Abstract:

Based on the data on the daily temperature of the 23 representative stations from 1961 to 2017 and the growth period of double-cropping late rice of the 14 agricultural meteorological observation stations in Jiangxi province from 1984 to 2017, the spatio-temporal variation characteristics of cold-dew wind in different developmental stages of late rice were analyzed using the mathematical-statistical method.The results show that the mild cold-dew wind occurs in the highest frequency before mid-September in Jiangxi province.Specifically, it occurs once every 3 years in northern Jiangxi, three times every 10 years in central Jiangxi, and once every 5 years in south Jiangxi, and its frequency of occurrence increases gradually from southeast to northwest.The frequency of moderate cold-dew wind is relatively lower before mid-September in Jiangxi province and is once every 10 years in northern and central Jiangxi and once every 20 years in south Jiangxi.The frequency of severe cold-dew wind is extremely low before mid-September in Jiangxi province and is 0.4% and 1.2% in central and northern Jiangxi, respectively.Meanwhile, the frequencies of moderate and severe cold-dew wind increase gradually from south to north.The frequencies of mild and moderate cold-dew wind are 34.1% and 7.5% from the panicle differentiation stage to heading and flowering period of late rice and are 26.9% and 8.0% in the grain-filling period, respectively.The severe cold-dew wind has a relatively small effect on late rice and its frequency of occurrence is less than 2% in each developmental period of late rice.

Key words: Cold-dew wind, Spatio-temporal variation, Late Rice