The aim of this paper is to quantify comparative analysis of heat damage during flowering stage of summer maize, and detailed evaluation the spatial and temporal distribution of heat damage during flowering stage of summer maize. Time span of flowering stage was analyzed based on observed growth stages by agrometeorological experiment station during 1981 to 2018. Average high temperature days during flowering stage, frequency of high temperature days over 3 days and 5 days during flowering stage in a different period in Henan province according to the daily maximum temperature during 1970 to 2018. Temperal and spatial distribution of high temperature during summer maize flowering stage were analyzed. The result indicated that high temperature days from 1970 to 1999 kept steadily, and high temperature days from 2000 to 2009 were least among the three periods, high temperature days increased obviously since 2010. Then the area of Henan province was divided into five sections: the eastern part of Henan, the southern part of Henan, the western part of Henan, the northern part of Henan and the middle of Henan. While the high temperature days in the southern part of Henan are the most, followed by the eastern part of Henan, the middle of Henan, the western part of Henan and the northern part of Henan. The average high temperature days were 4 to 6 days in most part of Henan province, 2 to 4 days in parts of the northern part and the western part of Henan, and 6 to 8 days in part of the southern part of Henan. The frequency of high temperature days over 5 days was highest in the southern part of Henan with 2 to 3 time per ten years. The frequency of high temperature days over 5 days was declined with the date pushed back. Ten-year recurrence rate of high temperature days over 5 days was below 1 time between 9th august and 18th august in most parts of Henan.
国家重点研发计划项目(2017YFD0301104); 中国气象局•农业气象保障与应用技术重点开放实验室开放研究(AMF201706)；河南省气象局气象科学技术研究项目(KZ201709)。Supported by: National Key Research and Development of China(2017YFD0301104)；CMA/Henan Key Laboratory of Agrometeorological Support and Applied Technique(AMF201706)；Research Projects of Meteorological Science and Technology of Henan Meteorological Service(KZ201709)