施氮时期对春玉米果穗不同粒位籽粒发育及产量的影响

Effect of Nitrogen Application Period on Grain Development in Different Ear Positions and Yield of Spring Maize

施氮时期管理是调控玉米产量的关键环节,本试验以辽宁主栽玉米品种辽单575和郑单958为试材,设置3个氮肥时期处理,底肥∶拔节期∶大喇叭口期=1∶1.5∶1.5(T1)、底肥∶拔节期=1∶3(T2)、底肥∶大喇叭口=1∶3(T3)。通过对植株干物质积累、转运、不同粒位籽粒体积、干重积累、含水量变化动态、产量及构成因素等方面的数据分析,结果如下:1.T1提高了花期和成熟期植株地上干物质积累、干物质转运量和对籽粒贡献率,T2次之,T3最低;2.施氮时期对不同粒位籽粒体积的影响存在基因型差异,T1处理提高籽粒体积和干物质积累量,位序均为T1>T2>T3;3.T1提高了玉米品种单位面积粒数,从而获得高产。本试验中,拔节期和大喇叭口期追施氮肥,有利于促进花前干物质积累,增大花后不同粒位籽粒体积、粒数和粒重。通过以增加单位面积粒数为主,提高果穗上部和下部籽粒干重为辅的途径,有利于提高产量。

Nitrogen application stage management is a key link in the control of maize yield.In this experiment,Liaoning main maize varieties,Liaodan 575 and Zhengdan 958,were used as test materials.Three nitrogen treatments were set,base fertilizer∶nitrogen application at jointing∶nitrogen application at flare opening stage=1∶1.5∶1.5(T1)、base fertilizer∶nitrogen application at jointing stage=1∶3(T2)、base fertilizer∶nitrogen application at flare opening stage=1∶3(T3).Through the plant dry matter accumulation、transshipment、different grain volume and dry weight accumulation,seed moisture content change dynamic factors,yield and yield composition of data analysis,the conclusion are as follows:1.T1 improves the silking and mature plant dry matter accumulation,dry matter translocation and contribution rate to grain followed by T2 and T3;2.There were genotype differences in the effect of nitrogen application on the grain volume at different positions.T1 treatment increased the grain volume and dry matter accumulation,and the sequence was T1>T2>T3;3.T1 increased the number of grains per unit area of maize varieties,thus achieving high yield.In this experiment,applying nitrogen fertilizer at jointing and flare opening stage is beneficial to promote dry matter accumulation before silking,increase grain volume at different grain positions、grains number and weight.By mainly increasing the number of grains per unit area,and increase the dry weight of upper and lower grains as a supplement,and finally increase the yield.