氮锌配施对玉米果穗不同粒位籽粒灌浆特性的影响

Effect of Nitrogen and Zinc Application on Filling Characteristics of Grains at Different Positions of Maize Ear

以锌高效玉米品种郑单958和锌不敏感品种隆平638为试验材料,设置225 kg/hm^(2)(HN)、180kg/hm^(2)(MN)、90 kg/hm^(2)(LN)3个施氮量和不喷锌(F0)、拔节期和大口期1∶1喷锌4.5 kg/hm^(2)(F1)2个喷锌处理,研究氮锌配施对不同锌效率玉米品种不同粒位籽粒灌浆特性的影响及不同粒位籽粒灌浆特性与产量的相关性,为玉米生产上氮锌合理配施提供依据。结果表明,HN处理产量最高,其次是MN处理,两者差异不显著。其中,HN处理能够提高各粒位的粒质量,MN处理推迟了郑单958各粒位籽粒最大灌浆速率出现的时间,提高了上部粒位籽粒最大灌浆速率和下部粒位籽粒的活跃灌浆期;HN处理推迟了隆平638各粒位籽粒最大灌浆速率出现的时间,延长了活跃灌浆期,提高了上、下部粒位籽粒最大灌浆速率出现时的灌浆量,进而提高了产量。与F0处理相比,F1处理显著降低了果穗秃尖长(9.9%),显著提高了产量(2.0%),增加了郑单958籽粒上部和下部粒位的粒质量,延长了上部和下部粒位籽粒活跃灌浆期,推迟了上部和下部粒位籽粒最大灌浆速率出现的时间,提高了最大灌浆速率出现时的灌浆量。产量与果穗下部粒位最大灌浆速率出现的时间呈显著正相关,中部粒位粒质量与下部粒位粒质量呈极显著正相关。总体来看,施氮180 kg/hm^(2)配合拔节期和大口期1∶1叶面喷锌4.5 kg/hm^(2)能够推迟锌高效玉米品种果穗上、下部粒位最大灌浆速率出现的时间,延长活跃灌浆期,提高最大灌浆速率出现时的灌浆量和粒质量,进而促进玉米产量提高。

The high Zn efficiency variety Zhengdan 958(ZD958)and Zn no⁃sensitive variety Longping 638(LP638)were used as materials.The field plot experiment was conducted with three N rates[225 kg/ha(HN),180 kg/ha(MN)and 90 kg/ha(LN)]and two foliar Zn treatments[no Zn(F0),spraying Zn of 1∶1 at jointing stage and flare opening stage(F1)],and the effects of N and Zn application on the filling characteristics of grains at different positions and their relationship with grain yield of different Zn efficiency varieties were studied,so as to provide reference for N and Zn application in the maize production.The results showed that HN treatment had the highest yield,followed by MN treatment,and there was no significant difference between HN treatment and MN treatment.HN treatment increased grain weight at different positions.MN treatment delayed the time with the maximum grain⁃filling rate(T_(Gmax))at different positions,and increased the maximum grain⁃filling rate(Gmax)at upper position and active grain⁃filling period(D)at basal position of ZD958 ear,while HN treatment delayed T_(Gmax),prolonged D of different positions,and enhanced the grain weight with the maximum grain⁃filling rate(W_(Gmax))at upper and basal positions of LP638 ear,thus increasing grain yield.Compared with F0 treatment,F1 treatment significantly decreased the bare tip length by 9.9%,significantly increased the yield by 2.0%,increased the grain weight,extended D and postponed T_(Gmax)at upper and basal positions of ZD958 ear,and increased W_(Gmax).The grain yield was significantly positively correlated with T_(Gmax)at basal position of ear,and the grain weight at middle position of ear was extremely significantly positively correlated with the grain weight at basal position of ear.To sum up,applying 180 kg/ha N and spraying 4.5 kg/ha Zn of 1∶1 at jointing stage and flare opening stage can delay T_(Gmax)at upper and basal positions of ear,extend D,and increase W_(Gmax)and grain weight of high Zn efficiency maize genotype,thus promoting the increase of yield.