12叶展倒伏对夏玉米子粒灌浆特性和产量的影响

Effects of Lodging at V12 Stage on the Characters of Grain Filling and Yield of Summer Maize

选用先玉335(XY335)和浚单20(XD20)两个玉米品种,在种植密度为75 000株/hm2下设置不倒伏(CK)、根倒(RL)、茎折(SL)3个处理,分析品种和倒伏类型对夏玉米子粒灌浆特性、穗部性状、产量、产量三要素和产量损失率的影响。结果表明,12叶展(V12)倒伏使XY335和XD20显著减产,其中SL处理造成的减产幅度较RL高,XD20的减产幅度小于XY335。RL使XY335和XD20的产量、穗数、穗粒数、千粒重的损失率分别达到21.1%、7.2%、9.5%、7.3%和19.2%、6.0%、13.6%、11.9%;SL处理使XY335和XD20产量、穗数、穗粒数、千粒重的损失率分别达到61.0%、22.3%、42.3%、9.5%和41.8%、17.2%、19.4%、14.9%。倒伏后,穗部性状变差,SL的影响大于RL,XD20的穗部性状相对好于XY335。倒伏缩短了灌浆期,SL降幅大于RL;倒伏降低了平均灌浆速率,RL主要降低了XY335的缓增期灌浆速率,SL降低了XY335的渐增期灌浆速率,RL和SL均降低了XD20缓增期灌浆速率。V12倒伏造成夏玉米减产的原因从大到小依次为穗粒数、穗数和千粒重的降低。

Three treatments were designed in the field including no lodging（CK）, root lodging （RL）, and broken stem （SL） with two maize hybrids of Xianyu335（XY335） and Xundan20（XD20） under the density of 75000 plant/ha, and characters of grain filling, ear traits, yield, components of yield and yield loss rate were estimated. The results showed that the yield of XY335 and XD20 was significantly reduced under lodging at 12 collars（V12）, the effect of SL was higher than that of RL, and the range of yield loss of XD20 was lower than that of XY335. Ear number, grain number and 1 000-grain weight（TGW）＇were reduced evidently under lodging at V 12. The loss rate of yield, ear num- ber, grain number and thousands grain weight of XY335 and XD20 under RL was 21.1%, 7.2%, 9.5%, 7.3% and 19.2%, 6.0%, 13.6%, 11.9%, respectively, under SL was 61.0%, 22.3%, 42.3%, 9.5% and 41.8%, 17.2%, 19.4%, 14.9%, respectively. The characters of ear became bad under lodging at V12, it was worse under SL than RL, and the ear diameter, grain number per row of XD20 under lodging showed converse. The grain filling at V12 were more than XY335, and length of bare tip duration was shorted under lodging at V12, it was shorter under SL than RL, and the decrement in grain filling duration of XY335 under RL was lower than XD20, there was a converse result under SL. RL and SL reduced mean grain filling of XY335 and XD20. For XY335, RL mainly decreased the grain filling rate at slowly increasing stage, SL mainly decreased the grain filling rate at slightly increasing stage. For XD20, RL and SL both reduced the grain filling rate at slowly increasing stage. The reasons for the yield loss under lodging at V12 from big to small was reduction of grain number, ear number and TGW.