中国农业气象 ›› 2024, Vol. 45 ›› Issue (02): 189-200.doi: 10.3969/j.issn.1000-6362.2024.02.008

• 农业气象灾害 栏目 • 上一篇    下一篇

用逐步趋近法确定南阳秋季丹桂开花低温预报指标

王宇翔,薛萌   

  1. 1.河南省南阳市气象局,南阳 473000;2. 河南省内乡县气象局,内乡 474300
  • 收稿日期:2023-04-03 出版日期:2024-02-20 发布日期:2024-01-31
  • 作者简介:王宇翔,高级工程师,主要从事农业气象、气象防灾减灾研究,E-mail:nyqxwyx@163.com
  • 基金资助:
    中国气象局∙河南省农业气象保障与应用技术重点开放实验室应用技术研究基金(KM202354)

Determination Forecast Index of Low-temperature before Flowering of Orange Osmanthus in Nanyang by Stepwise Approach Method

WANG Yu-xiang, XUE Meng   

  1. 1.Nanyang Meteorological Bureau in Henan Province, Nanyang 473000, China;2.Neixiang Meteorological Bureau in Henan Province, Neixiang 474300
  • Received:2023-04-03 Online:2024-02-20 Published:2024-01-31

摘要: 采摘、观赏桂花需要进行开花始期预报,基于2016−2022年南阳市丹桂开花全过程多批次的开花始期记录,依次统计每年第一批次开花前,以及上一批次开花结束至下一批次开花期间的日最高气温、日平均气温和日最低气温的最小值,从中挑出各自最大值作为各气温表达形式的低温日指标,根据低温日指标统计低温过程,将间隔时间较短的不连续的低温过程合并为一个低温过程,并与连续低温过程统一为合并低温过程进行分析,统计合并低温过程开始日和期间负有效积温,分析南阳丹桂开花始期与合并低温过程开始日的关系、开花批次属性与合并低温过程期间负有效积温的关系,用相关系数和一元线性回归法对预测结果进行检验。结果表明:(1)逐步趋近法确定南阳丹桂开花前低温指标以日最高气温效果最好,优于采用日平均气温和日最低气温的结果;(2)丹桂开花前低温日指标为日最高气温<22.3℃;(3)丹桂开花前低温过程指标为,日最高气温<22.3℃自然低温过程间隔日数≤1d的合并低温过程,第1个日最高气温<22.3℃合并低温过程期间负有效积温>3.4℃·d时丹桂开花一次完成,≤3.4℃·d则丹桂开花不能一次完成,当再次出现日最高气温<22.3℃后丹桂还将开花,直至日最高气温<22.3℃合并低温过程期间负有效积温>3.4℃·d丹桂才完成本开花季最后一次开花;(4)丹桂开花始期与低温过程的关系为,日最高气温<22.3℃合并低温过程次序与丹桂开花批序一一对应,合并低温过程开始日后4~13d为丹桂开花始期,每一个日最高气温<22.3℃合并低温过程开始日(X)与丹桂开花始期(Y)的一元回归方程为Y = 1.1255X+1.4683,二者呈极显著直线正相关关系。

关键词: 丹桂, 多批次开花, 逐步趋近法, 低温指标, 负有效积温, 预报

Abstract: From 2016 to 2022, the flowering phenomenon of a orange Osmanthus tree in the courtyard Nanyang Meteorological Bureau had observed for 7 consecutive years. The observing was according to the "Agricultural Meteorological Observation Code and Natural Phenology Volume" woody plant flowering period observation standard, i.e. when "the petals of one or several flowers on the observation tree begin to fully open, it is the beginning of flowering", and when "the petals on the observation tree wither and fall off, leaving a very small number of flowers" is recorded as the end of flowering. The first flowering period of Osmanthus fragrans in autumn is recorded as the first batch of flowering. The phenomenon of a second flowering after the first batch of orange Osmanthus blossomed is recorded as the second batch of orange Osmanthus blossoming, just like the first flowering period. After the second flowering of orange Osmanthus, it was observed that in some years, one or several flowers on the observed orange Osmanthus tree had fully opened petals and withered and shed was recorded as the third batch of flowering. Seldomly, the fourth batch of flowering was observed and recorded until no further flowering occurred. From 2016 to 2022, the flowering number of batches of orange Osmanthus flowering in the autumn of Nanyang every year and the initial flowering period and attributes of each batch of flowering were totally different. First, from the aspects of number and attributes of flowering batches, only one batch of flowers was bloomed per year from 2016 to 2019, which was completed at one time, and the 1st batch was also the last batch. From 2020 to 2022, 2-4 batches was bloomed every year, of which the 2nd batch in 2020, the 4th batch in 2021, and the 3rd batch in 2022 are the last batch. The 1st batch in 2020, the 1st to 3rd batch in 2021, the 1st and 2nd batches in 2022 are not the last batch. From the beginning of each batch of flowering, the earliest is August 25 and the latest is October 19. According to previous studies, as a plant that blooms in autumn, the flowering of Osmanthus is caused by the gradual decrease in temperature to a certain limit. Then, each batch of Osmanthus flowers has at least 1 day of low-temperature process that temperature below this limit, Osmanthus blooming cannot be completed at one time must be the previous low-temperature process did not meet all the conditions that should be achieved, and there is at least 1 day of low-temperature process that temperature below this limit again, and it blooms again. As long as the temperature values of each batch before flowering are statistically analyzed in turn, we can gradually approach to finding this limit. With this boundary, the low-temperature process can be counted, so as to find out the conditions that should be met when all flowers bloom compared with the flowering situation of Osmanthus. Daily temperature values include daily average temperature, daily minimum temperature and daily maximum temperature, which respectively express the average situation and range of daily temperature fluctuation, and should be analyzed to identify their respective functions. This article is based on years of continuous observation records of the multiple batches flowering phenomenon of orange Osmanthus in Nanyang, the minimum temperature values with daily maximum temperature, daily average temperature, daily minimum temperature before the first batch of flowering each year be counted in sequence, the minimum temperature values with daily maximum temperature, daily average temperature, daily minimum temperature between the previous batch of flowering and the current batch of flowering be calculated in sequence when the second and subsequent batches of flowering each year. Their respective maximum values selected as that daily index of low-temperature in each expression form of temperature, statistics of natural low-temperature process according to daily index of low-temperature, merge the discontinuous natural low-temperature process with short intervals into one combined low-temperature process, after the start date and negative effective accumulated temperature of the combined low-temperature process are calculated, analyze the relationship between the beginning of flowering of orange Osmanthus and the start date of the combined low-temperature process, as well as the relationship between the attributes of each batch of flowering and the negative effective accumulated temperature during the combined low-temperature process, the index of low-temperature before flowering which can be used for forecasting the flowering period of each batch of orange Osmanthus to be determined. Tested by correlation coefficients and univariate linear regression methods, the results showed that:(1)the method of stepwise approach method is used to determine the index of low-temperature before flowering of orange Osmanthus in Nanyang, the best effect is to use the daily maximum temperature, which is better than using the daily average temperature and daily minimum temperature. (2) The daily index of low-temperature before flowering of orange Osmanthus is the daily maximum temperature <22.3℃. (3) The process index of low-temperature before flowering of orange Osmanthus is the daily maximum temperature <22.3℃ natural low-temperature process interval days ≤1d merged into one combined low-temperature process, when the negative effective accumulated temperature during the daily maximum temperature <22.3℃ combined low-temperature process >3.4℃·d, the orange Osmanthus flowering once completed, when the negative effective accumulated temperature during the daily maximum temperature <22.3℃ combined low-temperature process ≤3.4℃·d, the 1st batch of orange Osmanthus flowering is not the last batch, if the daily maximum temperature <22.3℃ again, orange Osmanthus will bloom again, until the negative effective accumulated temperature during the daily maximum temperature <22.3℃ combined low-temperature process >3.4℃·d, the orange Osmanthus flowering is the last batch. (4)The relationship between the beginning of flowering of orange Osmanthus and the low-temperature process is as follows: the sequence of daily maximum temperature <22.3℃ combined low-temperature process corresponds to the batch sequence of flowering of orange Osmanthus, the beginning of flowering of orange Osmanthus was 4-13d after the start date of the combined low-temperature process, the specific flowering date Y is predicted by the univariate regression equation that the factor X be the start date of each combined low-temperature process with daily maximum temperature <22.3℃, and Y=1.1255X+1.4683, which is a very significant positive correlation linear relationship.

Key words: Orange Osmanthus, Multiple batches of flowering, Stepwise approach method, Index of low-temperature, Negative effective accumulated temperature, Forecast