Effect of Sowing Date on Growth，Development and Yield of Different Maize Varieties

Climatic factors，especially high temperature，affecting growth，development and yield formation of maize were studied by adjusting sowing date.In this experiment，four main planted maize varieties of Jingnongke 728，Denghai 618，Zhengdan 958 and Xianyu 335 were selected as materials and planted at three sowing dates of June 5（T1），June 15（T2）and June 25（T3）in 2019，respectively.Results showed that growth periods of four maize varieties were prolonged with postponement of sowing date.In terms of dry matter accumulation at maturity stage，there was no significant difference between leaves and stems of four maize varieties at different sowing dates，but dry matter accumulation of seeds and ears were higher in early sowing treatment than in late sowing treatment，possible reason was temperature in early sowing treatment was higher than that in late sowing treatment.In terms of kernel number per ear，weight per hundred grains and yield，variety and sowing date had a significant effect on yield.Variety and sowing date had significant interaction with grain number per ear，weight per hundred grains and yield.Jingnongke 728，Denghai 618，Zhengdan 958 and Xianyu 335 four varieties of spike grain number，hundred kernel weight and yield were T2 processing，maximum minimum were T1 treatment，possible reason was T1 treatment on yield traits in flowering pollination stage were confronted continuous high temperature weather，lead to T1 with strong sex was bad.So，in maize growth and yield formation，high temperature has a great influence on it.In absence of high temperatures，timely early sowing would be more beneficial to increase of corn yield.