sincerely,

Ning Zhang

Doctor

Faculty of Forestry, The University of British Columbia,

Vancouver, British Columbia, Canada

Additional requirements

1. When submitting your revision, we need you to address these additional requirements.

Please ensure that your manuscript meets PLOS ONE's style requirements, including those for file naming. The PLOS ONE style templates can be found at

https://journals.plos.org/plosone/s/file?id=wjVg/PLOSOne_formatting_sample_main_body.pdf and

https://journals.plos.org/plosone/s/file?id=ba62/PLOSOne_formatting_sample_title_authors_affiliations.pdf

Response: Thanks for your reminder. The manuscript has been revised to meet PLOS ONE's style requirement.

2. We note that the grant information you provided in the ‘Funding Information’ and ‘Financial Disclosure’ sections do not match.

When you resubmit, please ensure that you provide the correct grant numbers for the awards you received for your study in the ‘Funding Information’ section.

Response: The Funding Information has been revised.

3. Thank you for stating the following in the Acknowledgments Section of your manuscript:

("The authors gratefully acknowledge financial support from China’s National Key Research and Development Program under grant 2016YFC0701106 and from China’s National Science Foundation through grants 51978591 and 51578473.")

We note that you have provided funding information that is not currently declared in your Funding Statement. However, funding information should not appear in the Acknowledgments section or other areas of your manuscript. We will only publish funding information present in the Funding Statement section of the online submission form.

Please remove any funding-related text from the manuscript and let us know how you would like to update your Funding Statement. Currently, your Funding Statement reads as follows:

("The authors gratefully acknowledge financial support from China’s National Key Research and Development Program under grant 2016YFC0701106 and from China’s National Science Foundation through grants 51978591 and 51578473.")

Please include your amended statements within your cover letter; we will change the online submission form on your behalf.

Response: The funding-related text has been removed from the manuscript.

In the Funding Statement,

“The authors gratefully acknowledge financial support from China’s National Science Foundation through grants 51978591 and 51578473.”

4. We note that you have stated that you will provide repository information for your data at acceptance. Should your manuscript be accepted for publication, we will hold it until you provide the relevant accession numbers or DOIs necessary to access your data. If you wish to make changes to your Data Availability statement, please describe these changes in your cover letter and we will update your Data Availability statement to reflect the information you provide.

Response:

Data Availability Statement

All data, models, or codes that support the findings of this study are available. The functions of the model are explained in detail in the manuscript. The data of weather and yield are attached as supporting information.

To Reviewer 1

Reviewer #1: The survey reports an interesting topic that points out the effect of climate change on maize phenology and its sensitivity. The manuscript presents a certain gap in standard English. A large amount of reliable references lacks to statements making the manuscript with low basis on previous study (that are largely found). The manuscript didn’t show any effect of climate change on detailed phenological stages. It only showed the effect of climate change on yield and on all phenological stages. It is a huge gap that lead me to take my decision concerning the manuscript. Additionally, authors mentioned several times the term “weather” which is not the case of studying meteorological parameters over a 50 years-period (being climate rather than weather). Moreover, results weren’t approximately discussed nor compared to previous studies, which was also one of the major gaps of the manuscript. Authors mentioned that all the data were present in the manuscript and its supporting files; while it is not the case as the data on which they relied to present the predictions and all presented models isn’t available. I think that the manuscript doesn’t fully merit to be published in PLOS One; however, I ask authors to take into consideration the following comments which will help them to improve their manuscript.

Response:

We have studied the comments carefully and tried our best to improve the manuscript. These suggestions are very helpful for us to improve our manuscript. We wish to take this opportunity to thank you for your consideration and instructive comments. The statement about “climate” is incorrect, and it has been replaced by “weather”. For Data Availability Statement, all data, models, or code that support the findings of this study are available from the corresponding author upon reasonable request. We would like to submit the revised manuscript with all revisions marked in blue color.

1. Page 1, line 12: Kindly adjust as follow: “ultimately its yield”.

Response: Thanks for your comment. It has been revised in the manuscript.

2. Page 1, lines 13–14: Kindly replace “in different growth periods of maize” by “in different phenological stages of maize”.

Response: It has been revised in the manuscript. Thanks.

3. Page 1, line 14: Kindly replace “historical weather” by “climate” as the climate is a state of weather at a very long time starting 30 years and more.

4. Page 1, line 15: Kindly adjust the sentence as follow: “The comprehensive suitability model showed capability of correctly…”

5. Page 1, lines 15–18: “The comprehensive… data”: The sentence is quite long; accordingly, kindly reformulate it to be more concise.

Response: The author agrees with the revises of questions 3-5.

6. Page 1, lines 18–19: “The correlation… are analyzed”: Kindly mention the type of correlation and its strength in the abstract part. You cannot mention it as an analyzed factor while the objective is to mention what did you find in the abstract’s results mention.

Response: It has been replaced by “The results of correlation showed that the yields are more closely related to multi-weather factors, temperature and precipitation than to solar radiation and wind. “

7. Page 1, lines 19–20: “The sensitivities… method”: Same recommendation as mentioned in the previous comment.

Response: It has been replaced by “The sensitivity analysis illustrates that temperature and precipitation are the dominant weather factors affecting yield changes based on a direct differentiation method. ”

8. Page 3, lines 37–42: “Many… quality”: This whole section lacks reliable sources (references); accordingly, kindly provide them.

Response: Five literature have been added for reference, see Ref.29-33.

9. Page 3, line 42: Kindly adjust as follow: “Gu et al. [13,14]”.

Response: It has been revised in the manuscript.

10. Page 3, line 43: “for growing particular crops”: Kindly mention these crops.

Response: It has been revised in the manuscript, such as maize and wheat.

11. Page 3, line 43: Kindly adjust the sentence as follow: “Gonzalez et al. [15] established a model…”

Response: They have been revised in the manuscript, including Questions 12-72.

12. Page 3, line 46: Kindly remove reference 16 as it has no relation with the mentioned statement.

13. Page 3, line 46: Kindly adjust the sentence as follow: “Lamptey [17] used…”

14. Page 4, lines 48–49: Kindly adjust as follow: “Wang et al. [18]”.

15. Page 4, line 51: Kindly remove “[18]”, adjust as follow: “Robin [19] and provide the corresponding reliable source “19” in the references list as the one present is different than mentioned in the text.

16. Page 4, line 55: Kindly remove “but”.

17. Page 4, lines 58–59: Kindly adjust the sentence as follow: “The model is mechanistic and takes into account thermal effects, insolation, and different varieties [20-22].”

18. Page 4, line 59: Kindly adjust the sentence as follow: “Zhao et al. [23] used fuzzy…”

19. Page 4, line 61: Kindly remove “[23]”.

20. Page 4, line 62: Kindly adjust as follow: “Yao et al. [24]”.

21. Page 4, line 65: Kindly remove “[24]”.

22. Page 4, lines 65–66: Kindly adjust as follow: “systematic research on…”

23. Page 4, line 66: Kindly remove “That was the object of this study.”

24. Pages 4–5, lines 69–71: “The model… corn”: These statements are related to the Materials and methods section as they describe the approaches take on. Accordingly, kindly remove them.

25. Page 5: Kindly add the title: “2. Materials and methods”.

26. Page 5, line 74: Kindly adjust the title numbering as: “2.1. A comprehensive climate suitability (CCS) model for maize”.

27. Page 5, lines 75–76: “Kindly adjust the sentence as follow: “its whole growth period can be divided…”

28. Page 5, line 79: Kindly adjust “considers” and remove “should”.

29. Page 5, lines 82–83: Kindly adjust the sentence as follow: “Therefore, the independent suitability models need to be first established for the four factors.”

30. Page 5, line 84: Kindly adjust the title numbering as: “2.2. Temperature suitability model”.

31. Page 6, line 103: Kindly adjust the title numbering as: “2.3. Precipitation suitability model”.

32. Page 6, lines 104–106: “Winter… accumulation”: These statements lack reliable sources (references); accordingly, kindly provide them.

33. Page 7, line 108: Kindly adjust as follow: “Wei et al. [26] suggested…”

34. Page 7, line 108: The sentence is incomplete; accordingly, kindly reformulate it.

35. Page 7, lines 108–109: Kindly remove “In this paper” and adjust the sentence as follow: “the precipitation suitability was calculated using the following equation”.

36. Page 7, lines 114–115: “That generates… Table 2”: The sentence is badly written in standard English; accordingly, kindly reformulate it.

37. Page 7, line 121: Kindly adjust the title numbering as: “2.4. Sunshine suitability model”.

38. Pages 7–8, lines 122–126: “Maize… maize”: These statements lack reliable sources; accordingly, kindly provide them.

39. Page 8, line 124: Kindly remove “every day”.

40. Page 8, line 125: Kindly adjust as follow: “inadequate” and “slows down”.

41. Page 8, lines 127–129: “In a certain… suitable”: These statement lack reliable sources; accordingly, kindly provide them.

42. Page 8, lines 129–130: Kindly adjust as follow: “Li et al. [27] suggested…”

43. Page 8, line 138: Kindly provide the source of Table 3 parameters details.

44. Page 9, line 143: Kindly adjust the title numbering as: “2.5. Wind suitability model”.

45. Page 9, lines 144–148: “Wind… variety”: These statements lack reliable sources (references); accordingly, kindly provide them.

46. Page 9, lines 148–149: Kindly adjust this sentence as follow: “In the current study, focus was made on flowering…”

47. Page 9, lines 149–151: “During that… yield”: These statements lack reliable sources (references); accordingly, kindly provide them.

48. Page 9, lines 154–155: “which are taken as 6.0m/s and 10m/s in this discussion”: Kindly remove “in this discussion” and mention the source you relied on to state these numbers as suitable to adopt.

49. Page 9, line 157: “where nw is the number of days in the flowering period—15 days in this discussion”: Kindly remove “in this discussion” and mention the source you relied on to state this number as suitable to adopt.

50. Page 9, line 158: Kindly adjust the title numbering as: “2.6. A comprehensive reduced yield model”.

51. Page 10, lines 159–163: “The ideal… correlation”: These statements lack reliable sources (references); accordingly, kindly provide them.

52. Page 10, line 173: Kindly adjust the title numbering as: “2.7. Sensitivities of comprehensive reduced yield model”.

53. Page 10, lines 174–178: “The climatic… one unit”: These statements lack reliable sources (references); accordingly, kindly provide them.

54. Page 10, line 178: Kindly replace “In this paper” by “In the current study”.

55. Page 11, line 191: Kindly replace this title by “3. Results and discussion”.

56. Page 11, lines 194–195: “It is assumed… factors”: This statement lacks a reliable source (reference); accordingly, kindly provide it.

57. Page 11, line 199: Kindly adjust as follow: “YL”.

58. Page 11, line 200: You’re discussing a climate change over 50 years, you cannot say “weather” !!

59. Page 12, line 206: Kindly remove “firstly”.

60. Page 12, line 207: “Based on the meteorological data of Henan Province from 1971 to 2020”: We are not able to observe the detailed data in these years; accordingly, kindly provide them in a supplementary file”.

61. Page 12, line 209: Kindly adjust as follow: “The relationship between…”

62. Page 12, line 214: Kindly replace “set in this paper” by “adopted in the current study”.

63. Page 14, line 229: Kindly adjust as follow: “The relationship between…”

64. Page 14, lines 230–232: “That is not… 15 days”: The sentence is badly written in standard English; accordingly, kindly reformulate it.

65. Page 14, line 236: Kindly remove “So”.

66. Page 14, line 239: Kindly replace “in this paper” by “in the current study”.

67. Page 15, line 240: Kindly adjust as follow: “to simulate”.

68. Page 15, line 243: Kindly adjust as follow: “in previous literature”.

69. Page 16, line 264: Kindly adjust as follow: “The fluctuation of temperature and precipitation”.

70. Page 16, lines 264–267: “The decrease… decrease them”: These statements lack reliable sources (references); accordingly, kindly provide them.

71. Page 17, line 271: Kindly remove “In summary”.

72. Page 17, lines 271–279: This whole section is a summary of the current’s study findings. Kindly remove it.

Response: We would like to express our grateful thanks to the reviewer for the above suggestions. We have studied the comments carefully and tried our best to improve the manuscript. These suggestions are very helpful for us to improve our manuscript.

To Reviewer 2

Reviewer #2: "Responses and sensitivities of maize phenology to climate change from 1971 to 2020 in Henan Province, China" is well written. It is about the climate change effects on maize under particular conditions of China.

Response:

We would like to express our grateful thanks to the reviewer for his/her valuable comments. All the doubts and remarks have been answered carefully. The numbers for sections, figures, tables, and pages refer to the revised version of the manuscript unless otherwise noted. The modifications are highlighted in blue in the revised manuscript.

To Reviewer 3

Reviewer #3: Dear author

In a general review of your paper, I found that the computational and mathematical aspects of this paper are predominant, and such writing certainly demonstrates the authors' mastery of the concepts of simulation and the use of performance prediction models using real farm multi-year data.

Therefore, considering the importance of predicting the change of yield of important crops such as corn in the face of climate change, I consider this article to be very important and practical. However, it is necessary to use specialized words that are generally accepted by experts in this field in expressing biological topics. I have suggested some tips in this regard.

In addition, I found the method of referring to the research of others unconventional in the text of your article. However, to address this shortcoming, I have written some suggestions for you that I hope you will find useful.

Response:

We have studied the comments carefully and tried our best to improve the manuscript. These suggestions are very helpful for us to improve our manuscript. We wish to take this opportunity to thank you for your consideration and instructive comments. We would like to submit the revised manuscript with all revisions marked in blue color.

ABSTARCT

- The final sentence of the abstract section should inform the final and practical result of the research. Please rewrite this section.

Response: Thanks for your comment. The final and practical result of the research has been added in the revised abstract.

- Line 13: Replace "sunshine": with the "solar radiation". The later one is more professional word to talk about crop yield and its climatic requirements.

Response: It has been replaced.

- Line 18: Correct predicated…. to ……. Predicted.

Response: The typos have been revised.

KEYWORDS

- As article keywords: It is recommended to use words that are not used in the title.

Response: The KEYWORDS has been revised. Thanks for your comment.

INTRODUCTION

- Lines 35: Replace appropriate seeds to "appropriate genotypes".

- Line 39: Replace indexes with " indices"

- Line 40, 56, 61, 64, 79: Replace "sunshine": with the "solar radiation".

Response: The above three inappropriate words have been revised.

- Line 42: Change, Gu and his colleagues… to " Gu et al. It seems the journal guidelines have preferred the number-based citation format, and you are accustomed to reviewing sources, start with citations to the authors' names. It is recommended that you use passive verbs to avoid this inconsistency. For example, instead of "Gu and his colleagues used the climate model," say " the climate model was used ( ). And at the end of the sentence, bring the relevant reference number.

- Line 43: same correction as Line 42 is needed for Gonzales….

- Line 46: same correction as Line 42 is needed for Lamptey….

- Line 47: Correct Yields ---------�  yield

- Line 48: same correction as Line 42 is needed for Wang's group…..

- Line 54: same correction as Line 42 is needed for Robin ……

- Line 56: Replace " some scholars with " a few researcher"

- Line 56-61: no conventional citation: Agroup led by Zhao …. . Same correction as Line 42 is needed for that.

- Line 62: same correction as Line 42 is needed for Yao ……

Response: The method of referring has been revised.

- Line 68: Delete the repeated word "effect". So rewrite the sentence having the shared word "effect" for all parameters.

Response: It has been replaced by

“This paper establishes a comprehensive weather suitability model to quantify the effect of temperature, water, solar radiation, and wind in a maize growth cycle based on the maize physiological growth model.”

- Line 72: Instead of pointing directly to the application of this article, which is an unproven claim, say: The practical purpose of this research is to be able to provide a tool for accurately predicting corn yield in the face of climate change.

Response: Thanks for your comments. The application of this article has been revised.

- Line 73: is there difference between maize yield (line 72) and yield of summer maize (line 73)??

Response: There is no difference between maize and summer maize. The “summer maize” has been replaced by “maize” in this manuscript.

- Line 74: you applied several models to simulate the weather and meteorological parameters effects on maize yield during a 50 years duration. So these part and their subtitles should be named as Methids and Materials.

Response: It has been named in the revised manuscript.

- Line 76: Replace the summer maize with "the crop".

Response: It has been replaced.

- Line 79, 82, 121, 123, 124, 126, 128, 129, 130, 133, 136, 137, 138, 140, 162, 163 and 165: Replace "sunshine": with the "solar radiation".

Response: It has been replaced.

- Line 109: same correction as Line 42 is needed for Wei and his colleagues ……

Response: It has been revised.

- Line 122: Rewrite this simple but important sentence using a better and an academic expression. You severely recommended to emphasizing into the carboxylation pathway of the maize (C4) which indicating its high demand of solar radiation.

Response: Thanks for your comments and advice. They have been revised in Line 137 of the manuscript.

- Line 124-125: this concept has been repeated in above line. So delete this sentence: Maize need a large amount of sunshine.

Response: It has been deleted.

- Line 145: correct the unit format to : m. s-1

Response: It has been revised.

- Line 148: Replace variety ----------�  cultivar

- Line 150: Do you mean the wind speed? You mentioned to the wind force!! They are different. If your answer is YES, write the unit for wind speed: m.s-1

Response: YES. I am sorry for that. The wind force has been replaced by wind speed.

- Line 154: correct the unit format to : m. s-1

Response: The following questions have been revised.

- Line 160: Change elements with: parameters".

- Line 168: Replace indexes with " indices"

- Line 171: Replace indexes with " indices"

- Line 178: Change the paper with the " article"

- Line 191: Write the main title for this part of the article : "Results and Discussion"

- Line 200 : Correct radio -------- > ratio

- Figurr 1: correct the unit typesetting as : kg. ha-1

- Line 206: Replace indexes with " indices"

- Line 223, 224, 228, 236, 259, 266: 282 and 289 : Replace "sunshine": with the "solar radiation".

- Figure 7 and figure 8: Replace "sunshine": with the "solar radiation".

- Line 271: Replace the paper with the "article"

Response: We would like to thank you again for the above suggestions. We have studied the comments carefully and tried our best to improve the manuscript. These suggestions are very helpful for me to improve my manuscript.

Submitted filename: Response to Reviewers.docx

Click here for additional data file.

19 Dec 2021

19 Dec 2021

Journal: PLOS ONE

Title: Responses and sensitivities of maize phenology to climate change from 1971 to 2020 in Henan Province, China

Manuscript ID: PONE-D-21-35009

Dear Prof. Vassilis G. Aschonitis,

Thank you very much for your letter that enclosed the reviewers’ comments for our manuscript. We have studied the comments carefully and tried our best to improve the manuscript. We would like to submit the revised manuscript with all revisions marked in blue color. The following are our responses to the reviewers’ comments. Some essential contents have been added in the revised manuscript, however, these changes will not influence the conclusions.

We wish to take this opportunity to thank you and all the reviewers for your consideration and instructive comments. Look forward to hearing from you!

Sincerely,

Ning Zhang

Doctor

Faculty of Forestry, The University of British Columbia,

Vancouver, British Columbia, Canada

To Reviewer 1

Reviewer #1: After careful and deep observation of all the authors corrections, for which I am deeply grateful for taking all my comments and recommendations into consideration, I find that the manuscript has now a merit to be published in “PLOS One” in its current form. Authors provided all the reliable sources that were lacking in literature (Introduction), Materials and methods and Discussion parts, adjusted all the sentences that were unclear or badly written in standard English and provided all the supporting data that they were asked for as additional files. I am deeply grateful for this big improvement in the manuscript, that made me completely change my mind in its concern.

Response:

We have studied the comments carefully and tried our best to improve the manuscript. We are very excited that you have changed your mind. All of your comments are very helpful to improve our manuscript. Thank you again.

Best wishes

To Reviewer 3

Reviewer #3: I reviewed the authors' responses to my points and comments, as well as their responses to the suggestions of two other respected referees. I hereby confirm that the authors have taken note of all comments made by the reviewers and have made any necessary changes to the text of the revised version of the article. However, I consider it necessary to pay attention to the following two points and make the relevant correction.

Response:

We have studied the comments carefully and tried our best to improve the manuscript. These suggestions are very helpful for us to improve our manuscript. We wish to take this opportunity to thank you for your consideration and instructive comments.

- 1- The author did not understand the meaning of reviewer No. 1, who basically rejected the article, and changed the correct phrase "Climate Change" to the incorrect phrase "weather" in manuscript title, abstract and a few sentences of the body. Do not forget the weather gives temperature, radiation, humidity, etc. in a short period of time, such as 24 a day and 7 day a week. Meanwhile whenever we talk about the status of these parameters in the long run, the term climate should be used. Since this article also uses atmospheric structural data for a period of 50 years, it is appropriate to use the term "climate change" like the original version of the article.

Response:

We agree with your comments on "Climate Change". As you said, we focus on the atmospheric structural data for a period of 50 years. We believe that "Climate Change" is more appropriate. The “weather” has been replaced by "Climate Change" in the revised manuscript.

Thanks very much for your comments.

- 2- Although in the text of the article, the typographical error about the word "ratio" that was written as "radio" have been, the authors forgot to correct this point in the relevant figures as well. In this regard, in Figures 2, 3, 4 and 5 in its vertical axis, the word "radio" should be modified to the word "ratio". There is also a grammatical error in the text of the legend inside the figures. In Figures 2, 3, 4, and 5, which refer to reduced yield in terms of temperature, rainfall, solar radiation, and wind, respectively, in the legend, the word "reduces" must be corrected to "reduced".

Response:

Thanks for your comment. " radio" is a typographical error. We are very sorry that we missed this error when we revised the manuscript for the first time. They have been revised in the updated manuscript. In addition, "reduces" has been corrected to "reduced"

Submitted filename: Response to Reviewers.docx

Click here for additional data file.

21 Dec 2021

Responses and sensitivities of maize phenology to climate change from 1971 to 2020 in Henan Province, China

PONE-D-21-35009R2

Dear Dr. Zhang,

We’re pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it meets all outstanding technical requirements.

Within one week, you’ll receive an e-mail detailing the required amendments. When these have been addressed, you’ll receive a formal acceptance letter and your manuscript will be scheduled for publication.

An invoice for payment will follow shortly after the formal acceptance. To ensure an efficient process, please log into Editorial Manager at http://www.editorialmanager.com/pone/, click the 'Update My Information' link at the top of the page, and double check that your user information is up-to-date. If you have any billing related questions, please contact our Author Billing department directly at authorbilling@plos.org.

If your institution or institutions have a press office, please notify them about your upcoming paper to help maximize its impact. If they’ll be preparing press materials, please inform our press team as soon as possible -- no later than 48 hours after receiving the formal acceptance. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information, please contact onepress@plos.org.

Kind regards,

Vassilis G. Aschonitis

Academic Editor

PLOS ONE

Additional Editor Comments (optional):

Reviewers' comments:

12 Jan 2022

PONE-D-21-35009R2

Responses and sensitivities of maize phenology to climate change from 1971 to 2020 in Henan Province, China

Dear Dr. Zhang:

I'm pleased to inform you that your manuscript has been deemed suitable for publication in PLOS ONE. Congratulations! Your manuscript is now with our production department.

If your institution or institutions have a press office, please let them know about your upcoming paper now to help maximize its impact. If they'll be preparing press materials, please inform our press team within the next 48 hours. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information please contact onepress@plos.org.

If we can help with anything else, please email us at plosone@plos.org.

Thank you for submitting your work to PLOS ONE and supporting open access.

Kind regards,

PLOS ONE Editorial Office Staff

on behalf of

Dr. Vassilis G. Aschonitis

Academic Editor

PLOS ONE