Responses Of Maize Growth Process To Sowing Date And The Factors Of Light And Temperature

This study was conducted with seven varieties that sowed on different dates under natural conditions to analyze the effects of light and temperature factors on growth period and active accumulated temperature requirement of maize, confirm the relationship between light and temperature factors and maize growth period and identify the regulation of accumulated temperature requirement changes under different light and temperature conditions. It could provide a useful reference to accomplish rational distribution of different maize varieties making full use of the limited light and temperature. The results from two years of2012and2013indicated that:1)With the delay of sowing date, maize growing process got faster and the whole growth period shortened. But when the seeds were sowed too late, the growth period would prolong and even couldn’t mature fully. During the stage of sowing to emergence, it needed one week on the normal sowing date and changed late.2) Temperature is the most important factor affecting the growing process of maize. If the active accumulated temperature increased by1℃, days prolonged by0.03～0.05d at seedling stage, spike stage, anthesis and kernel stage and whole growth period. If daily mean temperature increased by1℃, the period of seedling stage, spike stage, anthesis and kernel stage and whole growth stage shortened0.8d,1.7d,1.9d,5.9d respectively in the year of2013,1.2d,1.8d,2.3d,5.3d respectively in the year of2012. The ground temperature at10cm level had a greater influence on the period of sowing to emergence. In2013, the daily mean underground temperature increased by1℃, emergence emerged0.2d in advance, the daily mean temperature increased by1℃, emergence emergence emerged0.2d in advance too.3) Under different light and temperature conditions, growth periods of different maize varieties showed different. The difference ranges were4.8～12.9d in2012and12.7～20.0d in2013. The difference was mainly aroused by the difference at seedling stage and anthesis and kernel stage.4) There was a highly significant positive correlation between active accumulated temperature requirement and growth period. At different stages, the duration was longer, the requirement of active accumulated temperature was more. The active accumulated temperature requirement at whole growing period of different maize varieties showed diversity on different sowing dates. The difference ranges were253.3～389.1℃in2012and175.3～335.5℃in2013. Although there were differences in active accumulated temperature requirement among different varieties and years, overall, the difference at anthesis and kernel stage was the main factor arousing the difference of whole growing period and that at seedling stage was in the second place. During sowing to emergence or mature period, there wasn’t different in active accumulated temperature among varieties but different between two years.5) Before sowing to emergence and mature periods, the coefficient variation was higher than that at other stages because the durations of both periods were shorter.