施氮量对不同夏玉米品种籽粒灌浆特性、产量和品质的影响OACSTPCD

Two maize varieties Dika 517(DK 517,with faster dehydration rate)and Zhengdan 1002(ZD 1002,with slower dehydration rate)were used as the materials to explore the effects of nitrogen rate[0 kg/ha(N0),180 kg/ha(N1)and 300 kg/ha(N2)]on grain filling characteristics,dehydration rate,yield and quality of summer maize,so as to provide a theoretical basis for the high-quality and efficient production of summer maize in Huang-Huai-Hai region.The results showed that with the increase of nitrogen rate,the dry grain weight of DK 517 and ZD 1002 generally gradually increased,grains number per row and yield first increased and then decreased,crude protein content of grains increased,and crude starch content decreased.In general,N1 treatment had the highest biomass under maximum grain filling rate and maximum grain filling rate,the longest active filling period,the highest grains number per row,then the highest yield,which was 9 694.60 kg/ha and 11 204.56 kg/ha for DK 517 and ZD 1002,respectively,and the grain crude protein content was higher.Different nitrogen application rate treatments had different effects on grain filling characteristics of maize varieties with different dehydration rates.At 15-24 days after pollination,there were significant differences in grain moisture content under different nitrogen application rate treatments.At 58 days after pollination,the grain moisture content of DK 517 showed N2＞N1＞N0,and that of ZD 1002 showed N1＞N0＞N2.At 49-58 days after pollination,the dehydration rate of grain was the highest under N0 treatment.Compared with ZD 1002,DK 517 had higher biomass under maximum grain filling rate and maximum grain filling rate,earlier days reaching maximum filling rate,shorter active filling period,lower grain moisture content,lower grain dehydration rate at the early filling stage and higher rate at the middle and late filling stages,lower grains number per row,100-grain weight,yield and crude fat content of grain,and higher crude protein and starch content.The dehydration rate of grains was significantly negatively correlated with spike diameter and bald tip length,and significantly positively correlated with spike length and crude starch content.To sum up,nitrogen application rate of 180 kg/ha can promote grain filling,and improve yield and crude protein content of grain.