Impact of Sowing Periods on the Yield of Maize in Penzhou Maintain Area

[Objective] The study aimed to research the effect of sowing period on high yield mechanism of maize and research the optimum sowing period of different maize varieties.[Method] The test with two factors spilt plot design was used to research the effect of 4 sowing periods on the leaf growing feature and yield component factors of 3 maize varieties(Chuandan 428,Zhenghong 311 and Chuandan 418) through the determination on dynamic change of morphological index and yield.[Result] In the Penzhou maintain area,the average yield of 3 maize varieties was highest when the sowing period was in the March 27,reaching 6 565.84 kg/hm2,which was 2.02%,8.18% and 14.53% higher than that in other 3 sowing periods(April 6,March 17 and April 16).Under optimum sowing period(March 27),the grains per spike and 1000-grain weight of maize were all higher;the index of leaf area was higher and its difference was remarkable when comparing with that in other sowing periods;the relative content of chlorophyll was higher with great rising amplitude in prophase and slow decrease amplitude in anaphase.[Conclusion] The sowing period had great effect on maize growing feature and yield component factors and the optimum sowing period was around March 27.