Abstract:

Based on the daily observation data of spring maize in the whole growth periods and temperature at 5 weather stations in Shenyang of Liaoning Province from 1960 to 2016, the heat index models of spring maize in different growth periods were established according to the membership function in fuzzy mathematics. And on this basis the spatio-temporal dynamic characteristics of spring maize heat index were investigated. The results show that the heat index of spring maize was highest with small fluctuation at the tasseling to milk ripe stage, followed by the seeding to seven-leaf stage, while that was lowest with big fluctuation at the sowing to seeding stage and seven-leaf to jointing stage in Shenyang. The heat index of spring maize at milk ripe to mature stage appeared a slight decreasing trend, while that appeared an increasing trend with different levels in other growth stages in Shenyang from 1960 to 2016, but the change trend at milk ripe to mature stage and seven-leaf to jointing stage passed the significance test with 0.05 level. The increasing trend was more obvious at the sowing to seeding stage and seven-leaf to jointing stage. Spatially, there was significant difference of heat index in northern and southern Shenyang. The heat index was high in the north and low in the south at milk ripe to mature stage, while that generally increased from the north to the south in other growth stages. The heat index in different growth stages was low in Kangping and Faku of northern Shenyang, but its increasing trend was more obvious, especially at seven-leaf to jointing stage, which had a positive effect on the growth process of spring maize and would be beneficial to the growing of spring maize in the future.

Key words: spring maize, growth periods, heat index, variation characteristics

摘要：

利用模糊数学的隶属函数计算1960—2016年沈阳地区春玉米各生育阶段的热量指数，并对其时空变化特征进行分析。结果表明：沈阳地区春玉米抽雄—乳熟期热量指数最高，变异系数最小，其次是出苗—七叶期，播种—出苗期和七叶—拔节期热量指数最低，变异系数最大。近57 a沈阳春玉米除乳熟—成熟期热量指数略有下降，其他生育阶段及全生育期均呈不同程度的升高趋势，其中热量指数最低的播种—出苗期和七叶—拔节期升高趋势较为明显。空间上，除乳熟—成熟期热量指数北部高于南部外，其他发育期北部均不同程度低于南部；热量指数偏低的北部法库、康平地区，近57 a来热量指数升高趋势较明显，特别是七叶—拔节期，未来温度变化对沈阳北部地区该时期春玉米生长影响具有正效应，利于春玉米生长发育。

关键词: 春玉米, 发育期, 热量指数, 变化特征