Effect Of Sowing Date On Seedling Physiological Characteristics And Yield Of Spring Maize

Soil temperature and moisture conditions of seeding time are the most importantlimiting factors restricting the quality of maize emergence rate. In order to studyemergence rate of spring maize under different sowing date and its relationship withrelated factors, a field experiment with three maize varieties with different growthperiod of Songyu419(early-maturing variety), Jinchan5(medium maturing variety)and Zhengdan958(mid-late variety) was conducted, maize planting date were April7,13,19,24,29, and on May4,9,14,20. The main research conclusions are as follows:1. Maize emergence rate were significantly and very significant influence by soiltemperature and Soil volumetric moisture content, respectively. From April7to May20, soil temperature of0-10cm depth layer range9.5-16.7℃, regression equationbetween the surface soil temperature and the emergence rate created by: Y=0.9959X-7.9993(R2=0.9537); And soil volumetric moisture content ranged of9.5-16.7m3/m3, regression equation between surface soil volume moisture content and emergencerate of was: Y=0.3737+1.0822X (X <13.1), Y=13.1(X>13.1).2. Maize leaf peroxidase activity and proline content in seedling stage was on thedecline, as the sowing date delayed, and it had a significant degree of correlation withtemperature and water content.3. Maize leaf peroxidase activity and proline content in seedling stage was on thedecline, as the sowing date delayed, and it had a significant degree of correlation withtemperature and water content.4. Plant height and leaf area first increased at first and then decreased, which gota maximum value with sowing date between April27to May9.Ear height increasedfor early maturing varity Jinchan5with the change of plant height, but ear height increased more slowly with the sowing date delayed for medium maturing andmid-late variety.5. Sowing date had a significantly effect on maize grain yield under differentsowing date processing for different cultivars. Favorable seeding-time was from April24, to May4, seeding for early maturity variety Jinchan5，which had a higher yieldproduction than other sowing date; For medium maturing variety, the treatment ofplanting date with April29, the yield increased by6.66%than Farmers conventionalplanting date; For mid-late variety Zhengdan958, its yield showed a trend of gradualdecline with sowing date delayed from April7to May20in this study, should besuitable for early sowing.