春季氮肥和多效唑调控对小麦生育和产量的影响

为明确春季调控措施对冬小麦生长发育和籽粒产量的影响,以冬小麦品种石新828为材料进行田间试验,4个处理分别为:起身期追全部氮肥(除基肥外,下同)并叶面喷多效唑(N1);起身期追2/3氮肥并喷多效唑+拔节期追1/3氮肥(N2);起身期追1/3氮肥+拔节期追2/3氮肥(N3);拔节期追全部氮肥(N4)。生育期间测定群体和个体生育特性,成熟期调查产量性状。结果表明,N1和N2处理小麦拔节期的总茎数、叶面积指数(LAI)和干物质积累量均显著高于N4和N3处理。孕穗期N4和N3处理小麦的总茎数、LAI和干物质积累量显著高于N1和N2处理。开花到成熟期各处理的总茎数、LAI和干物质积累量差异均不显著。孕穗期前,不同处理的株高差异不显著,孕穗期后,N4处理的株高最高,且显著高于N1处理。各处理基部节间直径和中上部节间长的差异不显著,N4处理基部第一节间长度显著大于其他处理。随追氮时期前移或前期施氮量增多,不孕小穗数减少,结实小穗和穗粒数增加,N1比N4处理不孕小穗数显著减少,结实小穗和穗粒数显著增多。N1处理小麦成熟期的千粒重最高,且显著高于N4处理。N1处理的籽粒产量最高,且显著高于N3和N4处理。起身期追氮配合多效唑调控,可以获得比拔节期追氮更高的穗粒数和千粒重,从而获得更高的产量。

Effect of Spring Application of Nitrogen and Paclobutrazol on Growth and Development and Yield of Winter Wheat

In order to clarify the effects of spring regulation measurements on growth and development,and the grain yield of winter wheat,a field experiment was carried out,with a winter wheat cultivar Shixin 828 as material. The experiment involved four treatments,i.e.,all nitrogen(basal nitrogen excluded,the same as below) topdressing at erecting stage(with irrigation,the same as below) and paclobutrazol spraying(N1),2/3 nitrogen topdressing at erecting stage with paclobutrazol spraying,and 1/3 nitrogen topdressing at jointing stage(N2),topdressing 1/3 nitrogen at erecting stage,and 2/3 at jointing stage(N3),and all nitrogen topdressing at jointing stage(N4). Population and individual plant traits were determined during growing period,and yield-related traits were determined at maturity. The results showed that,the culm(or spike) number,leaf area index(LAI) and dry matter accumulation amounts at jointing stage of wheat under N1 and N2 treatments were all significantly higher than those under N4 and N3. The culm(or spike) number,LAI and dry matter accumulation under N4 and N3 at booting stage were significantly higher than those under N1 and N2,but the above three parameters insignificantly varied among treatments from anthesis to maturity. The difference of plant height of wheat before booting was not significant among the four treatments. The plant height of N4 after booting,however,was always the tallest,which was significantly taller than that of N1. The diameter of basal internode and the lengths of the four top internodes were not significantly different among the four treatments. But the basal first internode of N4 was significantly longer than that of other treatments. With the earlier nitrogen topdressing or topdressing more nitrogen at earlier growth stage,the number of sterile spikelets was decreased,but those of fertile spikelets and spike grains were increased. The number of sterile spikelets of N1 was significantly less than that of N4,but the fertile spikelets and spike grains of N1 were significantly more than that of N4. The grain weight of N1 was higher than that of other treatments,and the 1 000 grain weight of N1 at maturity was the highest among the four treatments,which was significantly higher than that of N4. The grain yield of N1 was the highest,which was significantly higher than those of N3 and N4. These results showed that,topdressing all nitrogen fertilizer with irrigation and regulating by spraying paclobutrazol at erecting stage,could obtain more spike grains and grain weight than those by simply topdressing of nitrogen with irrigation at jointing stage,and obtain higher grain yield.