Abstract: Based on experimental data collected from different sowing dates with Danyu39 as tested variety and the contemporaneous meteorological observation data in Zhuanghe area from 2012 to 2014 as well as averaged occurrence dates of different growing periods and yield data during 1980-2010,the effects of different sowing dates on growth development process and yield of spring maize in Zhuanghe area were investigated.The results show that the variation of the sowing dates significantly affects the growth process of the spring maize,that is,with one-day delay in the sowing date,durations of the total growing period and the vegetative growth period shorten about 0.22-0.57 d and 0.48-0.69 d,respectively,while the reproductive growth period prolongs about 0.11-0.36 d.In addition,the duration of each growing period indicates evident difference among the different sowing dates.Specifically,the difference in the vegetation growth period is most significant,while those in the periods during heading-tasseling,tasselling-flowering,flowering-milky and milky-maturity are all not significant.The effect of the sowing dates on the maize yield is significant,which is reflected by firstly increasing and then decreasing yields with the sowing dates postponing in 2012 and 2013 except in 2014,but the interannual variation of yield is very significant.The meteorological factors affecting the growth period of the spring maize in Zhuanghe area are obviously different among the years from 2012 to 2014 and temperature,sunshine duration,average wind speed,water vapor pressure and evaporation are the main factors impacting the whole growth period,the vegetative and the reproductive growth period of the spring maize.

Key words: Different sowing dates, Growth process, Meteorological factors