Influence of temperature,solar radiation and precipitation on kernel set and filling in rain-fed maize system in central China
Junzhu Ge1,2,3Ying Xue1Xinyue Zhong1Shuya Li1,2Shaoyang Tian1Guoyin Yuan1,2Cougui Cao1Ming Zhan1Ming Zhao2
1. College of Plant Science and Technology,Huazhong Agricultural University/Key Laboratory of Crop Physiology,Ecology and Cultivation(Middle Reaches of the Yangtze River) of Ministry of Agriculture2. Key Laboratory of Crop Physiology and Ecology of Ministry of Agriculture,Institute of Crop Sciences,Chinese Academy of Agricultural Sciences3. College of Agronomy & Resources and Environment,Tianjin Agricultural University
摘要：Climatic factors have substantial effects on maize ear kernels number（EKN） and kernel weight（KW）.This study was conducted by three seasons,i.e.,spring maize（SpM）,summer maize（SuM） and autumn maize（AuM）,which were divided in central China by a 2-year field experiment.The growing degree days（GDD） and high temperature stress[killing degree days（KDD）]from V12 to silking always played negative roles on ear ovules number（EON） and EKN.EKN also had significantly positive relationships with GDD,mean temperature（MT） and accumulated solar radiation（Ra）from silking to 30 days after silking（DAS30）.After pollination,KW exhibited significant negative relations with GDD,MT,KDD and Ra,whereas mean temperature difference（MAT） and accumulated precipitation（Pr） palyed significantly positive roles on KW.The optimum MT from V12 to silking for EON was lower than 22 ℃,while GDD and KDD should lower than 183.6℃d and 31.6℃d,respectively.But in order to obtained more EKN,GDD and KDD from V12 to silking need lower than 183.6℃d and 31.6 ℃d,and from silking to DAS30,the optimum MT,GDD and Ra were 22 to 27.8℃,250 to368℃d and 200 to 339 MJ m-2,respectively.The optimum MT for KW were23 to 27℃,with KDD lower than 44.3℃d,and Ra and Pr were 710 to 925 MJ m-2 and 50 to 216 mm,respectively.SpM and SuM grown under optimal climatic conditions for EON and EKN setting,and then obtained more EON（20.7% and 9.6%） and EKN（32.1% and 18.5%） than AuM,However,SpM and SuM get lower KW（-12.5% and-17.5%） than AuM due to the higher MT and KDD after pollination.And so,grain yield for SpM significantly higher than SuM and AuM by 20.0% and 23.9%,respectively.