Abstract: Based on the meteorological data of sunshine durations in 35 years in the main tobacco growing areas of western Henan,the trend of climate change of sunshine durations at tobacco growth periods was analyzed.Accumulative anomaly analysis and slide T detection methods were used to examine the points with abrupt change of sunshine durations.The results showed that the changes of sunshine durations in western Henan had a rather wide range and had a decreasing trend in last 35 years,with the trend coefficient of-25.4 hrs/10y.Sunshine durations were long in May and June,and short in September.The decreasing trend of sunshine durations was significant(P<0.05)in root elongation stage.The trend coefficient at different growth periods was root elongation stage(-11.5 hrs/10y)> maturing stage(-11.3 hrs/10y) > vigorous growth stage(-2.6 hrs/10y).The sunshine durations during tobacco growth period in Sanmenxia were longer than those in Luoyang.Mutation analysis showed that the saltation of sunshine durations at tobacco growth period in western Henan occurred in 1981.

Key words: Western Henan, Western Henan, Sunshine durations, Tobacco growth stages, Climate characteristics