关键词: 夏玉米, 热害, 花期, 发生频率, 时空分布, 河南省

Abstract: Based on the daily meteorological data of 109 counties（districts）meteorological stations in Henan Province from 1957 to 2022，the duration days and cumulative days of daily maximum temperature≥35℃ at flowering stage of summer maize were calculated. The frequency and spatial and temporal distribution characteristics of heat damage at flowering stage of summer maize in Henan Province were analyzed from two aspects of continuous heat damage and non‑continuous heat damage，so as to provide scientific basis for disaster prevention and disaster avoidance in summer maize production in Henan Province. The results showed that in terms of time distribution，from 1957 to 2022，the frequency of heat damage at flowering stage of summer maize decreased first and then increased in Henan Province.After 2010，the frequency of heat damage showed a trend of frequent occurrence，and the frequency of continuous heat damage was higher. The higher frequency of heat damage happened in 1960s and after 2010，and the 1960s was dominated by moderate and severe heat damage，and after 2010，mild and moderate heat damage dominated.In terms of spatial distribution，the frequency of heat damage at flowering stage of summer maize was higher in eastern and southern Henan，and lower in western and northern Henan. The high‑risk areas of heat damage were south of Nanyang City，Zhumadian City，Zhoukou City and the east of Shangqiu City. The low risk areas of heat damage were Anyang City，Puyang City and Hebi City.In terms of the type of heat damage，the south of Shangqiu City was more prone to continuous heat damage；Luohe City and Zhoukou City were more prone to non‑continuous mild heat damage，southern Nanyang City was more prone to non‑continuous moderate and severe heat damage，and southern Zhumadian City was more prone to non‑continuous severe heat damage.

Key words: Summer maize, Heat damage, Flowering period, Frequency, Spatial and temporal distribution, Henan Province